Circulatory and Cardiovascular System Anatomy

cardiovascular system + lymphatic system; mediates continuous flow of body fluids

heart + closed circuit of vessels; transports O2 + nutrients to tissues; removes CO2 + metabolic waste; thermoregulation; distributes hormones + immune cells

highly modified muscular blood vessel; specialized for pumping blood

elastic arteries; muscular arteries; small arteries + arterioles; capillaries; venules + small veins; medium veins; large veins (venae cava)

carry blood AWAY from heart; thick walls; small lumen; tunica media predominant; smooth muscle + elastic tissue; withstand pressure changes

return blood TO heart; low pressure; thin walls; large lumen; tunica adventitia predominant; valves prevent backflow; skeletal muscle contractions aid flow (calf muscles)

circuit between heart + lungs; right ventricle > pulmonary arteries > capillaries > pulmonary veins > left atrium; deoxygenated blood sent to lungs to get oxygenated

heart to body tissues; left ventricle > aorta > systemic arteries > systemic capillaries > systemic veins > superior + inferior vena cavae > right atrium; exchange of CO2 + O2 + nutrients + wastes; distributes hormones

outside the heart; blind-ended lymph vessels; drainage without a pump; returns tissue fluid (lymph) to venous circulation after immunological screening

receiving chambers; right atrium + left atrium

discharging chambers; right ventricle + left ventricle

separate pump; pulmonary circuit

separate pump; systemic circulation

one-way blood flow; prevent backflow; 4 valves

between ventricle + artery; closed during heart relaxation; open during ventricular contraction; pulmonary semilunar valve + aortic semilunar valve

between atria + ventricles; anchored by chordae tendineae; open during heart relaxation; closed during ventricular contraction

AV valve; left side of heart

AV valve; right side of heart

heart strings; anchor AV valves in place

outermost layer of heart wall; visceral layer of serous pericardium; thin serous membrane; mesothelium (simple squamous) secretes lubricating fluid; LOCT; adipose tissue + blood vessels + nerves present; not an organ capsule

middle layer of heart; cardiac muscle; striated + involuntary; single nucleus; intercalated discs; contracts to pump blood into arteries

innermost layer of heart; lines chambers + covers valves; endothelium (simple squamous) + sub-endothelium (LOCT); Purkinje fibers below

heart sac; 2 layers; outer fibrous pericardium + inner serous pericardium

lines the fibrous pericardium; separated from epicardium by pericardial cavity

space between parietal serous pericardium + epicardium (visceral)

thin epithelium of mesothelial cells; simple squamous; lines heart + heart cavity; secretes lubrication fluid

attach adjacent cardiac cells; rapid transfer of electrical impulses between cells

loose CT; supports individual muscle fibers

dense CT; supports a muscle fascicle

dense CT; supports entire heart muscle

specialized cardiac muscle; conducting fibers; below endocardium

heart muscle contracts without nerve impulses; regular continuous sequential stimulation; sinoatrial node + AV node + bundle of His + Purkinje fibers

sets pace of heart; part of intrinsic conducting system

part of intrinsic conducting system; conducts impulse toward bundle of His

part of intrinsic conducting system; between AV node + Purkinje fibers

innermost layer of blood vessel; endothelium + sub-endothelium; equals endocardium of heart

middle layer of blood vessel; smooth muscle + elastic fibers; constriction + dilation; equals myocardium of heart; thicker in arteries

outer layer of blood vessel; collagen fibers; flexible support; resists collapse + injury; equals epicardium of heart; thicker in veins

elastin fibers; separates tunica intima from tunica media; present in arteries; absent in veins + capillaries

elastin fibers; separates tunica media from tunica externa; present in arteries; absent in veins + capillaries

blood supply of large blood vessel walls; found in tunica externa

nerve supply of large blood vessel walls; found in tunica externa

large arteries (aorta + pulmonary arteries); tunica media mainly elastin; fenestrated sheets of elastic tissue; distend + recoil to withstand pressure

medium arteries; tunica media smooth muscle bounded by IEL + EEL; regulate blood pressure + distribution

