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Chapter 20 Blood
I. Functions of Blood (Table 20.1) Blood is a connective tissue!
A. Transport: gasses, nutrients, wastes, hormones, antibodies etc.
B. Defense:
Leukocytes- white blood cells (neutrophils, eosinophils, basophils, monocytes, lymphocytes)
Antibodies: small proteins in blood
Complement: small proteins in blood
C. Regulation
1) Platelets form blood clots during injury & prevents excess blood loss.
2) Regulate body temperature w/ constricting/dilating blood vessels (circulation flow)
3) Salts & proteins keep content of water in plasma high (osmosis)- maintains blood pressure
4) Regulates pH & electrolytes in blood & interstitial fluid.
II. Plasma
A. Consists of inorganic & organic molecules dissolved in water.
55% of blood volume. water (90-92%), salts, gasses, hormones, vitamins, nutrients, cholesterol,
antibodies. etc.
B. plasma proteins:
1. albumin: 60%,most abundant & smallest. Mainly to maintain correct osmotic pressure of blood.
2. globulin:
a) immunoglobuins= antibodies. These will identify and attack foreign proteins.
b) Transport globulins: bind to insoluble substances that may be filtered out of kidney.
3. Fibrinogen inactive clotting factor . Activated form: fibrin.
III. Formed elements (Table 20.3)
A. Hemaotpoiesis- making of formed elements. Takes place in red bone marrow.
A pluripotent stem cell in red bone marrow 2 multipotent stem cells.
A multipotent stem cell maintains its population by replicating itself. Some of those new cells
will differentiate into other types of stem cells. When a stem cell differentiates, it commits
itself to a single developmental pathway.
Leukemia: cancer of white blood cells. Too much production in bone marrow, but cells put out into
blood are immature and not functional. Disrupts formation of normal blood cells.
B. 3 types of formed elements: cells & solid particles; 45% by volume
1. Erythrocytes
a) Small biconcave disks- shape gives it flexibility to move through small capillaries and a large
surface area (for diffusion of gasses)
b) rouleau: stack of RBC’s in small spaces
c) Enucleated- Survive 120 days in circulation, Destroyed in liver & spleen.
d) Hemoglobin: (Hb) Four subunit protein. Each subunit contains 1 heme group. Each heme
group contains an iron (Fe) atom which binds to oxygen. This is why we need iron in
the diet! 280 million molecules of Hb in one RBC!
- Anemia: condition where blood lacks enough healthy red blood cells or hemoglobin.
- Causes of anemia: disease (eg. malaria), genetic disorder, low iron in diet.
e) Hematocrit: % of RBC’s in blood. Normally about 45% for men and 40% for women
f) ABO blood typing & Rh factor (D antigen)
Blood Type
Can Donate to
Can receive blood from
Universal donor? Recipient?
A
B
AB
O
*= Nonspecific
immunity
2. Leukocytes
Fight infection- in blood, lymph nodes, lymph & other lymphatic tissues.
a) granular leukocytes
1.neutrophils*
Polymorphonuclear (PMN), mobile, phagocytic,
2. eosinophils*: pink, kidney shaped nucleus, fights parasites. Involved in allergy,
3.basophils*: dark granules, bilobed nucleus, mediates allergy, histamine production,
b) agranular leukocytes
1. monocytes*: in blood, immature. Large nucleus with a notch. Migrates to tissues.
- In the tissues, it matures into macrophage.
Phagocytic, non-specific.
2. lymphocytes: B & T cells. Specific immunity. Has “memory”.
- large round nucleus. Very little cytoplasm visible.
- cannot tell difference between T and B cell based on morphology
- B cells  antibodies, has memory
- T cells Kill virally infected cells, cancer cells. Recognizes foreign tissues,
Has memory
-Helper T cells: coordinates all arms of immunity (nonspecific cells, B
cells & T cells). HIV kills helper T cells. The person becomes
immunocompromised.
3. Platelets & Clotting factors
a) Megakaryocyte: giant precursor of platelets formed in bone marrow. This cell fragments
before leaving bone marrow. Fragments are called platelets
b) Hemostasis: “stop bleeding” 3 events that stop bleeding
1) vascular spasm: Smooth muscle lines blood vessels larger than capillary.
