Anatomy Final

functions of blood

• transportation of O2, CO2, nutrients, wastes

• regulation of pH, T, fluid volume

• immune response by producing antibodies

composition of blood in centrifugation

• erythrocytes = 45% of total blood volume (red blood cells)

• buffy coat = < 1% (leukocytes and platelets)

• plasma = 55% (mainly water)

lightest/top → heaviest/bottom = plasma, buffy coat, erythrocytes

blood plasma

• 92% water

• 7% plasma proteins

  • albumin (58%): fluid balance to hold water in blood and fatty acid transport

  • globulins (37%): antibodies, transport lipids/iron

  • fibrinogen (4%): activated as fibrin to help clot blood

  • regulatory proteins (1%): enzymes, hormones

• 1% other

  • nutrients, wastes, respiratory gases

  • has yellowish color

erythrocytes

• red blood cells

• not true cells (no nucleus/organelles)

• relatively small and concave

• migrate through capillaries in a rouleau (1 by one quarter width)

formed elements

• formed from same stem cells found in red bone marrow in hematopoiesis

• hematocrit

  • females: 38-46% total blood volume

  • males: 42-56%

    • men have higher muscle mass so need more O2

• include erythrocytes and platelets

hemopoiesis/hematopoiesis

• formation of blood cells

• formed elements have a short life span

  • constantly produced via hemopoiesis at red marrow

• occurs in:

  • hemocytoblasts → pluripotent stem cells

• development

  • myeloid: RBCs, platelets, WBCs (except lymphocytes)

  • lymphoid: lymphocytes (B + T cells)

hemoglobin

• there are 250-280 million hemoglobin molecules per RBC

• Hb reversibly binds O2 and CO2

  • transports O2 from lungs to tissues and CO2 from tissues to lungs

• 1 Hb can bind 4O2 or 4CO2

erythropoiesis

• RBC production

• stimulated by low O2 concentration in blood

  • detected by kidneys

• erythropoietin: hormone secreted by kidney that binds receptors at red marrow stimulates erythropoiesis

  • takes about 4 days

• RBCs have 120 day life cycle so need to be made frequently

• 3 mill RBC/sec, 200 bill/day, 25 trill total

blood doping

• increases number of RBCs in bloodstream for athletic advantage

• increased Hb for increased O2 delivery

• improved aerobic capacity

• faster injury recovery

• thickens blood to cause heart attack, stroke, blood clots, pulmonary embolism

leukocytes

• white blood cells

• true cells with nucleus and organelles

• initiate immune response to defend against pathogens

• 1.5-3x larger than RBCs

• diapedesis: when leukocytes migrate from blood to tissue

• chemotaxis: chemicals released by injured/dead/dying cells that call WBCs

types and classes of leukocytes

classes:

• granulocytes (G): cells w/small intracellular granules

• agranulocytes (A) no granules

types:

• neutrophils (G) = 50-70%, 1st to arrive to infection, phagocytic activity, bacterial/fungal infections

• lymphocytes (A) = 20-40%, immune response, B + T activated

• monocytes (A) = 2-8%, mature into macrophages, respond to bacteria/tumors

• eosinophils (G) = 1-4%, respond to allergies, parasites

• basophils (G) = 0.5-1%, secrete histamine (allergies) and heparin (injuries)

Never Let Monkeys Eat Bananas

platelets

• aka thrombocytes → cells that clot blood

• not true cells (no nucleus/organelles)

• cellular fragments of megakaryocytes

• ¼ size of RBCs

arteries vs. veins and blood flow

artery: carries blood out/away from heart

vein: carries blood into heart

systole vs. diastole

systole: heart chambers contract ejecting blood

diastole: heart chambers relax allowing refilling of blood

characteristics/functions of the heart

• unidirectional blood flow due to valves

• pulmonary circuit: directs blood to lungs

• systemic circuit: directs blood to body tissues

blood pressure

• force of blood on the walls of arteries

• distributes blood into vessels

• a minimum BP essential for circulation

pericardium of heart

• a tough sac that encloses heart

• made of:

  • fibrous pericardium: superficial, dense IRR CT

  • serous pericardium

    • parietal layer: inner surface of fibrous

    • visceral layer: lines the heart

      • pericardial cavity: between parietal/visceral filled w/serous fluid

pericarditis

• increased production of serous fluid

  • causes inflammation of the pericardium

layers of the heart wall

epicardium (superficial): visceral pericardium, areolar and adipose CT

myocardium: thickest, cardiac muscles

endocardium (deep): internal surface of chambers, simple squamous endothelium

right atrium

• receives venous blood from heart, the muscles, and systemic circulation

• 3 veins drain into it:

  • superior vena cava → head/upper limbs

  • inferior vena cava → abdomen/lower limbs

  • coronary sinus → heart wall

    • these 3 bring deoxygenated blood back to the heart

• tricuspid valve:

  • when ventricle contracts, valve opens

  • when ventricle relaxes, valve closes

right ventricle

• pumps deoxygenated blood from right atrium

• pulmonary semilunar valve:

  • when ventricle contracts, valve opens

  • when ventricle relaxes, valve closes

trabeculae carneae

• increase SA

• greater deposition of myocardium

• allows more blood to fill ventricles

left atrium

• receives oxygenated blood from lungs via pulmonary veins

• bicuspid valve:

  • when ventricle contracts, valve closes

left ventricle

• 3x thicker than r. vent because of pressure increase

  • has the greatest workload

• pumps oxygenated blood from left atrium

• aortic semilunar valve:

  • when ventricle contracts, valve opens

  • when ventricle relaxes, valve closes

pulmonary vs. systemic circulations

P: r. atrium → r. ventricle → pulmonary semilunar valve → pulmonary trunk → pulmonary arteries → lungs (out CO2, in O2) → pulmonary veins → left atrium

• carries deoxygenated blood from R side of heart to lungs and newly oxygenated to L side of heart

S: l. atrium → l. ventricle → aortic semilunar valve → aorta → systemic arteries → body tissues (out O2, in CO2) → systemic veins → r. atrium

• carries newly oxygenated blood from L side of heart to body and deoxygenated to R side of heart

XX = deoxygenated blood

XX = oxygenated blood

coronary circulation

• l. ventricle → heart wall → r. atrium

• branch of systemic circuit

• r/l coronary arteries travel w/in coronary sulcus and supply heart wall with O2 and nutrients

• only branches off of ascending aorta

  • heart is first tissue to receive blood

coronary arteries

• right coronary artery

  • right marginal: supplies right border

  • posterior interventricular artery: supplies posterior surface of ventricles

• left coronary artery

  • anterior interventricular artery: supplies anterior of ventricles

  • circumflex artery: supplies left atrium and ventricle

coronary veins

• venous return of blood from heart wall muscle

• great cardiac vein: drains anterior surface of ventricles

• middle cardiac vein: drains posterior surface of ventricles

• small cardiac vein: drains right border of heart

• coronary sinus: receives deoxygenated blood from all cardiac veins

conducting system of heart

• myocardium made of cardiac muscle fibers

  • it contracts as single unit

    • due to gap junctions made of intercalated discs shared by adjacent fibers

• electrical impulse distributed immediately/spontaneously throughout entire myocardium

  • heart exhibits auto rhythmicity

    • initiates independent of nervous system to make own beat/rhythm

    • parasym will decrease heart rate

    • symp will increase heart rate

  • impulse stems from sinoatrial node or primary pacemaker

    • SA is posterior wall of r. atrium and sends 70-80 impulses/min via parasymp

    • pathway: SA node → r/l atria → AV node → AV bundles/bundle of His → IV septum → Purkinje fibers → ventricular myocardium

types of myocardial cells

• contractile cells: to contract

• nodal cells: pacemaker cells

• conducting fibers: conduct APs through myocardium

innervation of heart

• innervated by parasympathetic and sympathetic NS

• symp: SA node increases rate and HR

• para: SA node decreases rate and HR

coordinated sequence of contraction

• SA node fires impulse

• atria contract (systole) and ventricles relax (diastole)