diameter <200 microns; thin smooth muscle layer; +/- IEL (disappears as smaller); regulate blood pressure; deliver blood under low pressure to capillary beds

thin relative to large arteries; IEL + EEL absent; tunica adventitia predominant; longitudinal bundles of smooth muscle

well-defined smooth muscle in tunica media (thicker than large veins); IEL + EEL absent; prominent adventitia (smaller than large veins)

smooth muscle disappears as diameter decreases; tunica media + adventitia absent in venules; walls lined by endothelium

most common; no pores; skin + muscle

endothelium has pores; endocrine organs + portions of GIT

larger diameter; slower blood flow; large pores; incomplete basement membrane; bone marrow + liver + spleen

wall is only endothelium + basement membrane; no tunica media or externa

artery = high; thick distinct tunics; lumen circular + open; vein = low; thin tunics; lumen flat + collapsed

artery thick wall (thickest = T. media); sparse or empty lumen; vein thin wall (thickest = T. adventitia); commonly packed with RBCs; broader adventitia

arterioles > capillary beds > venules; exchange between blood + tissues

veins hold large volume of blood; low pressure + large lumens

loose connective tissue

dense irregular connective tissue

stratified squamous keratinized epithelium

stratified squamous non-keratinized epithelium

protection by immune cells + antibodies

present at birth; nonspecific

active + passive

naturally acquired after exposure to infection; artificially acquired by vaccination

transmission of antibodies; maternal antibodies to fetus; immune serum medicine

immune surveillance + defense; immune tolerance (self vs non-self); absorbs lipids via lacteals in intestinal villi; maintains fluid balance by returning tissue fluid + WBCs to blood

bone marrow + thymus

lymphocyte stem cells; T + B lymphocytes originate; B cells mature + seed secondary organs; T cells move to thymus

tonsils + spleen + lymph nodes + diffuse lymphoid tissues (MALT)

mucosa-associated lymphoid tissue; mass of lymphoid tissue in mucosal surfaces (GIT + respiratory + genitourinary); B + T lymphocytes + macrophages + plasma cells

gut-associated lymphoid tissue; MALT in GIT; isolated + smaller follicles; B + T cells

bronchus-associated lymphoid tissue; MALT in respiratory tract + bronchial tree; surface epithelium = first line of defense; immune cells beneath = second line

largest GALT; mucosa of ileum; reactive follicles with germinal centres; B + T cells

differentiate into memory B cells + plasma cells

differentiate into helper + memory + cytotoxic cells; mature in thymus

mount immune response; produce antibodies; found in germinal centers + medullary cords

phagocytose foreign matter

initiate immune response

appendix + tonsils + Peyer's patches + lymph nodes; lymphocytes pass through endothelium; spread immunological information between body regions

cells + tissues that perform the organ's function

supporting framework of organ; usually CT; free cells (lymphocytes) + reticular cells + reticulin fibers

produce reticulin fibers

meshwork; allows lymph to pass through; CT support for parenchymal cells

clear watery fluid in lymphatic vessels

fills spaces between cells

originate as lymphatic capillaries; thin-walled; endothelium lined; highly permeable; valves for one-way flow; carry lymph toward heart; more valves than veins + lack pericytes

right lymphatic duct + thoracic duct

lymphatic = fluid + more valves + no pericytes; vein = usually has RBCs

flow 3 L/day; breathing movements + skeletal muscle contractions create pressure gradient

where lymph returns to venous circulation

flat lymphoid organ in upper chest; T-cell maturation; produces thymosin; most active in childhood; involutes after puberty (replaced by adipose); capsule DICT; lobulated by CT septae

hormone from thymus; promotes T-lymphocyte maturation

outer; thymocytes (immature T cells); cortical epithelial nurse cells support T-cell maturation

inner; Hassall's corpuscles; self-reactive T-cells removed here

keratinized dead epithelial cells; migrate inward from cortex; thymic medulla

cortical epithelial cells; support T-cell maturation

young = lobules + cortex + medulla + septae; old = fatty infiltration + lymphocyte depletion

spherical or kidney-shaped; along lymphatic vessels; axilla + groin + neck + lung hila + para-aortic + mesenteries; in-line filters; stimulate immune response; defense vs microorganisms; prevent spread of tumour cells

