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Online Anatomy Module 1 INTRO & TERMS CELL EPITHELIUM CONNECTIVE TISSUE MUSCLE NERVOUS SYSTEM AXIAL SKELETON APPENDICULAR SKELETON MUSCLES EMBRYOLOGY SKULL VERTEBRAL COLUMN RIBS SKELETON: Divisions PECTORAL GIRDLE LIMB BONES PELVIC GIRDLE LIMB BONES Marieb Fig 5.6, p 121 2 SKELETONS APPENDICULAR SKELETON PECTORAL GIRDLE CLAVICLE (Collar bone) omitted LIMB BONES upper PELVIC GIRDLE LIMB BONES lower appendicular skeleton hangs on the axial PECTORAL GIRDLE The pectoral girdle is not a 19thcentury corset for the upper chest On each side, it is a pair of bones that allows the arm to be fastened to the body, but to have an amazing range of movements & uses The arm is used for: swinging, crawling, reaching, pulling, throwing, twisting; & for positioning, orienting, stabilizing & controlling all that the hand does The bones of the pectoral girdle are the shoulder-blades & the collar-bones PECTORAL GIRDLE The bones of the pectoral girdle are the shoulder-blades & the collar bones SCAPULA or SHOULDER-BLADE CLAVICLE or COLLAR-BONE SCAPULA The SCAPULA is a peculiarly-shaped bone, with many surfaces, edges and protuberances for muscles (& ligaments) to attach. These are needed to control the arm directly, but also to position and stabilize the scapula for whatever the arm is doing The scapula is a highly mobile bone The arm is used for: swinging, crawling, reaching, pulling, throwing, twisting, etc; & for positioning, orienting, stabilizing & controlling all that the hand does SCAPULA Shoulder-blade PECTORAL GIRDLE The scapula is the major part of the pectoral girdle & lies posteriorly The scapula is a shallow dish, with the concave side facing anteriorly, as it fits over the muscles & ribs of the back SCAPULA: Terminology Acromion process Coracoid process Spine Vertebral margin Inferior angle Glenoid fossa Needless to say, each side and angle has a name. Here are enough to be going on with. SCAPULA: Parts I The SPINE rises and thickens from the medial edge going laterally, forming a triangular ridge ending in a protuberance termed the ACROMION Spine The spine defines territories above & below it, into which muscles fit Acromion = Acromion process SCAPULA: Parts II ACROMION PROCESS improves the angle of action of the deltoid muscle pulling the arm away from the body, & anchors the lateral end of the clavicle Medial/Vertebral margin Spine Coracoid process Lies by the spines of vertebrae from which muscles attach to it Glenoid fossa SCAPULA: Parts III Acromion process CORACOID PROCESS Anterior beak to improve angle of biceps muscle Spine Medial/Vertebral margin h u m e r u s GLENOID FOSSA Shallow socket for head of the humerus SCAPULA: Parts IV Viewed from side Acromion process Coracoid process Anterior beak to improve angle of pull of hbiceps muscle Spine Glenoid fossa u m e r u s SCAPULA & CLAVICLE The SCAPULA is a peculiarly-shaped bone, with many surfaces, edges and protuberances for muscles (& ligaments) to attach. These are need to control the arm, but also to position and stabilize the scapula for whatever the arm is doing The scapula is a highly mobile bone The arm is used for: swinging, reaching, pulling, throwing, twisting; & for positioning, orienting, stabilizing & controlling all that the hand does The CLAVICLE is the strut that: holds the shoulder out away from the trunk; absorbs shock; fastens appendicular to axial skeleton (at the sterno-clavicular joint) ; & anchors several muscles & ligaments CLAVICLE The arm is used for: swinging, crawling, reaching, pulling, throwing, twisting; & for positioning, orienting, stabilizing & controlling all that the hand does The CLAVICLE is the strut/brace that: holds the shoulder out, away from the trunk; absorbs shock; & fastens appendicular to axial skeleton (at the sterno-clavicular joint) & anchors several muscles & ligaments Connections between axial & appendicular skeletons I Sterno-clavicular joint CLAVICLE Sterno-clavicular joint Sternum S T E R N U M SCAPULA rotated unnaturally Connections between axial & appendicular skeletons I Sterno-clavicular joint CLAVICLE Jugular notch Manubrium Sternum body S T E R N U M Acromio-clavicular joint Scapula has no other joints, Hence NO joint with