• impulse reaches AV node then ventricles

• ventricles contract (systole) while atria relax (diastole)

heart sounds

lub = 1st sound made by closing of AV valves

dub = 2nd sound made by closing of semilunar valves

heart mumur made by insufficient AV valves (tricuspid)

types of blood vessels

arteries (blood away from heart)

veins (blood into heart)

capillaries (smallest site of metabolic exchange)

blood vessel tunics

• in arteries and veins (superficial → deep)

• tunica externa: CT anchors to organs, large vessels possess vasa vasorum

  • vasa vasorum: vessels of the vessel

• tunic media: circularly arranged smooth muscle

  • vasoconstriction = contraction to reduce blood flow/increase BP

  • vasodilation = relaxation to increase blood flow/decrease BP

• tunic intima: subendothelium areolar CT

  • simple squamous endothelium

types of arteries

• elastic arteries:

  • largest, most near heart

  • ex: common carotid, pulm. trunk, subclavian

  • elastic fibers in all 3 tunics to stretch/recoil in response to pressure

  • branch into muscular arteries

• muscular arteries:

  • medium diameter

  • elastic fibers in two concentric rings between 3 tunics

    • internal elastic lamina: separates tunica intima and media

    • external elastic lamina: separates tunica media and externa

  • thick tunica media

• arterioles:

  • smallest, <6 layers of smooth muscle in tunica media

  • symp and parasymp innervation

  • biggest impact on blood flow/pressure

    • vasoconstriction and dilation

capillaries

• smallest blood vessels

• diameter is just larger than RBCs

• wall is only tunica intima surrounded by basement membrane

• metabolic exchange

• form capillary beds

  • bed fed by metarteriole - proximal end surrounded by smooth muscle and distal end (thoroughfare channel) lacks smooth muscle

  • thoroughfare connects to postcapillary venue (where diapedesis)

    • no gas exchange

  • branches of metarteriole with ring of smooth muscle called true capillaries → gas exchange

types of capillaries

• continuous:

  • most common

  • endothelial cells form continuous lining surrounded by complete basement membrane

  • ideal for diffusion

  • ex: lungs, muscles, skin

• fenestrated:

  • endothelial cells have small pores

  • fenestrations and complete basement membrane

  • ideal for fluid transfer

  • ex: kidneys, small/large intestines

• sinusoid:

  • large fenestrations (holes) b/w endothelial cells

  • incomplete basement membrane

  • ideal for transport of large substances (cells)

  • ex: red marrow, liver, spleen

veins

• drain capillaries and return blood to heart

• pressure in veins = 0 mm Hg

• blood reservoirs at rest hold 60-70% of blood volume

• smaller/medium sized travel with muscular arteries

• large veins travel with elastic arteries

• thinner walls and larger lumen than arteries

• venous valves prevent backflow of blood

  • formed from tunica intima

venules

• smallest veins

• companion with arterioles

• smallest are located at distal end of capillary bed and called postcapillary venules

  • where diapedesis occurs

    • WBCs move through vessel walls into tissues

• venules merge to form medium veins

venous return

• no pressure in veins, so need help bringing blood back to heart

  • skeletal muscle pump

  • respiratory pump

skeletal muscle pump

• helps return blood to heart from lower limbs against gravity due to contractions

• skeletal muscles contract to compress veins

  • compression pushes blood up towards heart

• valves prevent backflow

respiratory pump

• helps return blood to heart during breathing due to pressure changes

• inhalation:

  • diaphragm contracts and decreases pressure in thoracic and increases pressure in abdomen

  • pressure difference pushes blood in abdomen to thoracic veins and into right atrium

• exhalation:

  • diaphragm relaxes and thoracic pressure rises slightly

  • blood moves forward still due to valves

BP highest to lowest

Aorta (highest)

arteries

arterioles

capillaries

venules

veins

venae cavae (lowest)

cranium blood flow

• internal carotid arteries enter through carotid canal

  • divide into anterior and middle cerebral arteries

    • supply brain and ophthalmic arteries (supply eyes)

• vertebral arteries branch from subclavian and travel through transverse foramina of cervical vertebrae

