CH 8 Urinary System

gross anatomy of urinary system (macroscopic)

kidneys, ureters, urinary bladder, urethra

main function of urinary system

produce urine by filtering the blood (plasma)

what part of the blood does urinary system filter

plasma

what structures give the urinary system its ability to filter blood?

the glomeruli

define glomerulus

a specialized cluster of capillaries in the nephron

each kidney is directly surrounded by a

renal capsule

the uretur, renal vein, renal artery, and nerves enter the kidney through the

hilum

Which part of the blood is filtered by kidneys

plasma

surrounding each kidney (superficial to the renal capsule) is _________ tissue

adipose

the golmeruli filter _______ based on _____

blood based on particle size

T/F: the glomeruli filter in red blood cells

F

T/F: the glomeruli filter in antibodies

F

The kidney filtration excludes:

the formed elements

the glomerulus is the first part of the

nephron

define nephron

functional units of the kidney that carry out all filtration to produce urine

components of the nephron

corpuscles, proximal/distal convoluted tubules, ascending/descending loops of Henle

nephrons drain into the

collecting duct

the 2 types of convoluted tubules:

proximal and distal

the 2 types of loops of Henle

ascending and descending

renal corpuscle

consists of the glomerulus and bowmans capsule

whats the difference between the glomerulus and renal corpuscle

glomerulus: bunch of capillaries

renal corpuscle: the glomerulus + bowmans capsule surrounding it

T/F: the glomerulus filters ions

T

T/F the glomerulus filters vitamins

T

The glomeruli filter solutes such as:

vitamins, ions, amino acids

T/F: the glomeruli filter solutes in the blood and produce urine

F: they produce filtrate not urine

difference between filtrate and urine

filtrate: the fluid produed when blood is filtered by the glomerulus

urine: the fluid thats made when the filtrate passes through the collecting ducts

T/F collecting ducts are a part of the nephron

F

the characteristics of a persons urine can be used to tell their

hydration

T/F: the characteristics of urine can change with excercise

T

What factors can change urines characteristics

excercise, outside temp, hydration, nutrient intake

What sould NOT be present in normal urine

glucose, ketones, nitrates, formed elements, most proteins

define oliguria

below average urine output

define polyuria

excessive urine production

define anuria

abscence of urine production

T/F: all structures involved in urine transport can be seen with the naked eye

T

how do the fluids change as theyre transported through the urinary system

Blood is filtered, and then the resulting filtrate is turned into urine

You see a model of a urinary system and the urethras length is 20 cm (long) with a gland directly below the bladder, what sex is it

male

You see a model of a urinary system and the urethras length is 4 cm (short) and no gland is present, what sex is it

female

how does the urethras length impact pathogen defense

a short urethra is less of a barrier to bacteria

voiding is another word for

urination

voiding is regulated by

the internal and external urinary sphincters

is movement of the internal urinary sphincter voluntary or involintary?

involuntary

is movement of the external urinary sphincter voluntary or involintary?

voluntary

Voluntary control of the external urethral sphincter is a function of which nerve?

pudendal

the pudendal nerve is responsible for voluntary control of the ____________

external urethral sphincter

what type of muscle is the internal urinary sphincter made of

smooth muscle

what type of muscle is the external urinary sphincter made of

skeletal muscle

reigons of the male urethra

1. pre prostatic

2. prostatic

3. membranous

4. spongy

innervation of the urethra in males vs females

no difference theyre the same

function of the urinary bladder

collect urine from the ureturs

is the bladder is a peritoneal or retroperitoneal organ?

partially retroperitoneal

are the kidneys and ureters retroperitoneal or peritoneal?

completely retroperitoneal

why is the bladder only partially retroperitoneal

the bladder has a peritoneal covering only on its dome

how are the ureters placed into the bladder to prevent backflow?

they turn medially as they approach the bladder and peirce it obliquely

why is the specific placement of the ureters in the bladder important?

it creates a one way valve (physiological sphincter) preventing reflux of urine

children born lacking the oblique insertion of the ureter through the bladder are prone to

vesicoureteral reflux

define vesicoureteral reflux

backflow of the urine

besides being born with ureter defects, ________ also increaeses risk of vesicoureteral reflux

pregnancy

vesicoureteral reflux dramitcally increases the risk of

UTI

micturition is another word for

urination or voiding

define micturition reflex

the autonomic reflex to pee once your bladder is filled past a certain point

the micturition reflex in infants vs children/adults`

micturition reflex is active in infants but with maturity children learn to override the relfex

nerves involved in the control of urination (holding in pee)

hypogastric, pelvic, and pudendal

T/F: the kidneys are not well vascularized

F

the kidneys are externally protected by:

muscle, fat, 11th-12th ribs

how much cardiac output is recived by the kidneys

the kidneys recive 25% of cardiac output

why are kidneys well vascularized

their function is to filter the blood so they need a large blood supply

The renal capsule is directly surrounded by a layer of _____ called the ______

layer of adipose tissue called the renal fat pat

the renal fat pad is directly surrounded by the:

renal fascia

T or F: some of the filtrate gets reabsorbed into the interstitial fluid instead of getting turned into urine

T

T or F: all of the filtrate produced by the glomerulus gets turned into urine, none of it gets reabsorbed

F

Different parts of the nephron utilize these specific processes to produce urine:

filtration, reabsorption, secretion

GFR

glomerular filtration rate

what % of blood enters the kidneys to be filtered

20

how much blood is pumped by the heart under resting conditions (in L)

5 L

what % of filtrate is reabsorbed into circulation

99%

average amount of filtrate produced per day (for both sexes)

150 or 180

why do we only produce 1-2 L of urine if we produce 150-180 L of filtrate?

99% of filtrate gets reabsorbed

how does filtrate get “reabsorbed”

it crosses the barrier of the nephron and goes into the interstitial fluid

primary functions of nephrons

balance the plasma contents to specific levels and excrete toxins through the urine

secondary functions of nephrons

control: BP, red blood cell production, and calcium absorption

function of the Bowmans capsule

captures and directs filtrate into the proximal convoluted tubule

features of the renal corpuscle that allow for filtration

fenestrations in the glomerulus, podocytes, pedicles of the podocytes.

the features of the renal corpuscle that facillitate filtration are collectively called:

the filtration membrane

what types of capillaries are in the glomerulus

fenestrated

Afferent Arteriole

vessel is feeding INTO glomerulus

the glomerular basement membrane is _____ charged

negatively

most proteins of the plasma such as albumin are _____ charged

negatively

because the glomerular basement membrane is negatively charged, it repels _____ charged substances and attracts _____ charged subtances

negative, positive

the neg charged glomerular basement membrane attracts positively charged substances such as

electrolytes

what filtration barriers must solutes pass in the renal corpuscle

1. fenestrations in glom. capillaries

2. glomelular basement membrane

3. gaps between podocyte fingers (filtration slits)

the gaps between podocyte pedicles are called:

filtration slits

in the renal corpuscle, filtration slits (podocyte gaps) filter molecules based on:

size

in the renal corpuscle, the basement membrane filters molecules via their

pos or neg scharge

the fenestrations in the renal corpuscle filter filter molecules based on ______, preventing what kind of substances from entering?

size, large proteins and blood cells

the glomular capillaries have _____ pressure

high

what percentage of glomerular filtrate gets reabsorbed

99%