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Anatomy – Exam 2 (Part 2) Pelvis (Viscera) ○ Objectives Describe the surfaces of the urinary bladder and the viscera which contacts them Describe the pelvic course of the ureters Define the bladder trigone Describe the pelvic course of the vas deferens Describe the position and gross anatomical structure of the seminal vesicles Discuss the route of a sperm cell during emission and ejaculation Describe the anatomy of the posterior wall of the prostatic urethra Define the lobes of the prostate and understand how enlargement effects urine flow and retention Describe the accessory reproductive glands of the male and define the contribution of each to semen Describe the peritoneal reflections on the pelvic viscera in both sexes Define the parts of the broad ligament List the structures that lie between the lamellae of the broad ligament Delineate the parts of the uterus and vagina Define the normal position of the uterus and the terms anteversion/anteflexion and retroversion/retroflexion Define the ligamentous supports for the uterus Explain the relationships and importance of the pelvic peritoneal pouches Distinguish between false and true pelvis and understand which organs are located in each Explain the relationships of the vaginal fornices to surrounding structures ○ Reminder False Pelvis – pelvic brim to top of ilium True Pelvis – pelvic brim to levator ani ○ Male Stuff No major organs between bladder and rectum in male Prostatic Venous Plexus – unique to males; on anterior bladder surface Prostate – has three lobes defined by the urethra and ejaculatory duct Anterior Lobe – in front of the urethra Posterior Lobe – behind the urethra and ejaculatory duct Median Lobe – in between urethra and ejaculatory duct ○ Most susceptible to benign enlargement ○ Benign Prostatic Hyperplasia – almost all males over 50 have it, but only bad if it encroaches Upward Encroachment – creates bump in urinary bladder and urine can become trapped and stagnant leading to bladder infection Urethral Encroachment – impedes flow of urine causing weak stream, urgency to urinate (often at night), hard to start urinating, urinating in small amounts, trouble stopping urination Simple surgery can treat this Arterial Supply to Prostate ○ Prostatic Artery – a terminal branch of the inferior vesical artery Seminal Glands – on posterior bladder surface Does not actually contain semen, just a component of it Ductus Deferens – travels superior to the union of the ureter to the bladder The two sides do not unite Ampulla of the Ductus Deferens – unites with the seminal gland of the same side to form the ejaculatory duct This union occurs right at surface of prostate gland Note – peritoneum is loose at anterior wall to urinary bladder junction Rectovesical Pouch – lowest point in peritoneal cavity; is the only recess down there in males Note – best place to enter pelvis surgically is just above the pubic symphysis because then you don’t get into the peritoneal cavity Bladder Internal Urethral Sphincter – made of circular muscle extensions of detrussor muscle ○ Closes during sexual arousal, especially during emission and ejaculation to prevent retrograde flow of semen ○ Only in males Involuntary Urinary Continence – Both Sexes ○ The neck region of the bladder creates a passive sphincter that is normally closed due to the CT and elastic tissue in that region Urethra ○ Pelvic part becomes the prostatic part and is longer in males ○ Membranous part goes from superior part of UG diaphragm to perineal membrane; least distensible ○ Penile/spongy part is everything after the perineal membrane Prostatic Part of Urethra Urethral Crest – a ridge along the posterior portion Seminal Colliculus – highest point on urethral crest Prostatic Utricle – embryonic remnant of the vagina; no function Two openings of the ejaculatory duct – just below prostatic utricle Prostatic Ducts – around 30 of them; just little openings in the prostatic sinus Emission - delivery of contents of ejaculatory ducts and prostatic ducts into urethra When these substances are combined you get semen Caused by peristaltic waves from epididymus, ductus deferens, and contraction of smooth muscle in seminal gland and prostate gland Feels good; Ejaculation will occur right after Male Accessory Reproductive Organs Seminal Gland – contributes 60% of semen ○ Creates mucoid substance to help keep semen in vagina ○ Contents Fructose, citric acid and other nutrients for sperm Prostaglandins – react with cervical mucous to make the environment more conducive to sperm movment ○ Reverse peristalsis especially in uterine tube to move sperm toward egg ○ Note – sperm in upper vagina can reach ampulla in 5 minutes Fibrinogen – clotting factor that maintains the mucoid consistency to hold semen in upper vagina Prostate – contributes 30% of semen ○ Creates alkaline, thin and milky substance ○ Citrate, phosphate, calcium for sperm ○ Profibrinolysin – converted to fibrinolysin which, after a delay, causes the lysis of the mucoid clot of semen Sperm make 10% of the semen ○ Note – sperm cells mature in epididymus and can live for 40 days there Bulbourethral Gland – produces contents only during sexual stimulation and does not store secretion ○ Secretions are typically not mixed with semen, they are released ahead of it ○ Male Sex Response Erection – engorgement of erectile tissue due to contraction of perineal muscles Controlled by parasympathetic nervous system Helicine arteries – blood vessels curled in helix and contain smooth muscle ○ Under parasympathetic stimulation the smooth muscle relaxes and causes arterial blood to be dumped into venous erectile tissue Emission Contraction of smooth muscle in ductus deferens, prostate and seminal vesicles Contraction of internal urethral sphincter Release of secretions from testes, prostate gland, seminal vesicles, and bulbourethral glands Mediated by sympathetic nervous system If emission occurs, ejaculation will occur Ejaculation – rhythmic, spasmodic contraction of the perineal muscles, levator ani, external anal sphincter and gluteal muscles causes propulsion of semen along penile urethra Initiated by secretions entering penile urethra Mainly somatic innervation Detumescense/Resolution – return of erectile tissues to flaccid state Involves refractory period which is age dependent Sympathetic nerves cause helicine arteries to contract ○ Female Sex Response Arousal ↑ secretions (vestibular and vaginal) ○ No glands in the wall of the vagina and thus the secretions are a watery transudate from the wall ○ Cervix secretes mucoid substance Erection of clitoris – same as in males, due to parasympathetic stimulation of helicine arteries Plateau – can last minutes to hours General vascular engorgement (clitoris, labia, breast, lower vagina) Erection of nipples “Sex flush” – reddish vascular flushing of skin over breasts and chest Dilation of upper vagina Uterine Tenting – uterus elevated up higher in pelvis so that vagina is longer Orgasm – if orgasm then probably a greater chance of fertilization Rhythmic contractions of perineal muscles (1 second intervals) ○ Number and intensity of rhythmic contractions is highly variable Dilation of cervix Uterine contractions (due to release of oxytocin) helps move sperm to fallopian tubes Uterine Dipping – uterus drops into vagina and pushes vaginal cervix into the semen Resolution – return to pre-excitement stage No refractory period ○ Pelvis Piriformis muscle – goes through greater sciatic foramen Obturator Internus muscle – Tendinous Arch – Urogenital Diaphragm – urinary and genital structures go through; on a flat plane Muscles of Pelvic Diaphgram – no clear distinction Note - Levator Ani is just the iliococcygeus and pubococcygeus Iliococcygeus – originates on tendinous arch over obturator internus and goes to coccyx Ischiococcygeus – ischial spine to coccyx Pubococcygeus – anterior pubic area to coccyx ○ Puborectalis - Medial-most fibers of pubococcygeus meet posterior to rectum (don’t connect to coccyx) Are in constant tension and pull anal-rectal junction anteriorly to create the 80º anorectal junction ○ Are essential for fecal continence During defecation, this muscle is relaxed Note – same in males and females Female Specific Things ○ Rectoceole – rectum not supported by pelvic diaphragm and encroaches on vagina ○ Urethrocoele – same thing, but with bladder ○ Kegal Exercises – retone muscles of pelvic floor to support weight of pelvic organs (leading to prolapsed uterus or bladder etc.) Do these after vaginal birth because they get stretched Nerves of the Pelvis Branches of Sympathetic Trunk ○ Gray Rami Communicantes – joins the ventral rami of S2-S4 and goes to lower limb ○ Sacral Splanchnic – come off in sacral region and stay in the pelvis to supply sympathetic innervation to the pelvis ○ Pelvic Splanchnic Nerves – split off of S2-S4 and provide parasympathetic innervation to organs in pelvis and perineum Feed into the Inferior Hypogastric Plexus The only part or this that leaves the pelvic cavity the part for the external genitalia (nerves for erection) ○ ‘S2, 3 and 4 keep the penis off the floor’ Sacral Plexus – plexus that forms from ventral rami of S2-S4 and the lumbar plexus ○ Goes through greater sciatic foramen to supply lower limb Superior Hypogastric Plexus – entirely sympathetic nerve plexus that feeds to hypogastric nerves Hypogastric Nerves – right and left and heads down into inferior hypogastric plexus Inferior Hypogastric Plexus – receives innervation also from pelvic splanchnics and thus contains parasympathetics and sympathetics ○ Is posterior to the rectum ○ Gives off innervation for a bunch of named plexi (ie uterovaginal plexus) Vessels of the Pelvis Supplied by branches of Internal Iliac ○ Lots of variation in these branches ○ Posterior Division of Internal Iliac Iliolumbar artery – leaves true pelvis and goes to false pelvis Lateral Sacral arteries – multiple branches go to wall of true pelvis and cauda equina Superior Gluteal Artery – largest branch; leaves pelvis between lumbrosacral trunk and S1 ventral ramus and goes into greater sciatic foramen ○ Anterior Division of Internal Iliac Obturator artery – links with obturator nerve and leaves pelvis through obturator foramen ○ 40% of the time it actually comes from the inferior epigastric artery Umbilical artery – gives off superior vesicle arteries and becomes patent (goes to umbilicus as the medial umbilical fold) ○ Superior Vesicle Arteries – for urinary bladder Uterine Artery – typically gives off Vaginal Artery Inferior Vesicle Arteries – for neck region of bladder ○ Can give off Vaginal Artery Middle Rectal Artery – often shares a common trunk with the inferior vesicle arteries Internal Pudendal artery – leaves through greater sciatic foramen Inferior Gluteal artery – leaves through greater sciatic foramen Note – ureter crosses underneath the uterine artery at junction of vagina and cervix ○ ‘water flows under the bridge’ Lymphatics of the Pelvis They basically just follow vessels Perineal drainage (including most of the genitalia) goes to inguinal nodes ○ Exception – testicular lymph drains into nodes around the aorta because its lymph goes through inguinal canal and along testicular vessels ○ Ways to Give a Pudendal Nerve Block Ischioanal fossa - Bathe pudendal nerve through ischioanal fossa associated with ischial spine Transvaginally – palpate ischial spine through vagina and inject there Note – mons pubis and anterior labia won’t be affected because they are from ilioinguinal nerve Gluteal Region and Posterior Thigh ○ Objectives Describe the dermatome pattern for the lower limb Demonstrate the sacrotuberous and sacrospinous ligaments and describe how they contribute to the formation of the sciatic foramina Review the anatomy of the bones of the pelvis and the femur Demonstrate the surface anatomy of the sciatic nerve Demonstrate the large gluteal muscles and understand their role in gait as well as their nerve and blood supply Describe the course structures take from the pelvic cavity to the gluteal region Demonstrate the six lateral rotator muscles of the hip Understand the course structures take from the gluteal region to the perineum Define the hamstring muscle group and delineate their actions, nerve supply, and blood supply ○ Review three parts of the hip bone and note that they only fuse completely by 22 years ○ Review bones and ligaments of the pelvis Femur Tibia Fibula Greater Trochanter – Intercondylar eminence – Head, Neck and Shaft – Lesser Trochanter – Lateral Malleolus – Medial and Lateral Chondyle Tibial tuberosity – Note – is buried in muscle Head, Neck and Shaft Intertrochanteric line – just outside lateral border of Anterior Border – Note – is lateral the neck subcutaneous Note – doesn’t articulate Intertrochanteric crest – Medial malleolus with femur Gluteal Tuberosity – on posterior side Linea aspera – ridge; starts around gluteal tuberosity Medial and Lateral Supracondylar ridge – continuous with linea aspera Popliteal surface – between the suprachondylar ridges Adductor Tubercle – Medial and Lateral Condyles – smooth surface where it articulates with tibia Intercondylar fossa – between the condyles ○ Angle of Inclanation – long axis of femur vs head and neck Normal – around 135º; variation between sexes Coccsa Valgus - ↑ angle; causes lateral deviation; ‘bow-legged’ Coccsa Varus - ↓ angle; causes medial deviation; ‘knock-kneed’ ○ Callipygous – a wonderful ass ○ Gluteal Region – bounded by iliac crest and gluteal fold Gluteal Fold – lower edge of gluteus maximus where dermis is attached to deep fascia Dermatome – basically just S1 (lateral) and S2 (medial) Nerves and Veins of Cutaneous Region Most subcutaneous blood drains into saphenous veins Inferior cluneal nerves – sensory innervation to lower gluteal area Dorsal rami supply medial portion Ventral rami supply lateral portion Muscles Fascia Lata – deep fascia of the gluteal region and thigh ○ Iliotibial Tract – thickening of fascia lata laterally Tensor Fascia Lata Muscle – ASIS → iliotibial tract ○ Action – flexor of hip joint ○ Buried in fascia lata Gluteus Maximus – fibers run at 45º angle ○ Origin – ala of ilium, sacrum, sacrotuberous ligament ○ Insertion – gluteal tuberosity (lower ¼), iliotibial tract (upper ¾) ○ Action – extensor of hip Very minimal action during flat surface walking; kicks in for running, stairs, etc. ○ Innervation – inferior gluteal nerve (the only thing that inferior gluteal nerve supplies) ○ Blood Supply – inferior gluteal artery Gluteus Medius and Minimus – medius is superficial to minimus ○ Origin – ala of ilium ○ Insertion – greater trocanter ○ Action – essential for normal gait Non-weight bearing – abductor of lower limb Weight-bearing – tips lateral portion of pelvic bone ↓ on weight bearing side to elevate opposite side of pelvis so that opposite limb can clear the ground ○ Innervation - superior gluteal nerve ○ Blood Supply - superior gluteal artery ○ Pathology Trendelenburg’s Gait – when both sides are paralyzed each leg swings out laterally so it doesn’t drag Trendelenburg’s Test – positive when you have patient stand on leg of affected side (assuming only one superior gluteal nerve is affected) and lift non-affected leg causing the pelvis to tilt downward on non-affected side. This could cause an affected patient to fall Laterally Running Posterior Muscles inserting on Greater Trochanter ○ Insertion – Greater Trochanter ○ Innervation – each by their own named nerve from the sacral plexus ○ Action – lateral rotation of the lower limb ○ Blood Supply – inferior gluteal artery (and maybe some others) ○ Piriformis – sacrum → greater trocanter goes through the greater sciatic foramen ○ Superior Gemellus Muscle – ischial spine → greater trocanter ○ Obturator Internus Muscle – internal side of obturator foramen → greater trochanter Goes through lesser sciatic foramen ○ Inferior Gemellus Muscle – ischial tuberosity → greater trochanter ○ Quadratus Femoris Muscle – ischial tuberosity → greater trochanter Obturator Externus Muscle – external side of obturator foramen → greater trochanter ○ this is on anterior side and is underneath quadratus femoris ○ Innervation – obturator nerve Piriformis Syndrome – hypertrophy of piriformis muscle as it exits the greater sciatic foramen causing compression of structures exiting the foramen ○ Mimics lumbar disc herniation causing sciatica ○ Things that go through greater sciatic foramen into the gluteal region Inferior pudendal nerve and vessels, sciatic nerve, posterior cutaneous nerve of the thigh, nerve to obturator internus May not be a complete list Vessels and Nerves Superior Gluteal Vessels and Nerves – go in between gluteus medius and minimus to supply both of those and tensor fascia lata muscle Inferior Gluteal Nerve – supplies gluteus maximus only Inferior Gluteal Artery – supplies gluteus maximus and others Pudendal - ? Posterior Cutaneous Nerve of the Thigh – comes out near gluteal fold and supplies skin of posterior lower limb to behind the knee ○ Supplies largest area of skin of any other nerve Sciatic Nerve –a grouping of the tibial and common fibular nerves from the sacral plexus by a fascial sheath ○ Normally the sciatic nerve comes out the greater sciatic foramen below the piriformis ○ Variations – sometimes the tibial and common fibular nerves separate and if so the common fibular nerve will either pierce the piriformis or will come out anterior to it ○ Tibial and common fibular nerve separate in distal 1/3 of femur Tibial stays mid-dorsal and common fibular goes lateral Butt Injections – can’t give them anywhere over the gluteus maximus, there is a safe area lateral and superior to the gluteus maximus, but below the iliac crest where you can inject stuff ○ Posterior Thigh Most muscles go from gluteal crease to knee joint Posterior Cutaneous Nerve of the Thigh – stays deep to superficial fascia lata and just gives branches out to tissue Small Saphenous Vein – pierces superficial fascia lata just above knee and goes deep Drains middle posterior portion of leg Great Saphenous Vein – drains medial aspect of leg Compartments Anterior Compartment – contains extensors; bounded by lateral and medial intramuscular septa Posterior Compartment – contains flexors; bounded by lateral and posterior intramuscular septa Medial Comparment – contains adductors; bounded by posterior and medial intramuscular septa Note – each septa is attached to the linea aspira All compartments bounded superficially by fascia lata Posterior Compartment Hamstrings – called that because they are used to hang a ham hock ○ Origin – ischial tuberosity (can be seen when hip is flexed) ○ Innervation – tibial nerve ○ Action – extend the hip and flex the knee ○ Biceps Femoris Muscle (long head) – crosses laterally Insertion – head of fibula ○ Thus crosses both joints ○ Semitendinosus Muscle – has a nice long tendon and crosses medially; is medial to semimembranosus Insertion – proximal tibia ○ Semimembranosus – tendon is sheetlike/membranous and crosses medially Insertion – proximal tibia ○ Note – some people’s hamstrings are shorter or longer than others ○ Note – all can be palpated behind knee Biceps Femoris (short head) – ○ Origin – midway down shaft of femur ○ Insertion – head if fibula (common with long head) ○ Innervation – common fibular nerve Terms for Muscles that Span Two Joints Active Insufficiency – if you flex one joint, then the extension of the second one will be weaker ○ Ex. flex knee then extend hip Passive Insufficiency – if you fully flex one joint then you will get farther if you flex the second too ○ Ex. a high kick, you can get farther if your knee is bent Thigh and Leg ○ Objectives Identify the bones of the thigh and leg and the major anatomical features of each Define the boundaries and the contents of the femoral triangle Explain the anatomy of a femoral hernia and distinguish it from the inguinal hernias Demonstrate the course and the primary branching pattern for major vessels and nerves of the thigh and leg Identify arteries of the lower limg from which a pulse may be palpated Describe the course of the major superficial veins of the lower limb List the contents of the subsartorial canal Demonstrate the muscles found in each anatomical “compartment” of the thigh and leg Describe the nerve and blood supply for muscles of the thigh and leg Define active and passive insufficiency as it relates to muscles Define the major actions of muscles acting on the hip, knee, ankle and digital joints Define the boundaries of the popliteal fossa and describe its contents Describe the relationship of muscles, vessels and nerves as they cross the ankle to enter the foot Describe the vessels involved in collateral circulation for the hip, knee and ankle ○ Cross Section of Thigh Note – there is not a neurovascular bundle in the posterior compartment (but there is one in the others) ○ Dermatomes (see above) L4 – contains patella ○ Anterior Thigh