Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOL 1191 > Ch. 26 - Urinary System > Flashcards

Ch. 26 - Urinary System Flashcards

1
Q

What are some functions of the kidneys?

A
  • regulate blood ionic composition (Na+, K+ Ca2+, Cl-)
  • regulate blood pH, blood volume, BP, blood glucose level
  • maintain blood osmolarity
  • produce hormones
  • excrete wastes and foreign substances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a hilum?

A

region through which ureter leaves

- where BV, lymphatic vessels and nerves enter/exit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 layers surrounding each kidney?

A

renal capsule, adipose capsule, renal fascia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the difference between the renal capsule and renal fascia layers?

A

capsule - transparent membrane that is continuous with ureter; barrier for protection and maintains organ shape

fascia - dense irregular CT that holds kidney against back body wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are minor and major calyces?

A

minor - cuplike structures that collect urine from papillary ducts of papilla

both - empty into renal pelvis which empties into ureter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 capillary beds of kidneys?

A
  1. glomerular capillaries (where blood is filtered)
  2. peritubular capillaries in cortex
  3. vasa recta in medulla
    * both 2&3 carry away reabsorbed substances from filtrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 3 functions of a nephron?

A

filtration, reabsorption, secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 2 major parts of a nephron?

A

renal corpuscle - filters blood

renal tubule - where filtered fluid passes through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are parts of the renal corpuscle and what is its function?

A

glomerulus and Bowman’s capsule

- site of plasma filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the parts of the renal tubule and what is its function?

A
  1. PCT,
  2. loop of Henle (dips into medulla, descending/ascending limbs)
  3. DCT
  4. collecting ducts (where it empties; converge to form papillary ducts to drain urine to renal pelvis and ureter)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 2 types of nephrons?

A

cortical and juxtamedullary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do cortical and juxtamedullary nephrons differ?

A

cortical - short nephron loop, receives blood from peritubular capillaries, creates urine with similar osmolarity to blood

juxtamedullary - long nephron loop, receives blood from peritubular cap & vasa recta, thick/thin ascending limbs, secrete concentrated urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What do efferent arterioles around the nephron give rise to?

A

peritubular cap & vasa recta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the glomerular capsule comprise of?

A
  • visceral layer: consists of podocytes (modified simple sq cells)
  • parietal layer: consist of simple sq e that forms outer wall of capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the JG apparatus?

A

macula densa + JG cells that regulate BP in kidney (with ANS)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the macula densa? JGC?

A

macula densa - where ascending loop contacts the afferent arteriole

JGC - smooth musc cells on wall of afferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the 3 basic processes of nephrons/collecting ducts?

A
  1. glomerular filtration - portion blood plasma filters into kidney
  2. tubular reabsorption - water & substances are reabsorbed into blood
  3. tubular secretion - wastes are removed from blood and secreted in urine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the rate of excretion?

A

filtration + secretion - reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is glomerular filtrate?

A

fluid that enters the capsular space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the filtration fraction?

A

fraction of plasma in kidney’s aff arteriole that becomes filtrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the 3 barriers filtered substances must cross?

A
  • glomerular endothelial cells
  • basal lamina
  • filtration slit formed by podocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are mesangial cells?

A

contractile cells that increase glomerular filtration when relaxed
- located bt aff and eff arterioles, among glomerular cap

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the purpose of the basal lamina? What is it composed of?

A

prevents filtration of larger proteins; collagen fibers and proteoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the slit membrane? Filtration slits?

A

thin membrane that extends across filtration slit; permits passage of molec that have a smaller diameter; spaces between pedicels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 3 pressures that compose net filtration pressure (NFP) ?

A
  1. glomerular BHP (GBHP)
  2. capsular hydrostatic pressure CHP)
  3. blood colloid osmotic pressure (BCOP)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is GBHP?

A

BP in glomerular capillaries; promotes filtration by pushing water and solutes out of cap through filtration membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is CHP?

A

hydrostatic pressure exerted against filtration membrane by fluid already in capsular space of glomerular capsule; opposes filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is BCOP?

