Urinary Apf

Front 1

Describe the urinary system's roles in excretion, elimination, and homeostatic regulation of blood.

Back 1

Removes organic waste products from body fluids

Discharges waste products into environment

Regulates blood volume/pressure, regulates plasma ion concentrations, stabilizes blood pH, conserves nutrients

Front 2

Describe the role of the kidney, ureter, urinary bladder and urethra.

Back 2

Produces urine

Transports urine toward urinary bladder

Temporarily stores urine prior to elimination

Conducts urine to exterior

Front 3

Label Diagram 1

Back 3

1. Medulla
2. Cortex
3. Renal Pyramic
4. Connection to minor calyx
5. Renal sinus
6. Minor Calyx
7. Adipolse tissue in sinus
8. Major calyx
9. Renal pelvis
10. hilus
11. Renal lobe
12. Ureter
13. Renal columns
14. Renal papilla
15. Renal capsule

Front 4

Label Diag 2

Back 4

1. Segmental artery
2. Suprarenal artery
3. renal artery
4. renal vein
5. interlobar arteries
6. interlobular arteries
7. interlobar veints
8. Arcuate veins
9. Arcuate arteries
10. interlobular artery
11. arcuate artery
12. arcuate vein
13. afferent arterioles
14. nephron
15. interlobar vein
16. interlobular artery

Front 5

Role of renal corpuscle

Back 5

Production of filtrate

Front 6

Role of prxoimal convoluted tubule

Back 6

Reabsorption of water, ions, organic nutrients

Front 7

Role of loop of Henle

Back 7

Further reabsorption of water (descending limb) and Na/Cl ions (ascending limb)

Front 8

Role of distal convoluted tubule

Back 8

Secretion of ions, acids, drugs, toxins; variable reasbsorption of water, Na/Ca ions (under hormonal control)

Front 9

Role of collecting duct

Back 9

variable reasborption of water and or secretion of Na/K/H/Bicarbonate ions

Front 10

Role of papillary duct

Back 10

Delivery of urine to minor calyx

Front 11

Which structures make up the collecting system of a nephron?

Back 11

Collecting duct and papillary duct

Front 12

Label Diag 3

Back 12

1. proximal convoluted tubule
2. capsular space
3. glomerulus
4. efferent arteriole
5. afferent arteriole
6. bowman's capsule
7. renal corpuscle
8. descending limb of loop begins
9. renal capsule
10. thin descending limb
11. descending limb
12. loop of henle
13. ascending limb
14. thick ascending limb
15. ascending limb of loop ends
16. distal convoluted tubule
17. collecting duct
18. capillary duct
19. minor calynx

Front 13

Difference between cortical and juxtamedullary nephrons?

Back 13

Cortical make up ~85% of all nephrons; loops on henle of juxtamedullary extend deep into renal pyramids

Front 14

Name 2 ways in which urine production maintains homeostasis

Back 14

Regulated blood volume/composition

Excretes waste products (urea, creatinine, uric acid)

Front 15

Compare plasma and urine contents of Na, K, Cl, HCO3, glucose, lipids, amino acids, proteins, urea, creatinine, ammonia, uric acid

Back 15

More, much more, more, much less, much less, much less, much less, much much less (0), much more, much more, much more, much more
(in terms of urine)

Front 16

Describe the 3 main steps of urine formation

Back 16

Filtration: BP forces water and solutes across glomerular capillaries into capsular space, solute molecules small enough to pass thorugh filtration membrane are carried by surrounding water moleulces

Reabsorption: removal of water and solutes from filtrate

Secretion: transport of solutes from peritubular fluid into tubular fluid

Front 17

Describe the four methods of carrier mediated transport employed by filtration.

Back 17

Facilitated diffusion: carrier protein transports molecules along gradient

Active transport: ATP hydrolysis against membrane

Cotransport: two substrates cross membrane while bound to carrier protein. Substrate follow concentration gradient of one of substances. (reabsorption of organic/inorganic compounds from tubular fluids)

Countertransport: two transported ions (like in cotransport) move in opposite directions (PCT, DCT, collecting system)

Front 18

What is transport maximum? What does it determine?

Back 18

Concentration at saturation of a carrier protein; determines renal threshold: plasma concentration at which a specific compound/ion begins to appear in urine

Front 19

What happens to concentrations higher than Tm?

Back 19

No further transport, they are excreted

Front 20

Compare the renal threshold of glucose, amino acids, and water soluble vitamines

Back 20

HIGH, MEDIUM, LOW

Front 21

Describe flow of nutrients in proximal convoluted tubule and their destination.

Back 21

reabsorb and release into peritubular fluid

Front 22

Describe flow of nutrients in distal convoluted tubule and their destination.

Back 22

reabsorb sodium ions from tubular fluid

Front 23

What process occurs in the renal corpuscle? How does this differ based on the size of the molecule?