  • enter cranium through foramen magnum and merge into basilar artery

  • basilar artery and internal carotid create anastomosis of arteries called cerebral arterial circle

• most venous blood of cranium drains through dural venous sinuses

  • between 2 layers of dura mater

  • no valves, blood flows bidirectionally

hepatic portal system

• network of veins that drain blood from GI organs and shunts it to liver

• hepatic portal vein delivers blood to liver

  • made of 3 veins

    • superior mesenteric: drains small intestines, proximal colon, stomach

    • inferior mesenteric: drains distal colon

    • splenic: drains spleen, pancreas, stomach

• hepatic veins collect blood from liver and returns it to inferior vena cava

respiratory system functions

• respiration: inspiration and expiration

• gas conditioning: air is warmed, cleansed, and humidified

• sound production: vocal chords w/in larynx

• olfaction: olfactory receptors in superior nasal cavity

• defense: goblet cells (release mucin), lysozyme (anti-bacterial enzyme)

anatomical vs. functional resp. system

anatomical = upper and lower resp. tracts

functional = conduction portion and resp. portion

upper respiratory tract

• nose

• oral cavity: non keratinized stratified squamous epithelial (NKSSE)

• nasal cavity: pseudostratified ciliated columnar epithelium (PCCE)

  • choanae, nasal septum, nasal conchae

• paranasal sinuses

  • paired air spaces

  • communicate w/nasal cavity about mucus

  • PCCE

• pharynx

  • nasopharynx: choana to soft palate, PCCE

  • oropharynx: soft palate to hyoid/esophagus, NKSSE

  • laryngopharynx: hyoid to superior esophagus, NKSSE

    • shared by resp. and digestive systems

lower respiratory tract (conducting portion)

larynx, trachea, bronchi, bronchioles

larynx

• larynx connects pharynx to trachea

  • superior to vocal folds = NKSSE, inferior = PCCE

  • the voice box

  • thyroid cartilage:

    • made of hyaline cartilage

    • largest, shield shape

    • anterior and lateral wall, no posterior

    • has laryngeal prominence (adam’s apple)

  • cricoid cartilage:

    • made of hyaline cartilage

    • narrow anterior wall, large posterior wall

  • epiglottis:

    • made of elastic cartilage

    • spoon shaped

    • swallowing causes it to drop/block entrance to larynx glottis

      • prevent food in wrong tube

trachea

• lined with PCCE and goblet cells

• mucous escalator: ciliated cells move mucus up and out of resp. tract

• smokers: PCCE undergoes metaplasia to become stratified squamous

bronchi

• PCCE

• r. primary bronchus (1 each) → 3 secondary bronchi → 8-10 tertiary bronchi

• l. primary bronchus (1 each) → 2 secondary bronchi → 8-10 tertiary bronchi

• as branching continues and bronchioles get smaller:

  • incomplete rings of cartilage become smaller and less numerous

  • all bronchi lined w/PCCE

  • bronchi branch into bronchioles that lack rings of cartilage and lined w/ciliated simple columnar or simple squamous epithelium

  • smaller the diameter the less mucus present

bronchioles

• less than 1 mm in diameter

• walls = thick layer of smooth muscle

• bronchoconstriction = parasymp

• bronchodilation = symp (epinephrine)

• branch into:

  • terminal bronchioloes: last structure of conduction portion

    • branch into respiratory portion

lower respiratory tract (respiratory portion)

• terminal bronchioles → respiratory bronchioles → alveolar ducts

• alveoli

alveoli

• site of metabolic/gas exchange

• alveolar type 1 cells: simple squamous, form walls of alveoli

• alveolar type 2 cells: secrete pulmonary surfactant

  • lipid rich and produces surface tension of water in alveoli

  • prevents alveolar collapse

• alveolar macrophage (dust cell) engulfs microorganisms/particles that reach alveoli

respiratory membrane

• connection b/w alveolar T1 cells and capillary endothelial cells to promote gas diffusion

• diffusion barrier consists of:

  • PM of T1 alveolar cell

  • PM of capillary cell

  • fused basement membrane of both cells

hilium of lung

• bronchi, pulmonary vessels, lymphatic vessels, nerves pass into/out of lungs

• all structures in hilium termed root of lung

pulmonary ventilation (breathing)