Superficial Nerves and Veins Lateral Cutaneous Nerve of Thigh – does what it says Great Saphenous Vein – begins on dorsum of foot and goes up medial side to the saphenous opening where it joins femoral vein ○ A great source of vein for any sort of vascular transplant ○ Saphenous Opening – opening in the fascia lata in the femoral triangle that lets the great saphenous through ○ There are a lot of communicating branches going from superficial to deep veins, if some of the valves in those get damaged then superficial veins will back up and cause varicose veins Lymph Drainage Superficial Inguinal Nodes – drain UG and anal triangle (except testicles), the anterior abdominal wall below the umbilicus and all of the superficial area of the lower limb Deep Inguinal Nodes – deep to fascia lata and receive drainage of superficial inguinal nodes through the saphenous opening ○ Sends lymph on to external iliac nodes Muscles Tensor Fascia Lata ○ Action – flexes knee joint Puts tension on fascia lata which allows knee extensors to relax when knee is at full extension ○ Innervation – Superior Gluteal Nerve (only exception in anterior compartment) Quadriceps ○ Origin – femur, except rectus femoris, which inserts on the ASIS ○ Insertion – they all come together to form a common tendon, the Quadriceps Femoris which contains the Patella and then inserts on the tibial tuberosity Patellar Ligament – continuation of quadriceps femoris from patella to tibial tuberosity ○ Action – extension of knee ○ Innervation – femoral nerve ○ Rectus Femoris – only quad to cross the hip joint Origin – AIIS Action – also a weak flexor of the hip ○ Vastus Lateralis – ○ Vastus Medialis – ○ Vastus Intermedius – under rectus femoris; lots of tendon Sartorius – runs lateral to medial; basically lets you cross your legs ○ Origin – ASIS ○ Insertion – proximal tibia ○ Innervation – femoral nerve ○ Action at hip – flex and lateral rotation ○ Action at knee – flex ○ Medial Compartment Muscles - ‘Muscles of Virtue’ Origin basically the pubis Iliopsoas basically the pubis Pectineus Adductor Longus Gracilis Obturator Externus Adductor Magnus basically the pubis basically the pubis outside obturator foramen basically the pubis Insertion Action Supply - Femur (lesser trochanter) - Femur (lesser trochanter) - hip flexor (most powerful) - adduction - Femur (lesser trochanter) - tibia (crosses knee) - Femur (greater trochanter) - adduction - adduction (very weak) - adduction - lateral rotation - adduction (most powerful) - vertical fibers extend knee - obturator - femoral and - sometimes obturator - obturator - obturator - obturator - Femur (linea aspira) - medial epichondyle - obturator - tibial basically the pubis - Femur (lesser trochanter) - adduction - obturator Adductor Brevis Extra Notes ○ Blood Supply – muscular branches of profunda femoris & obturator artery ○ Gracilis – basically expendable; useful for muscle transplant, especially external anal sphincter ○ Obturator Externus – underneath pectineus; becomes tendinous ○ Adductor Magnus – mainly under adductor longus Holes in Tendinous Aspect ○ 4-5 – allow perforating vessels through ○ Adductor Hiatus – gap at proximal end Femoral artery and vein pass through and enter posterior compartment to become Popliteal vessels Saphenous nerve (branch of femoral) also passes through ○ More Thigh Stuff Femoral Triangle Boundaries ○ Sartorius – lateral border ○ Inguinal Ligament – base ○ Adductor Longus – medial border ○ Roof – skin and fascia lata, thus a great place to stop bleeding of lower limb Contents ○ Femoral Nerve – most lateral; becomes a bunch of branches here ○ Femoral Artery – halfway between ASIS and pubic tubercle Profunda brachii branches just distal to triangle ○ Femoral Vein – most medial Great saphenous vein drains into femoral vein here ○ Clocay’s Lymph Node – one lymph node in femoral canal Femoral Sheath – extension of fascia of abdominopelvic cavity that covers femoral vessels, not the femoral nerve ○ Femoral Canal – CT medial to femoral vein that is a weak point and likely spot for hernias Femoral Hernia – hernia at femoral canal; most common in females ○ Intestines can even become subcutaneous if they come through saphenous aperature Adductor Canal/Subsartorial Canal – roof made by sartorius; mainly on medial thigh Contents – femoral artery, femoral vein, saphenous nerve and nerve to vastus medialis Nerves and Arteries Femoral Nerve – becomes a bunch of branches in femoral triangle, the two most notable are the Nerve to Vastus Medialis and Saphenous because they are long and medial Tibial ○ Saphenous nerve – sensory nerve for medial leg only Travels with femoral vessels in thigh then passes through adductor hiatus to travel with the great saphenous vein Obturator Nerve – motor to medial compartment Femoral Artery – gives off only profunda femoris and doesn’t supply anything in the thigh Profunda Femoris/Deep Artery of the Thigh – branches off femoral artery just below femoral triangle ○ Ends above knee ○ Branches Lateral Femoral Circumflex – goes around hip superior to hip joint ○ Descending branch of lateral femoral circumflex – supplies most of anterior compartment Muscular Branches – supply most of medial compartment Medial Femoral Circumflex – goes around hip posterior to hip joint Perforating Arteries – go through adductor magnus and supply most of posterior compartment Thigh Innervation Review Medial Compartment – obturator nerve except for pectineus (which is femoral) & adductor magnus Anterior Compartment – all femoral nerve Posterior Compartment – tibial except for short head of biceps femoris (common tibial) ○ Leg Popliteal Fossa Boundaries ○ Lateral – biceps femoris (long head) ○ Medial – semitendinosus ○ Distal – two heads of gastrocnemius Contents ○ Popliteal vessels – extensions of femoral vessels after going though adductor hiatus Give off Genicular Arteries that provide collateral circulation for the knee) ○ Sciatic Nerve – here it divides into tibial and common fibular Note – you can get a pulse in popliteal artery if you flex the knee and push into popliteal fossa Soleal Line – oblique ridge on proximal tibia Interosseous Membrane – between tibia and fibula; has a gap in proximal and distal end Cross Section Anterior Compartment – bounded by tibia and anterior intermuscular septum (connects to fibula) Lateral Compartment – bounded by anterior and posterior intermuscular septum (connects to fibula) Posterior Compartment – bounded by posterior intermuscular septum and tibia ○ Transverse intermuscular septum – divides posterior compartment into deep and superficial Crural Fascia – deep fascia of the leg which is continuous with the fascia lata Muscles Posterior Compartment ○ Superficial Posterior Compartment - Superficial Origin Insertion Action Innervation - plantar flexion Gastrocnemius (medial - femur (distal) and lateral head) - calcaneal tendon - tibia (soleal line) - plantar flexion (most powerful) Soleus - femur - wussy Plantaris Notes ○ Plantaris has a very long tendon that goes between gastrocnemius and soleus Tendon looks like a nerve and is a great source for tendon/ligament transplant If ruptured, hurts just like a calcaneal tendon rupture, but no balled up muscle big toe Tibialis Posterior Flexor Digitorum Longus Popliteus Interosseous membrane Tibia Extensive insertion on plantar surface Base of distal phalanx of lateral 4 toes Lateral chondyle of femur Tibia above soleal line -plantar flexion -inversion -plantar flexion -inversion -flexes toes -plantar flexion -inversion -rotates knee to unlock it Tibial ○ If the calcaneal tendon breaks, it makes a sound like a rifle and the muscle will ball up ○ Deep Posterior Compartment - Deep Origin Insertion Action Innervation Base of distal phalanx of -flexes great toe Flexor Hallucis Longus Fibula Note – the muscles that originate on leg and insert on the foot are called extrinsic foot muscles Note – popliteus muscle gets blood from the popliteal artery “Tom Dick ANd Harry” – order of the tendons at medial malleolus from medial → lateral ○ Tibialis posterior, Digitorum, posterior tibial artery, tibial nerve, Hallucis Anterior Compartment Anterior Compartment Origin Insertion Action Supply Tibia -Tarsal bone -mainly dorsiflexion Tibialis Anterior Extensor Hallucis Longus Extensor digitorus longus Fibularis Tertious Interosseous membrane Fibula -is the lower fibers of extensor digitorus longus -Metatarsal of big toe -base of big toe -lateral 4 toes th -5 metatarsal tubercle -inversion -mainly extends big toe -dorsiflexion -mainly extends toes -dorsiflexion -weak everter Deep Fibular Nerve Anterior Tibial Artery ○ Note – fascia of anterior layer binds anterior muscles really tightly thus not much room for edema Shin Splints – tearing of anterior compartment muscles or tendons ○ Occurs after new overuse Anterior Tibial Syndrome – edema in anterior compartment that compromises arteries and causes anoxia, maybe even necrosis ○ Exibits the same pain as shin splints Lateral Compartment Lateral Compartment Origin Insertion Action Supply st Fibula 1 metatarsal -eversion (very strong) Fibularis Longus - Superficial Fibularis Brevis Fibula 5th metatarsal tubercle -plantar flexion -eversion -plantar flexion Fibular Nerve - Branches of Fibular Artery Inversion – movement of sole to the medial plane Eversion – movement of sole to the lateral plane Nerves and Vessels Superficial ○ Small Saphenous Vein – starts at foot and dumps into popliteal vein in popliteal fossa Travels with Surrel Nerve Popliteal artery branches into → posterior tibial artery and anterior tibial artery ○ Posterior Tibial Artery – goes to ankle around medial malleolus with tom dick and harry Gives off Fibular Artery – goes a little lateral and then runs down in the flexor hallucis longus ○ Multiple branches supply the lateral compartment muscles ○ Ends before getting to the ankle Note – posterior tibial artery is prone to plaque buildup ○ Intermittent Claudication – intense pain caused by vascular insufficiency to posterior muscles; goes away with a little rest ○ Anterior Tibial Artery – shortly after branching it leaves the posterior compartment through the proximal end of the interosseus membrane and enters anterior compartment courses deep to tibialis anterior with deep fibular nerve into foot Tibial nerve - courses down posterior leg to Tom Dick and Harry then into foot Common Fibular Nerve – courses around the neck of the fibula and then branches into: ○ Superficial Fibular Nerve – supplies the lateral