axial skeleton. SCAPULA rotated unnaturally Sterno-clavicular joint Marieb Fig 5.20, p 133 CLAVICLE Left versus Right I The clavicle has a lumpy sternal end & a blade-like acromial end The upper surface is smoother* than the inferior one, because ligaments etc come from below to attach to tuberosities The clavicle is a pulled-out S-shape Use these three features to ID left from right thus: “Smooth” - feel on yourself CLAVICLE Left versus Right II 1 Place the clavicle on your chest with the lumpy end at your breast-bone 2 Try on right & left sides to make the first curvature going outward from the breast-bone face forward Front Back 3 If the upper surface is not the smoother one, move the clavicle (keeping orientations 1 & 2) to the other side It should now be identifiable as Rt or Lft Connections between axial & appendicular skeletons II Sacro-iliac joint SACRUM of axial is wedged into the hip bones of the appendicular pelvic girdle For stability & the transmission of load via the hip bones to the legs Sacro-iliac joint Marieb Fig 5.18, p 132 COMMON BONE TERMS PROCESS Protuberance Tuberosity small bump Spine Margin Border Edge Angle Spine Head FOSSA Shallow depression COMMON BONE TERMS PROCESS has become an overused word In anatomy, as noun, it means something that sticks out or protrudes from a cell, from a bone, or from a soft organ In anatomy, as noun, process still also means the way in which something occurs - the process of cell division, the process of shrinking, of winking To give slow-witted politicians more time to think, the last example has been horribly extended by their speech-writers - for example, ‘deciding’ is a noun and does not need to be the ‘decision-making process’. Thus, “deciding that won’t be easy” , “wine-making is fun” are natural & correct English HUMERUS Viewed from behind Is the single bone of the ARM Proximally, it articulates with the scapula at the shoulder Distally, it articulates with two bones of the forearm at elbow joint It has specially shaped surfaces at the elbow to allow the ulna & radius their movements At the elbow, it has depressions engaging processes of the ulna to limit its movement It has several tuberosities and much surface , including epicondyles, for the attachment of muscles HUMERUS I Viewed from front HEAD Deltoid tuberosity Coronoid Fossa Lateral Epicondyle Capitulum Medial Epicondyle Trochlea HUMERUS II Viewed from behind HEAD Deltoid tuberosity Olecranon Fossa Medial Epicondyle Trochlea Lateral Epicondyle HUMERUS Right versus Left 1 On yourself, place the rounded head of the humerus at either shoulder 2 Turn the head so that it faces medially (inward) at that shoulder At the elbow end, look for the shallow coronoid fossa on one side & the deeper olecranon fossa on the other 3 Keeping orientations 1 & 2, move the humerus to the side that has the deep olecranon fossa facing posteriorly As one extends the elbow, the olecranon process of the ulna locks into the fossa on the humerus, preventing hyperextension DISTAL HUMERUS Viewed from front Trochlear is a noun, not an adjective The Trochlear is a spool-like rolling surface for the ulna The Capitulum is a little sphere-like structure: a surface for rotation The Capitulum matches a dimple in the symmetrical head of the radius bone For the name, remember that capital punishment used often to include beheading RADIUS I Viewed from in front Head Neck Radial tuberosity Styloid process Articular surface for wrist/carpal bones RADIUS II Viewed from in front Head Neck Radial tuberosity Sharp edge - Interosseous border/margin Concave surface space for muscles Feel for yourself: the back of the forearm is bony, the front, squishy Styloid process Articular surface for wrist/carpal bones RADIUS: Right versus Left Head lies at elbow end Radius lies laterally to ulna Sharp edge faces medially towards ulna Concave surface space for muscles faces forward Styloid process sort-of points laterally RADIUS & ULNA: Cautions Head Styloid process The head of the ulna is at the wrist end The ulna also has a styloid process. The two help hold the carpal bones in place. ULNA I Viewed from in front Radial notch Olecranon Palpable at the back of the elbow, when you flex & extend it Caution - on the ulna ! Coronoid