Lecture 1: Into and Overview (Bolsor)

Question 0

which 2 organs have greatest control on extracellular pH? How?

Answer 0

lungs via elimination/retention of CO2

kidneys via reabsorption or secretion of H+ or HCO3

Question 1

Main functions of the kidney

Answer 1

1) removal of wastes

2) maintaining body fluid/electrolyte/acid-base balance

Question 2

what 3 systems control water balance, extracellular fluid osmolality and blood pressure?

Answer 2

CNS, Cardiovascular, and renal

Question 3

where is ADH released?

Answer 3

anterior pituitary gland

Question 4

increased venous volume –> ADH secretion?

Answer 4

decreases

Question 5

decreased plasma osmolality —> ADH release

Answer 5

decreases

Question 6

decreased ADH –> water excretion

Answer 6

increases

Question 7

Which is faster in it’s response to pH change: respiratory or renal system?

Answer 7

respiratory (but renal is usually needed for full compensation)

Question 8

what hormone controls sodium reabsorption by the kidneys? Where is it released?

Answer 8

aldosterone (adrenal gland)

Question 9

how do kidneys regulate blood pressure?

Answer 9

via regulation of extracellular water and electrolytes

Question 10

urea

Answer 10

a metabolic waste product that is important in the maintenance of the intrarenal medullary concentration gradient

Question 11

renin

Answer 11

released in response to reduced NaCl delivery to the macula densa. Catalyzes the formation of angiotensin II in the lungs, which then elicits the release of aldosterone from the adrenal cortex to increase Na reabsorption

Question 12

aldosterone fx in kidneys

Answer 12

stimulates sodium reabsorption

Question 13

common markers of renal failure

Answer 13

elevated metabolic waste products, such as urea, creatinine, bilirubin, and uric acid

Question 14

erythropoetin

Answer 14

renal hormone that stimulates erythrocyte production by bone marrow

Question 15

how are kidneys influential in communication?

Answer 15

urine can carry pheromones

Question 16

three renal capillary beds

Answer 16

1) glomerular
2) peritubular
3) vasa recta

Question 17

glomerular capillary bed

Answer 17

• specifically for filtration
• afferent and efferent arterioles within the glomerulus
• high BP forces solutes out of the blood

Question 18

peritubular capillary bed

Answer 18

• for absorption
• arises from efferent arterioles that drain the glomerulus
• operates under low pressure
• absorbs solutes and water from the tubules

Question 19

vasa recta capillary bed

Answer 19

• long, thin walled looping arterioles that follow the loop of Henle
• serve juxtamedullary nephrons

Question 20

what receptors detect decreased plasma volume and signal production of ADH?

Answer 20

atrial receptors

Question 21

increased renin –> angiotensin II

Answer 21

increases

Question 22

increased angiotensin II —> aldosterone

Answer 22

increases (see p. 8 diagram in scavma notes)

Question 23

Levels of multiscale systems physiology:

Answer 23

subcellular processes –> cellular processes –> tissue –> organ –> whole body –> behavior –> population. Each step influences the next. Physiology influences behavior

Question 24

initiation of hormonal cascade by renin ultimately stimulates which hormone?

Answer 24

aldosterone

Question 25

nephron

Answer 25

functional subunit of the kidney. Filtrates and reabsorbs arterial plasma components.

Question 26

Bowman's capsule

Answer 26

where plasma filtration occurs within a nephron. Always located in the renal cortex

Question 27

how does age effect #/size of nephrons?

Answer 27

As you get older, nephrons get fewer in number but larger in size

Question 28

proximal tubule

Answer 28

first part of nephron attached to the Bowman's capsule

Question 29

Flow from arcuate artery to bladder through the nephron (10 steps)

Answer 29

arcuate artery --> afferent arterioles --> Bowman's capsule --> proximal tubule --> loop of Henle --> distal tubule --> collecting duct --> renal pelvis --> ureters --> bladder

Question 30

What occurs in the afferent arterioles in kidney?