stromal (lymphocytes + APCs); lymphatic/sinus (sieve/filter for antigens); vascular (sinusoids + vessels; nutrients + lymphocytes)

capsule; cortex; medulla; hilum; afferent + efferent lymphatic vessels

DICT

CT from capsule extending into parenchyma

bring lymph into node; enter via capsule to subcapsular space

leave at hilum; go to lymphatic ducts

lymph node indentation; efferent lymphatics exit

space under capsule; lymph enters from afferents

lymph passes through toward medulla

B + T lymphocytes + macrophages + dendritic cells

outer cortex; germinal center + mantle zone

dark zone; resting B cells + helper T cells + follicular dendritic cells + macrophages

pale zone; B-lymphocyte proliferation; rich in plasma cells; active B cells become plasma cells on antigen stimulation

inner cortex; only T-lymphocytes; no follicles

continuous with cortex; medullary cords + medullary sinuses

T-lymphocytes + majority plasma cells

separate medullary cords

largest lymphoid organ; left upper abdomen; encapsulated; blood from splenic artery; drains via splenic vein to hepatic portal system

immune response vs blood-borne antigens (antibody-forming); destroys aged erythrocytes + defective platelets; repository of phagocytes (red pulp) + lymphoid cells (white pulp) + platelets; hemopoiesis in fetus + hemolytic anemia; recycles iron

hepatic portal vein carries blood from spleen + GIT to liver for metabolism before heart

DICT; continuous with trabeculae; some smooth muscle

lymphoid nodules; basophilic; B + T lymphocytes around central arteriole

peri-arteriolar lymphoid sheath; T + B lymphocytes surrounding central arteriole in white pulp

in white pulp; surrounded by PALS

highly vascular; bulk of spleen parenchyma; splenic cords + sinusoids; reticulin CT; T + B cells + macrophages; drains to hepatic portal vein

elongated structures in red pulp; between splenic sinuses

lined by endothelium; in red pulp

highlights reticulin fiber meshwork

solid non-encapsulated lymphoid organ; SSNK luminal epithelium; epithelium invaginates to form crypts; hemi-capsule at base; follicles with germinal centres + mantle zones

blind-ended invagination of epithelium

lingual tonsil + pharyngeal tonsil + palatine tonsils

skin

skin + appendages (hair + nails + glands)

largest organ; cutaneous membrane; 15-20% of body weight; epidermis + dermis + hypodermis

protection (barrier + immunological); sensation; movement + growth without injury; exocrine (water + urea + ammonia + uric acid); endocrine (vitamin D); immunity; homeostasis (thermoregulation + water conservation + gas exchange + excretion); subtle sexual attractant

outermost layer; SSK; avascular; waterproof barrier; skin tone; vitamin D synthesis; self-generating 50-60 days; thickness determines skin category

beneath epidermis; LOCT + DICT; hair follicles + sweat glands + sebaceous glands; vascular; nerve receptors; wound healing; mechanical strength; nourishes epidermis

deep layer; adipose + CT; structural support; insulation; shock absorption; lobules separated by CT septae

palms + soles; 5 strata; thick epidermis; sweat glands present; hair + sebaceous glands absent; prominent rete ridges; has stratum lucidum

rest of body; 4 strata; thin epidermis; sweat glands + hair + sebaceous glands present; less prominent rete ridges; no stratum lucidum

90% of epidermal cells; produce keratin; arise from stratum basale; desmosomes; lamellar bodies; lifespan 50-60 days

cells from stratum basale fill with keratin; reach stratum corneum; then desquamation

shedding of dead surface cells; maintains normal epidermal thickness

5% of skin cells; melanin pigment; protect from UV; dendritic; no desmosomes; between stratum basale + spinosum; number constant in all races; activity variable

pigment from melanocytes; skin colour; UV protection

loss of melanocytes; patchy depigmentation

dendritic cells; macrophages of skin; antigen presenting cells to T-cells; stratum spinosum

tactile cells; mechanoreceptors; cutaneous sensation; keratin + neurosecretory granules; nerve endings; stratum basale; desmosomes; need IHC stain