compartment and goes down into foot ○ Deep Fibular Nerve – supplies the anterior compartment and goes down into foot ○ Trauma to Neck of Fibula Causes common fibular nerve and/or deep fibular nerve irritation/damage Results in foot drop (foot becomes plantar flexed) and weakened eversion Foot ○ Objectives Demonstrate the relationship of extrinsic foot muscles to nerves and vessels of the foot Understand the function of intrinsic foot muscles Define the arches of the foot and understand how each is maintained Define the role of the plantar aponeurosis Understand the communication of dorsal and plantar arteries of the foot Identify the retinacula of the ankle region Describe the sensory innervation for the foot ○ Bones Tarsal Bones Calcaneous – heal ○ Sustentaculum Tali – extension of calcaneous that supports the talus Talus – where the tibia and fibula articulate Cuboid – lateral side Navicular – medial side Cuneiform (medial, intermediate & lateral) – Metatarsals – 5 of them Sesamoid Bones – two of them near distal end of 1st metatarsal Phalanges – 14 of them ○ Nerve Supply Dermatome (see above) L4 L5 Dorsal Foot Big toe Toes 2-4 S1 Little toe Plantar Foot Big toe Toes 2-4 Most of plantar surface Little toe Edges Surrel Nerve – sensory to lateral edge Saphenous Nerve – sensory to medial edge (a branch of femoral nerve) Dorsum of Foot Superficial Fibular Nerve – innervates muscles and skin of lateral compartment then ○ Skin over dorsum of the foot except for small area (see picture) Deep Fibular Nerve – innervates anterior compartment then ○ Skin on adjacent sides of 1st and 2nd toes Plantar Foot Lateral and Medial Plantar Nerves – terminal branches of tibial nerve ○ Lateral Plantar Nerve – sensory innervation to lateral 1.5 toes (and to muscles) ○ Medial Plantar Nerve – sensory innervation to medial 3.5 toes (and to muscles) ○ Blood Supply Anterior tibial artery becomes Dorsal Artery of the Foot after ankle Dorsal Artery of the Foot – runs with deep fibular nerve to between the 1st and 2nd toes ○ Deep Plantar Artery – immediately dives deep between 1st and 2nd metatarsals onto plantar surface to supply medial side of deep plantar arch ○ Arcuate Artery – runs at 90º angle between tarsals and metatarsals Dorsal Metatarsal Arteries – run between metatarsals and gives off dorsal digital branches Posterior tibial artery becomes Lateral and Medial Plantar Arteries Lateral Plantar artery – has deep branch that passes between layers 3 & 4 to supply lateral side of deep plantar arch Deep Plantar Arch – runs at base of metatarsals and receives blood from the deep plantar artery medially (a branch of the dorsal artery of the foot) and the lateral plantar artery laterally (a branch of the posterior tibial artery) ○ Where to find a pulse in the lower limb Femoral artery in femoral triangle Popliteal artery in popliteal fossa Posterior tibial artery posterior to medial malleolus Dorsal artery of foot (‘pedal pulse’) in between EHL and EDL tendons ○ Extensor Retinacula (Superior and Inferior) – specializations of deep fascia/crural fascia on dorsal side ○ Dorsum of Foot Superficial Muscles Innervation – deep fibular nerve Action – insignificant weak extensors Extensor Hallucis Brevis – inserts on big toe Extensor Digitorum Brevis – inserts on toes 2-4 Clinical Connection – if you drop something on your foot then these will likely get hematoma or bruise Note – fibularis tertius, tibialis anterior and extensor hallucis longus tendons are here too ○ Plantar Surface of Foot Note – intrinsic muscles of the foot start and end in the foot Superficial Very thick skin Plantar aponeurosis – calcaneous → toes; maintains integrity of arch of foot ○ Plantar Fasciitis – aponeurosis gets stretched or torn and causes stabbing/sever pain at beginning of weight bearing First Layer Origin Insertion Action Supply Abductor Hallucis Medial Plantar Flexor Digitorum Nerve Phalanges of respective Calcaneous Maintain foot integrity Brevis toe Lateral Plantar Abductor Digiti Nerve Minimi Second Layer Origin Insertion Action Supply Calcaneous Tendon of FDL Redirects flexing action Lateral Plantar Quadratus Plantae Lumbricals Tendon of FDL 4 toes Note – lumbricals prevent toes from buckling under of FDL to long axis -Flex MP joint -Extend IP joint Nerve (except lumbrical #1, which is medial plantar nerve) Tendons of extrinsic muscles FHL & FDL also present Third Layer Origin Insertion Flexor Hallucis Brevis Each tendon has a sesamoid bone flanking tendon Action Supply -Flex big toe Medial Plantar Nerve Lateral Plantar Nerve of FHL to prevent crushing -Flex 5th toe Flexor Digiti Minimi Brevis Proximal lateral Big toe -prevents bones from Adductor Hallucis metatarsals? splaying out (oblique head) th Distal 5 Adductor Hallucis metatarsal (transverse head) Note – reference point for adduction and abduction is the 2nd toe Fourth Layer Tendons of Extrinsic Muscles ○ Fibularis Brevis Tendon – inserts on 5th metatarsal ○ Fibularis Longus Tendon – comes from lateral side and goes underneath long plantar ligament to insert on 1st metatarsal and medial cuneiform Intrinsic Muscles ○ Dorsal Interosseus – ‘DAB’; bipennate Insert – lateral proximal phalanges of toes 2-4 plus medial proximal phalanx of toe 2 ○ Plantar Interosseus – ‘PAD’; unipennate Insert – medial proximal phalanges of toes 3-5 ○ Innervation – lateral plantar nerve ○ Blood Supply – deep plantar arch Joints of the Lower Limb ○ Objectives Identify the major extra and intracapsular ligaments for the hip, knee and ankle Explain the movements possible in each major joint of the lower limb Explain the position of each major joint of the lower limb when it is most vulnerable to injury Demonstrate the simple clinical tests to determine integrity of the support structures for the knee joint ○ Sensory innervation for any major joint – provided by the same nerves that act on the muscles that move the joint ○ Hip Joint Intrinsic Ligaments – thickenings of the joint capsule Iliofemoral Ligament – ASIS → intertrochanteric line (of femur) ○ Taught when hip is extended; thus prevents hyperextension Pubofemoral Ligament – pubis → intertrochanteric line (of femur) ○ Taught when hip is abducted Ischiofemoral Ligament – on the posterior pubis (inserts on greater tuberosity?) ○ Taught when hip is extended Note – all three of these ligaments originate on a different bone of the hip Inside the Joint Acetabular Labrum – C-shaped lip of CT around edge to make acetabulum deeper Transverse Acetabular Ligament – connects the two parts of the C Ligament of the head of the Femur – not really a ligament, just contains a branch of the obturator artery ○ Obturator artery supplies blood to head of femur Note – not all of the acetabulum is articular Clinical Connections Dislocations are rare because this joint is quite stable Broken Hip – neck of femur is broken; often intracapsular ○ Neck of femur is supplied by circumflex arteries, which is different from the head and body of the femur Movements – circumduction, abduction/adduction, flexion/extension, rotation ○ Knee Joint Intrinsic Ligaments – all seen best from posterior view, except patellar ligament Oblique Popliteal Ligament – extension of the semimembranous tendon that makes a U-Turn Arcuate Popliteal Ligament – goes over popliteus muscle and thus makes popliteus intracapsular Medial/Tibial Collateral Ligament (MCL) – intimate with the capsular fibers of the joint ○ Broad and flat ligament Fibular (Lateral) Collateral Ligament – not intimate with the capsular fibers of the joint because there is a gap for the popliteus muscle; cord-like ligament Patellar Ligament – inserts on tibial tuberosity Intracapsular Things Anterior Cruciate Ligament (ACL) – anterior portion of tibia → lateral chondyle of femur ○ Taught when knee is in full extension; thus prevents hyperextension ○ Weaker and more prone to injury Posterior Cruciate Ligament (PCL) – posterior portion of tibia → medial chondyle of femur ○ Taught during flexion Menisci ○ Intrasynovial ○ Are C-Shaped Outer edge thickest and vascular (supplied by geniculate arteries) Inner edge thinner and avascular (nutrients from synovial fluid) ○ Medial Meniscus – MCL is attached to it and is thus less mobile and more prone to injury ○ Lateral Meniscus – fibular collateral ligament is not attached to it and is thus more mobile and less prone to injury Note – ACL and PCL are not intrasynovial, but the menisci are Patella – articulates in groove between chondyles of femur Prepatellar Bursa – not connected with synovial membrane Common site for irritation if on knees too much Trauma to Knee Joint Blow from the Lateral Side with leg extended and weight on it ○ Medial side injured, specifically the unhappy triad (ACL, MCL and medial meniscus) Fall on Knees ○ Drives tibia posteriorly and injures the PCL Anterior and Posterior Drawer Test – determines integrity of ACL and PCL ○ Have patient sit on table with leg dangling, if doc can: Pull tibia anteriorly → ACL broken Pull tibia posteriorly → PCL broken ○ Joints of Foot Hindfoot (calcaneus and talus), midfoot, forefoot (metatarsals and phalanges) A joint between each of these segments plus hindfoot to leg Arches Lateral Longitudinal – most touches ground Medial Longitudinal – easily seen; usually doesn’t touch ground Transverse – Remember, talus lays on top and articulates with the calcaneus Talus acts as the ‘keystone’ of the arch of the foot (the most important thing that keeps everything together Ligaments connect adjacent pieces Aponeurosis and long plantar ligament connects opposite ends of the arch Extrinsic muscles of the foot act as suspensors of the arch Ligaments and Tendons Plantar View ○ Tibialis Posterior Tendon – this is the extrinsic muscle with an extensive insertion on plantar foot Comes in from the medial side ○ Long Plantar Ligament – is deep and acts as a ‘tie beam’ connecting opposite ends of the arch ○ Plantar Calcaneonavicular (“Spring”) Ligament – contains elastic fibers and is springy Is just deep to talus and supports the talus Lateral View ○ Called the ‘lateral collateral ligaments’ ○ Anchor the lateral malleolus to the tarsal bones ○ Calcaneofibular Ligament – calcaneous → fibula ○ Anterior and Posterior Talofibular Ligaments – talus → fibula Medial View ○ Called the ‘deltoid ligament’ because they form a triangle ○ Anchor the medial malleolus to the tarsal bones ○ Anterior and Posterior Tibiotalar Ligaments – ○ Tibiocalcaneal Ligament – connects medial malleolus to the sustenaculum tali of the calcaneous ○ Tibionavicular Ligament – Trauma to Ankle Joint Inversion or eversion injuries are more likely to break the malleolus on either side than the ligaments since the ligaments are so strong Autonomic Innervation of the Abdomen and Pelvis ○ Objectives Review the basic organization of the sympathetic and parasympathetic division of the ANS What is the general organization of the sympathetic innervation to abdominal viscera? Describe the following terms: thoracic splanchnic, lumbar splanchnic, prevertebral ganglia, paravertebral ganglia Describe the details for sympathetic innervation for all viscera of the abdomen What is the distribution of the vagus nerve in the abdomen? Describe the formation and distribution of pelvic splanchnic nerves What is the basic organization of sympathetic innervation to pelvic viscera? Describe the following terms: superior hypogastric plexus, hypogastric nerve, inferior hypogastric plexus and sacral splanchnic What is the basic organization of parasympathetic innervation to pelvic viscera? ○ Sympathetic Preganglionic neurons from lateral horn T1-L2 Postganglionic neurons in paravertebral ganglia or prevertebral ganglia Prevertebral ganglia are mainly for organs below diaphragm ○ Parasympathetic Preganglionic nerves from CN 3, 7, 9, 10 and lateral horn S2, S3, S4 Postganglionic nerves mainly in terminal ganglia ○ Enteric System – self sustaining; has afferents and efferents; modifiable by sympathetics and parasympathetics ○ Autonomic Innervation of Abdominal Viscera Sympathetics That end in skin, sweat glands, erector pili and BV ○ Lateral Horn T1-L2 → ventral root → white ramus communicans (only exists from T1-L2) → synapse in paravertebral ganglia → grey ramus (at every level) → dorsal and ventral rami That end in the Abdomen ○ In general they go straight through paravertebral ganglion, to a splanchnic nerve and synapse in a named prevertebral gangion Organs Preganglionic Preganglionic fibers Prevertebral Postganglionic cell body (Splanchnic Nerve) Ganglion Fibers Foregut – supplied Celiac plexus etc. T5-T9 Greater splanchnic Celiac Ganglion by celiac trunk Midgut – supplied T10-T11 Lesser splanchnic Superior Mesenteric Superior mesenteric by SMA plexus etc. Ganglion Hindgut – supplied L1-L2 Lumbar splanchnic Inferior Mesenteric Inferior mesenteric by IMA plexus etc. Ganglion Renal plexus, Kidneys & Gonads T12 (T11) Least splanchnic Aorticorenal suprarenal plexus, Ganglion gonadal plexus On all above NONE Follows vessels to Suprarenal Glands T8-T12 splanchnics suprarenal medulla ○ Note – the postganglionic fibers often travel along blood vessels in plexi named after where they are going (ex will travel along superior mesenteric artery and then branch with the artery and go along middle colic plexus) ○ Note – the prevertebral ganglia all kinda blend together Note – splanchnic nerves can have sympathetic or parasympathetic fibers in them Solar Plexus – accumulation of autonomic ganglia in the area of the celiac ganglia and SM ganglia etc. Parasympathetics Vagus Nerve – supplies all organs of GI associated with celiac and superior mesenteric artery, kidney and gonads ○ Preganglionics travel from brainstem → along esophagus → distributed in the celiac and superior mesenteric pelxi → synapse in terminal ganglia (efferent plexi of the enteric system) ○ Note – vagus nerve also supplies kidney and gonads; these are distributed in renal and gonadal plexi Pelvic Splanchnic Nerves – contain only parasympathetics ○ Supplies anything supplied by the inferior mesenteric artery ○ Lateral horn S2-S4 → ventral root → ventral ramus → pelvic splanchnic nerve → distributed in the inferior mesenteric plexus → synapse in terminal ganglion Terminal ganglia located in Auerbach’s plexus of the gut wall Note – preganlionic parasympathetics modulate enterics Note – suprarenal gland does not receive parasympathetic innervation ○ Autonomic Innervation for Pelvic Viscera Supplying urinary bladder, rectum, uterus fundus, vagina, seminal vesicle etc. Sympathetics – have two routes Via Lumbar Splanchnic ○ Pathway – lateral horn L1-L2 → ventral root → white ramus → paravertebral ganglia → lumbar splanchnic → aortic plexus (I’M NOT SURE IF IT GOES HERE) → superior hypogastric plexus (can synapse here) → hypogastric nerve → inferior hypogastric plexus (or can synapse here) → organ Thus has two places where it can synapse, the superior and inferior hypogastric plexi ○ Superior Hypogastric Plexus – continuation of aortic plexus (made by greater, lesser and least splanchnic) after aortic bifurcation onto sacral promontory Only sympathetic fibers ○ Hypogastric nerves – right and left; connect superior hypogastric plexus to inferior Only sympathetic fibers ○ Inferior Hypogastric Plexus – plexi that course along branches of internal iliac artery Both sympathetic and parasympathetic fibers Via Sacral Splanchnic ○ Pathway – lateral horn L1-L2 → ventral root → white ramus → paravertebral ganglia → sympathetic trunk → paravertebral ganglia around S2-S4 (can synapse here) → sacral splanchnic → inferior hypogastric plexus (or can synapse here) → organ Thus can synapse in the sacral paravertebral ganglia or the inferior hypogastric plexus ○ This means that the sacral splanchnic nerve can have pre or post ganglionic neurons Parasympathetics Pathway – lateral horn S2-S4 → ventral root → ventral ramus → pelvic splanchnic → inferior hypogastric plexus → synapses in terminal ganglia This is why inferior hypogastric plexus has both sympathetic and parasympathetic neurons Note – once anything hits the inferior hypogastric plexus they are then distributed to organs in their own individual plexi Visceral Afferents ○ Objectives What is a visceral afferent? What sensations does this afferect mediate? As an example, describe the course of a visceral afferent fiber carrying information about pain from the duodenum. Where would pain from the duodenum be referred? As an example, describe the course of a visceral afferent carrying information about stretch of the intestinal wall ○ Visceral Afferents – send sensory information from organs to CNS Almost everything that receives visceral efferents will also send visceral afferents along the same pathway ○ ○ ○ ○ ○ Visceral information differs from somatic in quality not intensity Visceral pain is vague/diffuse but can still be very intense Neurons are pseudounipolar General Pathways Pain information follows along sympathetic routes ○ Exception – structures supplied by pelvic splanchnic nerves send pain afferents along parasympathetic pathways State of organ information follows along sympathetic routes Vagal vs. Spinal Neurons Spinal neurons – receptor in capsule or wall of organ → dorsal root ganglion houses cell bodies → ends in dorsal horn of spinal cord Vagal neurons – receptor in capsule or wall of organ → vagal/jugular ganglion houses cell bodies → ends in brain stem Pelvic Pain Line – imaginary line/division that marks whether or not pain afferents will follow sympathetic or parasympathetic pathways In general, structure is sympathetically supplied by the pelvic splanchnic nerve then it will fall below pelvic pain line In general, if structure is in contact with pelvic peritoneum then its visceral afferents will follow a sympathetic pathway, if below that then they will follow a parasympathetic pathway Ex. top of urinary bladder will follow sympathetics, while neck of bladder will follow parasympathetics Visceral Afferents with Pain Information Organs Above Pelvic Pain Line Pathway – receptor in wall of organ → along blood vessels to named ganglia (celiac, superior mesenteric etc.) → a thoracic splanchnic nerve (greater, lesser, etc.) → paravertebral ganglia → white ramus → cell body in dorsal root ganglia → ends in dorsal horn Organs Below Pelvic Pain Line Pathway - ?? S2-S4 Referred Pain - Pain caused by the fact that visceral afferent cell bodies share the same ganglia (the dorsal root ganglia) as somatic afferent cell bodies and this causes stimulation of the related dermatome Note – appendix refers pain to the umbilicus Note – uterine tube and fundus refers pain to L1 (lower back pain?) There is a nice picture showing which organs are linked to which spinal nerves, but I'm not going to memorize it Somatic Referred Pain – if gallbladder or liver are irritated then they irritate the peritoneum of diaphragm which is innervated by the phrenic nerves (which are somatic) Visceral Afferents with Condition/State Information Travel along parasympathetic pathways, either the vagus nerve, or S2-S4 Vagus Nerve Pathway – receptor in wall of organ → missing something? → cell body in the vagus/jugular ganglion → ends in brainstem No refered pain in vagus system because no somatic cell bodies in vagus ganglion S2-S4 Pathway – follows pathway of pelvic splanchnic nerve?? Note – splanchnic nerves contain visceral afferents too Visceral Reflexes – reflexive loop made by visceral afferents and efferents only requiring an intact spinal cord at S2-S4 Includes micturition, erection, defecation Defecation Reflex – a?nal c?an?al visceral afferents carrying state info → travel via pelvic splanchnic nerve → and synapse on S2-S4 preganglionic parasympathetic efferent neuron in lateral horn → leave via pelvic splanchnic nerve → end/synapse on terminal ganglion in wall The parasympathetic efferents also inhibit tone of the internal anal sphincter Tone on external anal sphincter then released via internal pudendal and higher order processes Cross-Sections of Abdomen and Pelvis ○ Objectives Review key features of plain films and CT or MRIs of abdomen and pelvis Identify the key landmarks of the abdomen to be used as guides in cross-sectional anatomy of the region Review representative levels of the abdomen and pelvis and identify specific structures listed in the handout at each level ○ You will be given the vertebral level ○ T-10 – right around the xyphoid process apex of heart, descending aorta, IVC, azygos, hemiazygos, stomach, spleen, left lung, right lung, liver, diaphragm ○ T-12 stomach, large intestine, spleen, pancreas, splenic artery (going right through pancreas), kidneys, IVC, aorta, crus of diaphragm, liver, portal vein, biliary tree (green), hepatic artery Note – portal vein is most posterior Note – cortex and medulla of suprarenal glands can be differentiated Note – crus of diaphragm on either side of aorta is diagnostic of T-12 Note – stomach is variably shaped, identify it by its folds Note – identify SI by having lots of folds in lumen, LI by