Lecture 23

Question 1

what are the 6 functions of kidneys?

Answer 1

regulation: BP, ECF volume, osmolarity | maintain ion balance | homeostatic regulation of pH | excrete waste | produce hormones

Question 2

What hormone do kidneys produce?

Answer 2

erythropoietin

Question 3

Can you live with 1 kidney?

Answer 3

yes

Question 4

What is a nephron?

Answer 4

smallest functional unit of the kidney

Question 5

What role do major blood vessels and blood pressure play in the renal system?

Answer 5

dictates how much filtration will go into the lumen of the nephron | increase BP = increase filtration

Question 6

What are nephrons made out of?

Answer 6

epithelial cells

Question 7

What does the lumen of the nephron collect?

Answer 7

filtrate = water, urine, waste

Question 8

What is the capsule of a nephron?

Answer 8

connective tissue covering the kidney

Question 9

What is the cortical medulla?

Answer 9

inner section of the kidney

Question 10

What is a key characteristic of the cortical medulla?

Answer 10

contains a concentration gradient of solutes and an osmolarity difference between both sides of the medulla

Question 11

What is important about nephrons being vascularized throughout the kidney cortex?

Answer 11

increase surface area = more things can move from the blood to the nephron lumen (vice-versa) = more things can be filtrated

Question 12

What are the 2 types of nephrons?

Answer 12

cortical nephrons | juxtamedullary nephrons

Question 13

What are cortical nephrons?

Answer 13

nephrons only within the cortex of the kidney

Question 14

What are juxtamedullary nephrons?

Answer 14

nephrons within and next to the medulla of the kidney

Question 15

What major role do juxtamedullary nephrons play? What do they have on their surfaces?

Answer 15

major role in reabsorption | has different sets of protein channels for different types of molecules, all under control by a hormone (vasopressin)

Question 16

What are the 2 types of capillary beds intertwining the nephrons?

Answer 16

peritubular capillaries and vasa recta

Question 17

What are the peritubular capillaries?

Answer 17

capillaries closely associated with the rest of the nephron from the glomerulus

Question 18

What is the vasa recta?

Answer 18

peritubular capillaries of the juxtamedullary nephrons

Question 19

What are the 3 nephron structures does the cortex of the kidney contain?

Answer 19

Bowman’s capsules | proximal tubules | distal tubules

Question 20

What are 2 nephron structures does the medulla of the nephron contain?

Answer 20

loop of Henle | collecting ducts

Question 21

What is the glomerulus?

Answer 21

site of filtration

Question 22

What is the Bowman’s capsule?

Answer 22

encapsulates the glomerulus

Question 23

What is the proximal tubule?

Answer 23

first segment of nephron after glomerulus

Question 24

What is the distal tubule?

Answer 24

connects to the collecting duct

Question 25

What is the collecting duct?

Answer 25

empties filtrate and secreted fluids into renal pelvis --> bladder

Question 26

How many nephrons can connect to one collecting duct?

Answer 26

many

Question 27

Percentage-wise, about how many nephrons are contained within the cortex of the kidney and in the medulla of the kidney?

Answer 27

80% cortical nephrons | 20% juxtamedullary nephrons

Question 28

What is the portal system in the kidney?

Answer 28

capillary beds in series

Question 29

What is the renal corpuscle?

Answer 29

glomerulus + Bowman's capsule

Question 30

What are the 4 sets of membranes that filtration, secretion, and excretion go through?

Answer 30

2 in nephrons and 2 in capillaries

Question 31

What is the juxtaglomerular apparatus?

Answer 31

when ascending limb of the nephron comes into contact with the glomerulus

Question 32

What is the important role in which the juxtaglomerular apparatus plays in?

Answer 32

secretion of renin

Question 33

What are the macula densa cells?

Answer 33

sense distal tubule flow and release hormones renin = affect afferent arteriole diameter

Question 34

What is renin?

Answer 34

an enzyme involved in salt and water balance | can change/regulate BP

Question 35

What factor affects the reabsorption capacity of a nephron?

Answer 35

the length of the descending and ascending limbs of the LOH

Question 36

Which nephron is longer?

Answer 36

juxtamedullary nephrons

Question 37

What are the 3 hormones that control the kidney?

Answer 37

vasopressin | calcitonin | parathyroid hormone

Question 38

What are the 3 basic processes of the nephron?

Answer 38

filtration | reabsorption | secretion

Question 39

What is filtration?

Answer 39

fluid moves from blood to nephron lumen | ONLY in renal corpuscle | considered to be outside of body

Question 40

What is reabsorption?

Answer 40

fluid moves from filtrate back into blood vessels = peritubular capillaries

Question 41

What is secretion?

Answer 41

selective movement = use of transporters and channels | fluid moves from blood to filtrate