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Renal Exam 1 > Review of Renal A&P > Flashcards

Flashcards in Review of Renal A&P Deck (62)
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1
Q

Functions of the kidney

A
  • Removal of metabolic waste products
  • Water/ electrolyte balance
  • Acid-base balance
  • Regulation of arterial BP
  • Secretion of hormones (erythropoietin, renin)
  • Gluconeogenesis
2
Q

Where are the kidneys in the body?

A

Lie on the posterior wall of the abdomen

3
Q

how much does each kidney weigh?

A

150 grams (size of a clenched fist)

4
Q

2 major regions of the kidney

A

• 2 major regions (KNOW THESE)
○ Renal cortex= outer
○ Renal medullary segment= inside

5
Q

renal pyramids

A

medulla further divided into cone-shaped masses of tissue where nephrons are packed in

6
Q

the renal artery branches into ___

A

interlobar arteries (Gives initial supply of oxygen to renal arteries)

7
Q

hilium

A

indented region on the kidney

where the renal artery and renal vein enter in

8
Q

renal blood supply

A

renal artery→ afferent arterioles→ glomerular capillaries→ distal end of glomerular capillaries then branches into efferent arterioles→ peritubular capillaries

9
Q

2 capillary beds in the kidney

A

glomerular and peritubular capillaries

10
Q

afferent arteriole

A

supplies glomerulus with blood

11
Q

efferent arteriole

A

where it terminates from the first capillary bed of the kidney (glomerular) (High pressure capillary bed (60 mm Hg))

12
Q

peritubular capillary bed

A

○ Next to the tubules

○ Low pressure compared to glomeruli (13 mm Hg)

13
Q

nephron

A

functional unit of the kidney (each kidney is made up of 1 million nephrons)

14
Q

renal corpuscle

A

consists of glomerular capillaries and Bowman’s capsule

15
Q

Loop of Henle

A

composed of the straight part of the proximal tubule, the descending thin limb (which ends in a hairpin turn), the ascending thin limb, and the ascending thick limb

16
Q

capillary endothelium

A

contains a number of large holes called fenestrae leading to the endothelium’s weak barrier characteristics

17
Q

macula densa

A

goes right b/w afferent and efferent arteriole

18
Q

basement membrane

A

contains a meshwork of collagen and proteoglycans which filter a large amt of water and small solutes
carries a negative charge

19
Q

what is the primary restriction point for plasma proteins?

A

basement membrane

20
Q

epithelial cells

A

not continuous and contain slit pores whereby the glomerular filtrate moves

21
Q

what is the filterability of solutes determined by?

A

size and electrical charge

22
Q

tubuloglomerular feedback

A

decreased sodium or vol will cause the macula densa cells to signal the juxtaglomerular cells to secrete renin

23
Q

where is the juxtaglomerular complex found?

A

consists of the macula densa cells in the initial portion of the distal tubule and juxtaglomerular cells in the walls of the afferent and efferent arterioles (jux cells secrete renin)

24
Q

renin

A

catalyzes the formation of Ang II

constricts the efferent arteriole → increases glomerular hydrostatic pressure and returning GFR to normal

25
Q

what 3 processes does excretion involve?

A
  1. filtration
  2. reabsorption
  3. secretion
26
Q

average GFR

A

125 mL/min

180 L/day

27
Q

excretion equation

A

filtration rate - reabsorption rate + secretion

28
Q

reabsorption

A

solute moving from tubular fluid back into the blood

Goes into peritubular capillary bed (low pressure)

29
Q

secretion

A

in the direction of the blood back into the tubular fluid

Positive effect overall on excretion

30
Q

what 2 barriers must a substance cross through to be reabsorbed?