2) platelet plug formation:
3) clotting factors & fibrin coagulate the blood
c) Thrombus= clot. Components: 1) platelets 2) clotting factors 3) trapped RBC’s
d) Hemophilia: genetic disorder where a person is not making one clotting factor. A person is
not able to form a proper blood clot. Treated with taking the clotting factor. Must take
medication their entire life.
Chapter 21 Outline: Heart (numbers in italics corresponds to heart model)
I. Orientation
A. mediastinum, pericardial cavity, behind sternum, within lungs, base, apex
B. Pulmonary circuit : between heart and lungs
C. Systemic circuit. : between heart and body
II. Walls of Heart
A. Endocardium: endothelium, simp. squamous epith., lines inside of heart & covers heart valves.
Endocarditis: inflammation of this internal lining.
B. Myocardium
Cardiac muscle, intercalated discs, branched, striated. Organized by CT in networks called
bundles. Requires O2, has many mitochondria, myoglobin & glycogen reserves
C. Pericardium.
1) visceral pericardium “epicardium”
2) parietal pericardium
3) fibrous pericardium
-Inferiorly: attaches to diaphragm, Superiorly: attaches to large vessels of heart.
D. Pericardial fluid- found between the epicardium and parietal pericardium. Reduces friction between the
two serous membranes in beating heart
III. Heart Anatomy (organized by how blood flows through)
-Right side of the heart deals with deoxygenated blood, left side deals with oxygenated blood.
A. Right Atrium (1)
1. Receives O2-poor blood from:
a) superior vena cava (#16) (receives blood from above diaphragm)
b) inferior vena cava (#26) (receives blood from below diaphragm)
c) coronary sinus (#27) (posterior- receives blood from heart itself)
d) small vessels of anterior cardiac veins (anterior- receives from heart itself)
2. pectinate muscles (also in left atrium) – prominent ridge from right auricle into the right atrium
3. sinoatrial node (SA node) (#32) upper chamber
4. atrioventricular node (AV node) (#36)lower chamber
B. Right atrioventriculuar valve (tricuspid valve) (#35)
1. structure
-3 cusps, chordae tendinae
2. function
- prevent backflow into right atrium,
Ventricle relaxedOpen & blood flows past.
Ventricles contract blood forced up, & pushes flaps together.
Chordae tendinae (#40) attached to papillary muscles prevent valve from everting.
C. Right Ventricle (#4)
1. trabeculae carnae (#62): textured muscular wall of both ventricles
2. papillary muscles: (#42) conical muscles extending from walls that attach to chordae tendinae
3. pumps blood to lungs via pulmonary trunk
D. Pulmonary semilunar valve (#37)
1. structure
3 pocket-like cusps.
Ventricle contracts, blood  semilunar valves & forced to open.
Ventricles relaxed, blood in the vessels flow back & due to the shape of cusps, they
shut ensuring no backflow. Shuts when blood flows backwards.
2. function
- prevent backflow into right ventricle
E. Pulmonary trunk (#9) divides to form right & left pulmonary arteries
Brings deoxygenated blood to lungs
F. Pulmonary veins (#8) (right & left)
Brings oxygenated blood back to heart – into left atrium
G. Left atrium (#7) Left auricle (#51)
Receives oxygenated blood from right and left pulmonary veins
H. Left atrioventricular valve (bicuspid valve or mitral valve) (#41)
Structurally similar to tricuspid valve
I. Left Ventricle (#6)
Myocardium thickest- pumps blood to rest of body, Pumps blood into aorta.
J. Aortic semilunar valve (structurally similar to pulmonary semilunar valve)
K. Ascending aorta (#11), aortic arch (#12),, descending aorta(#19),
Branches off ascending aorta: coronary arteries. Right Coronary artery- (#31) ,Left CA- (# 29)
Branches off aortic arch: brachiocephalic (#13), left common carotid (#14),, left subclavian a. (#15)
IV. Heart Contraction
A. Heart Beat
Systole= heart muscle contraction (atrial systole, ventricular systole)
Diastole= heart muscle relaxation
(for blood pressure, systolic vs diastolic pressure refers to ventricles.)
- Heart beat “lub-dup” sounds are caused when valves close.
Heart murmur: ineffective valves that cause blood to pass back into atria or ventricles
B. Conduction system
Heart beats approx 2.5 billion times in a lifetime!
- Nodal tissue: has both muscle & nervous characteristics.