having few/smooth lumen ○ L1-L2 stomach, transverse colon, jejunum (based on plicae circularis), descending colon, kidneys, psaos major, quadratus lumborum, duodenum, bile duct, pancreas, superior mesenteric artery, superior mesenteric vein, gallbladder, liver Note – descending colon is retroperitoneal diagnostic It is also the first side of the colon to be seen Note – SMA and SMV can be anterior to pancreas Note – don’t need to differentiate between jejunum and ileum ○ L2-L3 small intestine, horizontal duodenum, descending colon, psoas major, quadratus lumborum, cauda equina, aorta, IVC, right kidney (is lower), ascending colon, liver No more ribs here, thus you can see all three abdominal muscles ○ L4-L5 small intestine with mesentery, descending colon, iliopsoas (can see psoas and iliacus portions), ilium bone, gluteal muscles, common iliac branches, IVC Make sure you can identify the ilium bone from a muscle First place you can see pelvis Remember that the abdominal aorta branches at L4 and the IVC branches at L5 Note – quadratus lumborum not seen ○ Male Pelvis Can see gluteus maximus in all levels S5 – above pubic symphysis rectus abdominis, spermatic cord, femoral vessels, seminal vesicles, bladder, rectum Note – since this is above the pubic symphysis you can still see the rectus abdominis Coccyx pubic symphysis, prostate, urethra, obturator internus, greater trochanter, pelvic diaphragm, rectum, ischioanal fossa Remember that the obturator internus and pelvic diaphragm make two borders of the ischioanal fossa You can see the full course of the obturator internus Lower ischial tuberosities (thus can see the UG and anal triangles), external anal sphincter or puborectalis, corpus cavernosum ○ Female Pelvis Know it Note – cervix looks a lot like prostate, but can be differentiated because it is in a different location ○ Make sure to know erectile tissue in both sexes ○ CT Scans – know them Female Reproductive System ○ Objectives Describe the process of oogenesis and indicate the embryologic origin of the primordial germ cells Indicate in which stage of meiosis the oocyte exists prior to ovulation, at ovulation but prior to fertilizations, and following fertilization Describe the morphology of the ovary including the surface covering, the capsule, the cortex, and medulla. Identify and contrast the components of each Describe and integrate the development and morphology of ovarian follicles, beginning with primordial follicles and ending with Graafian follicles. Relate the follicular components to their origin, sites of hormonal production and describe their effects on the other components of the female reproductive tract Describe the structure and functions of the theca cells Define and contrast an atretic follicle with other follicles Describe the development and fate of the corpus luteum and how it changes when fertilization occurs. Include the theca lutein and granulose lutein cells, their origin, their function, sites of hormonal production and describe how this affects other components of the female reproductive tract Name the four parts of the uterine tube and distinguish their histological differences. Relate how the morphology integrates with its function Describe the regions and the layers of the uterus and relate the morphology to its function Identify and contrast the main phases of the menstrual cycle. Describe the morphological changes in the endometrium during each phase of the menstrual cycle and integrate this with its functions. Indicate the principle hormones responsible for the morphology of each phase and from where they arise Integrate the various hormones that impact and are produced by the female reproductive system and what effects they have on their target organs. Also be able to relate the control mechanism for these hormones Describe the specific type of epithelium and the shape of glands found in the uterine cervix, as well as the epithelial lining of the vagina. Be able to contrast the morphology and function of the vagina with that of the esophagus Describe and integrate the blood supply and function of the ovary, endometrium and fallopian tube Identify the components of the breast. Explain how the morphology of the breast changes from the resting state to the active state Be able to relate and integrate the types and modes of secretions from the various female reproductive organs with their functions Be able to relate where and when fertilization and implantation normally occur ○ Introduction Ovary has exocrine portion that cytocrinely secretes the ova, and an endocrine portion that secretes sex hormones Fallopian tubes, uterus and vagina are considered ducts Gonadotropic Hormones – released by pituitary and initiate puberty Menarche – first menstrual flow Menopause – occurs between 45-55; reproductive organs partially involute ○ Ovary Suspensory Ligament of the Ovary – attaches it to posterior wall of pelvis Hilum – where blood vessels and nerves enter Medulla – very vascular, contains helicine arteries (coiled and off of ovarian artery) which allow for changes in position/size of ovary Cortex – each contains about 800,000 ova at birth, 200,000-400,000 at puberty Germinal Epithelium – fancy word for the mesovarium (part of peritoneum) ○ simple cuboidal epithelium Tunica Albuginea – under germinal epithelium; dense irregular CT Layer containing Stromal Cells – cells which look like spindle-shaped smooth muscle cells Prenatal Follicular Development Oogonia migrate from yolk sac endoderm into UG ridge Follicular cells derived from primitive mesonephros sex cords or coelomic mesodermal cells Follicular Development Ova are surrounded by a layer of follicular cells ○ Ovarian Follicle – ovum & surrounding follicular cells Follicle Stimulating Hormone (FSH) – controls follicular development ○ Secreted by anterior pituitary gland Phases of Follicular Development ○ Primordial follicle → Primary Follicle → Secondary Follicle → Graafian Follicle → ovulation → corpus hemorhagicum → corpus luteum → corpus albicans ○ Moves from cortex to deep medulla? Luteinizing Hormone (LH) – causes follicle to rupture/ovulation Primordial Follicles – diagnostic – single layer of flattened follicular cells around ovum ○ Contains primary oocyte that is diploid and arrested in prophase of 1st meiotic division Meiosis-inhibiting factor – keeps oocyte in prophase Large cell, large nucleolus, light staining cytoplasm ○ 10-20 start development at each menstrual cycle ○ The follicular cells develop receptors for FSH at puberty ○ Activin – secreted by oocyte and causes follicular cells to multiply and hypertrophy to become primary follicles Primary Follicles – diagnostic – single or multiple layer(s) of cuboidal follicular cells ○ If more then one layer then called multilaminar ○ Granulosal Cells – new name for follicular cells ○ Zona Pellucida – barrier of glycoproteins surrounding and made by the oocyte Microvilli of oocyte and filapodia of granulosal cells allow for exchange ○ Theca layers start to form outside primary follicle under control of activin, not FSH Secondary (Antral) Follicle – diagnostic – antrum (fluid filled space in follicle) present and ovum pushed to side ○ Now under FSH control ○ Follicular Liquor – plasma-like fluid in antrum, contains lots of substances Mainly secreted by granulosa cells? ○ Cumulus Oophorus – ova displaced to the side, along with surrounding zona pellucida and corona radiate (single layer of follicular/granulosa cells immediately around ova) ○ Theca develops into two layers Theca Externa – outer layer of CT Theca Interna – inner layer that is highly vascular; contains steroid producing cells which secrete androgen ○ Note – androgen is converted to estrogen by granulosal cells ○ This creates ↑ levels of estrogen in the blood Mature (Graafian) Follicle – diagnostic – largest follicle (1-2 cm), bulges into cortex ○ Membrana Granulosa – cells making up wall of follicle ○ High levels of estrogen in blood → Inhibition of FSH release LH surge ○ Causes release of Meiosis Inducing Substance, which Causes completion of 1st meiotic division (to secondary oocyte) and stops at metaphase of 2nd division Causes ovulation (secondary oocyte and 1st polar body are expelled) Corpus Hemorrhagicus – diagnostic – ruptured capillaries cause blood to fill lumen of follicle ○ Walls of follicle collapse ○ Granulosal cells secrete folliculostatin and inhibin which cause ↓ FSH release Corpus Luteum – diagnostic - ? ○ Under influence of LH (increases with increasing levels of LH) ○ Cells differentiate into 2 types of steroid producing cells Granulosal Luteal Cells – develop from granulosal cells ○ Make up majority of the cells ○ Pale red, foamy appearance; with large folds ○ Secrete progesterone ○ Continues to convert androgens from theca into estrogen Theca Luteal Cells – develop from the theca interna ○ Smaller and darker ○ Secrete progesterone, but mainly androgens ○ Different Outcomes Depending on Occurance of Pregnancy If No Pregnancy – corpus luteum grows in size but ↑ progesterone causes ↓ LH and thus ↓ size of corpus luteum If Pregnancy – corpus luteum continues to enlarge (5cm) and is maintained by human chorionic gonadotropin produced by the placenta Corpus Albicans – degeneration of corpus luteum with invation of fine CT forming a scar ○ Slowly contracts with age (thus largest ones are the youngest) Note ○ Atretic Follicles – degenerating follicles that initially responded to FSH but were not ovulated Usually about 10-20 of them in each cycle These undergo atresia, which is basically programmed cell death Each one forms a small scar and sometimes the theca does not degenerate and forms an interstitial body ○ Fallopian Tubes Muscular tubes Infundibulum – fibriae (finger-like processes) extend from edge Ampulla – has highly folded luminal surface where fertilization usually occurs Isthmus – narrow portion Interstitial Portion – part going through uterine wall Structure Mucosa ○ Epithelia - simple columnar epithelium Peg Cells – diagnostic – no cilia ○ Secrete viscous fluid that protects and provides nutrients for sperm ○ Allows for full maturation of sperm and capacitation Cilliated Cells – diagnostic – have cilia ○ Cilia beat in unison towards the uterus ○ Greatest number in ampulla, but decrease closer to uterus ○ Lamina Propria – CT ○ Highly folded, especially in ampullary region Muscularis – inner circular and outer longitudinal not well defined ○ Gets thicker closer to usterus Serosa – thin layer of CT covered by peritoneum