Urinary Physiology

Question 1

What’s the functional unit of the kidney

Answer 1

Nephrons

Question 2

No of nephrons in the kidney

Answer 2

1 million .

Question 3

Nephron is made up of 4 regions

Answer 3

Bowman’s capsule
PCt
Loop of henle
DCt .

Question 4

Function of the collecting duct

Answer 4

To collect urine from the nephrons

Question 5

3 phases of urine formation

Answer 5

Glomeruler filtration
Slelective tubuler reabsorption
Tubuler secretion of H+ and k+ .

Question 6

Tubuler secretion is secretion of 2 things
/

Answer 6

H+ and K+

Question 7

Define glomerulus
Site

Answer 7

Mass of capillaries in bowman’s capsule

Question 8

Contains how many arterioles and which one is smaller than the other

Answer 8

Afferent and efferent atrterioles
Efferent arterioles is smallein sized

Question 9

PCT reabsorbes what passively and what actively

Answer 9

Water passively
Solute actively

Question 10

Percentage of filtrates in the pct

Answer 10

80% of filtrates are reabsorped in the pct

Question 11

% of glucose that is absorbed in the PCT

Answer 11

If the plasma levels of glucose is within normal range then it’s completely absorbed by the PCT .

Question 12

What do we mean by renal thereshold
And what changes occur to it in pregnancy

Answer 12

The maximum limit of solute that can be reabsorbed .
It decreases in pregnancy

Question 13

Which part of the nephron has tha main function to concentrate urine

Answer 13

The loop of henle

Question 14

Which part of loop of henle rebasorb solutes and which part rebsorb water

Answer 14

The ascending loop reabsorb solute s
And the descending loop reabsorbs water

Question 15

Which part of the nephron is impermeable to water

Answer 15

The ascending loop limb of henle is impermeable to water

Question 16

% of the filtrate that will reach DCT is

Answer 16

5%

Question 17

Main role of DCt

Answer 17

Water reabsorption

Question 18

DCT is under the effect of which two hormones

Answer 18

Is under the effect of ADH and aldosterone .

Question 19

Juxtaglomerular apparatus composed of 2 types of specialized cells what are they

Answer 19

Ascending loop of henle macula dense measures sodium concenrtration
Afferent arterioles = juxtaglomeruler cells ; sensitive to pressure modified i]endothelial cells .

Question 20

Macula dense
Site function

Answer 20

It’s on of the juxtaglomeruler apperatus specialized cells
At the ascending loop of henle f n to measure sodium concentration

Question 21

Juxtaglomeruler cells
Site
Definition m
Main fxn

Answer 21

Modified endothelial cells at the Afferent arterioles ; sensitize pressure ; pressure sensitive .

Question 22

Renin is secreted by

Answer 22

Juxtaglomeruler cells

Question 23

If Nacl is high what happens to macula dense the Afferent arterioles rPF GFR

Answer 23

Macula densa sectetes adenosine which increases diameter of Afferent arterioles increasing RPF and GFR thus decreasing NA reabsorption .

Question 24

If NACl is low شو بصير

Answer 24

بنروح بنادي على ال joggers cells we tell her to produce renin renin produce angiotensin which I will go and constrict eh]the efferent arterioles thus decreasing GFRand increasing NA reabsorption

Question 25

Function of the kidney

Answer 25

1 formation of urine 2 synthesis of A glucose B EPO erythropoietin C vitamin D

Question 26

Renal blood supply % of the CO

Answer 26

25% of CO

Question 27

Renal blood supply amount

Answer 27

1.2L/min

Question 28

Renal plasma flow

Answer 28

660 ml/min

Question 29

Creatinine clearance

Answer 29

120ml/ min

Question 30

GFR

Answer 30

120ml/min

Question 31

Filtration fration

Answer 31

= GFR/ RPF = 0.18 = 20% .

Question 32

Layers of the ureter 3 mention them

Answer 32

Outer layer fibrous layer Middle layer muscular layer Inner layer transitional epithelium layer

Question 33

When is the bladder stimulated

Answer 33

Bladder is stimulated at 300 ml volume .

Question 34

Nerve supply of the bladder is via

Answer 34

Le-frankenhauser plexus Which is part of the inferior hypogastric plexus Present at each side of the cervix

Question 35

Voiding is under which control and it’s mediated by what

Answer 35

Is under voluntary control mediated by pontine reticular formation at the cerebellum

Question 36

Bladder contractility is mediated by

Answer 36

Sacral spinal reflex

Question 37

Urethral function is external urethral sphincter is innervsted by

Answer 37

Pudendal nerve

Question 38

Mention the 3 phases of micturition

Answer 38

1 storage 2 initiation 3 voiding

Question 39

Storage is under which neural control

Answer 39

Is under sympathetic control T11-L2 ; which inhibit detrusor muscle contactility and stimulate internal sphincter thus closing it

Question 40

Initiation phase is under which neuronal supply

Answer 40

Is by parasympathetic s2 s3 s4 , which has inhibiting effect on the descending impulses of the sympathatic one thus stimulate detrusor muscle activity and inhibits internal sphincter so initiation of balladeer initiation phase before all of that pelvic floor muscle relaxation occurs . Those parasympathetic fibers works on m2 , ,3 muscerenic receptors .

Question 41

Voiding phase is under somatic control by

Answer 41

Pudendal nerve when rising and falling urethral pressures equalize .

Question 42

Urethral fxn is mediated by

Answer 42

Pudendal nerve .

Question 43

https://youtu.be/Zl4VoTpxluQ Study this video 3 times

Question 44

In bladder fill if ( storage) which is under sympathetic control Ascending impulses pass from ————:——:_——-:———;——- What does descending impulses do

Answer 44

Bladder wall receptors ( stretch receptors )—> pelvic splanchnic nerves—-> sacral roots s234—> lateral spine thalami’s tract —-> higher centers . Descending impulses inhibit detrusor contraction . Via sympathatic nervous system .

Question 45

Voiding phase starts with what changes to the intravesical and urethral pressure changes

Answer 45

It start when the rising intravesical pressure and the falling urethral pressure equalize .

Question 46

Residual volume of the bladder

Answer 46

50 ml

Question 47

1st sensation to void at which volume of the bladder

Answer 47

At 200 ml

Question 48

Voiding volume

Answer 48

400 ml

Question 49

Maximum capacity of the bladder

Answer 49

600 ml

Question 50

Flow rate of urination

Answer 50

15ml/min .

Question 51

Neglicable rise in detrusor pressure at filling

Answer 51

<15 mmhg

Question 52

Maximum voiding detrusor pressure

Answer 52

<50 mmhg

Question 53

Intraurethral at rest when sphincter is contracted is

Answer 53

50-100mmhg

Question 54

During filling what happen to the detrusor pressure

Answer 54

There is absence of detrusor pressure while voiding .

Question 55

Parasympathetic impulses in the bladder work at which receptors

Answer 55

M3 m4 muscerinic receptors

Question 56

Sympathatic inhibitory fibers work on two types of receptors mention them with their site of each on

Answer 56

Alpha receptors on the bladder neck and urethra , increase outlet urethral sphincter resistance . Beta receptors going on the detrusor muscle causes detrusor muscle relaxation .

Question 57

Trig one of the bladder site

Answer 57

On the posterior wall of the bladder

Question 58

Which is voluntary and unvoluntary EUS / IUD

Answer 58

EUS voluntary IUS involuntary .