A
  1. tubular epithelial memb (into renal interstitial fluid)

2. peritubular capillary memb (back into blood)

31
Q

passive reabsorption

A

usually controlled by bulk

Has to go through apical membrane and basal membrane

32
Q

paracellular diffusion

A

passive

diffusion b/w cells

33
Q

transcellular diffusion

A

passive

diffusion across cell memb

34
Q

osmosis

A

passive

from region of low solute conc to region of high solute conc

35
Q

active transport

A

moving a solute against an electochemical gradient and requiring energy

36
Q

primary active transport

A

Na+,K+-ATPase that functions w/in most parts of the renal tubule
(exists on the basolateral side of the tubular epithelial cell)
hydrolyzes ATP and uses the energy to transport Na out of the cell into the intersitium at the same time K+ is transported from the interstitium to the inside of the epithelial cell

37
Q

secondary active transport

A

2 or more substances interact w/ a specific memb protein and are transported across the memb

38
Q

co-transport

A

2’ active transport
Ex. movement of Na from the tubular lumen interior of the epithelial cell energizes the movement of glucose and AA (achieved by multiple types of Na+ cotransporters)

39
Q

counter transport

A

2’ active transport

Ex. inward movement of Na+ providing energy for the outward movement of H+

40
Q

proximal tubular reabsorption

A

65% of filtered load of Na+ and water

41
Q

special cellular characeristics of proximal tubule

A

high metabolic capacity
extensive luminal brush border
large amt of co-transport proteins and counter transport protein

42
Q

Loop of Henle 3 segments

A
  1. descending thin limb
  2. ascending thin and thick segments
  3. ascending thick limb
43
Q

descending thin limb

A

highly permeable to water

44
Q

ascending thin and thick limb

A

virtually impermeable to water (important for urine concentration!)

45
Q

ascending thick limb

A

25% of filtered load of Na+, K+, Cl- (along with some Ca, bicarb, and Mg)
**Tubular fluid in ascending thick limb becomes very dilute

46
Q

early distal tubule

A

first part of distal tubule forms the juxtaglomerular complex which porvides feedback control for GFR and blood flow
next part functions much like the ascending thick limb (reabsorbs most ions and impermeable to water)

47
Q

late distal tubule and cortical collecting ducts cell types

A
  1. principle cells

2. intercalated cells

48
Q

principle cells

A

reabsorb Na+ and water from the lumen

secrete K+ into the lumen

49
Q

intercalated cells

A

reabsorb+ from the lumen and avidly secrete H+ into the lumen
H+ATPase= acid-base regulation

50
Q

aldosterone

A

controls the reabsorption of Na+ and secretion of K+ by LDT and CCD

51
Q

ADH

A

controls water permeability in LDT and CCD
(Normally segments are impermeable to water except when ADH is released)
helps water get reabsorbed

52
Q

medullary collecting duct

A
  • reabsorbs <10% of filtered water and sodium (fine tunes the filtrate)
  • controlled by ADH
  • permeable to urea
  • can secrete H+ (acid-base balance)
53
Q

excess water in body makes urine ___

A

dilute

osmolarity can go as low as 50 mOsmo/L

54
Q

deficit of water in body makes urine ___

A

concentrated

osmolarity can go as high as 1200-1400 mOsm/L

55
Q

ADH AKA ___

A

arginine-8 vasopressin (AVP)

secreted by the posterior pituitary

56
Q

high levels of ADH

A

signal the kidneys to excrete concentrated urine

57
Q

low levels of ADH

A

signal the kidneys to excrete dilute urine

58
Q

aquaporins

A

exist as homotetramer with each subunit bearing an individual water channel
permeable to water but not to other solutes

59
Q

ADH effect on aquaporins

A

increased ADH causes a luminal translocation of water channels in the medullary collecting ducts

60
Q

MOA of ADH

A

increase in intracellular cAMP in principle cells of medullary collecting duct → Activation of Gs/adenylyl cyclase system and PKA → phos AQP-2 → fuze to the cell memb and function to move water down the osmotic gradient

61
Q

what are the basic requirements for forming a concentrated urine?

A
  1. high level of ADH

2. high renal medullary interstitial fluid osmolarity

62
Q

changes seen in dilute urine

A

descending Loop of Henle has water reabsorbed by osmosis, thus tubular fluid is conc → ascending loop of Henle Na+, K+, and Cl- are avidly transported so tubular fluid is dilute → distal tubule/ cortico and medullary collecting duct= with no ADH means water is impermeable which makes tubular fluid even more dilute