• Boyle’s law: inverse relationship b/w pressure and volume

  • during inspiration:

    • diaphragm and external intercostals contract

      • increased lung volume and decreased lung pressure

        • air flows in

    • major muscles: sternum, ribs, ext. intercostal, diaphragm

  • active inspiration: sternocleidomastoid, scalenes

  • during passive expiration:

    • relaxation of inspiratory muscles

      • decreases lung volume to increase pressure

        • air flows out

  • active expiration: internal intercostal and abdominal muscles

innervation of resp. system

• larynx, trachea, bronchial tree, lungs under autonomic control

• sympathetic and parasympathetic fibers form pulmonary plexus

• sympathetic: bronchodilation (airways widen) increase airflow for more O2 delivery

• parasympathetic: bronchoconstriction (airways narrow) to slow breathing and conserve energy

• allergy/asthma meds target ANS to open the airways

  • either mimic sympathetic or block parasympathetic

respiratory centers of the brain

• medulla oblongata

  • controls breathing rhythm and integrates sensory output

• pons

  • smooths breathing transitions between inhalation and exhalation

  • adapt breathing to speech, sleep, exercise, emotions

digestive organs

• contain food, directly involved in digestion and/or absorption

• GI tract

• oral cavity, pharynx, esophagus, stomach, small and large intestines

accessory digestive organs

• assist GI tract in digestion of materials by providing secretions

• may or may not contain food

• teeth, tongue, salivary glands, liver, gall bladder, pancreas

functions of digestive system

• ingestion: taking in food and liquids

• digestion: mechanical and chemical breakdown of foods from large to small substances

• propulsion: movement of food through GI tract via muscular action

• secretion: enzymes, mucus, bile, acids involved in digestion

• absorption: nutrients from gut to blood

• elimination of wastes

phases of digestion

1. cephalic: changes at brain to stimulate appetite/initiate GI activity

   1. 10% of gastric secretions

2. gastric: food enters stomach

   1. 80% of gastric secretions

3. intestinal: chyme (food) enters duodenum

   1. 10% of gastric secretions

abdominal GI tract tunics

mucosa (deep)

• superficial epithelium: simple columnar, in contact w/food

• lamina propria: areolar CT

• muscularis mucosae: thin layer of smooth muscle, aids in secretion

submucosa → areolar and dense CT

• lymphatic ducts, mucin secreting glands, blood vessels

  • nerves: submucosal (sensory) nerve plexus

muscularis → smooth muscle

• inner circular layer: sphincters

• outer longitudinal layer (3 layers of smooth muscle)

  • esophagus and stomach

• myenteric (motor) nerve plexus

adventitia/serosa (superficial)

• outermost layer

• covered/lined with serous membrane

• areolar CT, collagen, elastin
  

peristalsis vs. segmentation

both are movement of food along GI tube

• peristalsis: wave like contraction of smooth muscle to propel food forward

  • circular and longitudinal muscle

  • esophagus, stomach

• segmentation: back and forth mixing of food

  • more circular muscle

  • small and large intestines

mesenteries

• folds of peritoneum that support and stabilize intraperitoneal GI tract organs

• blood vessels, lymphatic vessels, nerves are sandwiched between 2 folds and supply digestive organs

• greater and lesser omentum, mesentery proper, mesocolon

oral cavity (mouth)

• 1st site of mechanical and chemical digestion

• mix food, saliva, and bolus (food)