process Ulnar head Styloid process ULNA II Viewed from in front Radial notch Olecranon Palpable at the back of the elbow, when you flex & extend it Caution - on the ulna ! Coronoid process Head of ulna Ulnar head The bump lying laterally on the back of your wrist, when it is pronated (palm down) Styloid process ULNA III Olecranon Coronoid process Radial notch allows the radius to rotate against the ulna for supination-pronation movements Interosseous margin Concave surface space for muscles for strong fibrous attachment to the radius Head Styloid process ULNA IV Olecranon Viewed from lateral side Radial notch allows the radius to rotate against the ulna for supinationpronation movements Coronoid process a ligament holds the radius in place The elbow end of the ulna is distinctive, with its hook-like olecranon process for raking in the chips at the neolithic gaming table HUMERUS Viewed from behind It has specially shaped surfaces at the elbow to allow the ulna & radius their movements At the elbow, it has depressions engaging processes of the ulna to limit its movement - behind, the Olecranon fossa takes olecranon of ulna to limit extension of the elbow Back to the forearm Right FOREARM BONES RADIUS ULNA RADIUS on thumb side ULNA on littlefinger side A relation kept during pronation ANTERIOR Right FOREARM: Radius & Ulna SUPINATED Thumb lateral Radius rotates on two radioulnar joints Two bones are held together by ligaments & the interosseous membrane PRONATED Thumb medial ULNA: Right versus Left Olecranon is at elbow end Ulna lies medially to radius Radial notch faces laterally toward radius Sharp edge faces laterally towards radius Concave surface - space for muscles - faces forward Styloid process sort-of points medially Rt U LIMB Anterior RE-ASSEMBLY surfaces Head HUMERUS Capitulum RADIUS Thumb ULNA WRIST & HAND III This is a view of the DORSUM (back) of the hand. The other is the PALMAR (palm) side Head of ulna Little finger/ Pinky Ring finger Middle finger Thumb Index finger/ Forefinger WRIST & HAND I Digits CAUTION One thinks of the wrist as what one grips on someone, using one’s whole hand Knuckles Head of ulna However, the wrist bones carpals - are only those that lie under two fingers’ width just distal to the end of the ulna HAND II: BONES Phalangeal bones Metacarpal bones 8 Carpal (wrist) bones HAND II: BONES Phalanges (Phalangeal bones) 3 per finger Terminal Distal Middle Proximal 2 for the thumb Proximal V IV III II I Terminal Metacarpal bones 8 Carpal (wrist) bones WRIST & HAND II Knuckles of the fist are the heads of the metacarpals However, the wrist bones - carpals - are only those that lie under two fingers’ width just distal to the end of the ulna Carpal bones Head of ulna But the carpal bones articulate with the radius: wrist is the radio-carpal joint BROKEN ‘WRIST’ is a term to arouse caution The carpal bones articulate with the radius: wrist is the radio-carpal joint, so falling on the hand may break the distal radius However, the wrist bones - carpals - are only those that lie under two fingers’ width just distal to the end of the ulna Carpal bones And one bone in particular of these true wrist ones is sometimes fractured MAINLY SPONGY BONE LOSS causes fractures in 1 Bones that are mostly spongy, e.g. vertebra compression fracture 2 Spongy part of long bones where leverage “Wrist” end concentrates loading of radius “Hip” fracture at neck of femur from falling on the hand WRIST FOR COMMUNICATION Passing through the wrist are: Arteries Veins Nerves Tendons to flex Tendons to extend All critical & vunerable, & with little muscle or fat to protect them Some protection comes from running many structures on the palmar side Some of the carpal bones create a tunnel for more protection LEFT CARPAL TUNNEL Schematic cross-section Ulnar artery Flexor retinaculum - sheet of fibrous tissue roofing in the tunnel Median nerve Ulnar nerve Tendons to flex CARPAL BONES Tendons to extend outside tunnel, on dorsal side of wrist lubricated spaces/compartments for structures to glide in Discomfort of C-T syndrome from compromised median nerve RADIAL ARTERY: Pulse Concave surface - space for muscles - faces forward & Radius lies laterally to ulna also protects vessels, e.g., radial