Test 3

Urinary and Gastrointestinal Systems

ureter

long, thin, muscular tube that conveys urine from the kidneys to the urinary bladder

urinary bladder

located retroperitoneally on the pelvic floor posterior to pubic symphysis

transitional epithelium

dome shaped cells that can stretch and flatten, unique to bladder and ureter

external urethral sphincter

skeletal muscle surrounding urethra as it passes through the urogential diaphrragm

internal urethral sphincter

thickening of the detrusor muscle at the bladder-urethra junction

trigone

inferior bladder opening leading to urethra

rugae

thick and thrown folds present in collapsed bladder

detrusor

three layers of smooth muscle in anterior bladder that thickens inferiorly hilto form internal urethral sphincter

prostatic urethra

passes through the prostate gland

membranous urethra

“intermediate”; passes through urogential diaphragm

spongy urethra

“penile”; passes through the length of the penis

renal cortex

outermost region of kideny containing nephron

renal medulla

middle region of kidney conating “medullary” or renal pyramids

renal papillae

apexes of renal pyramids

lobe of kindey

renal pyramid and cortical tissue in contact with it’s base

renal columns

regions between pyramids composed of cortical tissue

core of kidney

renal pelvis and adipose tissue

renal pelvis

funnel shaped top of the ureter with branches and extensions of major and minor calyces

fibrous capsule

encloses kidney, in contact with the renal cortex

renal corpuscle

blood filtering component of nephron composed of glomerulus and glomerular capsule

glomerulus

tuft of capillaries in renal corpuscle

glomerular capsule

cup-shaped hollow sturucture surrounding glomerulus

proximal convoluted tubule

portion of nephron formed by simple cuboidal epithelium with microvilli facilitating rebsorption

loop of Henle

portion of nephron formed by simple squamous epithelium permeable to water essential in the formation of concentrated urine

acending limb of Henle

portion of nephron formed by cuboidal to low-columnar epithelium, impermeable to water, and containing NaCl pumps

distal convoluted tubule

portion of nephron formed by simple cuboidal epithelium leading to collecting duct

cortical nephrons

most numerous and reside mostly in the cortical region of kidney having shorter loops of Henele

juxtamedullary nephrons

lie close to border of cortex and medulla with longs loops of Henele deep in medullary region establishing medullary osmotic gradient

segmental arteries

“lobar” branches of renal artery in the renal pelvis

interlobar arteries

branches of lobar arteries between adjacent pyramids

arcuate arteries

branches of interlobar arteries which arch over the pyramids

efferent arteriole

carries blood away form glomerulus

afferent arteriole

carries blood into the glomerulus from cortical radiate arteries

cortical radiate arteries

branches of arcuate arteries extending into the cortex

peritubular capillaries

branching of efferent arteriole leading into cortical radiate vein surrounding the proximal and distal convoluted tubules of cortical nephrons

vasa recta

branching of efferent arteriole extending deep into the medulla important in forming concentrated urine

located between visceral parietal layers of glomerular where filtrate of renal corpuscle ends up

capsular space

juxtaglomerular apparatus (JGA)

monitering structure where afferent and efferent arterioles contact composed of macula densa and granular cells

mucula densa

formed by cells of distal convoluted tubule which monitor and respond to changes in the NaCl conc in that tubule

juxtaglomerular cells

specialized “granular cells” in the wall of the afferent arteriole that can sense blood pressure

glomerular hydrostatic pressure

chief force pushing water and solutes out of the blood across the filtration membrane

intracellular fluid (ICF)

all fluid within the body’s cells

extracellular fluid (ECF)

plasma and interstitial fluid

interstitial fluid (IF)

fluid surrounding cells not in blood

distribution of Na

most abundant negative ion found in blood and interstitial fluid

distribution of K

main positive ion found in intracellular fluid

distribution of Cl

negative ion found in blood and interstitial fluid

hydrostatic pressure

pressure of fluid through a system

osmotic pressure

measure of the tendency for a solvent to move into a more concentrated solution

dehydration

leads to cells being in hypertonic solution

overhydration

leads to cells being in hypotonic solution

renal fascia

outer dense fibrous connective tissue anchoring the kidney to surrouding structures

glomular filtration

passive process involving hydrostatic pressure forcing fluid and solutes thorugh a membrane in the renal corpuscle

tubular reabsorption

selective process of reclaiming substances from filtrate the body needs to keep; glucose, aminos, water, salt etc. all esle becomes urine

tubular secretion

selective process of mvoing substances from the blood into the filtrate in the renal tubule and collecting duct

podocytes

interdigitate the outer surface of glomular capillaries forming filtration slits and form visceral layer of filtration membrane with glomerulus

glomerular hydrostatic pressure (GHP)

chief outward force from water to blood which is extraordinarily high (55 mm Hg) compared to other capillary beds