cheeks, lips, palate, tongue

• cheeks made of buccinator muscles

  • end as lips

• gingivae (gums) cover alveolar processes of teeth

• palate forms roof of oral cavity

  • hard and soft palate

• uvula elevates during swallowing to close off nasopharynx

• tongue manipulates and mixes food and saliva to make bolus

salivary glands

• produce and secrete saliva into mouth

• mucous cells: secrete mucin

• serous cells: secrete ions, lysozymes, amylase

• parotid glands (largest) secrete serous = 30% of saliva

• submandibular glands secrete mucus and serous = 60-70% of saliva

• sublingual glands secrete mucus and serous = 3-5% of saliva

functions of salivary gland

• moistens food for easier passage

• moistens, cleanses, lubes oral cavity

• chemical digestion: secretes amylase

• antibacterial action: lysozyme

• dissolves food to stimulate taste receptors

deglutition

• swallowing

• soft palate contracts

• uvula elevates to block nasopharynx

• larynx elevates, epiglottis tips down to block entrance into resp. tract

teeth

• known as dentition

• dentin forms mass of tooth, harder than bone

• cementum covers the root

• dentin covered with enamel → hardest substance in body

• pulp cavity (center) contains CT pulp

• root canal goes through apical foramen

  • blood vessels and nerves pass through

deciduous vs. permanent teeth

D: erupt from 6-30 months, called milk teeth

P: replace deciduous and have 32 in number

• wisdom teeth also

permanent teeth

• incisors in front have single root

• canines have pointed tips for puncturing/tearing

• premolars have cusps for crushing/grinding

• molars: thickest and most posterior for crushing and grinding ingested materials

esophagus

• tubular passageway from pharynx to stomach lined w/NKSSE → abrasive foods and liquids

• esophageal hiatus: hole in diaphragm esophagus passes through

  • prevents regurgitation (heartburn) into esophagus

• 25 cm long

• sphincters:

  • superior esophageal sphincter: skeletal muscle (voluntary) where pharynx and esophagus meet

  • inferior esophageal sphincter: smooth muscle (involuntary) weak but aided by esophageal hiatus

stomach functions

• continues process of chemical digestion

• chyme = paste like mix of bolus and gastric secretions

• stores food for 4-6 hrs

• mix and churn chyme

• kill bacteria w/HCl

• very little absorption except alcohol, NSAIDs, caffeine

3 layers of stomach

• oblique layer (deep)

• muscular layer

• longitudinal layer (superficial)

• lined with mucosa → simple columnar, numerous gastral pits

gastric pits

• lined w/gastric glands that produce gastric secretions

• at base is gastric glands

• 5 types of cells

cells of gastric glands

• mucous surface cells: secrete alkaline mucus to buffer pH of stomach, protect stomach lining

• mucous neck cells: secrete acidic mucus to enhance acidic environment for gastric secretions

• parietal cells: secrete HCl, intrinsic factors

  • HCl kills bacteria, denatures proteins

  • IF aids absorption of V. B12 in SI

• chief cells: secrete pepsinogen that is activated by HCl to pepsin to chemically digest proteins

• G cells: secrete gastrin (hormone) that increases gastric secretions

• D cells: secrete somatostatin (hormone) that inhibits G cells

accessory digestive organs

• liver

  • produces and secretes bile

  • bile emulsifies fat into smaller fat molecules to aid digestion

• gall bladder

  • stores bile

  • cystic duct releases bile into duodenum

• pancreas

  • endocrine and exocrine (pancreatic juice secreted into duodenum) fxs

  • pancreatic juices = digestive enzymes and bicarbonate

    • furthers chemical digestion and buffers acidic chyme from stomach

• biliary apparatus

biliary apparatus

• network of thin ducts to transport bile from liver to GB to duodenum

• l/r hepatic ducts, common hepatic duct, common bile duct, cystic duct

small intestines

• finishes chemical digestion

  • site of 90% of absorption

• 12 hours and 6 meters (20 feet)

• duodenum → jejunum → ileum

  • jejunum is where most absorption occurs

histology of small intestines

• circular folds: folds of mucosa that slow rate of chyme and increase SA

• villi: shaggy hair that increases SA

• microvilli: majorly increases SA, numerous folds of apical surface

large intestines

• lie around small intestines

• absorbs remaining water in chyme and ions

• stores feces

• cecum → ascending colon → transverse → descending → sigmoid → rectum → anal canal

