Unit 5 urinary system

Question 1

functions of the urinary system

Answer 1

filter and cleanse blood!
-regulation of blood composition, volume, and pH
-excretion of metabolic wastes (urea, uric acid, creatinine)
-secretion of hormones

Question 2

structure of kidneys

Answer 2

right and left, anterior is covered by peritoneum, some protection from rib cage

Question 3

function of ureters

Answer 3

walls contract to conduct urine from kidney to urinary bladder by peristalsis

Question 4

function of urinary bladder

Answer 4

expandable, stores urine, three openings. detrusor (smooth) muscle contracts to release urine

Question 5

function of urethra

Answer 5

tube from bladder to external orifice. Males is longer, carries urine and semen.

Question 6

Structures of the kidneys

Answer 6

-hilum
-adrenal gland
-fibrous capsule

Question 7

hilum function

Answer 7

entry/exit for ureter and renal A&V

Question 8

adrenal gland function

Answer 8

cortex produces steroid hormones, medulla produces epinephrine and norepinephrine

Question 9

fibrous capsule function

Answer 9

covers each kidney

Question 10

internal features of the kidney

Answer 10

-renal cortex: outermost region
-medulla: middle region, contains pyramids and coulmns
-pelvis: innermost region, collection of urine from all major calyces

Question 11

urine flow

Answer 11

1. wastes collected in collecting duct (located inside renal pyramid of renal medulla)
2. empties into minor calyx then major calyx
3. drains into renal pelvis-> ureter-> bladder->urethra-> external orifice

Question 12

blood flow

Answer 12

aorta-> renal artery-> segmental artery-> interlobar artery-> arculate artery-> cortical radiate artery-> afferent arterioles-> glomerulus (capillary)-> efferent arteriole-> peritubular capillary-> renal vein-> IVC

Question 12

nephron structure

Answer 12

microscopic system of tubules intertwined with capillaries

Question 13

nephron function

Answer 13

urine producing units. occurs through filtration, reabsorption, secretion

Question 14

cortical nephrons

Answer 14

located mostly in cortex. associated with peritubular capillaries.

Question 15

juxtamedullary nephrons

Answer 15

located in both cortex and medulla. associated with vasa recta

Question 16

regions of a nephron

Answer 16

renal corpuscle (glomerulus and glomerular capsule), renal tubules, proximal convuluted tubule (PCT), loop of the nephron. distal convuluted tubule (DCT), multiple nephrons drain into a collecting duct

Question 17

glomerular capsule structure

Answer 17

hollow cup like structure. parietal layer: simple squamous epithelium. visceral layer: podocytes surrounding glomerulus (part of filtration membrane)

Question 18

glomerulus structue

Answer 18

fenestrated capillaries (moderately permeable). filtrate=solute-rich lfuid from blood that enters the capsular space.

Question 19

PCT structure

Answer 19

cuboidal epithelium with dense microvilli, proximal to corpuscle. microvilli= brush border increases SA for reabsorption

Question 20

DCT structure

Answer 20

cuboidal epithelium with few microvilli, distal to corpuscle

Question 21

which structure has more absorption: PCT or DCT and why?

Answer 21

PCT has more absorption because of the increased Surface Area due to more microvilli.

Question 22

loop of nephron structure

Answer 22

u-shaped loop, with descending then ascending limbs, portions may be thick or thin

Question 23

collecting duct structure

Answer 23

not part of nephron! located within renal pyramids, collects filtrate from many nephrons. ducts fuse, then dump filtrate into minor calyces. cells regulate water balance

Question 24

urine formation steps

Answer 24

1. glomelular filtration 2. tubular reabsorption 3. tubular secretion

Question 25

filtration membrane structure

Answer 25

separating blood and inside of capsule

Question 26

fenestrated endothelium of capillary

Answer 26

pores allow everything but blood cells to pass through

Question 27

basement membrane (basal lamina)

Answer 27

glycoproteins that block large proteins (also repels proteins due to negative charge)

Question 28

foor processes of podocytes

Answer 28

membranes between processes trap any macromolecules

Question 29

what enters the tubules of the nephron?

Answer 29

enters capsular space, becomes filtrate: water, solutes, nutrients, nitrogenous wastes REMAINS IN CAPILLARY: blood cells, plasma proteins

Question 30

Glomerular filtration is like what?

Answer 30

washing grapes in a strainer grapes represent blood cells

Question 31

renal artery branches into many smaller arterioles,

Answer 31

arteriole brings blood to glomerulus

Question 32

filtration

Answer 32

passive process where blood is filtered

Question 33

filtrate enters capsular space due to...

Answer 33

hydrostatic forces

Question 34

what remains in capillary after glomerular filtration?

Answer 34

blood cells and plasma proteins!

Question 35

increase in glomerular filtration rate (GFR) is caused by...

Answer 35

increase in urine output, decrease in blood volume and pressure

Question 36

glomerular filtration rate (GFR) is affected by

Answer 36

-filtration pressures (main factor) -surface area available -permeability

Question 37

glomerular filtration rate (GFR) is highly regulated by

Answer 37

-autoregulation (intrinsic control) -nervous and endocrine systems (extrinsic controls)

Question 38

pressures in the glomerulus:

Answer 38

include hydrostatic and osmotic pressures of glomerular capillary vs. capsular space

Question 39

positive NFP means..

Answer 39

outward pressures greater than inward pressures, fluid moves out of capillary into capsular space

Question 40

Tubular reabsorption key idea

Answer 40

water and solutes return to capillary (from nephron tubules-> to peritubular capillaries)

Question 41

at the PCT what are reabsorbed and where?

Answer 41

water, nutrients, and ions are reabsorbed. they are reabsorbed into peritubular capillaries.

Question 42

transport occurs through which routes?

Answer 42

trans or paracellular routes

Question 43

how does sodium cross the apical membrane?

Answer 43

secondary active transport

Question 44

how does sodium pass the basolateral membrane?

Answer 44

primary active transport

Question 45

how do glucose and amino acids pass the apical membrane?

Answer 45

secondary active transport

Question 46

how do glucose and amino acids pass the basolateral membrane?

Answer 46

facilitated diffusion

Question 47

what is passively absorbed?

Answer 47

-lipid-soluble substances by simple diffusion -Ions and urea through paracellular diffusion -water by osmosis through aquaporins

Question 48

which tubule absorbs the majority of the filtrate?

Answer 48

PCT

Question 49

transport proteins are _ to substance and _.

Answer 49

specific, limited

Question 50

when transporters are saturated...

Answer 50

maximum transport is met, so excess excreted in urine. Occurs with diabetes-> glucose in urine

Question 51

what is reabsorbed by osmosis?

Answer 51

water

Question 52

the ascending limb is impermeable to what? so it reabsorbs what?

Answer 52

water, solutes reabsorbed by secondary active transport

Question 53

the descending limb is impermeable to what? so it reabsorbs what?

Answer 53

solutes, water reabsorbed by osmosis