Excretory System

Question 1

kidney function

Answer 1

• regulates BP
• regulates pH
• synthesis RBC

Question 2

kidney structure

Answer 2

• cortex on outside
• medulla in the middle
• pelvis on inner (filtrate exits kidney)

Question 3

how is urine created and its path

Answer 3

• created in nephron
• enters renal pelvis > ureter > bladder > urethra

Question 4

main functions of nephron

Answer 4

filtration, reabsorption, secretion, and excretion

Question 5

where does filtration occur

Answer 5

in renal corpuscle

Question 6

what does filtration consist of

Answer 6

glomerulus and Bowmann’s capsule

Question 7

filtration

Answer 7

• blood enters afferent arteriole and is filtered through glomerulus as a seive
• hydrostatic pressure forces plasma through the sieve
• Bowman’s capsule podocytes surround glomerulus to form fenestrations
• small substances (water and solutes) filter into Bowman’s capsule
• larger substance (proteins and RBC) remain in blood
• blood leaves via efferent arteriole –> peritubuluar capillaries

Question 8

filtration membrane

Answer 8

• endothelial fenestration pore: prevents filtration of blood cells but allows all components of blood plasma to pass through
• basal lamina: prevents filtration of collagen, glycoproteins
• silt membrane: prevents filtration of medium-sized proteins

Question 9

reabsorption

Answer 9

useful materials (water and solutes) are reabsorbed

Question 10

where does reabsorption occur

Answer 10

occurs in proximal convoluted tubule via active transport

Question 11

distal convoluted tubule

Answer 11

reabsorption absorbs Na+ and Cl-

Question 12

what is almost completely reabsorbed?

Answer 12

glucose and aa because they are important in the body

Question 13

secretion

Answer 13

urea, waste, drugs, are secreted into nephron by active and passive transport

Question 14

Loop of Henle

Answer 14

concentrates urine only by allowing water to exit on the way down and salts to exit on the way up

Question 15

what surrounds the loop of henle

Answer 15

vasa recta (capillaries)

Question 16

where is water reabsorbed

Answer 16

down the descending limb (filtrate becomes more concentrated)

Question 17

ascending limb

Answer 17

• impermeable to water
• solutes reabsorbed as it travels up ascending limb
• filtrate becomes less concentrated

Question 18

longer loop =

Answer 18

MORE concentrated urine

Question 19

what secretion occurs at distal tubule

Answer 19

K+/H+/HCO3-

Question 20

excretion

Answer 20

• loop of henle –> DCT
• DCT: Na+ and Cl- rebabsorbed and water follows
• DCT –> collecting ducts; water moves passively out and concentrates urine

Question 21

excretion pathway

Answer 21

collecting ducts –> renal pelvis –> ureter –> bladder (stores urine)
* singal sent to excrete urine –> urine leaves via urethra

Question 22

juxtaglomerular apparatus

Answer 22

detects changes in blood pressue and blood volume
* LOW BP = secretes renin
* sympathetics = increase renin

Question 23

renin

Answer 23

draw out diagram and insert pic!!

Question 24

angiotensin II effects

Answer 24

• increase aldosterone release
• increase Na+ reabsorption from PCT
• vasoconstriction = increase TPR
• increase thirst so increase in blood volume

Question 25

ADH/vasopressin

Answer 25

• release from posterior pitutary upon stimulation from hypothalamus
• causes aquaporins to insert into the collecting duct of nephron (increase water reabsorption)
• alcohol inibits ADH = urinate more

Question 26

aldosterone

Answer 26

• produced from adrenal cortex
• increase salt and water reabsorption
• K+ secretion in distal tubules and collecting ducts

Question 27

atrial natriuretic peptide (ANP)

Answer 27

• produced by atrial cells in rsponse to atrial distension by increase BP and pressure
• increase GFR –> decrease Na+ reabosrption and increase Na+ excretion
• inhibits renin and RAAS