U R I N A R Y

Question 1

list pathway from collecting duct until leaving kidney

Answer 1

1. collecting duct
2. papillary duct
3. renal pyramid
4. minor calyx
5. major calyx
6. renal pelvis
7. ureter
8. urinary bladder
9. urethra

Question 2

structure and function of glomerulus

Answer 2

blood-filtering structure of the kidney, passive, glomerular mesengial cells

parietal & visceral layers

Question 3

glomerulus parietal layer

Answer 3

outer structural layer, simple squamous

Question 4

glomerulus visceral layer

Answer 4

podocytes (foot processes), capsular space; capillary endothelium, basement membrane, foot processes of glomerular capsule

Question 5

which structures bring blood to and from the glomerulus and why is this particular blood vessel type good for the job?

Answer 5

afferent and efferent arterioles

protect glomerulus from fluctuation in BP, reinforce glomerular BP, decrease hydrostatic pressure of peritubular capillaries, high resistance to blood flow

Question 6

describe the structure, location, and function of the macula densa

Answer 6

structure: tall, columnar, closely-packed cells
location: DCT
function: act as chemoreceptors that sense NaCl content of filtrate

Question 7

trace blood flow through kidney beginning at renal artery

Answer 7

(aorta)
1. renal artery
2. segmental artery
3. interlobar artery
4. arcuate artery
5. cortical radiate artery
6. afferent arteriole
7. glomerulus (capillaries)
8. efferent arteriole
9. peritubular capillaries or vasa recta
10. cortical radiate vein
11. arcuate vein
12. interlobar vein 
13. renal vein
(inferior vena cava)

Question 8

trace filtrate through nephron, starting with glomerular capsule

Answer 8

1. glomerular capsule
2. PCT
3. descending thin limb
4. thin ascending limb
5. thick ascending limb
6. DCT
7. CD
8. papillary duct
9. minor calyx
10. major calyx
11. renal pelvis

Question 9

hydrostatic pressure

Answer 9

push due to high BP

Question 10

osmotic pressure

Answer 10

pull due to presence of plasma proteins

Question 11

how does the kidney use renin to raise BP?

Answer 11

converted to angiotensin 2

1. constricts arteriolar smooth muscle, causing MAP to rise
2. stimulates the reabsorption of Na+
   - acts directly on renal tubules and triggers adrenal cortex to release aldosterone (target at principle cells to reabsorb Na+)
3. stimulates hypothalamus to release ADH and activates the thirst center
4. constricts efferent arterioles, decreasing peritubular capillary hydrostatic pressure and increasing fluid reabsorption

Question 12

what 2 parts of the nephron are responsible for concentrating urine and how is this accomplished?

Answer 12

1. collecting duct
2. DCT

presence or absence of ADH & aquaporins

Question 13

where to ADH and aldosterone act to affect urine concentration?

Answer 13

DCT & CD of kidney tubule cells (principle cells)

- facultative water reabsorption

Question 14

how does aldosterone affect urine concentration?

Answer 14

1. increases reabsorption of Na+

2. targets principle cells to insert Na+/K+ channels and pump (increases BP and decreases K+)

Question 15

how does ADH affect urine concentration?

Answer 15

cause principle cells to insert aquaporins for increased water reabsorption

Question 16

what substance is rarely found in filtrate in the renal tubules under normal conditions?

Answer 16

plasma proteins

Question 17

would plasma proteins affect glomerular hydrostatic pressure most or osmotic pressure most?

Answer 17

osmotic pressure

Question 18

ureter function

Answer 18

paired tubes that transport urine from the kidneys to the urinary bladder

Question 19

urinary bladder function

Answer 19

temporary storage for urine

Question 20

urethra function

Answer 20

tube that carries urine from urinary bladder to body exterior

Question 21

major functions of the kidneys

Answer 21

regulate body’s total water volume (ADH) & total concentration of solutes in that water ( Aldosterone)

1. regulate ion concentration in ECF
2. long term acid/base balance (lungs)
3. excrete metabolic wastes and foreign substances
4. produce erythropoietin and renin
5. convert vitamin D to its active form
6. carry out gluconeogenesis during prolonged fasting

Question 22

transport maximum (Tm)

Answer 22

for every reabsorbed substance, number carriers in renal tubules available for facilitated diffusion or cotransport mechanisms

• carriers saturated > excess excreted in urine (hyperglycemia)
  
  • glucose in urine: glycosuria
    excess glucose in urine holds water and more urine is excreted with glucose

Question 23

renal threshold

Answer 23

the concentration of a substance dissolved in the blood above which the kidneys begin to remove it into the urine

Question 24

GFR

Answer 24

vol of filtrate formed per minute by both kidneys
(normal: 120-125 ml/min)

GFR is directly proportional to:

1. NFP
2. total surface area available for filtration
3. filtration membrane permeability

High BP = high GFR

Question 25

what is the countercurrent multiplier and what is its function?

Answer 25

loop of Henle creates gradient 1. efficiently reabsorbs solutes and water before reaching the DCT & CD 2. establishes concentration gradient that permits passive reabsorption of water from CD

Question 26

differentiate active and passive transport and explain the advantage of active over passive in the loop of Henle

Answer 26

passive does not require energy; need active to transport Na+ across & out of thick segment of ascending limb of loop

Question 27

what makes up the trigone are and what is its significance?

Answer 27

triangular area outlined by openings of ureter and urethra clinically significant because infections tend to persist in this region

Question 28

what's involved in the micturition reflex that causes urination?

Answer 28

1. contraction of the detrusor muscle by the ANS 2. opening of the internal urethral sphincter by the ANS 3. opening of the external urethral sphincter by the SNS

Question 29

name and differentiate the 2 types of nephrons in the kidneys

Answer 29

cortical: (85%), short nephron loop, glomerulus further away from cortical-medullary junction, efferent arteriole supples peritubular capillaries juxtamedullary: long loops deep in medulla, ascending limb has thick and thin segments, important in production of concentrated urine, PCT/DCT/glomerulus in cortex, glomerulus closer to cortical-medullary junction, efferent arteriole supplies vasa recta

Question 30

vasa recta

Answer 30

bundles of "straight" vessels parallel to loop of Henle arise from efferent arterioles of juxtamedullary nephrons thin-walled work with loop to concentrate urine

Question 31

peritubular capillaries

Answer 31

low pressure porous for absorption arise from efferent arterioles of cortical nephrons cling to adjacent renal tubules in cortex empty into venues readily absorb solutes and water from tubule cells as they reclaim these from filtrate closely-packed

Question 32

what is osmosis, where does it occur in the nephron, and what is the benefit?

Answer 32

passive water reabsorption in the PCT aided by aquaporins movement of water concentrates and allows solutes to move down concentration gradients water moves from areas of low to high solute concentration

Question 33

list each part of the nephron tubule system and tell what major event happens at each

Answer 33

PCT: reabsorption (secretion) due to microvilli DCT: secretion CD: intercalated cells (with microvilli (acid/base balance) and principle cells (Na+/H2O balance)

Question 34

in which part of the nephron tubule do ADH and aldosterone exert their effects, and what are the benefits from these 3 hormones?

Answer 34

DCT & CD increased BP increased BV