chapter 26 Flashcards
1
Q
organs of the urinary system
A
- kidneys
- ureter
- bladder
- urethra
2
Q
kidneys
A
filter blood
3
Q
ureter
A
transports urine to urinary bladder
4
Q
bladder
A
storage tank for urine
5
Q
urethra
- definition
- length in female
- length in male
A
- conducts urine to outside
- 1-2 in long
- 7-8 in long
6
Q
3 functions of the urinary system
A
- excretion
- elimination
- homeostatic regulation
7
Q
excretion
A
removal of organic waste products from body fluids
8
Q
elimination
A
discharge of waste products into the environment
9
Q
homeostatic regulation
-5
A
- regulates blood vol and pressure
- regulates concentration of plasma ions
- helps stabilizes blood pH
- helps conserve valuable nutrients
- assists liver in detoxification
10
Q
kidney
- location
- embedded in
- ___ long, ___ wide, ___ thick
A
- posterior abdominal wall; behind the peritoneum (retroperitoneum)
- fat
- 4 in long, 3 in wide, 1 in thick
11
Q
9 structures of the kidney
A
- renal medulla
- renal cortex
- renal capsule
- renal pyramid
- renal papilla
- renal columns
- calyces
- renal lobe
- renal pelvis
12
Q
renal capsule
A
CT covering
13
Q
renal pyramid
A
triangular structures that make up the renal medulla
14
Q
renal papilla
A
end of the pyramid
15
Q
renal columns
A
extensions of the cortex between pyramids
16
Q
calyces
A
cup shaped drain near papilla
17
Q
renal lobe
- definition
- function
A
renal pyramid that is part of the renal column and renal cortex; functional unit
-produce urine
18
Q
renal pelvis
A
connected to the ureter
19
Q
what is the functional unit of the kidney
A
the nephron
20
Q
nephron
- aka
- site of
- how many does each kidney had
A
- renal tubule
- urine production
- 1.25 x 10 ^6
21
Q
8 nephron structures
A
- renal corpsule
- bowman’s capsule
- proximal convoluted tubule (PCT)
- distal convoluted tubule (DCT)
- collecting duct
- loop of henle
- descending limb of the loop of henle
- ascending limb of the loop of henle
22
Q
proximal convoluted tubule
A
reabsorption of H2O, ions and all organic nutrients
23
Q
distal convoluted tubule
-2 functions
A
- secretion of acids, ions, drugs and toxins
- some reabsorption of H2O, Na+, and Cl- ions
24
Q
collecting duct
-2 functions
A
- some reabsorption of H2O
2. some secretion of Na+, K+, H+, and HCO3- ions
25
peritubular space
- definition
- contains
- area surrounding the nephron
| - contains peritubular fluid
26
loop of henle
reabsorption of H2O, Na+ and Cl- ions
27
descending limb of the loop of henle
reabsorption of H2O
28
ascending limb of the loop of henle
reabsorption of Na+ and Cl-
29
renal corpuscle
- function
- what is it
produces filtrate
| -Bowman's casule and glomerulus
30
2 types of nephrons in the kidneys
1. cortical nephron
| 2. juxtamedullary nephron
31
cortical nephron
- ___ of all nephrons
- function
- 85%
| - performs most of the reabsorption and secretory functions of the kidney
32
juxtamedullary nephrons
enable kidneys to produce a concentrated urine
33
blood supply to the kidney
1. renal artery
2. segmental artery
3. interlobar artery
4. arcuate artery
5. interlobular artery
6. afferent arteriole
7. glomerulus
8. efferent arteriole
9. peritubular capillaries
10. vasa recta
11. interlobular vein
12. arcuate vein
13. interlobar vein
14. renal vein
15. inferior vena cava
34
where does blood enter the kidney from
the aorta
35
interlobar artery
between renal pyramids in renal columns
36
arcuate artery
boundary between cortex and medulla
37
interlobular artery
in the cortex of the renal lobes
38
afferent arteriole
brings blood into glomerulus
39
efferent arteriole
where blood exits the glomerulus
40
vasa recta
- location
- function
- juxtamedullary nephron
| - modification to supply long loops of Henle
41
interlobular vein
blood returning to inferior vena cava
42
juxtaglomerular complex
| -structures
1. macula densa
2. juxtaglomedullar cells
3. juxtaglomerular apparatus
43
macula densa
modified epithelial cells of the DCT
44
juxtaglomerular cells
modified smooth muscle cells in the afferent arteriole
45
function of the JGC
- type of structure
- 2 functions
- endocrine structure
- 1. hormone erythropoietin
2. renin enzyme
46
renin
- part of what
- function
- part of renin angiotensin system
| - increases anti diuretic hormone and aldosterone release
47
what does increase antidiuretic hormone and aldosterone release do
-restricts H2O and salt loss at the kidneys, stimulates thirst and increase BP
48
factors stimulating renin release
1. sympathetic stimulation
2. decline in renal blood flow
3. decline in osmotic concentration of tubular fluid at macula densa
49
glomerular filtration
- definition
- driving force
movement of fluid across the wall of the glomerulus and into the capsular space
-BP
50
composition of filtrate
1. glucose
2. AA
3. Salts
4. H2O
5. dissolved gases
7. vitamins
8. urea
9. other drugs
51
3 layers for the filtration of plasma
1. capillary epithelium