Function Transport of ovum to uterus ○ Estrogen causes dilation of vessels in infundibulum causing swelling and the infundibulum to cover the ovary ○ Ciliated cells move ovum to uterus ○ Peristaltic waves move ovum to uterus Fertilization ○ Takes 5 days for zygote to move down tube ○ Gonorrhea – bacterial infection that can cause scaring of uterine tubes and increases likelihood of ectopic pregnancy (due to zygote getting stuck) ○ Uterus Wall Perimetrium – outermost layer; actually a continuation of the peritoneum on the fundus of the uterus Myometrium – thickest layer; 3 layers of smooth muscle cells; not sloughed off with menstrual cycle ○ Usually 40-90 µm, but increase to 500 µm during pregnancy ○ Normally there are shallow contractions that increase during intercourse or menstruation Under influence of prostaglandins and oxytocin Contractions ↑ during pregnancy and delivery ○ Cervical region has CT and elastic fibers instead of smooth muscle Endometrium – mucosal layer ○ Epithelium - simple columnar ○ Lamina Propria – CT ○ Lines Uterine Glands ○ Functionalis – superficial layer that undergoes changes during menstrual cycle and is sloughed off ○ Basalis – inner layer that is not sloughed off Regenerated by the functionalis ○ Menstrual Cycle Typically 28 days, but if different it is due to lengthening of proliferative phase Proliferative (Follicular) Phase – days 7-14 Due to estrogen produced by follicles ↑ thickness of functionalis – diagnostic ↑ amount of CT stroma Uterine glands straight to slightly wavy with narrow lumen – diagnostic Coiled arteries between uterine glands near base Functionalis Divided into Two Parts ○ Functionalis Compacta – superficial layer, not many glands, mostly CT ○ Functionalis Spongiosa – deep and thick; glandular Secretory (Luteal) Phase – days 15-27; gets uterus ready for implantation Due to progesterone produced by granulosal cells of corpus luteum Starts at ovulation Uterine glands become coiled – diagnostic Stroma CT between glands ↓– diagnostic Uterine gland lumens dilated with glycogen-rich secretions – diagnostic Nuclei basally located Coiled arteries not readily seen On-going process and at the end thickness of functionalis decreases a little Menstrual Phase – days 1-5 Due to blood supply of endometrium and progesterone levels Endometrium thinnest due to sloughing of functionalis layer (mostly basalis) – diagnostic ○ Luminal surface is ragged – diagnostic ○ Stroma left is full of blood – diagnostic Blood Supply to Uterus ○ Uterine Artery → arcuate arteries (in myometrium and go around) → radial arteries (dive deep to endometrium) branch into: Straight Arteries – supply endometrium basalis Coiled Arteries – supply endometrium functionalis ○ Have coiled longitudinal smooth muscle cells with progesterone receptors ○ Remember – corpus luteum makes progesterone and when progesterone levels increase eventually this causes LH to increase, which causes corpus luteum to die and thus progesterone levels ↓ ○ If ↓ progesterone then the smooth muscle cells intermittently contract and cut off blood flow to functionalis Intermittent ischemia breaks down blood vessel walls and thus next time blood goes through it gets into stroma Eventually progesterone levels fall so low that the coiled arteries stay shut and functionalis falls off → menses Epithelium resurfaces by proliferation and migration of epithelium from the uterine glands of basalis At end of cycle, FSH release by pituitary is prompted, starting the whole thing over again Clinical Connections Endometritis – inflammation of endometrium Endometriosis – presence of endometrial material inside the pelvic cavity ○ Hemorrhage of this tissue is very painful and can cause lesions or organs strangulated ○ Cervix Portio Vaginalis – portion protruding into vagina Endocervical Canal – lumen from external to internal cervical os simple columnar epithelium Similar to body of uterus, but: Branched cervical glands – diagnostic ○ Glands are mucous secreting and can become plugged forming Nabothian Cysts No coiled arteries Myometrium is mainly dense irregular CT and elastic fibers ○ Vaginal-Cervical Junction Usually just inside external cervical os, but after childbirth moves out onto portio vaginalis Abrupt change from simple columnar to stratified squamous non-keratinizing epithelium Clinically Important Place of weakness; can get infected; stratified squamous tissue here is most likely start of cervical cancer Pap Smears – take cells from here to check for cancer ○ Vagina 8-9 cm (<4 inches) in length Mucosa Epithelium - stratified squamous non-keratinizing – diagnostic ○ Produces lots of glycogen (stimulated by estrogen) ○ Naturally occurring bacteria make lactic acid which keeps pH ↓ Lamina Propria – CT that is highly vascular with no glands Muscularis – not layered but has longitudinal and circular fibers Adventitia – CT that holds organs to surrounding structures Histological Look-A-Like – Esophagus, but vagina: Does not have glands in lamina propria – diagnostic Does not have layered muscularis externa – diagnostic ○ Mammary Gland Controlled by hormones of the reproductive tract Modified apocrine sweat gland; exocrine; has ducts Divided into 15-25 lobes that radiate out from nipple; separated by CT and adipose tissue Each lobule drained by single lactiferous duct Lactiferous sinus – dilation of each duct just behind nipple for milk storage Two Physiological States Inactive – resting state, no milk produced ○ Mainly adipose tissue and small amounts of glandular tissue Active – makes milk ○ Mainly glandular tissue (replaces the adipose tissue and produces milk) ○ Stimulated by estrogen and progesterone of pregnancy ○ The ducts branch and grow ○ Glandular units form alveoli which are surrounded in basement membrane and myoepithelial cells ○ Clostrum – protein rich substance containing immunoglobulins that the alveoli produced prior to birth and secreted immediately after birth ○ Histological Look-A-Like – Thyroid Gland (which is endocrine) Difference is the presence or absence of ducts – diagnostic Mechanism of Milk Secretion ○ Prolactin Hormone – secreted by pituitary gland and stimulates cells to produce and secrete milk into alveolar lumen ○ Sucking on nipple – sends impulses to hypothalamus and causes release of ○ Oxytocin – secreted from pituitary gland and causes myoepithelial cells to contract, forcing milk out of alveoli into ducts Milk Ejection Reflex Components ○ Merocrine Secretion – protein portion of milk ○ Apocrine Secretion – lipid portion of milk Male Reproductive System ○ Objectives List the organs and ducts of the male reproductive system Describe and integrate the components and their morphology of the testis with the function of the testis Describe the process of spermatogenesis and indicate how it differs from oogenesis. Distinguish spermatogenesis from spermiogenesis Describe and identify the adluminal and basal compartments of the seminiferous tubules Describe, in detail, the morphology and function of the epithelium in the seminiferous tubules including the different germ cells and the Sertoli cell. Identify the phases of spermatogenesis Explain what is meant by the cycle of seminiferous epithelium Describe and integrate the hormonal secretions that controle the development and maintenance of the normal male reproductive system Describe the specific epithelial lining of the tubuli recti, rete testis, efferent ductules, epididymus, ductus deferens and ejaculatory duct. Identify examples of each and be able to integrate their morphology with their function Describe and integrate the morphology and function of the seminal vesicles, prostate and bulbourethral glands. Be able to list characteristics necessary to distinguish one from the other. Explain the clinical significance of the mucosal glands, submucosal and main glands of the prostate Describe the morphology of the penis including the fascial layers, erectile tissue, blood vessels, as well as the site and epithelial lining of the penile urethra. Be able to relate and integrate the morphological components of the penis in the flaccid and erect condition Be able to trace the normal pathway of sperm secretion. Be able to describe the morphology of the pathway and how it relates to the specific function of each part Describe the process of ejaculation and integrate it with the function of the various male reproductive components ○ Introduction Testis – exocrine portion produces sperm (cytocrine secretion); endocrine portion makes testosterone Duct System – Intratesticular and Extratesticular Ducts Accessory Glands – seminal vesicle, prostate gland, bulbourethral glands ○ Testis Tubular gland Tunica Vaginalis – peritoneal outpocketing lined by simple cuboidal epithelium with visceral and parietal layers Tunica albuginea – capsule of CT Mediastinum Testis – thickened CT on posterior aspect, basically surrounding the rete testis Septula – divide testis into about 200 lobules Each lobule holds 1-4 seminiferous tubules Seminiferous Tubules – highly coiled, 1/3 mile in total length ○ Drains into straight tubule in the mediastinum testes region ○ Exocrine portion of tetis that secrete spermatozoa (cytocrine secretion) Leydig Cells (Interstitial Cells) – clumps of steroid secreting cells between the tubules in the lobules Endocrine portion of the testis that secrete testosterone (merocrine secretion) Seminiferous Tubule Lined with special stratified epithelium called germinal epithelium which is 4-8 cells thick Spermatogenic Cells – most prevalent; undergo meiosis ○ Spermatogenesis – differentiation of spermatogonia into functioning spermatozoa Spermatogonia – most primitive ○ Located in basement membrane of tubule – diagnostic ○ A Cells – the stem cell; darker ○ B Cells – the cells that differentiate and migrate; lighter Primary Spermatocytes – most common cell ○ Undergoing 1st meiotic division; thus still diploid ○ Can see clumped chromosomes – diagnostic Secondary Spermatocytes – very brief; won’t be seen ○ Undergoing 2nd meiotic division; thus are haploid Spermatids – round, solid dark chromatin pattern – diagnostic ○ Located near surface of Sertoli cells Spermatozoa – head (dark flagellated nuclei) & long tails – diagnostic ○ Located at apex of Sertoli cells Spermiogenesis - transformation of spermatids into mature spermatozoa Process ○ Takes 64 days to complete ○ Cycle of seminiferous epithelium – spermatogenesis occurs all the way down the seminiferous tubule, but there are three different portions of the