HCP 10

Question 1

functions of the kidney

Answer 1

water and electrolyte balance, excretion of toxic metabolic waste products, maintenance of acid base balance, hormonal and metabolic functions

Question 2

hormonal and metabolic functions of kidney

Answer 2

renin regulate BP, erythropoietin to stimulate RBC production in bone marrow, converting vitamin D to active form

Question 3

blood flow from right coronary artery to kidney to inferior vena cava

Answer 3

right coronary artery -> posterior interventricular artery -> middle cardiac vein -> coronary sinus -> right atrium -> right ventricle -> pulmonary trunk -> pulmonary artery -> pulmonary capillaries -> pulmonary veins -> left atrium -> left ventricle -> aorta -> abdominal aorta -> left or right renal artery -> 5 segmental arteries -> interlobar arteries -> arcuate arteries -> interlobular (cortical radiate) arteries -> afferent arteriole -> glomerular capillaries -> efferent arteriole -> peritubular capillaries or vasa recta -> interlobular (cortical radiate) veins -> arcuate veins -> interlobar veins -> renal veins -> inferior vena cava

Question 4

blood flow from left coronary artery-circumflex to kidney to inferior vena cava

Answer 4

left coronary artery -> circumflex branch of the left coronary artery -> posterior vein of the left ventricle -> coronary sinus -> right atrium -> right ventricle -> pulmonary trunk -> pulmonary artery -> pulmonary capillaries -> pulmonary veins -> left atrium -> left ventricle -> aorta -> abdominal aorta -> left or right renal artery -> segmental arteries -> interlobar arteries -> arcuate arteries -> interlobular (cortical radiate) arteries -> afferent arteriole -> glomerular capillaries -> efferent arteriole -> peritubular capillaries or vasa recta -> interlobular (cortical radiate) veins -> arcuate veins -> interlobar veins -> inferior vena cava

Question 5

blood flow from left coronary artery-left anterior descending to kidney to inferior vena cava

Answer 5

left coronary artery -> left anterior descending artery -> great cardiac vein -> coronary sinus -> right atrium -> right ventricle -> pulmonary trunk -> pulmonary artery -> pulmonary capillaries -> pulmonary veins -> left atrium -> left ventricle -> aorta -> abdominal aorta -> left or right renal artery -> segmental arteries -> interlobar arteries -> arcuate arteries -> interlobular (cortical radiate) arteries -> afferent arteriole -> glomerular capillaries -> efferent arteriole -> peritubular capillaries or vasa recta -> interlobular (cortical radiate) veins -> arcuate veins -> interlobar veins -> renal veins -> inferior vena cava

Question 6

where is the kidney located

Answer 6

retroperitoneal

Question 7

how many segmental arteries are there

Answer 7

5, superior, inferior anterior (superior and inferior), posterior

Question 8

terminal end of medulla

Answer 8

renal papilla

Question 9

medulla contains

Answer 9

loop of hence and collecting duct

Question 10

cortex contains

Answer 10

glomerulus, PCT, DCT

Question 11

cortex is located

Answer 11

outer portion of kidney and in renal columns between medullary pyramids

Question 12

renal corpuscle consists of

Answer 12

bowman’s capsule and glomerulus

Question 13

development of renal corpuscle

Answer 13

tubules develop as blind-ended tubes consisting of simple cuboidal epithelium -> ends of tubules dilate and are invaginated by primitive glomerulus -> visceral layer differentiates into podocytes -> basement membrane of endothelial cells and podocytes fuse ->small amount of connective tissue remains to support capillaries (mesangium)

Question 14

glomerular filtration barrier made up of

Answer 14

interdigitated secondary process of podocytes (pedicles), basement membrane, fenestrated capillaries

Question 15

filtration slits

Answer 15

secondary processes of two podocytes interdigitated, 4-6nm

Question 16

2 types of nephrons

Answer 16

short-looped cortical nephrons (majority), long-looped juxtamedullary nephrons

Question 17

PCT histology

Answer 17

cuboidal to low-columnar epithelium, abundant microvilli

Question 18

loop of henle histology

Answer 18

thick/thin descending, thick/thin ascending, Thick limbs cuboidal epithelium, thin limbs simple squamous epithelium, no brush border

Question 19

DCT histology

Answer 19

simple cuboidal, few microvilli (no brush border)

Question 20

CD histology

Answer 20

cuboidal to columnar cells

Question 21

PCT reabsorbes

Answer 21

100% of a.a. and glucose, longest most convoluted tubule

Question 22

collecting tubules to minor calyx

Answer 22

DCT -> collecting tubules -> several CT’s -> collecting duct -> descends through cortex in medullary rays -> merge to form large ducts of bellini -> open at tips of renal papillae -> minor calices

Question 23

PCT function

Answer 23

located entirely in the cortex reabsorb majority of water,

Question 24

map out renal handling of calcium

Answer 24

67% PCT, 25% TAL, 8% DCT, excretion <1%

Question 25

map out renal handling of sodium

Answer 25

67% PCT, 25% TAL, 5% DCT, 3% CD, excretion <1%

Question 26

map out renal handling of potassium

Answer 26

67% PCT, 20% TAL, reabsorbed in DCT if low K+ diet

Question 27

explain what happens at the macula densa and JG apparatus

Answer 27

senses sodium

Question 28

map out renal handling of phosphate

Answer 28

70% PCT, 15% thick descending limb, 15% excreted

Question 29

explain countercurrent exchange

Answer 29

NaCl is reabsorbed from the thick ascending limb by the Na+ K+ 2Cl- cotransport it creates a gradient in the interstitium (maximum 200 mOsm/L at a time because paracellular diffusion of ions back into eventually counterbalances transport of ions out of lumen when 200mOsm/L concentration gradient is achieved) -> Urine in the descending limb now equilibrate osmotically with the interstitium and water leaves -> Flow of urine now moves hyperosmotic urine into the ascending limb and the NaCl transport creates another gradient -> The loop configuration creates a counter-current multiplier for the effect of the Na+ pump to create the cortico-medullary gradient (300-1200 mOsm/Kg)

Question 30

what is the function of the vasa recta

Answer 30

supply oxygen and nutrient to the medulla and papilla while maintaining the corticopapillary concentration gradient As the blood descends through the descending limb of vasa recta, water diffuses out and NaCl diffuses in to equilibrate with the increasing osmolarity of medullary interstitial fluid (ISF) from top to bottom established by countercurrent multiplier -> As the blood ascends through the ascending limb of vasa recta, NaCl diffuses out to equilibrate with the decreasing osmolarity of medullary interstitial fluid (ISF) from bottom to top -> Blood entering the descending limb of vasa recta is ~ 300mOsm/L and Blood leaving the ascending limb of vasa recta is ~ 325mOsm/L. Only slight increase in the solute content of the blood going out of the medulla shows that the medullary concentration gradient is maintained as most of the solute is left in the interstitial -> The process continues and the equilibrium is never reached.

Question 31

what is urea, and does it have a function

Answer 31

urea is produced in the urea cycle to excrete nitrogenous waste via urinary excretion. Urea is also used in the counter current multiplier system in response to ADH to increase urea reabsorption -> medullary osmolarity -> further water reabsorption