1. SA node(#32), (sinoatrial node): Pacemaker generates impulse every 0.85 seconds
2. AV node (#36), (atrioventricular node)
3. atrioventricular bundle (bundle of His) (#38 & 43), found in interverntricular septum
4. Perkinje fibers (#39),
* ventricles contract from bottom up; good for blood flow direction
C. Modification of heart beat
Cardioregulatory center in medulla oblongata carried out by sympathetic &parasympathetic
fibers via vagus nerve)
D. Echocardiogram (ECG, EKG)
- measures the depolarization of the heart’s chambers.
1. Bradycardia: slow heartbeat: (Fewer than 60 heartbeats/min.)
2. Tachycardia: fast heart beat (more than 100 beats/min.)
3. Fibrillation: heart beats rapidly, but in an uncoordinated manner- heart can be defibrillated by
applying a strong electrical current to chest.
V. Blood supply to the heart
A. Right coronary artery: from right side of aorta, descends in coronary sulcus- marks border btwn
atria &
ventricles.
1. Branches to form the right marginal artery (#63),.
2. Posterior: large branch, posterior interventricular (descending) artery (#61), (in posterior
interventricular sulcus) Serves right atrium & ventricle
B. Left coronary artery: from left side of aorta, under pulmonary trunk; forms 2 branches:
1. anterior interventricular (descending) artery(#50), ( in anterior interventricular sulcus)
branches to serve both ventricles
2. circumflex artery (#49), (in coronary sulcus) serves left ventricle and atrium.
C. Cardiac veins
- #1-3 Draining into the coronary sinus:
1) great cardiac vein: in anterior interventricular sulcus
2) middle cardiac vein (#60),: in posterior interventricular sulcus
3) small cardiac vein: running along heart’s inferior right margin.
4) anterior cardiac veins (near #4): in anterior surface of Rt. Ventricle, small horizontal veins. empty
directly into right atrium.
VI. Common Coronary Artery Disease Procedures
1. balloon angioplasty: plastic tube is threaded into the arteries & balloon is inflated to
open up the vessel. A stent holds the vessel open.
2. Bypass surgery:
Use a vessel from another part of the body to re-route blood around the blockage.
Outline Chapter 22: Vasculature
I. Blood Vessel
A. Layers
1) tunica interna (tunica intima) – lines lumen
a) Endothelium
b) internal elastic membrane (in largest vessels)
2) tunica media – layer in which atherosclerosis develops
a) smooth muscle
b) elastic & collagen (am’t varies)
3) tunica externa (adventitia)
- dense CT, stabilize & anchor blood vessels to other structures.
4) Vasa vasorum: blood vessels of larger blood vessels
B. Arteries - carry blood away from heart.
1. Elastic arteries: (2.5-1cm diameter).
Aorta & major branches
1) allow vessel to expand & recoil- help push blood. When not expanded, the artery is
contracted & has a pleated appearance on the inside.
2) dampen pressure produced by heart beat.
2. Muscular artery: (1cm-0.3mm diameter). “distribution artery”
Tunica media thickest.
Vasodilation & vasoconstriction changes am’t of blood going into each organ.
3. Arterioles: smallest arteries. Tunica media only has 1-2 layers of smooth muscle cells.
C. Capillaries
1. endothelium only
2. capillary beds & capillary sphincters pre and post cap. Sphincters are present and are smooth muscle
3. Continuous capillary vs Fenestrated capillary (porous).
D. Veins -carry blood towards the heart
1. Venules: one layer of endothelium plus outer sheath of collagen. Sizes vary
2. Veins
a) Medium veins: - more distensible than large veins because of less smooth muscle.
move via skeletal muscle contraction, contains valves
b) Large veins: great veins, IVC, SVC
3. Varicose veins: faulty valves
II. Major ARTERIES of the body
A. Branches off aorta …
Ascending aorta
1. Right & left coronary arteries branches (mentioned previously with blood supply to heart)
Arch of Aorta
1. Brachiocephalic trunk (divides into Right subclavian & Right common carotid)
2) Left common carotid
3) Left subclavian
Thoracic Aorta
Bronchial – to lungs, esophagus
Esopheal- to esophagus
Mediastinal- lymph nodes & CT of posterior mediastinum
Pericardial- to pericardium
Posterior intercostal- back muscles, spinal cord, distal 9 intercostal spaces.