artery Close to the wrist, where the muscles thin & give way to tendons, the pulse can be felt by pressing the artery against the bone with the finger tips BRACHIAL ARTERY: Pulse Brachial refers to the arm Humerus The brachial artery lies protected on the medial side of the humerus Close to the elbow, where the muscles thin, the pulse can be felt by pressing the brachial artery against the humerus, or listened for with a stethoscope LOWER APPENDICULAR SKELETON Lower appendicular skeleton supports the axial skeleton and upper body & provides locomotion & other activities It comprises the lower LIMB BONES & the PELVIC GIRDLE stabilizing them & connecting with the axial skeleton The connection is secured by wedging the axial sacrum between the hip bones to create the bony pelvis SACRUM ILIUM LOWER APPENDICULAR SKELETON Lower appendicular skeleton supports the axial skeleton upper body & provides locomotion & other activities It comprises the lower LIMB BONES & the PELVIC GIRDLE stabilizing them & connecting with the axial skeleton The connection is secured by wedging the axial sacrum between the hip bones to create the bony pelvis PELVIC GIRDLE HIP BONES Ilium Ischium Pubic bone Connections between axial & appendicular skeletons II Sacro-iliac joint SACRUM of axial is wedged into the hip bones of the appendicular pelvic girdle For stability & the transmission of load via the hip bones to the legs Marieb Fig 5.18, p 132 PELVIS Viewed from in front Is an assembly of the axial sacrum & two SACRUM threesomes - hip bones The three bones are fused together, but there are three pelvic joints: two sacro-iliac & one pubic symphysis ILIUM The pelvis protects the pelvic organs, but has four openings, two large The pelvis is a stable device for transferring axial load to the legs at the hip joints The hip joints allow the legs freedom of movement think gymnasts & ballet Hip has much surface , including crests, for the attachment of muscles Anterior view HIP JOINT SACRUM ILIUM Acetabulum - socket for balllike head of femur/ thigh bone This is a deep dislocationresistant ball-&-socket joint, unlike the shoulder joint PELVIS: Lines of sight In general, some of the views of bones used here are a little different from those in the textbook in order to add to your ideas on the pieces of the skeleton View from above - Superior ILIUM View from in front & above Most of Marieb’s Figs View from in front - Anterior Anterior view PELVIC GIRDLE + SACRUM Two hip bones are fused assemblages of three bones each. They have the sacrum wedged between them behind & fasten at the front by a fibrocartilaginous joint - symphysis Sacroiliac joint SACRUM ILIUM Ischium Pubic symphysis Pubic bone ILIUM is the major bone PELVIC GIRDLE + SACRUM II Anterior view SACRUM ILIUM Obturator foramen - hole defined by Ischium below Pubic bone above Acetabulum Anterior view OBTURATOR FORAMEN SACRUM ILIUM Superior pubic ramus Obturator foramen Acetabulum Inferior pubic ramus Ischial tuberosity Ischial ramus Ramus (L) - a branch, bough Anterior view OBTURATOR FORAMEN II NOTE on 1 SIDE Two pubic rami, one ischial ramus Lower ramus has a join halfway along Unseen that the ischium is larger than the pubic bone SACRUM Superior pubic ramus Obturator foramen Ischial tuberosity Inferior pubic ramus Ischial ramus Lateral view HIP/COXAL BONES = ONE OS COXA HIP BONES Ilium Ischium Pubic bone ILIUM Acetabulum Ilium Ischium Lines of fusion of 3 bones during childhood Pubic bone Obturator foramen HIP/COXAL BONES = ONE OS COXA CAUTION - Ask When the term ‘hip bones’ is used, is the reference to: ILIUM the two composite hip bones of each side? the three bones making up one hip bone? Ilium the six bones making up both hip bones? Ask Ischium Pubic bone SUB-PUBIC ANGLE SACRUM ILIUM Obturator-foramen shape Sub-pubic angle (Pubic arch) is one of many variables between female & male pelves, aimed at having the female pelvis suited for childbirth, as well as the other pelvic functions ISCHIUM I Lateral view Anterior view SACRUM ILIUM ILIUM Sciatic notch Ischial ramus Ischial tuberosity what one sits on Ischial tuberosity PELVIS & ISCHIUM II Superior view SACRUM Mid-pelvic diameter Ischial spines create a hazardous constriction in the pelvic (birth) canal Please