capsular hydrostatic pressure (CsHP)

pressure exerted by filtrate already in the golmerular capsule

blood colloid osmotic pressure (BCOP)

pressure tending to draw water out of the filtrate into the plasma

net filtration pressure (NFP)

combination of GHP, CHP, and GCOP

glomerular filtration rate (GFR)

the amount of filtrate that is prodcued by both kidneys in one minute

capsular colloid osmotic pressure

pressure tending to draw water into the filtrate

intrinsic GFR controls

work to keep GFR constat via renal autoregulation within the kidney

extrinsic GFR controls

work to keep blood pressure constant via neural and hormonal mechanisms outside the kidney

myogenic mechanism

intrinsic response of smooth muscle within affferent arteriole

tubuloglomerular feedback

intrinisc response of JGA macula dense cells monitor NaCl, a high concentration suggests poor reabsorption, and affect afferent arteriole diameter accordingly

sympathetic mechanism

extrinsic response of sympathetic nervous system to extreme stress causing vasoconstriction of afferent arteriole

renin-angiotensin mechanism

extrinsic response related to low blood pressure causing granular cells to release renin then angiotensin II circulation in the blood causing vasoconstriction and aldosterone release

bicarbonate HCO3-

reabsorbed by proximal tubule to control pH homeostasis

thick ascending limb

composed of cuboidal epithelial cells impermebale to water and actively pump NaCl into interstitial fluid

thin descending limb

composed of simple squamous epithelium permeable to water making filtrate more concentrated

countercurrent exchanger

vasa recta which loses H2O to ascending limb and gains it form the descending limb

ADH

inserts aquaporins in the epithelium of collecting duct reclaiming water

aldosterone

promotes soidum ion reabsorption in exchange for pottasium ion secretion and thus water reabsorption and H+ secretions

tunics of GI organ

a layer of tissue that surrounds and protects organs

1. mucosa

2. submucosa

3. muscularis

4. serosa

mucosa

the innermost tunic composed of most epithelium layer, the lamina propria, and muscularis mucosae

submucosa

tunic composed of dense connective tissue containing blood vessels, submucosal plexus of enteric nervous system, lyphatic vessels, elastic fibers, and submusocal glands

muscularis externa

tunic composed of inner circular and outer longitudinal layers of smooth muscle sandwiching and controlled by the myenteric plexus all responsible for moving food through the GI tract

serosa

tunic composed of connnective tissue and mesothelium is the outermost layer and protects the GI tract from injury; sometimes absent, then adventitia

moist epithelium lining

layer composed of simple columnar epithelium with goblet cells and mucosal glands responsible for absorbing nutrients, protection, and secreting lubricant

lamina propria

middle layer composed of highly vascularized loose areolar connective tissue which recieve absorbed nutrients and contain protective lymphatic nodules

muscularis mucosae

deep layer composed of smooth muscle

adventitia

a connective tissue layer that blends in with the rest of the connective tissue of the body wall replacing serosa when organ is suspended in mesentery

greater omentum

fold of peritoneum which hangs from the greater curvature of the stomach and contains fat, blood vessels and lymphatics

parietal (oxyntic) cells

secrete hydrochloric acid and intrisic factor

chief (zymogenic) cells

produce pepsinogen, an inactive form of pepsin which is activated by the acidic environment made by oxyntic cells

entero-endocrine cells

produce a variety of hormones into the lamina propria

pilcae ciculares

folds of mucosa that increase surface area of small intestine and slow chyme

goblet cells

secrete mucous, on villi of small intestine

lacteals

lymphatic cessels located in intestinal villi able to accept large materials like fats into lymph and eventually bloodstream

teniae coli

longitudinal bands of smooth muscle seen on the outside of the large intestine the resting muscle tone which puckers the wall of the large intestine into pocketlike sacs called haustra 

hepatocytes

cells of liver which process nutrients and produce bile

hepatic portal vein/ portal vein

nutrient rich, oxygen poor blood to liver

hepatic vein

nutrient poor, oxygen poor away form liver

respiratory acidosis

accurs during periods of hypoventilation allowing CO2 to build up thus lowering pH through the creation of carbonic acid

gastric phase

the presense of food in the stomach inititates production of gastric secretions and increases motility of the stomach muscularis

intestinal phase

the presence of chyme in the small intestine initiates secretion of bicarbonate, digestive enzymes and bile

enkephalins

slow intestinal moltility, contract the gastrointestinal sphincters. and inhibit intestial secretions

gastrin

released by enteroendocrine cells in the mucosa of the stomach in response to the presence of food increasing hydrochloric acid release from the partietal cells of the gastric glands

CCK (cholecystokinin)

released into the duodenum when chyme is detected stimulating the gall bladder to release bile, exocrine gland cells in the pancreas release digestive enzymes, and relaxes hepatopancreatic sphincter to ensure everything reaches the duodenum