Superior phrenic- superior diaphragm
Abdominal Aorta
Inferior phrenic
Celiac trunk (Left gastric , Common hepatic, Splenic)
Superior mesenteric- right small intestine, ascending colon
Suprarenals (adrenals)
Renals
Lumbars
Gonadals (Testicular or ovarians)
Inferior mesenteric: left colon, sigmoid colon, rectum
Middle sacral
Common iliac
B. Subclavian Branches -down the arm (R & L side are the same)
1. vertebral branch: one of 2 major arteries to brain, supplies spinal cord & neck muscles
2. Subclavian artery continues to become  axillary artery at the level of rib 1: supplies shoulder
muscles, thoracic wall (serratus anterior), triceps & breast.brachial artery: supplies all arm muscles,
humerus & elbow joint.
Brachial artery branches to become a) radial artery: supplies elbow joint, radial side of arm, wrist,
thumb, index finger deep palmar arch
b) Ulnar artery: Supplies elbow, flexor muscles on ulnar side,
passes along medial forearm superficial palmar arch digital
arteries serves fingers 2-5.
C. Common carotid branches
1. Internal carotid -with carotid sinus. Carotid sinus has carotid body that detects CO2/O2 changes
2. External Carotid- supplies external head, face and neck with 8 branches
D. Arteries to the brain
1. Posterior brain: vertebral arteries supply the posterior brain
- transverse foramina foramen magnum
- basilar artery: branch to serve cerebellum, pons and inner ear.
- posterior cerebral arteries (supply occipital lobe, inferior & medial temporal lobe)
-posterior communicating arteries of internal carotids
2. Middle & Anterior brain:
-Internal carotids
-middle cerebral artery : temporal & parietal lobes
-anterior cerebral artery: frontal & parietal lobes
-anterior communicating artery
3. Circle of Willis: Form a loop around pituitary and optic chiasma and it unites the brain’s anterior
& posterior blood supply
Vessels of the circle include: posterior cerebral, posterior communicating, anterior cerebral,
anterior communicating. (sometimes internal carotid is included here)
E. Leg
1. Internal iliac – pelvic wall & organs, genitals, upper thigh
2. External iliac- serves lower abdominals & pelvic muscle under inguinal ligament to become femoral
artery
Femoral- all thigh, external genitals. Passes through adductor magnus muscle to become
popliteal. Popliteal splits….
Anterior tibialdorsalis pedis -supplies dorsum of foot dorsal arch  digitial a.
Posterior tibial plantar arch – bottom of foot
Fibular a.
digital a.
III. Major VEINS of the body
A. Around heart
R & L internal jugular vein
R & L subclavian vein
R & L brachiocephalic veins (heart model R brachiocephalic #17; L brachiocephalic # 18)
superior vena cava.
Inferior vena cava
B. Drainage from Head
Dural sinus (superior sagittal, transverse, sigmoid; inferior sagittal, straight)  internal jugular
Internal jugular & external jugular drain into subclavian veins  brachiocephalic veins  SVC
C. Drainage from upper extremity
Arm has 3 large veins
(deep) 1. brachial vein
2. cephalic
axillary vein  subclavian vein superior vena cava
3. basilic
cephalic and basilica veins are joined by a median cubital vein
From forearm:
1. Deep & superficial palmar arches of the hand empty into the radial and ulnar veins then
empty into the brachial vein
2. Superficial palmar arch  cephalic & basilic  axillary v.
D. Drainage from thorax
Blood from thoracic viscera & intercostals drain into azygos system.
Azygos vein (#59) “unpaired” – along right side of thoracic vertebrae. Arises as a continuation of the
right ascending lumbar vein, empties into the superior vena cava.
Receives blood from:
Hemiazygos vein- ascends on left of vertebral column, receives blood from left intercostals,
some from esophageal veins
E. Drainage from abdomen
* All these reach the inferior vena cava. These run with their corresponding arteries
Inferior phrenic vein
Hepatic vein
Suprarenal (adrenal) veins
Renal vein
Gonadal veins (testicular or ovarian)
Lumbar veins
Middle sacral
Common iliac vein
F. Hepatic Portal system
Blood from the digestive system first go to the liver via the portal vein.