basal layer; one layer cuboidal or low columnar cells; repeated mitosis; hemidesmosomes to basement membrane; desmosomes to neighbours; melanocytes + Merkel cells

spiny layer; 8-10 layers polyhedral keratinocytes; prominent desmosomes with tonofilaments; Langerhans cells

granular layer; 2-4 layers; basophilic keratohyalin granules; cells degenerate; lysosomal activity increases

clear layer; flat closely packed cells; eleidin; +/- nuclei; thick skin only

corny layer; 20-30 layers of dead flat cells; keratin fibers + glycophospholipid; waterproof barrier + prevents wear and tear

superficial to deep = corneum + lucidum + granulosum + spinosum + basale; Can't Let Good Skin Burn

hold keratinocytes together

attach stratum basale to basement membrane

filaments in desmosomes of stratum spinosum

basophilic granules in stratum granulosum

fills cells of stratum lucidum

skin disease; blistering

skin disease; scaly skin

scalloped margin; interpapillary pegs + dermal papillae interdigitate; more apparent in thick skin

downward projections of epidermis

upward projections of dermis

undulating structures at DEJ; friction ridges; enhance grip; resist friction

superficial; LOCT; fine collagen + elastin; forms dermal papillae

deep thick layer; DICT; thick collagen bundles + elastin; skeletal muscle attachment (face + scalp); smooth muscle (arrector pili + scrotum + areolae + anus); sweat glands

hair follicles + sebaceous glands + eccrine sweat glands + apocrine glands

associated with sebaceous glands; duct of sebaceous gland; stratified squamous surface epithelium

secrete sebum; simple branched acinar; associated with arrector pili + hair follicle

hair follicle + sebaceous gland + arrector pili muscle

smooth muscle; attached to hair follicle

secretion of sebaceous glands

palms + soles + forehead; secrete sweat; evaporation cools body; excretes Na+ + Cl- + urea + ammonia + uric acid; simple coiled tubular; secretory = simple cuboidal; excretory = stratified cuboidal; myoepithelial cells

axilla + breast areolae + genital regions; viscid milky secretion; simple coiled tubular; myoepithelial cells; functional at puberty; budding appearance

contractile smooth-muscle-like cells; contract to push secretions from exocrine glands

control blood flow + thermal regulation; shunt blood between small arteries + small veins

deep dermis or hypodermis; deep pressure + high frequency vibration

dermal papillae; low frequency stimuli; light touch

deep dermis + hypodermis; sustained stress; skin stretch

GI tract (alimentary canal) + accessory structures

pharynx + esophagus + stomach + small intestine (duodenum + jejunum + ileum) + large intestine + anus; one continuous coiled hollow tube

oral cavity + salivary glands + liver + gallbladder + pancreas

taking in food; mastication + deglutition + peristalsis

chewing; coordinated movement of mandible + teeth + lips + tongue

swallowing

continuous involuntary muscle movements; alternating contractions; move bolus toward stomach

food ball; bound by mucous secretion

semi-digested liquid; delivered from stomach to small intestine

breaking food down physically + chemically

movement of nutrients into bloodstream; pancreatic enzymes + bile enter duodenum for fat digestion

rids body of indigestible waste

gates between parts of digestive system

vestibule + oral cavity proper; lips + cheeks + hard/soft palate + tongue

SSNK epithelium; exceptions = outer lip + dorsal tongue may be SSK; lamina propria DICT; many sensory receptors

exterior SSK with sebaceous + sweat glands; transitional zone SS with occasional sebaceous glands (no sweat glands or hair follicles); interior SSNK; skeletal muscle + salivary glands

muscular organ covered by oral mucosa; skeletal muscle; food manipulation + taste + speech; anterior 2/3 + posterior 1/3 divided by sulcus terminalis

divides anterior 2/3 from posterior 1/3 of tongue

threadlike bristles; no tastebuds

mushroom-shaped; tastebuds present

leaf-like; tastebuds present

serous glands at base; numerous tastebuds

taste sensation; located in cleft of papillae

SSNK epithelium + lymphoid tissue; lingual tonsil

parotid + submandibular + sublingual

thin watery suspension; serous cells (enzymes + inorganic ions + antibodies) + mucous cells (mucins); cleans teeth; moistens + lubricates food; dissolves molecules for taste; salivary amylase starts starch digestion