don’t squeeze my head Superior view Before reaching the ischial tuberosities, etc, of the pelvic outlet, the baby’s head has to enter the pelvic inlet Sacral promontory One of its critical dimensions is the INLET between the sacral promontory & the upper margin of the pubis SACRUM The sacral promontory & the lower edge of the pubis can be felt via the vagina for prior warning of trouble WORKING PELVIS Despite the number of views of the pelvis that we have seen ILIUM already, one more - the medial ILIUM view from SACRUM Medial is needed to understand a the midline looking working pelvis laterally The empty-appearing black Sciatic spaces shown within the notch contours of the pelvis are occupied by many muscles & ligaments Ischial spine Some holes also let nerves & vessels pass out Although, for diagrams, the pelvis is presented aligned with the screen or page margins, in life it is tilted in the body in the sagittal plane HIP/COXAL BONE Medial view from the midline looking laterally Iliac crest (felt at the ‘hip’) SACRUM ILIUM ILIUM Sciatic notch Pubic symphisis Ischial spine Ischial tuberosity Obturator foramen PELVIS IN POSITION The pelvis protects the pelvic organs, but has four openings, two large Abdominal cavity Pelvic inlet boundary between cavities At the top, it is freely open to the abdominal cavity Pubic symphysis ILIUM Pelvic cavity Underneath, the narrower opening is covered in by the muscles of the pelvic floor PELVIS IN POSITION Note the axis curves going through the pelvis The upper direction is taken as the fetus grows into abdominal territory At birth, the head must make several turns & twists to follow the axis down Pelvic inlet Abdominal cavity ILIUM Pelvic cavity Pubic symphysis Pelvic axis PELVIS: Female versus Male We have seen just about enough views to list some of the differences. So far, the pelvis shown has not really been sexually differentiated. SACRU M FEMALE More lightly built Pelvis wider & more shallow Obturator foramen oval Sub-pubic angle wide (greater than 800) Shorter, more curved sacrum Unseen here: pelvic inlet, oval; outlet, relatively large PELVIS: Female versus Male FEMALE Anterior view More lightly built Pelvis wider & more shallow Obturator foramen oval Sub-pubic angle wide (greater than 800) Shorter, more curved sacrum Unseen here: pelvic inlet, oval; outlet, relatively large Marieb Fig 5.23, p.137 PELVIS: Male versus Female MALE Anterior view More heavily built Pelvis deep Obturator foramen round Sub-pubic angle narrow (less than 800) Longer, straighter sacrum Unseen: pelvic inlet, heart-shaped; outlet, relatively small PELVIS: Female versus Male FEMALE More lightly built Pelvis wider & more shallow Sub-pubic angle wide (greater than 800) MALE Obturator foramen round Longer, straighter sacrum COXAL BONE: Right versus Left I Iliac crest (felt at the ‘hip’) ILIUM ILIUM Acetabulum (on lateral side) SACRUM will be absent Pubic symphisis For lab ID of one hip bone Place the bone on yourself with: the iliac crest superior, the acetabulum facing outward, and bone tilted so that the rough pubic symphysis faces a little down, and is right at the midline to meet its fellow of the other side COXAL BONE: Right versus Left II Place the bone on yourself with: the iliac crest superior, the acetabulum facing outward, ILIUM and bone tilted so that the rough pubic symphysis faces a little down, and is right at the midline to meet its fellow of the other side PELVIC ORGANS The pelvis protects the pelvic organs, but has four openings, two large Pelvic cavity: contents Genital/ reproductive Urinary bladder Ends of ureters Rectum Pelvic inlet boundary between cavities Vessels & nerves Abdominal cavity ILIUM Pelvic cavity Pubic symphysis Muscular pelvic floor holds contents up. PELVIC ORGANS: Prolapse Pelvic cavity: contents Genital/ reproductive Urinary bladder Ends of ureters Pelvic cavity Rectum Vessels & nerves Muscular pelvic floor holds contents up. ILIUM If the floor is weakened by trauma, giving birth, nerve damage, organs can drop - prolapse; sometimes to the point of hanging out of orifices FEMUR I Viewed from behind Is the single bone of the thigh Proximally, it articulates with the pelvic girdle at the hip At the hip , it has a prominent head