Urinary System Flashcards
1
Q
urinary system consists of…
A
- paired kidneys
- paired ureters
- bladder
- urethra
2
Q
endocrine functions of kidney
A
- secretion of renin
- secretion of erythropoietin (EPO)
- conversion of steroid prohormone vitamin D to active form
3
Q
function of renin
A
regulate blood pressure
4
Q
function of erythropoietin (EPO)
A
stimulate erythrocyte (RBC) production in bone marrow
5
Q
kidney
hilum
A
- concave medial border
- nerves, blood & lymph vessels pass
- ureter exits
6
Q
at the hilum the ureter expands as the ____
A
renal pelvis
7
Q
the renal pelvis divides into 2-3 ____
A
major calyces
8
Q
major calyces branch into the ____
A
minor calyces
9
Q
the kidney is divided into…
A
- outer cortex (mostly many renal corpuscle & tubules x-sections)
- inner medulla (mostly linear tubules & ducts
10
Q
attached to each minor calyx is a ____
A
renal pyramid (conical shaped region of medulla)
11
Q
bases of renal pyramids meet the cortex and are separated from each other by ____
A
renal columns (extensions of cortex)
12
Q
each pyramid, upper cortex, and surrounding renal column make up a ____
A
renal lobe
13
Q
the tip of each pyramid is called a ____
A
renal papilla
14
Q
renal papilla
A
projects into a minor calyx and collects urine by tubules in one renal lobe
15
Q
parallel ducts & tubules from the medulla that extend into the cortex form ____
A
medullary rays
16
Q
what is the fundamental structural & functional unit of the kidney?
A
nephron
17
Q
2 parts of the nephron
A
renal corpuscle
tubule system
18
Q
renal corpuscle extends from the ____
A
vascular pole (afferent & efferent arterioles)
19
Q
renal corpuscles are found…
A
only in the cortex
20
Q
renal corpuscle consists of…
A
- glomerulus (large tuft of capillaries)
- Bowman’s capsule
21
Q
tubule system leads from renal corpuscle at the ____
A
urinary pole
22
Q
PCT straightens into ____ and descends into the ____
A
proximal tubule (PT)
medulla
23
Q
PT thins into ____
A
thin Loop of Henle
24
Q
Loop of Henle
A
- descends further, takes hairpin turn
- begins to ascend back to cortex
- simple squamous epithelium
25
Loop of Henle thickens into ____
distal tubule (DT)
26
collecting tubules merge to form ____
collecting ducts
27
# renal corpuscle
afferent arterioles bring blood.... at the ____
to the glomerulus at the vascular pole
28
blood circulates through glomerular capillaries where ____ occurs
filtration
29
filtered blood exits the ____ at the ____
efferent arteriole at the vascular pole
30
initial plasma filtrate enters the ____ at the ____
PCT at the urinary pole
31
what helps to modify urine in the tubule system?
peritubular capillaries in the vasa recta
32
filtration
allows water & solutes in blood to leave vascular space of capillaries of glomerulus and enter Bowman's capsule
33
secretion
substances move from epithelial cells of tubules into lumen, usually after uptake from surrounding interstitium and capillaries (peritubular capillaries & vasa recta)
34
kidneys are highly ____ organs, receiving...
highly vascular
25% of cardiac output
35
in production of urine, blood is filtered into initial glomerular ultra ____, and modified by...
- plasma filtrate (pre-urine)
- selective reabsorption & secretion by cells of kidney tubules
36
vascular pole
afferent arterioles enter
efferent arterioles exit
37
urinary pole
PCT begins
38
Bowman's capsule
double-walled epithelial capsule
39
glomerulus
tuft of networking fenestrated capillaries
40
3 sub-parts of Bowman's capsule
1. parietal layer
2. visceral layer
3. Bowman's space
41
# Bowman's capsule
parietal layer
- outermost layer
- formed surface of renal corpuscle
- simple squamous epithelium
42
# Bowman's capsule
visceral layer
- inner portion
- closely envelops glomerular capillaries
- lined by epithelial cells called **podocytes**
43
# Bowman's capsule
Bowman's space
receives fluid (plasma filtrate/pre-urine) filtered through capillary wall & visceral layer
44
# glomerular function
podocytes
from each cell body, extend primary processes that curve around capillary below
45
# podocytes
primary processes give rise to ____
pedicels (foot processes)
46
pedicels are in direct contact with...
