Unit 8: Urinary System

Question 1

What are the 4 layers that support the kidneys

Answer 1

1. Fibrous capsule
2. Perinephric fat
3. Renal fascia
4. Paranephric fat

Question 2

Fibrous capsule

Answer 2

adhered to external surface of kidney, dense irregular CT, maintains kidney shape and protection

Question 3

Perinephric fat

Answer 3

adipose CT, cushion and support

Question 4

Renal fascia

Answer 4

dense irregular CT, anchors kidney to surrounding structures

Question 5

Paranephric fat

Answer 5

outermost layer, adipose CT, cushion and support

Question 6

Kidney anatomy: Renal cortex

Answer 6

outer layer of functional tissue

Question 7

Kidney anatomy: Renal medulla

Answer 7

inner layer of functional tissue

Question 8

Kidney anatomy: Renal column

Answer 8

extension of cortex projecting into the medulla (divides kidney into 6-8 lobes)
- provide framework for vessels to enter and exit

Question 9

Kidney anatomy: Renal lobe

Answer 9

consists of a real pyramid (medulla) and renal cortex above it

Question 9

Kidney anatomy: Corticomedullary junction

Answer 9

wide base of medulla meets cortex

Question 10

Kidney anatomy: Renal sinus

Answer 10

Medially located, urine drainage area:
major calyces
minor calyces
renal pelvis

Question 11

Minor calyces

Answer 11

drain into major calyces

Question 12

major calyces

Answer 12

drains into renal pelvis

Question 13

nephron

Answer 13

microscopic functional unit of kidney, modify filtrate into urine (filtrate> tubular fluid > urine)
- nephrons function to balance plasma to homeostatic set points and excrete toxins, they do this with 3 main functions

Question 14

What are the three main functions of the nephron

Answer 14

filtration
reabsorption
secretion

Question 15

filtration

Answer 15

blood enters glomerulus, forces fluid into nephron
regulated by; fenestrations - pores - capillary endothelial cells, filter based on size
podocytes - found on visceral layer, filtration slits, filter based on size
membrane charge - proteins embedded within pored are negatively charged
basement membrane - prevents medium-large proteins based on size

Question 16

Reabsorption

Answer 16

moves nutrients and water back into bloodstream, from tubular fluid to the blood

Question 17

Secretion

Answer 17

moves nutrients and water back into bloodstream, from tubular fluid to the blood

Question 18

renal corpuscle

Answer 18

major structure of nephron, filters blood plasma based on particles size, bulbous region, within cortex composed of: glomerulus, glomerular capillaries, and glomerular capsule

Question 19

Glomerulus

Answer 19

tangle of capillary loops (capillary bed)

Question 20

Glomerular capillaries

Answer 20

fenestrated

Question 21

glomerular capsule

Answer 21

visceral layer - directly overlies glomerular capillaries internal permeable
- parietal layer - external permeable
- capsular space - space between layers; receives filtration

Question 22

Juxtaglomerular (JG) apparatus

Answer 22

• at the junction where the afferent and efferent arterioles enter and leave the capsule - initial part of the DCT meets the arterioles

Question 23

Granular cells

Answer 23

modified smooth muscle cells - can contract and relax
- line the afferent arteriole

Question 24

macula densa

Answer 24

monitors fluid composition - NaCl concentration - DCT - signaling for renin release

Question 25

Renal tubule

Answer 25

major structure of nephron, secretion and reabsorption - proximal convoluted tubule (PCT)

Question 26

Nephron loop

Answer 26

specialized to recover sodium and water from the tubular fluid *gradient pulls water out of the tubular fluid*

Question 27

Countercurrent multiplier

Answer 27

creates the concentration gradient - fluid of descending and ascending loops flow in opposite directions (countercurrent) - solute pumps increases concentrations (multiplier)

Question 28

Descending Limb

Answer 28

permeable to water impermeable to salts

Question 29

Ascending limb (pump)

Answer 29

Impermeable to water permeable to salts

Question 30

What are the two types of neurons

Answer 30

Cortical nephron Juxtamedullary nephron

Question 31

Cortical nephron

Answer 31

- renal corpuscles near peripheral cortex - short nephron loop - 85% of nephrons

Question 32

Juxtamedullary nephron

Answer 32

- renal corpuscle adjacent to corticomedullary junction - long nephron loops - helps to establish salt concentration gradient - 15% of nephrons

Question 33

where do collecting tubules drain into

Answer 33

the nephrons drain into collecting ducts

Question 34

afferent arterioles branch...

Answer 34

branch of artery that enters glomerulus

Question 35

efferent arterioles

Answer 35

blood exiting through glomerulus, branches into 2 capillaries: peritubular capillaries Vasa recta

Question 36

peritubular capillaries

Answer 36

intertwined around PCT and DCT, cortex

Question 37

Vasa recta

Answer 37

associated with nephron loop, medulla

Question 38

filtrate

Answer 38

formed when blood flows through glomerulus and some of the plasma enters the capsular space

Question 39

tubular fluid

Answer 39

once filtrate enters the PCT

Question 40

Urine

Answer 40

flows within the renal sinus to ureter, bladder and urethra

Question 41

glomerular filtration rate

Answer 41

volume of filtrate formed by both kidneys per minute - influences by hydrostatic pressure and colloid osmotic pressure (OP) on either side of capillary membrane of glomerulus

Question 42

filtration membrane

Answer 42

a porous, thin, and negatively charged structure that serves as a filter. It is composed of three sandwiched layers formed by two layers of the glomerulus and the visceral layer of the glomerular capsule

Question 43

what is required for a substance in the blood to become part of the filtrate

Answer 43

it must be able to pass through these three layers of the 'filter', from innermost to outermost: endothelium of glomerulus basement membrane of glomerulus and visceral layer of glomerular capsule

Question 44

endothelium of glomerulus

Answer 44

is fenestrated. It allows plasma and its dissolved substances to be filtered while restricting the passage of large structures, such as the formed elements (erythrocytes, leukocytes, and platelets)

Question 45

Basement membrane of glomerulus

Answer 45

the porous basement membrane is composed of glycoprotein and proteoglycan molecules. It restricts the passage of larger plasma proteins, such as albumin, while allowing smaller substances to pass through

Question 46

visceral layer of glomerular capsule

Answer 46

is composed of specialized cells called podocytes