Distally, it articulates at the knee with one of the two leg bones It has specially shaped surfaces - condyles - at the knee to roll on the plateau of the tibia It has several tuberosities and much surface , including epicondyles, for the attachment of muscles FEMUR II Viewed from front Greater trochanter Femoral head Femoral neck Minor trochanter Lateral epicondyle Medial epicondyle FEMUR III Femoral head Viewed from behind Greater trochanter Femoral neck Minor trochanter Linea aspera Lateral epicondyle Medial condyle Intercondylar fossa Medial epicondyle Lateral condyle FEMUR IV: ID left from right Viewed from behind Femoral head facing in to the hip Gluteal tuberosity Linea aspera facing posteriorly Concavity for hamstring muscles & popliteal region to the back Rt viewed from front TIBIA & FIBULA I Lateral condyle Fibular HEAD TIBIA Medial condyle Tibial tuberosity Anterior crest Sharp edge to be felt down the front of the shin bone Lateral Malleolus Medial Malleolus FEMUR IV Patella Viewed from front The quadriceps muscles in the front of the thigh send their tendon across the knee joint to insert into the front of the tibia. As the tendon passes the knee, it includes a bone - the patella or knee-cap. The patella, on its posterior side, has cartilage-covered surfaces to articulate with the anterior femur (they feel smooth) Patella does not articulate with the tibia Patella The tendon continues on to anchor in the tibial tuberosity KNEE I Lateral view Anterior Posterior Quadriceps muscle Quadriceps tendon FEMUR Patella TIBIA Popliteal space for nerves vessels, muscles, etc Cruciate Ligament One of many robust ones stabilizing the knee The fibula does not participate KNEE II Anterior view The femoral condyles roll on the flatter condyles of the tibial plateau Patella F E M U R The motion is mostly in one plane for flexion & extension of the knee because of the many ligaments restraining motion However, some rotation is necessary TIBIA Wedge-shaped semicircular pieces of fibrocartilage lie medially & laterally, partially to cushion the opposing condyles. Each is a meniscus. The medial meniscus is held in place and often gets torn - a “torn knee cartilage”, with the piece(s) causing inflammation & interfering with motion FIBULA Fibular HEAD Lateral Malleolus In the lab, the fibula is a slender bone distinguished by its lack of distinction at either end TIBIA TIBIA & FIBULA II Rt. viewed from front Interosseous membrane fastening fibula to tibia , along with ligaments, e.g., Anterior tibiofibular ligament Lateral Malleolus Medial Malleolus TALUS Rt viewed from front TIBIA Right versus Left TIBIA Tibial tuberosity Anterior crest Sharp edge to be felt down the front of the shin bone Like the femur, more muscle is at the back, so the concavity should face rearwards Medial Malleolus other Malleolus is on the fibula Big toe FOOT I: BONES Rt foot from above Phalangeal bones Metatarsal bones Tarsal / ankle bones TALUS CALCANEUS heel-bone Big toe FOOT II: TARSAL BONES from above Phalangeal bones Metatarsal bones Tarsal/ankle bones TALUS CALCANEUS heel-bone Note contrasts with the wrist bones Two much larger bones Only one bone - talus articulates with the tibia & fibula Bones held together with strong ligaments Bones participate in constructing flexible arches for walking Marieb Fig 5.26, p. 139 7 bones instead of 8 TIBIA FOOT III: ANKLE JOINT Rt. viewed from front Interosseous membrane fastening fibula to tibia , along with ligaments, e.g., Anterior tibiofibular ligament Lateral Malleolus Medial Malleolus TALUS Rt. viewed from medial side The Talus spreads the load to the heel-bone and the heads of the metatarsals to transfer to the ground, tree, floor, mud, or wherever you live FOOT IV: Loading TALUS CALCANEUS Medial longitudinal arch of the foot. There are also lateral longitudinal, and transverse arches WHERE AM I? Online Anatomy Module 1 INTRO & TERMS CELL EPITHELIUM You are at the End Caution how you exit. CONNECTIVE TISSUE BACK on your browser is needed MUSCLE Unfortunately there is NERVOUS SYSTEM no way that you can directly reach other AXIAL SKELETON topics listed here by APPENDICULAR SKELETON clicking on them. You get there by going back MUSCLES to the Paramedical EMBRYOLOGY Anatomy menu