Answer 30

small molecules pass across the glomerular capillary epithelium into the Bowman's capsule

Question 31

when does "fluid" become "filtrate" in the kidney?

Answer 31

when it passes into the Bowman's capsule

Question 32

what happens in loop of Henle?

Answer 32

filtrate becomes more concentrated

Question 33

what happens in distal tubule of kidney?

Answer 33

sodium and water are removed and returned to the circulation

Question 34

primary site of action of ADH in the kidney

Answer 34

collecting ducts. Causes water reabsorption from tubular fluid

Question 35

juxtaglomerular apparatus

Answer 35

regulates renal blood flow and glomerular filtration rate. Formed when thick ascending limb of loop of Henle loops around to touch the vascular elements supplying the glomerular capillaries.

Question 36

macula densa

Answer 36

darkly staining band of cells in the thick ascending limb. Contain sodium sensing mechanisms that allow the kidney to regulate sodium balance by controlling blood flow through the glomerulus

Question 37

long or short loops of Henle more likely to be involved in urinary concentrating mechs?

Answer 37

Long

Question 38

3 types of cells in collecting ducts

Answer 38

1) Principal cells 2) Intercalated cells (type A) 3) Intercalated cells (type B)

Question 39

Principal cells

Answer 39

present in collecting ducts. Where ADH and aldosterone act to modify salt and H2O balance

Question 40

Type A intercalated cells

Answer 40

A stands for acid. Eliminate excess acid in collecting duct in case of acidemia

Question 41

Type B intercalated cells

Answer 41

B stands for base. Present in collecting ducts. Secrete base into the urine in case of alkalemia

Question 42

What area of the kidney are glomeruli ALWAYS located in? ***

Answer 42

the cortex

Question 43

Which structures of the nephron lie in the medulla?

Answer 43

collecting ducts, loop of Henle

Question 44

What structures of nephron lie in the cortex?

Answer 44

Glomerulus, proximal/distal tubules, part of the collecting ducts

Question 45

how does fluid osmolality change from outer cortex to inner medulla in the kidney?

Answer 45

osmolality increases as you move towards inner medulla. Cortex = isotonic

Question 46

thicker medulla --> ability to concentrate urine

Answer 46

increases

Question 47

xeric definition

Answer 47

something that needs very little water

Question 48

which groups of animals have loops of Henle in their nephrons?

Answer 48

Mammals and birds

Question 49

Which groups of animals have a renal portal system?

Answer 49

birds, reptiles, amphibians

Question 50

which groups of animals have a peritubular capillary network?

Answer 50

mammals only

Question 51

Which animals have salt glands?

Answer 51

birds and reptiles

Question 52

which animal groups excrete uric acid?

Answer 52

birds and reptiles

Question 53

Which species use "number of nephrons filtering" to regulate GFR?

Answer 53

birds, reptiles, amphibians

Question 54

Which group of animals uses "net filtration pressure" to regulate GFR?

Answer 54

mammals

Question 55

fx of salt glands

Answer 55

allows animals to excrete excess salt that kidneys alone could not accomplish

Question 56

how do salt glands and kidneys change in size with an increased salt load?

Answer 56

salt glands increase in size, kidneys don't change

Question 57

NaCl concentration in salt glands vs. kidneys

Answer 57

salt glands maintain constant NaCl concentration, while NaCl concentration varies in the kidney

Question 58

Composition of outflow in salt glands vs. kidneys

Answer 58

Salt glands --> almost exclusively NaCl | kidneys --> NaCl, K, other ions and inorganic solutes

Question 59

which has higher flow rate: salt glands or kidneys?

Answer 59

salt glands (2-fold higher)

Question 60

*vascular beds (primarily afferent and efferent arterioles) are control elements of circulation in the kidney*

Answer 60

:)