4 major vessels feed into hepatic portal vein:
1. Superior mesenteric vein: drains entire small intestine, right half of lg. intestine
2. Inferior mesenteric vein: drains left distal colon & superior rectum.
3. Splenic vein: no nutrients but any microbes escaped spleen  liver for destruction.
4. Gastric vein: from stomach
From hepatic portal vein liver R & L hepatic veins  inferior vena cava
G. Drainage from lower limb
- Most of the blood from the lower limb is returned by way of the deep veins
Posterior
Digital veins deep plantar arch plantar veins (sole of foot)  posterior tibial vein (joins with
fibular vein) popliteal vein femoral vein external iliac vein common iliac  inferior vena
cava.
Anterior
Dorsal venous arch dorsalis pedis vein anterior tibial vein popliteal femoral external iliac
vein common iliac IVC
Medial
Dorsal venous arch (dorsal surface of foot) greater saphenous vein (medial leg)  femoral vein
external iliac  common iliac  IVC
Lateral
Small saphenous vein  popliteal v.
IV. Fetal circulation
A. Umbilical system
Umbilical arteries branch of internal iliac artery & goes to placenta to pick up oxygen & nutrients, also
to rid waste into mother’s blood supply.
Umbilical vein blood to fetus. Blood to portal vein so nutrients can be processed by liver.
However, too much blood is coming in, most blood is diverted via the ductus venosus that
sends blood to hepatic vein inferior vena cava  right atrium.
In hepatic vein, this blood mixes with deoxygenated blood from baby’s system so blood has
intermediate O2 content which is why it is purple in diagrams.
* Birth: cut cord umbilical vessels in baby constrict & degenerate into fibrous bands called ligaments.
Eg) umbilical arteries = Umbilical ligaments
B. 2 ways that avoid pulmonary system
Fetal lungs need very little blood. Right atrium pumps blood  pulmonary trunk, however, lungs not
inflated & there is resistance. 2 shunts divert blood away from lungs:
1. foramen ovale: hole in RA. Has flaps which diverts some blood to left atrium. Flaps prevents
backflow into right atrium
2. ductus arterioisus: in pulmonary trunk. Most blood is diverted  aortic arch. small am’t lungs
Birth: at first breath, lungs inflate-no resistance in pulmonary vessels. Ductus arteriosus
constricts & closes, blood fills left atrium pushes foramen ovale closed.
Structures in the adult heart:
1. Fossa ovalis (#55) is the remnant of foramen ovale (fusion takes 1 year!)
2. ligamentum arteriosum (#10) is the remnant of ductus arteriosus. (about 3 months to form)
V. Heart Disease
A. Myocardial infarction: A portion of heart dies due to much reduced or total lack of blood supply, O2.
B. Angina pectoris: Sometimes, the heart may be getting enough blood supply under resting conditions, but
person can experience insufficient supply during exercise & cause pain. Reduced blood supply is
called ischemia- weakens the cardiac muscles but doesn’t kill them.
What causes these two conditions? Coronary Artery disease
C. Coronary artery disease- general name for condition in which heart muscle receives an inadequate
amount of blood. The main cause of coronary artery disease is arteriosclerosis
1. Arteriosclerosis : disease affecting arteries: thickened and stiffened arteries of all sizes. Most
commonly caused by the formation of plaques within the arteries. Plaques usually begin as
deposition of cholesterol & other fatty materials. Then those plaques harden & cause vessel
wall to be inflexible.
2. Atherosclerosis: thickened and hardened medium muscular & large elastic arteries
Most commonly involved: Aorta, femoral, popliteal & tibial, coronary, carotids, cerebral,
vertebral & basilar
D. Cerebrovascular accident (CVA) or stroke
Obstruction of circulation to the brain.
1. Ischemic stroke: interruption of blood supply due to an embolus traveling from another site (embolic
stroke). Embolus= plaque that was formed in one part of the body (eg. aorta), broke off & traveled to get
lodged in another part (eg. brain).
2. Hemorrhagic stroke: broken blood vessel in brain
Chapter 23 Lymphatic system
I. Functions:
1. Fluid balance - maintains homeostasis of interstitial fluid
2. Produce & mature lymphocytes
3. Lipid absorption – through lacteals in the small intestine
4. Alternate route for transport
II. Parts of lymphatic system
A. Lymph capillaries Located near blood capillaries in loose CT.
- Simple squamous cells, Edges of adjacent cells overlap: allows larger substances into capillaries
- Blind end: one way route for lymph
Different from vascular capillaries:
1) larger diameter 2) thinner walls 3) endothelium lacks continuous basal lamina
4) flat or irregular outline 5) anchoring filaments (collagen) keep it open 5) more permeable
B. Lymph vessels
1. Have the same 3 tunica layers of blood vessels, but much thinner. Lumens larger than arteries or veins
Base of each valve, the vessels bulge, fluid collects & forces valve closed. “String of beads.”
