Lecture 28: Kidneys

Question 1

adrenal glands also called

Answer 1

suprarenal

Question 2

outer part of kidney is

Answer 2

cortex

Question 3

what is the medulla

Answer 3

cortex and pyramid

Question 4

what separates diffferent pyramids

Answer 4

the columns

Question 5

where do the artery vein and ureter meet

Answer 5

hillum

Question 6

what does the ureter divide into

Answer 6

major and minor calyces

Question 7

what is attached to each minor calyce

Answer 7

medullary pyramid (medulla delimited by extensions of cortex)

Question 8

purpose of kidneys (basic)

Answer 8

filter blood and produce urine

Question 9

three things urine formation involves

Answer 9

filtration, secretion, reabsorption of fluid by renal corpuscles and tubules

Question 10

how much fluid filtered daily vs how much urine produces

Answer 10

180 L filtered, 1-2 liters of urine produced

Question 11

function of kidneys (more specific)

Answer 11

1- remove metabolic waste products, foreign substances, and drugs.
2- regulate vol and composition of water and electrolytes in extracellular fluid
3- control acid base balance

Question 12

what do kidneys synthesize

Answer 12

1) renine (regulation of arterial blood, ENDOCRINE)
2) erythropoietin (stim erythrocyte production in bone marrow ENDOCRINE)
3) convert vit D into active form for calcium balance
4) glucogenesis to make glucose from AA during starvation

Question 13

what is a nephron

Answer 13

functional unit of kidney

Question 14

how many nephrons per kidney

Answer 14

1 million

Question 15

what is the nephron composed of

Answer 15

renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule

Question 16

renal corpuscle

Answer 16

bowman’s capsule and glomerulus

Question 17

bowman’s capsule

Answer 17

parietal layer, visceral layer (podocytes) and bowman’s/urinary space

Question 18

glomerulus

Answer 18

tuft of capillaries supported by the mesangium (mesangial cells and ECM)

Question 19

loop of henle

Answer 19

thick descending limb (of proximal tubule) + thin limbs + thick ascending limb (of distal tubule)

Question 20

what does the nephron NOT include

Answer 20

collecting duct- different embryologic origin but functionally connected to nephron and VERY important

Question 21

where do nephrons originate

Answer 21

cortex at the renal corpuscle

Question 22

where is the thickest part of the ascending limb

Answer 22

macula densa (contact point of arterioles entering the flomerulus)

Question 23

what do the connecting tubules connect to on both sides

Answer 23

distal convoluted tubule and collecting duct

Question 24

what does the collecting duct do

Answer 24

transport urine to calyx

Question 25

the visceral layer of bowmans is composed of

Answer 25

modified epithelial cells called podocytes

Question 26

what vessel supplies the glomerulus and ddrains it

Answer 26

afferent glomerular arteriole and drained by efferent

Question 27

describe the path into the kidney

Answer 27

renal artery to afferent arteriole to capillaries (located in glomerulus and surrounded by mesangium)

Question 28

describe the path out of the kidney

Answer 28

capillaries to efferent arteriole to capillaries surrounding tubules OR vasa recta wrapping around loop of henle in medula to renal vein

Question 29

what does podocyte cytoplasm contain

Answer 29

actin filaments, lysosomes, and microtubules because it has contractile and phagocytic functions FORM PART OF GLOMELULAR BM

Question 30

what do podocyte primary foot processes give rise to

Answer 30

secondary foot proesses that rest on GBM and form filtration slits

Question 31

function of mesangium

Answer 31

mechanical support for glomelular capillaries

Question 32

Structural relationship of mesangium and glomerular capillaries

Answer 32

The capillary wall is deficient in BM at the site of attachment to the measngium, and the endothelial cells lie directly on the masangium.

Question 33

mesangial cells specific function

Answer 33

1) matrix production (support glomeular cap) 2) contractile (impact filtration) 3) vasoactive substance (endothelins induce constriction of afferent and efferent arterioles) 4) phagocytic (immune complex) 5) proliferative (in glomelular disease)

Question 34

cells in PCT vs DCT (Shape)

Answer 34

both simple cuboidal but proximal has brush border and a ragged luminal border

Question 35

LM cytoplasm and nuclei in PCT vs CT

Answer 35

PCT: cytoplasm is eosinophilic and nuclei is central or near base DCT: cytoplasm is pale, nuclei is towards the lumen

Question 36

LM nuclei number and cell border in PCT vs DCT

Answer 36

``` PCT = fewer nuclei per tubular XS and indictinct cell borders DCT = more nuclei per XS and cell borders are more distinct ```

Question 37

what absorbs 80% of ultrafiltrate

Answer 37

apical surface microvilli

Question 38

what do microvilli membranes do

Answer 38

transport proteins for transporting Na+, amino acids, and glucose into the cell

Question 39

what do endocytic vesicles and lysosomes do

Answer 39

absorption and degratation of filtered proteins

Question 40

what do BM plasma membranes do

Answer 40

Na K ATPase pump for active transport of sodium. AA and glucose also transported out of the cell

Question 41

what do mitochondria do

Answer 41

energy production for active transport

Question 42

function of BM plasma membrane infoldings in DCT

Answer 42

NA K ATPase pump for active transport of Na from tubular fluid to renal interstitium

Question 43

what hormone mediates active transport of sodium

Answer 43

aldosterone secreted by adrenal cortex

Question 44

what do thin limbs of loop do

Answer 44

generate potential to concentrate urine

Question 45

what does vasa recta contain

Answer 45

blood that has been filtered through the glomerulus

Question 46

what does the vasa recta do

Answer 46

provide nourishment and oxygen to medullary tissue

Question 47

collecting duct function

Answer 47

reabsorption of water from the ducts - controlled by antidiuretic hormon (ADH, vasopressin) from posterior pituitary

Question 48

justaglomeular apparatur is involved in

Answer 48

regulation of systemic blood pressure via renin-angiotensin-aldosterone system

Question 49

JG apparatus composed of

Answer 49

macula densa of DCT JG cells (renin producing, protease) Extragolmerular mesangial cells (lacis cells)

Question 50

where are JG cells found and what kind are they

Answer 50

modified smooth muscle in afferent arterioles containing renin but a few may be present in efferent

Question 51

is kidney endocrine or exocrine

Answer 51

endocrine

Question 52

exrectory passage

Answer 52

calyces, renal pelvis, ureter, urinary bladder, proximal urethera

Question 53

urinary bladder function

Answer 53

conduit of urine

Question 54

urinary bladder characteristics

Answer 54

impervious to water, resistant to bacteria, stretch to cover varying size of bladder (the cells do), there are plaques also btu we dont know why might just be for membrane strength and impermeability