Exam 4: Urinary System

Question 1

functions of urinary system (primary and associated both have 2)

Answer 1

primary: fluid and electrolyte balance and excretion of metabolic waste (bilirubin, urea)
associated: pH regulation (H+ and bicarb) and endocrine function (RAAS, erythropoetin)

Question 2

4 components of urinary system

Answer 2

paired kidneys
paired ureters
urinary bladder
urethra

Question 3

function of kidneys

Answer 3

carry out all urinary functions

release urine to rest of system for excretion

Question 4

function of ureters

Answer 4

use peristalsis to direct urine to the urinary bladder - goes around and enters at bottom of urinary bladder

Question 5

function of urinary bladder

Answer 5

holds urine until triggered by stretch receptors to release contents into the urethra
release is controlled by both involuntary and voluntary sphincters
internal sphincter: smooth muscle, opens from stretch receptors
external sphincter: you have control over

Question 6

function of urethra

Answer 6

excretes urine from body

o the male: path for sperm ejaculation

Question 7

location of kidneys

Answer 7

retroperitoneally in abdominal cavity
-in abdominal cavity but parietal peritoneum goes over them, not behind them

kidneys themselves have capsule that protects them with loose CT over it infiltrated with adipose tissue to anchor them to the back wall of cavity

Question 8

inside of kidney

Answer 8

outer cortex and inner medulla layer
cortical extensions coming from it - columns break it up into lobes
filtration units- nephrons

Question 9

development of kidneys

Answer 9

develop as multiple lobes that fuse into one

Question 10

nephron function and types

Answer 10

longer (juxtaglomerular) - for additional reabsorption to get volume down
medullary and cortical

all put filtrate into collecting tubes that deposit it into membranous center, renal pelvis

Question 11

renal pelvis

Answer 11

has funnel like extensions that go down

Question 12

shape of lobes of kidneys

Answer 12

come to point - renal pyramid
each point comes down to a minor calix
2 or more minor calices use into major calices with fuse into renal pelvis

sometimes if lots of filtrate with particulate it sits - can get stones if pH is off aggregates and kidney stone formation in any area where renal pelvis or calices are

Question 13

urinary system pathway

Answer 13

kidney filters blood and concentrate urine
- can do for solute but if well hydrated concentration means dec in volume not solute

urine collected from kidneys is transported by ureters usinf peristalsis to the urinary bladder

urinary bladder temporarily holds urine until it is excreted through urethra

Question 14

nephron

Answer 14

unit of filtration
each kidney has ~ 1 million nephrons

total filtration: 180L/day
urine production 1-2L/day

most are cortical (short)

10-15% are juxtamedullary nephrons
- these inc reabsorption

Question 15

blood flow through kidney

Answer 15

aorta
renal artery
segmental artery
interlobar artery
arcuate artery
cortical radiate artery 

nephron

cortical radiate vein
arcuate vein
interlobar vein
renal vein
inferior vena cava

Question 16

blood flow through nephron of kidney

Answer 16

arcuate arches over renal pyramid, cortical radiate artery and then afferent arteriole to the nephron - goes into capillary bed, glomerulus is where filtration occurs
then efferent arterioles go to another capillary bed that is plexus of many branches - peritubular capillary plexus - reabsorption

Question 17

vasa recta

Answer 17

aka peritubular capillary plexus

takes in all the branches

Question 18

renal corpuscle

Answer 18

filtration
glomerulus: capillary bed and bowman capsule that gather filtrate from capillary bed
glomerular filtrate comes out and forms the vasa recta

Question 19

proximal convoluted tubules

Answer 19

reabsorbs nutrients (organics, ions, water - aquaporins) we want to keep from the filtrate, now known as tubular fluid
convoluted: bends backwards on itself, does a LOT of work
thicker areas: tube same size but walls are thicker
do not recapture urea
excretion of H+ !!

countercurrent Na+ in and H+ out
open channels: allow Na+ in
Na/K ATPase pump
throw bicarb out with some Na

Question 20

nephron loop (loop of henle)

Answer 20

establishes osmotic gradient in renal medulla
promotes water reabsorption from tubular fluid in nephron system
ascending loop: passage of salt
descending loop: passage of water
ascending influences the descending

Question 21

distal convoluted tubule

Answer 21

secretion and reabsorption
hormonally - ADH and aldosterone
if dehydrated can pull in more salt or let some go into collecting tubules into calices and then out

Question 22

what is the primary force of filtration in the glomerulus

Answer 22

hydrostatic P that will overcome the oncotic P in blood

Question 23

mesangial cells

Answer 23

supportive

involved in regulating glomerular filtration rate (GFR) and repairing damage

Question 24

GFR less than 60 =

GFR less than 15 =

Answer 24

less than 60=renal disease
less than 15= renal failure
as GFR goes down, metabolic wastes are staying in the body

Question 25

podocytes

Answer 25

specialized cells of glomerulus, wrap around blood vessel and give extra filtration, slits to go through

Question 26

why should you be careful with certain medications, autoimmune crisis, cancer treatments, antibody antigen complexes

Answer 26

when lots of debris you have stuff coming through that normally would not
can damage podocytes, can get bigger openings and blood cells or large proteins going through
inflammation closing off area, hard to filter

Question 27

actions of the loop of henle

Answer 27

set up an osmotic gradient through countercurrent flow and differential permeability btw the descending and ascending limbs

Question 28

ascending limb

Answer 28

permeable to salt AND urea, NOT water

Question 29

thick ascending limb in loop of Henle actions

Answer 29

• uses NKCC symporter to move ions from tubule
• Na/K ATPase pumps move Na into renal medulla/vasa recta
• antiporters exchange bicarb for Cl-
• K+ and Cl- passively move through facilitative diffusion

Question 30

distal convoluted tubule (DCT) actions

Answer 30

impermeable to water
continues Na and bicarb reabsorption
secretes K+ and NH4+
produces hypo-osmotic filtrate; filtrate 100mOsmol, medulla 300mOsmol

Question 31

collecting duct

Answer 31

contains ADH regulated aquaporins
depending on need to regulate aid or base:
-actively secretes H+
-antiport exchanger for Cl- and bicarbonate

Question 32

ureters

Answer 32

take urine through peristalsis waves to be collected into the bladder

Question 33

micturition (urination) reflex has 2 sphincters

Answer 33

internal and external

Question 34

internal urinary sphincter

Answer 34

in smooth muscle, under parasympathetic control

Question 35

external urinary sphincter

Answer 35

visceral striated, under voluntary control

Question 36

when does the stimulus of stretch receptors begin

Answer 36

when bladder has 200ml
causes contractions in the detrusor muscle and continues with every 100ml increase

at 500ml the voluntary control is overridden and you will urinate

Question 37

median umbilical ligament - urakus

Answer 37

remnant of umbilical
from midline of bladder right to the abdominal wall
on top of bladder this is the apex