Back 23

Proteins/molecules smaller than 7nm pass into filtrate; larger cells/proteins stay in blood

Front 24

What does the proximal convoluted tubule secrete

Back 24

H+, NH4+, creatinine, toxins, drugs

Front 25

What does the distal convoluted tubule secrete?

Back 25

H+, NH4+, creatinine, toxins, drugs

Front 26

What is the role of the loops of henle?

Back 26

Regulate final volume/solute concentration

Front 27

How would a drop in BP affect glomerular filtration rate? How could this decreased BP be achieved?

Back 27

If drops to 40 mmHG, filtration ceases

Hemorrhaging, shock, dehydration

Front 28

Describe the methods of autoregulation in controlling GFR

Back 28

Diameter of blood vessels, decreased bp-->increased afferent arteriole diameter, dilation of capillaries, decreased efferent arteriole diameter
Increased BP causes decreased afferent arteriole diameter

Front 29

Describe the methods of hormonal control in regulating GFR.

Back 29

a drop in filtration pressure stimulated juxtaglomerular apparatus, releases rening + ertyhropoietn

Front 30

What role does the sympathetic nervous system play in regulating GFR?

Back 30

Vasoconstriction of afferent arterioles, decrases GFR+slows production of filtrate

Changes pattern of blood flow (to alter GFR)

Stimulates release of renin by JGA

Front 31

What type of fluid (in terms of similarity) does glomerular filtration produce?

Back 31

Plasma without proteins

Front 32

What is countercurrent multiplication?

Back 32

Exchange occurs between fluids moving in opposite directions: tubular fluid in descending limb flows toward renal pelvis, tubular fluid in ascending toward cortex
Multiplication: effect of exchange increases as movement of fluid continues

Front 33

How is countercurrent multiplication achievedand what is its effect on urine concentration?

Back 33

Descending limb is permeable to water, impermeable to solute, ascending limb is impermeable to water, but has active solute transport. So solutes pumped out of ascending (Cl-, Na+, and K+), thus forcing water out of descending (passively).
DCT and collecting duct have variable permeability to water and are impermeable to urea. So as water is reabsorped, urea concentration rises. Papillary duct permeability to urea accounts for 1/3 of solutes in deepest portion of medulla.

ION CONCENTRATION GRADIENT: high pressure towards medulla.

Front 34

What is the role of DCT? Describe its mechanism of action.

Back 34

Final adjustment of urine: active secretion or absorption

Tubular cells reabsorb (actively) Na and Cl from tubular fluid in exchange for potassium.

Reabsorption of HCO3- in exchange for H+ (secretes H+)

Front 35

How is pH controlled for in the collecting system?

Back 35

Secretion of H+ or bicabonate

Front 36

Describe the mechanism of action of ADH and how things function in its absence.

Back 36

Normally: H2O flows out of descending limb, and Na-Cl flows out of ascending, and the permeability of collecting duct is controlled and then you pee diluted urine.

WITH ADH, permeability of collecting duct increases for water, so water just flows out and gets reabsorbed (in DCT too), resulting in concentrated urine (smaller volume).

Front 37

Describe the role and function of the vasa recta. What is this principle known as?

Back 37

Solutes and water reabsorbed in medulla must be returned to general circulation without disrupting concentration gradient; this is mediated by vasa recta.

Blood entering vasa recta has an osmitc concentration ~300, as it descends it increases, involving solute gain and water loss (more solute gain though because of plasma proteins). Blood flow to cortex decreases in ostmotic concentration as solute concentration of preitubular fluid declines. In this case osmosis predominates (plasma proteins aint opposing osmotic flow of watr in blood).

NET RESULT: some solutes absorbed in descending portion of vasa do not diffuse out in ascending protion and more water moves into ascending protion of vasa than moved out.

THUS carries both water and solutes out of medulla. Precisely balances rate of reabsortpion and osmosis in medulla.

COUNTER CURRENT EXCHANGE

Front 38

What do the ureters connect? Main role? How is this achieved?

Back 38

From renal pelvis to bladder; transport; peristaltic contractions force urine toward urinary bladder

Front 39

Main role of urinary bladder? How is its function achieved?

Back 39

Storage reservoir of urine; contraction of detrusor muscle voids bladder

Front 40

What does the urethra connect? Function? How is it achieved?

Back 40

Extends from urinary bladder to exterior of body, passes through urogenital diaphragm (external urinary sphincter); differs in length and function in males and females

Front 41

What is the function of the micturition reflex? How is it intiated? Describe its mechanism of action.

Back 41

Corrdinates urination.
Intiiated by stretch receptors in bladder wall.
Urination requires coupling of micrution reflex with relaxation of external urethral sphincter.

Stretch receptor -->Afferent Sensory fiber in pelvic nerve-->SC-->IN to thala-->cerebral cortex

Also from afferent in SC-->Parasymp pregang MN in pelvic nerve-->efferent-->postgang in intramulral ganglion to stimulate detrusor muscle contraction