enzyme in saliva; starts chemical digestion of starches

compound acinar; mostly serous

compound tubuloacinar; serous + mucous

compound tubular; mostly mucous

numerous lobules separated by collagen septae; branching ducts

within the lobule; smaller diameter

between lobules; larger diameter

secrete serous substances; pyramid-shaped; round nuclei

secrete mucous substances; pyramid-shaped; flat nuclei

on surface of secretory units; resemble smooth muscle; contract to press acinus + release secretion into duct; between basal lamina + epithelial cells

largest gland ~1.5 kg; beneath diaphragm; left + right lobes separated by falciform ligament; functional unit = hepatocytes

exocrine (bile); endocrine (plasma proteins + hormones); detoxification; metabolism of fat + carbohydrate + protein; storage of iron + glycogen + vitamins A + B12 + D; fetal hematopoiesis

functional units of liver; large polyhedral cells; round nuclei + prominent nucleoli; binucleation; lipofuscin; store glycogen; form bile; reticular CT support

formed by hepatocytes; aids fat breakdown + absorption; stored in gallbladder; released into duodenum

wear and tear pigment

phagocytic; monocyte-macrophage defense system; remove bacteria + old RBCs; line sinusoids

hepatic lipocytes; store lipid droplets with vitamin A; produce ECM + collagen

between hepatocytes; lined by endothelial cells + Kupffer cells + Ito cells

liver capsule; DICT; covered by mesothelium (simple squamous)

carries oxygen-rich blood from aorta

brings nutrient-rich blood from GI tract to liver

carries bile away from hepatocytes toward gallbladder + duodenum

pentagon or hexagon shaped; hepatocyte plates + sinusoids radiate to center like bicycle spokes; central vein in middle; portal triad at corners

centrilobular vein; center of liver lobule

at each lobule corner; hepatic artery + portal vein + bile duct (+ lymphatic vessels)

muscular sac; hollow; up to 100 mL; stores + concentrates + releases bile

mucosa (simple columnar with microvilli + LOCT lamina propria + rugae); muscularis externa (smooth muscle in all directions not layered); serosa/adventitia LOCT

large gland ~15 cm; in curve of duodenum; exocrine + endocrine

majority of pancreas; acinar cells secrete digestive enzymes + pancreatic juices; compound acinar; lobulated by CT septae; intralobular + interlobular ducts

2% of pancreas; islets of Langerhans; secrete hormones directly into capillaries; control carbohydrate metabolism

pancreatic islets; clumps + cords of endocrine cells; alpha cells (glucagon) + beta cells (insulin) + delta cells + polypeptide cells

secrete glucagon; pancreatic islets

secrete insulin; pancreatic islets

mucosa + submucosa + muscularis externa + adventitia/serosa

innermost layer facing lumen; surface epithelium (SSNK or simple columnar) + glandular epithelium + lamina propria + muscularis mucosae

LOCT supporting epithelium; lymphoid tissue (MALT/GALT)

narrow band of smooth muscle in mucosa

LOCT; thick collagen bundles; blood vessels + lymphatics + nerves; Meissner's plexus; submucosal glands (esophagus + duodenum)

submucosal nerves; innervate muscularis mucosae + mucosal glands

inner + outer smooth or skeletal muscle layers; Auerbach's plexus between; exceptions = upper 1/3 esophagus skeletal + stomach 3 layers

nerves between muscle layers of muscularis externa; innervates smooth muscle

outermost layer; LOCT; covers organs facing body cavities

outermost layer; LOCT; attaches organs to surrounding tissues

esophagus to stomach; SSNK to simple columnar; squamocolumnar junction; physiological sphincter prevents reflux

stomach to duodenum; simple branched tubular (secretory) to simple tubular (absorptive); pyloric sphincter

ileum to cecum; villi to no villi; thickened muscularis externa + lymphoid aggregates; ileocecal valve

rectum to anus; simple columnar to SSK; squamocolumnar junction; gradual transition to skin with sebaceous + sweat glands