  • rectum stores accumulated fecal material prior to defecation

  • anal canal has internal (involuntary) and external (voluntary) sphincters

• teniae coli: regulate rhythm/strength of contractions to help push feces

• haustra: allows colon to expand/contract and promotes mixing

urinary system functions

• removal of waste products from bloodstream

• production of urine

• storage and excretion of urine

• blood volume regulation

• regulation of erythrocyte production

• includes kidneys, ureters, urinary bladder, urethra

kidney tissue layers

• fibrous capsule (deep) in direct contact w/outer surface of kidney

• perinephric fat: provides cushioning and insulation to kidney

• renal fascia: anchors kidney to posterior abdominal wall

• paranephric fat (super): outermost layer

tubing in renal sinus of kidney

• renal papilla projects into minor calyx

• several minor calyx form a major calyx

• major calyx fuse to form renal pelvis

  • collects total urine output and transports it to ureter

nephrons

• functional filtration unit of kidney

• 1.25 million nephrons per kidney

  • filtration of water and solutes into space of renal corpuscle

    • nonspecific filtration of blood at glomerulus

  • tubular reabsorption: substances move from tubular system back into bloodstream

  • tubular secretion: transport of solutes out of blood into tubular fluid

    • formation of urine

• made of renal corpuscle, proximal convoluted tubule, nephron loop, distal convoluted tubule

cortical vs. juxtamedullary nephrons

cortical: 85% of all nephrons

• the bulk of nephron structures lie in kidney cortex and small component enters medulla

juxtamedullary: renal corpuscle lies near corticomedullary junction and nephron loops extend into medulla

renal corpuscle

• contains glomerulus: thick tangle of fenestrated capillaries

  • glomerular capsule is epithelial covering of glomerulus

    • visceral layer made of podocytes

      • have long pedicel processes that are separated by filtration slits

        • slits and capillary wall make up filtration membrane that leaks plasma content into capsule

    • parietal layer made of simple squamous epithelium

• corpuscle has vascular pole (afferent arteriole enters and efferent exits) and tubular pole (proximal convoluted tubule exits)

proximal and distal convoluted tubules

proximal: walls made of simple cuboidal epithelium w/tall microvilli

• cells reabsorb almost all nutrients leaked through filtration membrane

• reabsorbed nutrients/water enter peritubular capillaries and returned to general circulation

distal: found in renal cortex, secretes K+ and H+ from peritubular capillaries into tubular fluid

juxtaglomerular apparatus

• important in regulation of BP

• made of juxtaglomerular cells: dense smooth muscle of afferent arteriole at vascular pole

• made of macula densa: epithelial cells that detect ion concentration in blood

  • stimulate juxtaglomerular cells to secrete renin to regulate BP

ureter

• fibromuscular tubes that move urine from kidney to bladder

• 3 layers

  • mucosa: inner layer w/transitional epithelium

  • muscularis: middle layer that makes peristaltic wavers to move urine

  • adventitia: outer layer, areolar CT

urinary bladder

• reservoir for urine

• walls:

  • mucosa: transitional epithelium that lines internal surface of bladder

    • rugae allow distension of bladder

  • submucosa: supports urinary bladder wall

  • muscularis: 3 layers of smooth muscle called detrusor muscle

    • has internal urethral sphincter muscle at opening

  • adventitia: outer layer of areolar CT

urethra

• fibromuscular space that originates at neck of bladder and conducts urine to exterior of body

• 2 sphincters control release of urine from bladder

  • internal: smooth muscle

  • external: skeletal muscle

• female: single function to transport urine to outside of body

• male: transports both urine and semen

  • prostatic urethra, membranous urethra, spongy urethra

gonads and gametes

gonads: primary sex organs → ovaries and testes

gametes: sex cells produced by gonads → oocytes and sperm

reproductive system homologues

• ovaries/testes: produce gametes and sex hormones

• clitoris/glans penis: ANS axons stimulate feelings of arousal and climax

• labia majora/scrotum: protect and cover reproductive structures

• vestibular/bulbourethral glands: secrete mucin for lubrication

ovaries

• paired, oval organs

• germinal epithelium: simple cuboidal superficial capsule

• tunica albuginea: deep CT capsule

• cortex and inner medulla:

  • cortex = ovarian follicles (1000s)

  • medulla = CT, blood vessels, lymph vessels, nerves