A

pressure due to presence of proteins in blood plasma; opposes filtration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the equation of NFP?

A

NFP = GBHP - CHP - BCOP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is GFR?

A

glomerular filtration rate; amount of filtrate formed in all renal corpuscles of both kidneys each minute

31
Q

What are 2 mechanisms that regulate GFR?

A
  1. change rate of blood flow into or out of glomerulus (GFR increases when blood flow increases)
  2. change amount of SA avail for filtration
32
Q

What are 3 ways that control blood flow through glomeruli?

A
  1. renal autoregulation by kidneys (myogenic mech, tubuloglomerular feedback)
  2. hormonal regulation
  3. neural regulation by sym NS
33
Q

What is myogenic mechanism?

A

response to stretching of walls of aff arteriole due to increase in BP
- sm muscle contacts, decreasing GFR

34
Q

What are 2 hormones that contribute to GFR regulation?

A

angiotensin II, atrial natriuretic peptide

35
Q

How does angiontensin II contribute to GFR?

A

decreases GFR; strong vasoconstrictor reducing blood flow

36
Q

How does ANP contribute to GFR?

A

increases GFR; increase in blood vol stretches atria, stimulating ANP release

37
Q

How does ANP contribute to GFR?

A

increases GFR; increase in blood vol stretches atria, stimulating ANP release

38
Q

How does neural regulation control GFR?

A

BV of kidneys supplied by sym ANS release NE; causing vasoconstriction of sm muscle in aff arterioles

  • requires strong sym stimulation such as exercise or hemorrhage
39
Q

What is reabsorption?

A

returning most of filtered water and solutes back to bloodstream

40
Q

In what part of the nephron does reabsorption occur the most?

A

epithelial cells with microvilli in PCT

41
Q

How is water reabsorbed? Solutes?

A

osmosis; active/passive processes; proteins/peptides reabsorbed via pinocytosis

42
Q

What are the 2 reabsorption routes from fluid in tubular lumen to a peritubular capillary?

A
  1. paracellular reabsorption - reabsorbed mat moves bt cells via diffusion
  2. transcellular reabsorption - material moves through both apical and basal membranes of tubule cell via active or passive transport
43
Q

Where does the apical membrane face? Basolateral?

A

tubular lumen; IS fluid

44
Q

How is Na+ reabsorbed via primary active transport?

A
  • Na+ diffuses into tubule cell
  • Na+/K+ pumps in (only) basolateral membrane; pump Na+ from tubule cell cytosol to IS fluid, where it diffuses into peritubular capillary (Na+ is one way process!!!)
45
Q

How are solutes reabsorbed via secondary active transport?

A
  • relies on ion gradient created by Na+/K+ pumps

- Na+ drags another solute molec as it moves down conc gradient into tubular cell via symporters or antiporters

46
Q

What are symporters?

A

2 or more solutes go in same direction

47
Q

What are antiporters?

A

2 or more solutes go in opposite directions

48
Q

What are the 2 patterns of H2O reabsorption?

A

1) obligatory 2) facultative

49
Q

What is obligatory water reabsorption?

A

when water is obliged to follow solutes being reabsorbed

  • occurs in PCT and descending limb of nephron loop bc both are permeable to water
50
Q

What is facultative water reabsorption?

A

capable of adapting to need

  • occurs in collecting duct under control of ADH
51
Q

What is tubular secretion?

A

transfer of materials from blood and tubular cells into tubular fluid; eventually becomes urine

  • controls blood pH via H+ secretion; eliminate certain substances (H+, NH4+, K+)
52
Q

Where does most water and solute reabsorption occur?

A

PCT

53
Q

What is the difference of Na+ symporters and antiporters?

A

S - help reabsorb substances from tubular filtrate (glucose, aa, SO4)

A - reabsorb Na+ and secrete H+ for elimination through urine (HCO3)

54
Q

How do reabsorbed solutes increase osmolarity?