basement membrane of capillary endothelial cells
47
spaces between pedicels form ___
filtration slits pores
48
glomerular basement membrane (GBM)
- between podocytes & endothelial cells of capillaries
- thick membrane made by fusion of podocyte & capillary endothelial cell basal laminae (basement membrane)
49
filtration occurs through the ____
glomerular filtration barrier
50
3 parts of glomerular filtration barrier
1. fenestrated capillary endothelium
2. thick combined basal laminae (GBM)
3. filtration slit pores between pedicels of podocytes
51
filtration slit pore act as a...
selective size barrier
52
mesangial cells
- cover capillary surface in renal corpuscle *not* covered by podocytes
- phagocytic
- extend contractile processes along capillaries (regulate glomerular blood flow)
53
mesangium consists of...
mesangial cells & their ECM
54
function of mesangium
- **structural support** to podocytes & capillaries
- **maintain optimal filtration rate:** adjust contractions in response to BP changes
- **phagocytic:** remove residues & protein aggregates in GBM, including antibody-antigen complexes
- **secretion**: cytokines & inflammatory mediators for immune defense & repair of GBM
55
renal corpuscle is the site of ____
blood filtration
56
nephron tubules are the site of...
secretion & reabsorption
57
epithelium of PCT
simple cuboidal with long microvilli and basolateral folds that interdigitate with neighboring cells
58
PCT epithelial cells help with...
reabsorption & secretion
59
# PCT
reabsorption & secretion are associated with ____
peritubular capillaries
60
PCT location
- begins at urinary pole, convolutes
- straightens before leaving cortex
- enters medulla as descending limb of proximal tubule
61
# (thin) loop of Henle
function
further adjusts salt & water content of filtrate
62
thin loop of Henle is associated with ____
capillaries (vasa recta)
63
DT location
ascends in straight path into cortex, then becomes tortuous as DCT
64
DCT epithelium
simple cuboidal with short microvilli
65
as DT approaches afferent arterioles of its nephron, it forms a ____
macula densa
66
macula densa
- DT cells become narrower, taller & more densely packed
- nuclei appear crowded
- part of juxtaglomerular apparatus (JGA)
67
function of juxtaglomerular apparatus (JGA)
special sensory structure that helps regulate BP
68
JGA consists of...
1. macula densa
2. extraglomerular mesangial cells (lacis cells)
3. JG cells
69
JG cells
- modified smooth muscle cells in tunica media of nearby afferent arteriole
- contain secretory granules containing renin
70
after the macula densa, the DT becomes the ____
DCT
71
function of DCT
further electrolyte adjustment
72
DCTs empty into ____
collecting tubules
73
epithelium of collecting tubules & ducts
- simple cuboidal transitions to simple columnar in larger collecting ducts
- distinct cell boundaries ("halo" around nucleus)
74
function of collecting tubules & ducts
final site of H2O reabsorption
75
papillary duct of Bellini
collecting duct descend through medulla towards apex of each renal pyramid, where several ducts merge near the renal papillae
76
function of ureters
transport urine from renal pelvis to bladder
77
mucosa of ureters
- lined by urothelium (transitional): apical umbrella-shaped cells
- supporting LP below epithelium
78
muscularis of ureters
2 layers of smooth muscle
79
layers of ureters
- mucosa
- muscularis
- adventitia
80
function of bladder
distensible reservoir for urine
81
mucosa of bladder
- lined by urothelium (transitional): apical umbrella-shaped cells
- supporting LP below epithelium
- umbrella cells exhibit dense **plaques** (uroplakins)
82
# bladder
plaques (uroplakins)
modified area of plasma membrane proteins that protect cells from prolonged contact with urine
83
muscularis of the bladder
3 layers of smooth muscle called the **detrusor muscle**
84
detrusor muscle function
help empty bladder
85
layers of bladder
- mucosa
- submucosa
- muscularis (detrusor m)
- adventitia
86
function of urethra
carries urine from bladder to exterior
87
urethra in males
serves as terminal duct for urinary & genital systems
88
urethra in females
shorter in length