2. basement membrane
3. filtration slits
52
filtration slits
allows only ions, nutrients, and AA to pass
53
glomerular filtration rate (GFR)
- definition
- average
- amount of filtrate the kidneys produce each min
| - 125 ml/min
54
controlling glomerular filtration rate
| -3 mechanisms
1. autoregulation
2. hormonal regulation
3. autonomic regulation
55
auto regulation
- response to
- constriction of the efferent arteriole =
- constriction of the afferent arteriole =
- response to local changes in BP and flow to the glomerulus; changes in the diameters of the afferent arteriole, efferent arteriole and glomerular capillaries
- increase in BP in glomerulus
- decrease in BP in glomerulus
56
hormonal regulation
| -2 components
- renin-angiotensin system
| - atrial natiuretic peptide (ANP)
57
renin angiotensin system
- enzyme released in response to
- results in
- renin is released in response to decreased GFR
| - activation of angiotensin
58
angiotensin
increases BP and blood vol
59
atrial natiuretic peptide
| -secreted in response to
-increased blood vol in right atrium
60
increased blood vol in right atrium causes
dilation of afferent arteriole and constriction of efferent arteriole = increased GFR and decreased blood vol (bc of urine output)
61
autonomic regulation
- type of response
- causes
- sympathetic response
- causes
- constriction of afferent arterioles= decreased GFR
62
reabsorption at the PCT
- osmolarity
- 1 mole of dissolved particles =
- body fluids =
- total number of solute particles in 1 liter
- 1 osm/L = 1000 mosm/l
- 300 mosm/l = isotonic
63
reabsorption at the PCT
- enter:
- osmolarity of filtrate entering the PCT
- osmolarity of tubular fluid exiting the PCT
- PCT will reabsorb ____ of filtrate vol
- filtrate from Bowmans's capsule
- 300 mosm/L
- 300 mOsm/L
- 60-70%
64
reabsorption in the loop of henle: descending limb
- definition
- enter
- osmolarity of tubular fluid entering the descending limb
- osmolarity of tubular fluid exiting the descending limb
- lumen of the nephron
- permeable to H2O but impermeable to solutes
- tubular fluid from PCT
- 300 mOsm/L
- 1200 mOsm/L (at the bottom of the limb)
- contains tubular fluid from PCT
65
reabsorption in the loop of henle: ascending limb
- definition
- enter
- osmolarity of tubular fluid entering the ascending limb
- osmolarity of tubular fluid exiting the ascending limb
- lumen of the nephron
- impermeable to water and solutes contains active transport mechanisms to pump Na+ and Cl- of tubular fluid
- tubular fluid from the descending limb
- 1200 mOsm/L
- 100 mOsm/L
- tubular fluid from descending limb
66
the countercurrent mechanisms
- definition
- why does exchange occur
- 2 functions
- mechanism for absorption along the loop of henle
- occurs because fluids are moving in opposite direction
- 1. reabsorbs solutes and water before tubular fluid reaches DCT and CD
2. establishes a concentration gradient that helps reabsorbs H2O in DCT and CD
67
the countercurrent mechanisms
- descending limb
- ascending limb
- water moves out, solutes do not move
| - solutes move out, water does not move
68
the countercurrent mechanisms
- where is Na+ Cl- pumped
- what does this do
- pumped into medulla
| - helps establish a concentration gradient and used to concentrate urine in DCT and CD
69
reabsorption in the DCT and CD
- definition
- controlled by what
- osmolarity of tubular fluid entering the DCT/CD
- osmolarity of tubular fluid exiting the DCT/CD
- make final adjustments to composition and vol of urine
- hormones
- 100 mOsm/L
- ~800-1000 mOsm/L (largely through removal of water and retention of urea)
70
```
producing a concentrated urine
-what cannot be adjusted
-vol of H2O loss is dependent upon what
-controlled through
-what does ADH do
what does the hypothalamus do
```
- water reabsorption in PCT and descending limb
- upon reabsorption in DCT and CD
- ADH
- increases the permeability of DCT and CD to H2O
- secreates ADH through the posterior pituitary gland, continuosly at low levels
71
effects of ADH on urine concentration
- absence of ADH
- presence of ADH
- water is not reabsorbed in DCT and CD
| - water is reabsorbed in DCT and CD
72
secretion at the PCT
- ions
- function
- primarily H+ ions
| - helps to regulate pH of body fluids
73
secretion at the DCT
| -ions/substances
1. K+
2. H+
3. creatine
4. ammonium ions
5. drugs
6. toxins
74
secretion at the CD
| -ions
H+ and HCO3-
75
micturition reflex and urination
- function
- stimulus
- reflex begins
- response
- controls the process of urination
- stretch receptors in wall of urination
- begins when bladder has ~200 ml of urine
- voluntarily relax of external sphincter which causes relaxation of internal urethral sphincter
76
micturition reflex and urination
| -where is sensation delivered to
cerebral cortex and become aware of fluid pressure in bladder
77
incontinence
inability to control urination voluntarily