tubule and each is at a different phase of spermatogenesis ○ Spermatogenic cells are temperature sensitive; need it 3-4º lower than body temp Crytorchidism – testis did not descend properly and result in sterility ○ Testosterone required for spermatogenesis Sustentacular Cells (Sertoli Cells) – physical and nutritive support for spermatogenic cells ○ Joined together by tight junctions ○ tall columnar and irregular shaped due to spermatogenic cells embedded into it ○ Oval shaped nucleus with prominent nucleolus – diagnostic ○ Basal Compartment – adjacent to basement membrane, below tight junction contains spermatogonia only ○ Adluminal Compartment – everything above the tight junction/lateral processes Contains primary spermatocytes on up ○ Function Forms blood-testis barrier, everything must pass through Sertoli cells ○ Prevents immune reactions with cells of different genetic makeup Produces testicular fluid to wash immobile spermatozoa out of tubule Phagocytizes excess cytoplasm from the spermatids Produces androgen binding protein to ↑ levels of testosterone in germinal epithelium Produces inhibin which stops FSH release from anterior pituitary Leydig (Interstitial) Cells – produce testosterone ○ Red and foamy – diagnostic ○ Vascular (since they are endocrine) and lots of sER ○ Controlled by Luteinizing (interstitial cell stimulating) Hormone released by anterior pituitary Testosterone in blood is picked up by androgen binding protein and allows levels to get high enough to stimulate spermatogenesis ○ Testosterone – stimulates and maintains function of accessory sex glands and secondary sex charact. Hormonal Control of Testis LH (ICSH) stimulates Leydig cells to produce testosterone FSH stimulates Sertoli cells to produce androgen binding protein which binds testosterone and accumulates it so that levels are high enough Feedback control ○ High levels of testosterone inhibit release of LH ○ Inhibin (produced by Sertoli cells) inhibits FSH production Senile Testis – spermatogenesis slowly tapers off because seminiferous epithelium dies off Sertoli cells still present and so are Leydig cells (which still produce testosterone) ○ Duct System Intratesticular Ducts Straight Tubules – lined by Sertoli cells only – diagnostic ○ Located at apex of tubule and are very short Rete Testis – network of interconnecting channels – diagnostic ○ Located in CT of mediastinum ○ simple cuboidal epithelium Efferent Ductules – alternating clumps of tall columnar ciliated to nonciliated low cuboidal, gives the epithelium a ‘cogwheel’ appearance – diagnostic ○ Ciliated cells – move nonmotile spermatozoa ○ Nonciliated cells – resorb testicular fluid Extratesticular Ducts Ductus Epididymis - pseudostratified columnar epithelium – diagnostic ○ Is a single long, highly convoluted tubule ○ Divided into head (where efferent ductules drain into), body and tail ○ Principle Cells – tall columnar with nonmotile stereocilia Reabsorbs 90% of testicular fluid and phagocytoses remnants of spermatozoa cytoplasm ○ Basal Cells – round dark nuclei adjacent to basement membrane; probably make principle cells ○ Smooth Muscle in wall causes peristaltic waves Circular layer in head, more layers added towards tail ○ Function Sperm is stored in tail; quality control; nutrition Where sperm finish spermiogenesis (become motile and fully functional) Secretes glycerophosphocholine that inhibits capacitation until in vagina Normally takes 20 days to get through, thus sperm take 84 days till ready Ductus (Vas) Deferens – large stellate lumen – diagnostic ○ pseudostratified columnar epithelia ○ Very thick muscularis – diagnostic (three layers: inner and outer longitudinal and middle circular) Peristaltic waves propel sperm to urethra during emission ○ Located in spermatic cord and is thus surrounded by pampiniform plexus – diagnostic Ductus deferens and artery are in the middle of the maze of pampiniform veins and the cool blood from the testis probably cools the sperm while going through spermatic cord ○ Surrounded by cremaster muscle ○ Vasectomy – bisect vas deferens for birth control ○ Remember – ampullary region is end end dilation and it joins with the more lateral seminal vesicle just before entering the prostate Ejaculatry Duct – beigins at junction of vas deferens and seminal vesicle and goes through prostate ○ No muscular walls, just simple columnar lining ○ Has two openings on seminal colliculus, both of which are below the prostatic utricle ○ Sidnote - prostatic utricle is the homologue to uterus and part of vagina Urethra – has three parts ○ Epithelium goes from transitional to simple columnar to stratified squamous at end ○ Accessory Sex Glands Seminal Vesicle – a large convoluted tube Mucosa creates numerous cavities of varying sizes – diagnostic ○ Things must cross tissue to get into the next lumen? Smooth muscle in muscularis layer Testosterone Dependent – secretions continue if testosterone present Makes thick viscous fluid; rich in fructose for sperm; 70% of semen volume; yellow pigment fluoresces Prostate Gland – relatively thick fibromuscular septa separating glands – diagnostic Contains 30-50 tubuloalveolar glands subdivided by their proximity to the urethra ○ Mucosal Glands – immediately next to urethra and drain into urethra Benign prostatic hypertrophy – theses are the cells that block urethra ○ Submucosal Glands – farther from urethra and drain into prostatic sinus ○ Main Glands – most prevalent; most peripheral and drain into prostatic sinus and urethra Prostate Cancer – most commonly arises here; most common cancer of males ○ Detected by Prostate Specific Antigen levels in blood Prostatic Concretions – diagnostic ○ Red staining bodies in lumen of duct; increase in size and number with age Young Prostate – glandular portion has varying size and shape of lumen – diagnostic ○ Ducts difficult to identify ○ Epithelium is variable Older Prostate – glandular portion has large irregular size and shape of lumen – diagnostic ○ Simple cuboidal epithelium Prostatic fluid is serous, rich in lipid, enzymes, citric acid (pH around 7) Bulbourethral Glands – secretes viscous mucous; located in UG diaphragm; lubricates urethra ○ Penis Glands of Littre – mucous secreting glands along penile urethra Erectile Tissue Note – the erectile tissue is surrounded by tunica albuginea a dense layer of CT Spongy tissue composed of fibromuscular trabecula and blood filled lacunae Remember – helicine arteries (from deep artery of penis) deliver blood to lacunae Erection Flaccid – deep artery of penis → helicine arteries are mostly closed and thus bypassed → most blood diverted via AV shunts to deep dorsal vein Erection – longitudinal muscles of helicine arteries relax and AV shunts contstrict in response to parasympathetic stimulus and Nitrous Oxide ○ Blood from helicine arteries floods the lacunae and veins collapse due to increased pressure End of Erection – helicine arteries close and AV shunts open due to sympathetic stimulation ○ Specialized veins at root of penis drain blood from lacunae. When pressure low enough, the collapsed veins open and erection quickly lost Impotence – can be caused by lots of things ○ Semen Normal is 50-100 million sperm/ml of semen; sterile is <20,000,000 Normal volume is 3 ml Sequence Bulbourethral glands secrete mucous that cleans penile urethra and lubricates it Prostatic secretions help sperm mobility and raise pH of vagina Emission – delivery of spermatozoa and glandular secretions through ejaculatory duct and prostatic urethra ○ Under sympathetic control ○ Sperm move from epididymus to ejaculatory duct and urethra Seminal vesicle contracts forcing its secretion and everything else out Ejaculation – forceful expulsion of semen, helped by contraction of the bulbospongiosus muscle around the corpora spongiosum Development of the Reproductive Systems ○ Objectives ○ Define/describe: urogenital sinus (three portions), mesonephric duct, Wolffian duct, paramesonephric duct, Muellerian duct, uterovaginal primordium, sinovaginal bulb, primary sex cords, cortical cords (secondary sex cords), seminiferous tubule, ovarian follicle, tunica albuginea. Describe the situation (location) of the embryonic gonad as it begins its development. What is the origin of the autonomic innervation and vascular supply of the developing gonad (both blood and lymphatic)? Describe the origin and migratory path of the primordial germ cells. Explain the roles of the SRY locus, Testis Determining Factor, androgenic hormones, Anti-Muellerian Factor (or Muellerian Inhibiting Substance), in development of the reproductive systems. Describe the migration of coelomic epithelial (mesothelial) cells into the mesenchyme of the gonad to produce the primary sex cords in the testes and the primary and secondary sex cords in the ovary. What ultimately develops from each generation of cords? What are the components and origin of each component of the seminiferous tubule, straight tubules, rete testes, efferent ductules, ductus epididymis, ductus deferens? Describe the formation of the seminal vesicle and the prostate. What is the origin of the interstitial cells of the testis, theca interna of the ovarian follicle, interstitial gland of the ovary? What is the primary determinant of genotypic (genetic) and phenotypic (morphologic) sex in humans? What substance (hormones) does the embryonic testis produce? What does each substance do in the body? Why does the testis use a duct system and the ovary does not? Describe the site of formation and the method of formation of the paramesonephric ducts. Describe the path or route of development of the paramesonephric ducts. Describe the formation and fate of the uterovaginal primordium, sinus tubercle, sinovaginal bulbs, vaginal plate, and hymen. Define/describe: labioscrotal swellings (genital swellings), urogenital folds (urethral folds), genital tubercle, phallic portion of urogenital sinus, cloacal membrane, urogenital membrane. Describe the complete formation of the male urethra. Define: true hermaphrodite, pseudohermaphrodite. What are several causes of pseudohermaphrodism? Define/describe the condition known as testicular feminization. Developmental error? Define/describe the condition of hypospadias; epispadias. Developmental error for each? Describe the underlying developmental errors leading to complete or partial duplication of the uterus and/or vagina. Describe the formation of the inguinal canal. Describe the process and path of migration of the testis and ovary
