PNB 2775 Exam 4

metabolic end products, drugs, other exogenous compounds

the kidney excretes…

xenobiotics

chemical compounds found in the body that are not made in the body

various essential elements/ions, osmolarity, pH, arterial blood pressure

the kidney regulates…

renin, erythropoietin, Vitamin D activator

the kidney secretes…

cortex

outer area of the kidney

cortical region

outer region of cortex

juxtamedullary region

inner region of cortex

medulla

inner area of the kidney

renal pyramids

subdivisions of renal medulla

calyces

regions of kidney in which urine passes through

renal papillae

the tips of the renal pyramids

nephron

functional unit of kidney

cortical nephron

make up 85% of nephrons, involved in reabsorption, contains peritubular capillaries and short loops of Henle

peritubular capillaries

small blood vessels that provide kidneys with blood

loops of Henle

creates concentration gradient of kidney

vasa recta

only located in juxtamedullary nephron, blood supply that accompanies long loops of Henle

juxtamedullary nephron

makes up 15% of nephrons, concentrates urine, contains vasa recta and peritubular capillaries, has a characteristically long loop of Henle

corpuscle and renal tubule

nephron components

bowmans corpuscle to proximal convoluted tubule to loop of Henle to distal convoluted tubule to collecting duct

order of nephron components

filtration

occurs only at Bowman’s capsule, involves movement form blood to lumen

reabsorption

involves lumen to blood movement

secretion

involves blood to lumen movement outside of Bowman’s capsule

glomerular filtration rate (GFR)

amount of plasma filtered from glomeruli into Bowman’s space per unit time, entire plasma is filtered roughly 60x a day

renal corpuscle

glomerulus+Bowman’s capsule

glomerulus

capillary network, has afferent arteriole and efferent arteriole

Bowman’s capsule

beginning of tubule, parietal and visceral epithelium, where filtration occurs

podocytes

another name for the visceral epithelium of Bowman’s capsule

filtration barrier elements

fenestrated capillary epithelium, basement membrane (basal lamina), pores formed by podocytes

glomerular capillary hydrostatic pressure (Ph)

usually 55mmHg, primary mechanism for GFR regulation, the only force that increases filtration

Bowman’s hydrostatic pressure

pressure pushing out of Bowman’s corpuscle, roughly 15mmHg, opposes filtration

colloid osmotic pressure

pressure created that opposes filtration, pushes fluid towards solute that was left behind at filtration point

myogenic response

method of GFR regulation in which afferent and efferent arterioles are constricted to increase or decrease GFR

tubuloglomerular feedback

paracrine control of GFR, the more NaCl sensed by macula densa, the more the afferent arteriole is constricted

juxtaglomerular apparatus

contains macula densa cells, granular cells (juxtaglomerular cells), and mesangial cells

macula dense cells

osmoreceptors (modified epithelial cells) in distal tubule

granular cells

a.k.a. juxtaglomerular cells, modified smooth muscle of afferent arteriole, secrete renin

mesangial cells

contractile, regulate glomerular filtration

Renin-angiotensin system

renin released when blood pressure drops, sympathetic innervation, and osmolarity of tubular fluid is too low

angiotensin II

restores BP by vasoconstriction of arterioles, aldosterone secretion, and thirst+ADH release from the CNS

atrial natriuretic peptide (ANP)

dilates afferent arteriole, increases glomerular filtration rate, inhibits renin secretion