Urinary Flashcards
(46 cards)
1
Q
organs of urinary system:
A
- 2 kidneys
- 2 ureters = carry urine from kidneys to bladder
- 1 bladder
- 1 urethra = carries urine from bladder to the outside of the body
2
Q
- kidneys are located:
A
behind the peritoneal membrane, near the lateral posts muscle
3
Q
- renal capsule
A
layer of adipose/fibrous connective tissue; cushions the kidneys against mechanical shock
4
Q
- parietal fat pad (adipose)
A
engulfs renal capsule acts as cushioning
5
Q
- renal fascia
A
thin connective tissue surrounds the adipose tissue and help anchor the kidneys to abdominal wall.
6
Q
urine flow path
A
- minor calyces
- major calyces
- renal pelvis
- ureters
- urinary bladder
- urethra
7
Q
afferent / efferent
A
affarent = sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system efferent = motor neurons that carry neural impulse away from the central nervous system and towards muscle to cause movement
8
Q
muscle in afferent and efferent arterioles
A
smooth muscle
9
Q
external urinary sphinkter:
A
controls flow of urine through urethra
10
Q
effect of ADH
A
- increase kidney reabsorption
- increase in number of aquaporins=membrane protein transfer water
- decrease in blood osmolarity
11
Q
renal fraction
A
potion of total cardiac output flows through the kidneys
12
Q
Function of Kidney
A
- excretion
- regulation of blood volume
- regulation of the concentration of solutes in the blood: Na+, Cl-, K+, Ca2+, HCO3-, HPO4 2-
- regulation of extracellular fluid pH = secrete variable amount of H+
- regulation of red blood cell synthesis = secrete hormone erythropoietin which stimulate RBC in red bone marrow
- regulation of vitamin D synthesis
13
Q
nephron
A
Function:
Regulate concentration of water and substances (Na) by filtering blood, reabsorbing what is needed, excreting the rest as urine
consists of 4:
- renal corpuscle
- proximal convoluted tubule
- loop of Henle (nephron loop)
- distal convoluted tubule
14
Q
major ions regulated by kidney:
A
- chloride Cl+
- bicarbonate HCO3-
- phosphate PO
- sodium Na+
15
Q
renal pelvis
A
- major calyces converge to form enlarged chamber
- surrounded by renal sinus
16
Q
bladder
A
locate in pelvic cavity posterior to the symphysis pubis
Store urine and drain into urethra
17
Q
filtration:
- positively charged ions -
- proteins less than 7nm -
- most blood cells
A
- pass freely into filtrate (dissolved ions)
- small amounts may enter the filtrate but will ultimately be reabsorbed
- cannot pass into filtrate
18
Q
impermeable to filtration barrier:
A
- proteins
- blood cells
19
Q
ADH on nephron water movement
A
- ADH bind to its receptor
- G-protein activates adenylate cyclase
- aquaporin-2 containing vesicle
- Cyclic AMP increase aquaporin-2 to increase permeability of the membrane to H2O
- water exits the tubule cells and enters interstitial fluid through aquaporin-3 and aquaporin-4water channel in the basal mambranes
20
Q
How ADH works
A
- stimulates water reabsorption stimulating insertion of “water channels” = aquaporins into membrane of kidney tubules
- these channels transport solute-free water through tubular cells and back into blood, leading to decrease in plasma osmolarity and increase osmolarity of urine
- leads vasoconstriction to increase arterial
21
Q
hormones involved in urine concentration:
A
- Renin
- ADH
- Aldosterone
22
Q
Glomerulus (Bowman’s capsule)
A
- Parietal layer: simple squamous epithelium
- visceral layer: podocytes wrap around glomerular capillaries
- hydrostatic pressure = 10mmHg
23
Q
glomerular filtration
A
blood pressure forces through the glomerular capitally walls into the glomerular capsule
24
Q
glomerular capillary pressure (GCP)
A
- outward pressure from blood pressing capillary walls (BP)
- forces fluid and solutes out of the blood into Bowman’s capsule
- higher than other capillaries of body because efferent arteriole diameter is smaller
25
capsular hydrostatic pressure (CHP)
- inward pressure from the pressure of filtrate accumulation in Bowman capsule
- filtrate pressing on the walls of Bowman capsule creates CHP = 10mmHG
26
micturition reflex
1. urine stretches wall of the urinary bladder
2. action potentials transmitted from stretch receptors along pelvic nerves to the sacral region of the spinal cord
3. action potential transmitted from the spinal cord to the urinary bladder by pelvic nerves
4. contraction of detrusor muscle of the urinary bladder
27
blood colloid osmotic pressure (BCOP)
| P.958see picture
- inward pressure due to the osmotic force of plasma proteins within the glomerular capillaries
- BCOP is greater at the end of glomerular capillary, because as fluid leaves capillary and enters Bowman capsule there is a higher protein concentration in th glomerular capillary = 30mmHg
28
ADH in order:
1. blood pressure greatly increases
2. ADH secretion is inhibited
3. reabsorption of water in kidney tubules is decreased
4. urine volume is increased
5. blood pressure and extracellular fluid volume is decreased
29
2 pressure in the glomerulus is determined by:
- colloid osmotic = plasma protein tends to pull water into the blood (opposite force to hydrostatic pressure)
- blood hydrostatic
30
podocytes
- visceral layer of glomerular capsule
- contain negatively charged glycoproteins = repel negatively charged plasma proteins to prevent them from exiting the blood
31
filtration pressure
Filtration(10mmHg)
= Glomerular capillary pressure (50mmHg)
- Capsular hydrostatic pressure (10mmHg)
- blood colloid osmotic pressure (30mmHg)
32
muscle force urine out from the bladder:
contraction of detrusor muscle
33
blood flow of Kidney
1. renal artery
2. segmental artery
3. interlobar artery
4. arcuate artery
5. Cortical radiate 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
34
renal fascia
connective tissue anchors the kidney, sorrows adipose tissue of kidneys
35
filtration
- first step of urine formation
| - movement of water, ion, small molecules through the filtration membrane under pressure
36
filtration membrane
1. fenestrae of glomerular capillary
2. basement membrane between capillary wall and the visceral ayer of Bowman capsule
3. podocytes of the visceral layer of Bowman capsule
* **More permeable than typical capillary!
37
autoregulation
maintain stable filtration rate (GFR) - 90mmHg ~ 180mmHg.
38
internal urinal sphincter composed of:
smooth muscle
39
Juxtamedullary nephrons = medullary region of Kidney
most responsible for the high concentration gradient of solutes to concentrate urine
40
micturition reflex
1. urine in the bladder stretches wall of the urinary bladder
2. action potentials transmitted from stretch receptors along pelvic nerves to the sacral region of spinal cord
3. action potentials transmitted from the spinal cord to the urinary bladder by pelvic nerves
4. contraction of detrusor muscle of the urinary bladder
41
external urinary sphincter
surrounds the urethra and extends through pelvic floor
42
high solute concentration region:
- vasa recta
| - loop of henle
43
substances secreted by the kidney tubules:
- hydrogen ions
- potassium
- drugs
44
urethra (epithelium)
stratified or pseudo stratified columnar epithelium
45
what increase urine formation?
- body fluid solute concentration decreases in response to a decrease in aldosterone
- increased blood pressure in response to increased blood volume
46
Function of Urinary system:
- filtering blood
- regulation of:
blood volume
concentration of solute
pH of extracellular fluid
blood cell synthesis
- VitaminD synthesis
- 1 liter of blood/min, 55% filtered. Kidney receive 12-30% of cardiac output