A
  • in tubule cell, then IS fluid, then in blood

- reabsorption of solutes create osmotic gradient that promotes reabsorption of water via osmosis in PCT

55
Q

Which limbs in the nephron loop are (im)permeable to water? Solutes?

A

thin - permeable to H2O, impermeable to solutes

thick - impermeable to H2O, permeable to solutes
- pumps Na+ and Cl- from tubular fluid to IS fluid

56
Q

What is countercurrent multiplication?

A

osmotic gradient generated in IS fluid via movement of Na+, Cl-, H2O in nephron loop

  • essential for concentrated urine production when ADH is present!
57
Q

How is PTH activity related to the DCT?

A

DCT is the major site where PTH stimulates Ca2+ reabsorption

58
Q

What are the 2 types of cells in the collecting duct and what do they do?

A
  1. principal cells - reabsorb Na+ and secrete K+ under control of aldosterone; increase H2O movement if ADH is present
  2. intercalated cells - reabsorb K+ and HCO3-, secrete H+
59
Q

What are the 4 hormones that affect reabsorption (of Na+, Cl-, H2O) and secretion (of K+) ?

A

angiotensin II, aldosterone, ADH, ANP

60
Q

How does angiotensin II affect reabsorption/secretion?

A
  1. decreases GFR by causing vasoconstriction of aff arteriole
  2. enhances reabsorption of Na+, Cl-, H2O in PCT by stimulating Na+/H+ antiporter activity (BP, blood vol increase!)
  3. stimulates aldosterone release from adrenal cortex (Na+ reabsorption, K+ secretion)
61
Q

How does aldosterone affect reabsorption/secretion?

A

regulates electrolyte reabsorption and secretion

62
Q

How does ADH affect absorption/secretion?

A
  • increases water permeability of principal cells in last part of DCT and collecting duct (stimulates insertion of aquaporin-2 into membrane)
  • increases facultative water reabsorption
63
Q

How does ANP affect absorption/secretion?

A

ANP is released in response to large increase in blood vol stretching atrial cells

  • inhibits Na+ and H2O reabsorption in PCT and collecting duct
  • suppresses secretion of aldosterone and ADH
  • natriuresis + diuresis leads to decreased blood vol/BP
64
Q

How does ADH control whether dilute or concentrated urine is formed?

A

low ADH - dilute urine

high ADH - concentrated urine bc more water reabsorbed

65
Q

Describe negative feedback control of ADH

A
  1. osmoreceptors in hypothalamus detect increase in plasma osmolarity
  2. stimulate ADH release
  3. principal cells more permeable and reabsorb more water
  4. plasma osmolarity decreases
66
Q

What is urinalysis?

A

measuring vol and physical/chem/microscopic characteristics of urine

67
Q

What are 2 blood tests used to evaluate kidney function?

A

1) blood urea nitrogen (BUN) test 2) plasma creatine

68
Q

What is renal plasma clearance?

A

measure how fast a particular substance is removed from blood plasma by kidneys

69
Q

How are kidneys capable of compensation in the event of dysfunction?

A
  • individual nephrons can increase in size/workload (i.e. increase filtration/urine production)
  • removal of one kidney causes enlargement of remaining kidney
70
Q

What is the trigone?

A

smooth flat triangular area in floor of bladder

  • 2 ureteral openings in posterior corners
  • internal urethral orifice in anterior corner
71
Q

Where is the urethra located in females?

A

post to pubic symphysis, orifice between clitoris and vagina

72
Q

Where is the urethra located in males?

A

passes through prostate and penis

- 3 regions: prostatic, intermediate, spongy

73
Q

Describe the urination reflex

A
  1. stretch receptors signal SC and brain when volume exceeds ~200-400 mL
  2. impulses sent to urination center (in S2 and S3) to trigger reflex
  3. parasympathetic fibers cause detrusor muscle to contract, ext/int sphincter muscles to relax
  4. filling causes sensation of fullness that initiates desire to urinate before reflex occurs
    - conscious control of ext sphincter

BIOL 1191 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions