Urinary System Chp. 25 (Test 4)

Question 1

What are the functions of the urinary system?

Answer 1

regulation of extracellular fluid environment in body. eliminating waste –> urine.
returning useful substances back to blood.
regulating blood volume and blood pressure.
make an secrete renin - controls blood pressure.

Question 2

What are the two types of nephrons?

Answer 2

cortical nephron and juxtamedullary nephron.

Question 3

What are the processes used by the kidneys in making urine?

Answer 3

glomerular filtration, tubular reabsorption, tubular secretion, and water conservation.

Question 4

What occurs in the process of glomerular filtration?

Answer 4

takes place in the renal corpuscle and produces a cell and protein free filtrate. a passive process.

Question 5

What occurs in the process of tubular reabsorption?

Answer 5

process of selectively moving substances from the filtrate back into the blood. almost everything filtered is reclaimed. glucose, amino acids, and 99% of water and salt.

Question 6

What occurs in the process of tubular secretion?

Answer 6

process of selectively moving substances from the blood into the filtrate.

Question 7

What occurs in water conservation?

Answer 7

water is returned to the blood.

Question 8

How does fluid pass the barriers that constitute the filtration membrane?

Answer 8

1. glomerular capillaries- are fenestrated. so they have pores and are “leaky”
2. basement membrane- physical barrier. blocks proteins.
3. filtration slits on foot processes of podocytes- slits are physical barriers that keep out proteins.

Question 9

What is glomerular filtration rate?

Answer 9

the volume of filtrate produced by both kidneys in a minute. the average GFR is 125 mL/min

Question 10

What are the interacting control mechanisms of the GFR?

Answer 10

renal autoregulation, sympathetic control, hormonal control.

Question 11

What is renal autoregulation of GFR?

Answer 11

ability of a nephron to regulate blood pressure to keep GFR steady.

• myogenic mechanism: smooth muscle in afferent arteriole constrict or dilate to maintain normal blood flow in the glomerulus.
• tubularglomerular feedback mechanism: juxtaglomerular complex controls, monitors, and influences GFR.

Question 12

What is sympathetic control of GFR?

Answer 12

also known as neural control. causes vasoconstriction. all arteries in kidney. reduction in GFR. decrease in filtrate production, decrease in urine production. increases blood volume, increases blood pressure. wins over renal autoregulation.

Question 13

What is hormonal control of GFR?

Answer 13

if drop in blood pressure, juxtaglomerular complex cells release renin. which makes angiotensin II, which causes whole body vasoconstriction. afferent and efferent arterioles vasoconstrict, which decreases GFR. increases blood pressure.
aldosterone causes sodium reabsorption. h2o follows sodium. increases of blood volume, increase in blood pressure.

Question 14

What process occurs in the proximal convoluted tubule?

Answer 14

65% of filtrate is reabsorbed. reabsorption of Na, H2O Cl, HCO3, and amino acids. reabsorption is not subject to hormonal control. there is a limit to the amount of solutes reabsorbed in the PCT.

Question 15

What is transport maximum?

Answer 15

maximum amount of transport proteins to reabsorb solutes.

Question 16

What process occurs in the nephron loop (loop of henle)?

Answer 16

generates a salt gradient. enables collecting duct to concentrate urine and conserve water. H2O is reabsorbed from the descending limb via osmosis. the ascending limb is impermeable to H2O. Na, Cl, and K are reabsorbed via secondary active transport.

Question 17

What process occurs in the distal convoluted tubule?

Answer 17

~25% of filtrate is still there. it is subject to hormonal control. Na and Cl are reabsorbed via primary active Na transport. Ca is reabsorbed by passive uptake via Parathyroid Hormone

Question 18

What are the hormones that effect the distal convoluted tubule?

Answer 18

aldosterone, antidiuretic hormone, atrial natriuretic peptide hormone, and parathyroid hormone.

Question 19

What is the action of aldosterone?

Answer 19

causes more reabsorption of Na, Cl, and H2O.

secretes K, lowers urine volume, lowers sodium levels in urine.

Question 20

What is the action of antidiuretic hormone?

Answer 20

DCT and collecting duct. makes them more permeable to H2O. increases H2O reabsorption. urine volume drops.

Question 21

What is the action of atrial natriuretic peptide hormone?

Answer 21

excretes Na and H2O in urine. blood volume decreases, blood pressure decreases. inhibits Na reabsorption.

Question 22

What is the action of parathyroid hormone?

Answer 22

promotes Ca reabsorption.

Question 23

What is countercurrent multiplier?

Answer 23

interaction between the flow of filtrate through the ascending and descending limb of nephron loop

Question 24

What is countercurrent exchange system?

Answer 24

flow of blood through ascending and descending limb of vasa recta.
vasa recta traps salt within interstitial fluid but transports H2O out of renal medulla.

Question 25

What is renal function?

Answer 25

is a clinical evaluation of kidney function. it’s an indication of state of the kidney and it’s role in GFR.

Question 26

Where is the internal urethral sphincter found?

Answer 26

smooth muscle. at the base of urinary bladder.

Question 27

Where is the external urethral sphincter found?

Answer 27

skeletal muscle. near the urogenital diaphragm.

Question 28

What is micturition?

Answer 28

urination

Question 29

What is the events of micturition?

Answer 29

1. bladder filling- reflex to spinal cord
2. motor response- detrusor muscle starts to contract.
3. relaxation of internal urethral sphincter
4. sensory signal- pons. pontine micturition center. cerebrum-is it appropriate?
   a. if appropriate- both sphincters relax. empty bladder.
   b. if not appropriate- pons inhibits relaxation of sphincters. holding your bladder

Question 30

What is the micturition reflex?

Answer 30

a series of contractions of the urinary bladder in response to increased pressure in the bladder

Question 31

What are the three ways that the body regulates acid/base balance?

Answer 31

buffer systems, respiratory control, and renal control.

Question 32

What is an acid?

Answer 32

any chemical that releases H+ ions

Question 33

What is a base?

Answer 33

any chemical that accepts H+ ions

Question 34

What is a buffer?

Answer 34

anything that resist change in pH

Question 35

What are the main buffer systems?

Answer 35

1. bicarbonate buffer system
   CO2+ H20 –> H2CO3 –> H+ + HCO3
   CO2 + H20 HPO4- + H+
   H2PO4

Question 36

What is the respiratory control of pH?

Answer 36

breathing. changing CO2 levels. 1-5 minutes.

Question 37

What is the renal control of pH?

Answer 37

ridding the body of hydrogen ions in urine. hours to days.

Question 38

What is acidosis?

Answer 38

too much H+. ECF pH falls below 7.35

Question 39

What is alkalosis?

Answer 39

too little H+. ECF pH rises above 7.45

Question 40

What is the cause of kidney stones?

Answer 40

hypercalcemia, dehydration, pH imbalances, kidney infections, or enlarged prostates.

Question 41

What is the treatment for kidney stones?

Answer 41

pain meds, lots of water, stone dissolving meds. in worse cases lithotripsy - breaking up of stones, or surgery. drinking cranberry juice is a preventative.

Question 42

What is renal insufficiency?

Answer 42

inability to filter blood properly, amount of filtrate produced is lowered greatly. leads to kidney failure. caused by chronic kidney infections, trauma, or heavy metal poisoning. symptoms are abnormal urine, blood in urine, and fatigue.

Question 43

What is hemodialysis?

Answer 43

artificial means of removing waste products from blood, due to the kidneys inability to do so.