2. movement through vessels: skeletal muscle contraction
3. Path of body fluid: blood capillaries  tissue fluid  lymphatic capillaries (lymph)  lymphatic
vessels lymph nodes  lymphatic trunks  Rt & Lt Lymphatic ducts venous blood stream
C. Lymph nodes
1. cervical, axillary, popliteal, inguinal, thoracic, abdominal ~500 lymph nodes in the body! 1mm-3cm.
Superficial nodes cervical, axillary & inguinal regions. Vs Deep nodes
Capsule (dense CT). CT of all lymphatic organs is reticular CT.
Difference of node vs nodule: “ nodules” don’t have tough CT covering whereas “nodes” do.
Lymph is usually free of pathogens by the time it leaves the last node & enters the veins.
2. Structures to identify of lymph node:
Hilum
Cortex (Inner cortex T cells, outer cortex B cells)
Afferent vessel (many)
Medulla with medullary sinuses (openings)
Efferent vessel (one)
Lymph sinus
Capsule & subcapsular space reticular CT, macrophages
Germinating centers (B, T, macrophage, Dendritic cells)
Trabeculae
D. Thymus
1. Posterior to the sternum, superior to the heart. 2 lobes & smaller lobules
2. Blood-thymus barrier: keeps antigens out, prevent premature stimulation
T cell maturation (Only 5% of cells leave thymus & go into circulation!)
3. Different from other lymphatic tissue because:
not reticular CT based- it is epithelial glandular tissue.
At age 20: 80% functional tissue, at 40: 5% functional tissue. Still produces T cells, but fewer as we age.
It is largest between 1 and 2 years old.
E. Spleen
1. Largest mass of lymphatic tissue in the body. It is situated in left superior abdomen. Thin capsule
Can you live without a spleen? . Size varies among people.
Functions:
Removes blood-borne pathogens- blood enters the spleen (not lymph)
Remove and destroy old or defective blood cells.
Site of hematopoiesis in the fetus & stores platelets for life.
2. White pulp: thick sleeve of lymphatic tissue around the blood vessels - immune screening
3. Red pulp: surrounds white pulp. Has venous sinuses: wide areas where blood leaks  macrophages
can engulf any defective or dead cells. Red pulp gives spleen’s ability to destroy old blood cells
F. Lymphatic nodules1. MALT eg. Peyer’s Patches in intestinal wall
2. Tonsils -crypt (crevice)
- Palatine (2), pharyngeal (adenoid) (1), tubal tonsils (2), lingual (2) at base of tongue
Chapter 24 Outline Respiratory System
I. Functions
A. Functions:
1. Allows oxygen from air to enter blood & carbon dioxide in blood to leave body in exhaled air.
- Inspiration & Expiration
2. help maintain proper acid-base balance of blood –CO2 in blood = carbonic acid
3. produces vocal sounds through phonation
B. Divisions
1. Upper respiratory system: Nose, paranasal sinuses, pharynx, nasal cavity.
“condition the air”: humidify, warm, filter (nose hairs, mucus). Protect lower respiratory systems
from debris, pathogens & temp. extremes.
2. Lower respiratory system: larynx, trachea, bronchi, lungs
II. Upper Respiratory System
A. Nasal cavity
1. superior, middle, inferior nasal conchae: for air turbulence & increase surface area for warming &
humidifying.
2. superior, middle, inferior meatus: spaces between conchae
3. nasal septum (made from ethmoid & vomer bones)
4. eustacian tube opening
B. Paranasal sinuses
1. Frontal sinuses(2), sphenoid air cells, ethmoid air cells, maxillary sinuses(2)
2. Reduce weight of skull, help voice resonate
C. Epithelium
1. Stratified squamous near nares.
2. ciliated pesudostratified columnar with goblet cells (respiratory epithelium)
3. olfactory epithelium
III. Lower Respiratory Tract
A. Larynx
- Superiorly, attaches to hyoid bone. Inferiorly it is continuous with the trachea.
1. Epiglottis- elastic cartilage
2. 9 cartilages support the larynx & vocal cords.