~6 inches; passageway for food + air; nasopharynx (not digestive) + oropharynx + laryngopharynx

SSNK mucosa; LOCT with elastin; no submucosa; muscularis externa skeletal voluntary (inner longitudinal + outer circular); outer buccopharyngeal fascia

laryngeal cartilage; flaps down to close airway during swallowing; up for breathing

~10 inches; pharynx to stomach through diaphragm; peristalsis; food only; 3 regions (upper + middle + lower 3rd)

upper = skeletal muscle; lower = smooth muscle

protective mucosa SSNK + LOCT + muscularis mucosa; submucosa with mucous-secreting esophageal glands (compound tubular); muscularis externa inner circular + outer longitudinal (upper 3rd skeletal; middle 3rd skeletal + smooth; lower 3rd smooth); adventitia LOCT

compound tubular; submucosal; secrete mucous

metaplasia from gastric reflux at gastro-esophageal junction; high risk of dysplasia + invasive carcinoma

muscular storage tank; food breakdown; pepsin starts protein digestion; delivers chyme to small intestine; left abdominal cavity

begins chemical breakdown of protein in stomach

internal mucosal folds; allow stomach distention

cardia + fundus + body + pylorus

lesser + greater

lower esophageal + pyloric

secretory type; gastric pits (simple columnar surface epithelium) lead to gastric glands (simple branched tubular); surface mucous protects from acid; LOCT + intraepithelial lymphocytes

invaginations of surface epithelium into lamina propria

3 layers (unique); inner oblique + middle circular + outer longitudinal; Auerbach's plexus between

gastric pits same length as glands; coiled glands; secrete mucous; surrounds lower esophageal sphincter

gastric pits 1/4 mucosa thickness; straight tubular glands; mucous + HCl + pepsin; stem + mucous + parietal + chief + enteroendocrine cells

deep gastric pits; branched coiled glands; mainly mucous cells + enteroendocrine cells; thick middle circular muscle forms pyloric sphincter

secrete HCl; fundus + body glands

secrete pepsinogen (pepsin); fundus + body glands

secrete mucous; protect stomach lining

hormone-secreting cells; stomach + intestines

circular smooth muscle; one-way gate from stomach to duodenum

pyloric sphincter to ileocecal valve; ~20 ft; major digestive organ; nutrient absorption; uses intestinal juice + pancreatic juice + bile

~10 in; attached to stomach; around head of pancreas; Brunner's glands in submucosa

~8 ft; increased number + size of plicae circulares

~12 ft; Peyer's patches in mucosa; extends to large intestine

brush border; ~1700 per cell; increase surface area

finger-like mucosal projections; contain lacteals; lined by enterocytes

lymphatic capillaries in villi; absorb lipids

circular folds of mucosa + submucosa; increase surface area

absorptive surface cells; simple columnar with microvilli

unicellular mucous-secreting glands; number increases from duodenum to rectum

intestinal glands; simple tubular; Paneth cells at bottom

bottom of crypts; eosinophilic granules; anti-microbial; absent in large intestine

only in duodenum submucosa; compound tubular; secrete alkaline mucins

ileocecal sphincter to external anal sphincter; resorbs water + mineral ions; forms + stores feces; 500+ bacteria species; bacterial fermentation

3 longitudinal bands of muscularis externa outer layer

pouches from sacculation; permanent segmentation

cecum + colon (ascending + transverse + descending + sigmoid) + rectum + anal canal

absorptive; simple columnar with goblet cells + microvilli; straight crypts; more goblet cells; fewer enteroendocrine cells; no Paneth cells + no villi + no plicae circulares

first 5-8 cm of large intestine

last 7-8 inches; narrows to anal canal

terminal inch; simple columnar to SSK

worm-like tube on cecum; immune function; reservoir for normal flora; histology like large intestine; lymphoid follicles with germinal centers in mucosa

terminal end of intestinal tract; external anal sphincter = skeletal voluntary; internal anal sphincter = smooth involuntary; closed except during defecation