Chapter 26 - Urinary System Flashcards Preview

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Flashcards in Chapter 26 - Urinary System Deck (60)
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31

renal corpuscle & both convulated tubules lie within ____ ___ 

Loop of Henle extends into __ __ but returns to renal cortex

renal cortex

renal medulla 

 

32

Distal convoluted tubule of several nephrons empty into?

a single collecting duct 

33

Urine flow:

Distal convoluted tubules → ? → ? ....

collecting duct → converge into 100s of papillary ducts → minor calyces 

34

collecting ducts & papillary ducts extend from? through? to?

 renal cortex through medulla to renal pelvis 

35

Loop of Henle in nephron connects?

(2) parts of Loop of Henle 

proximal & distal convoluted tubules. 

into renal medulla as 1) descending limb 

makes hairpin turn and returns to renal cortex as 

2) ascending limb

36

(2) types of Nephrons

1) Cortical 

2) Juxtamedullary

37

1) Cortical Nephron

location of renal corpuscles

Loop of Henle structure

80-85% of nephrons

renal corpuscles lie in outer portion of renal cortex (cortical zone)

short loops of Henle - mainly in cortex, penetrate only into outer region of renal medulla 

38

the short Loops of Henle in Cortical Nephrons recieve blood supply from..?

peritubular capillaries that arise from efferent arterioles 

39

Juxtamedullary nephrons

location of Renal corpuscle 

Loop of Henle structure

ascending limb

15-20% of nephrons

renal corpuscles lie deep in cortex (juxtamedullary zone)

long Loop of Henle - extends into deepest region of medulla

(2) portions off ascending limb - thin & thick 

40

Long loops of Henle in Juxtamedullary Nephrons recieve blood supply from?

peritubular capillaries & vasa recta that arrise from efferent arterioles 

41

Histology of Glomerular capsule

(2) layers

1) parietal layer

2) visceral layer

42

Glomerular Capsule

1) parietal layer

2) visceral layer

1) simple squamous epithelium - outer wall 

2) modified simple squamous epithelium = podocytes that wrap projections around single layer of endothelial cells of glomerular capillaries 

- inner wall

43

Fluid filtered from glomerular capillaries enters...

Glomerular (Bowman's) space - space between 2 layers of glomerular capsule (lumen of urinary tube)

44

Histology of Renal Tubule & Collecting duct

- PROXIMAL CONVOLUTED TUBULE

simple cuboidal epithelial cells 

prominent brush borderof microvilli on surface facing lumen

45

Histology of Renal Tubule & Collecting duct

DESCENDING & 1ST PART OF ASCENDING LIMB OF LOOP OF HENLE (THIN)

 

 

descending & thin ascending - simple squamous epithelium

thick - simple cuboidal to low columnar epithelium 

46

Macula densa

 area of closely packed specialized cells lining the wall of the distal convoluted tubule/final part of ascending loop of henle

47

Juxtamedullary cells 

modified smooth muscle fibers in walls of afferent (& sometimes efferent) arterioles alongside macula densa

48

Juxtamedullary Apparatus

macula densa + juxtamedullary cells

- help regulate blood pressure in kidney 

49

In the last part of the Distal Convoluted Tubule & continuing into collecting ducts, 

(2) different types of cells are present

1) principal cells - receptors for antidiuretic hormone (ADH) & aldosterone (2 hormones that regulate their functions) 

2) intercalated cells - play a role in homeostasis of blood pH 

 

50

(3) basic processes performed by nephrons & collecting ducts to produce urine

1) GLOMERULAR FILTRATION

2) TUBULAR REABSORPTION 

3) TUBULAR SECRETION

51

1) GLOMERULAR FILTRATION 

2) TUBULAR REABSORPTION

3) TUBULAR SECRETION

1) water & solutes in blood plasma move across wall of glomerular capillaries, filtered → move into glomerular capsule → renal tubule

2) as filtered fluid flows through renal tubules → collecting ducts - tubule cells reabsorb 99% of filtered water & other solutes which return to blood as it flows through peritubular capillaries & vasa recta 

3) as filtered fluid from renal tubules + collecting ducts, renal tubule & duct cells secrete other materials (waste, drugs, xs ions) into fluid 

 

 

52

solutes in fluid that drain into renal pelvis remain in fluid and are ___ as ___ 

excreted as urine

53

Excretion of any solute = ?

glomerular filtration  - reabsoprtion + secretion

54

Urinary bladder

hollow ditensible muscular organ

capacity: 700-800 mL

55

Micturition

discharge of urine from urinary bladder 

aka urination

56

Urination/Micturition involves combination of?

voluntary & involuntary muscle contractions 

57

When volume of urine in urinary bladder exceeds 200-400 mL, pressure increases &...

stretch receptors in wall transmit nerve impulses into spinal cord → micturition center in S2 & S3 → trigger (spinal reflex) micturition reflex → parasympathetic impulses to urinary bladder & internal urethral sphincter → contraction of detrusor, relaxation of internal urethral sphincter + inhibition of somatic motor neurons  in external urethral sphincter

58

External urethral orifice 

between clitoris & vaginal orifice

59

Internal urethral sphincter

detrusor muscle thickened, smooth muscle, involuntary control

60