1. Thyroid cartilage (2)- largest, 2 cartilage plates.
Laryngeal prominence
2. Cricoid cartilage- only cartilage forms a complete ring.
3. Arytenoid cartilage (2) anchor the vocal cords
4. Corniculate cartilage (2)
5. Cuneiform cartilage (2) elastic cartilage
3. Ligaments & Membranes
1. Thyrohyoid ligament
2. Thyroid membrane
3. Cricothyroid ligament
4. Cricotracheal ligament
B. Vocal Cords
1. Vestibular ligament (false vocal cord) – superior
play no part in producing sound.
2. Vocal ligament (true vocal cord)- inferior
- Between thyroid cartilage & arytenoid cartilages. Ligament that is covered with mucosal
folds. This mucosa is avascular: appear pearly white.
Sound production, pitch, Glottis space btwn true vocal cords
C. Epithelium
Below vocal cords: ciliated pseudostratified columnar with goblet cells = “respiratory epithelium”
Mucociliary escalator
D. Trachea
Connects the larynx to primary bronchi.
16-20 C-shaped hyaline cartilage rings. Open part of C faces the esophagus so you can swallow food.
Lined with respiratory epithelium
Carina: split of trachea
E. Bronchial Tree
1. Left and right primary (main) bronchi : which lead to left and right lungs.
Right side is shorter & straighter, so an accidentally inhaled object will probably go into right
lung.
2. Secondary bronchi (lobar) – goes into each lobe. Right lung: superior, middle, inferior lobar brochi. 3 lobes
Left lung : only superior and inferior lobar bronchi. 2 lobes
3. Tertiary bronchi (segmental)
- smooth muscle around smaller bronchi & bronchioles. *asthma is due to constriction of these
smooth muscles & causes airway to become smaller.
3. bronchioles (Less than 1mm) in diameter
- cartilaginous rings gone. Have elastin
- Neither cilia nor mucus secreting cells are in the bronchioles. Any debris that are not trapped
in mucus above the level of bronchioles must be removed by macrophages.
4. terminal bronchioles (less than 0.5mm)
5. respiratory bronchioles – have alveoli
6. Alveolar sacs with alveoli
a) Alveoli are made of very thin simple squamous cells called Type I cells (0.5 µm- 15 times
thinner than a sheet of tissue paper)
b) Alveolar sac is surrounded by capillaries. gas exchange. “Respiratory epithelium”
c) Type II cells: create surfactant: film of lipoprotein that lowers surface tension inside alveoli
d) Resident macrophages
* pneumonia - when the alveoli fill with fluid & gas exchange is compromised. Very dangerous condition.
IV. Pleura
1. Each lung is enclosed by this double serous membrane.
Parietal pleura & Visceral pleura
2. Pleural cavity:
Space between membranes filled with pleural fluid
V. Lungs
1. External Structures:
Apex: just deep to clavicle, pointed superior end.
Base: concave end that contacts the diaphragm
Costal surface: all surfaces that contact the ribs (anterior, lateral & posterior surfaces)
Hilum: it is the indentation where blood vessels/bronchi come in & exit lung
2. Right lung 3 lobes
superior middle & inferior
3. Left lung 2 lobes
superior & inferior
VI. Muscles of Respiration
A. Primary Respiratiory Muscles
1. Diaphragm
2. External intercostals (inhalation- elevate all ribs)
B. Accessory Respiration Muscles
Inhalation
1. sternocleidomastoid (lift sternum)
2. scalenes (lift first 2 ribs)
3. pectoralis minor (lift ribs 2-5)
4. serratus anterior (lifts ribs)
Exhalation
1. Tranversus abdominis (compress abdomen)
2. internal intercostals (depress ribs)
3. rectus abdominis & obliques (compress abdomen)
VI. Disorders
A. Emphysema: chronic & incurable disorder
Alveoli walls are damaged & distended. Surface area for gas exchange reduced. Less oxygen reaches
heart & brain- heart works overtime to pump blood to these areas.
B. Asthma: affects bronchi & bronchioles.
Smooth muscles around bronchi & bronchioles undergo spasms when introduced to an irritant (allergen,
cold air, smoke etc) Wheezing, breathlessness & cough.
Treatment:
Asthma can be treated with “inhalers” which contain bronchial dilators. For chronic asthma, corticosteroids
may be given to suppress immune to suppress allergic response
C.