Histology of the Kidney

Question 1

what is the name of the hormone that increases the production of red blood cells

Answer 1

erythopoietin

Question 2

what is erythopoietin

Answer 2

a hormone that increases the production of red blood cells

Question 3

where are nephrons found

Answer 3

at the junction between the cortex and the medulla of the kidney

Question 4

give a summary of the renal corpuscle

Answer 4

• a spherical structure in the cortex of the kidney that is foudn at the beginning of each nephrons
• it has a bowmans capsule, glomerulus, and urinary poles

Question 5

what is the bowmans capsule

Answer 5

a double layer epithelial capsule

Question 6

describe the outer layer of bowmans capsule

Answer 6

the outer layer is flat simple squamous epithelium.

Question 7

describe the inner layer of the bowmans capsule

Answer 7

made up of complex epithelial cells called podocytes, with large oval nuclei. they wrap around each of the capillaries and form narrow slits between the cells which filter blood to form the ultrafiltrate

Question 8

what is the glomerulus

Answer 8

a tuft of capillaries that supplies blood that is filtered to become the fluid known as filtrate.

Question 9

what allows the supply and draining of glomerular capillaries

Answer 9

the vascular pole

Question 10

what do the urinary poles do

Answer 10

these are where the ultrafiltrate is drained from the capsular space into the proximal convoluted tubule

Question 11

what is the function of the proximal convoluted tubule

Answer 11

reabsorbs the substances the body wants to keep, including organic nutrients, proteins and most of the water and electrolytes.
secretes anions and cations like hydrogen and ammonium into the lumen of the tubule for excretion

Question 12

why can the proximal convuluted tubule only be seen in cross sections

Answer 12

due to its winding path through the cortex

Question 13

describe the walls of the proximal convoluted tubules

Answer 13

simple cubioidal or columnar epithelial cells with long microvilli.

Question 14

describe the cytoplasm of the proximal convuluted tubule

Answer 14

eosinophilic

Question 15

what are the elements of the loops of henle

Answer 15

there is the proximal straight tubule, distal straight tubule, and the thin descending and ascending limb

Question 16

describe the proximal straight tubule

Answer 16

beginning of the loops of henle. thick descending limb. simple cuboidal or columnar epithelium and long microvilli.

Question 17

describe the thin descending and ascending limb

Answer 17

simple squamous epithelium that passively reabsorbs water.

Question 18

describe the distal straight tubule

Answer 18

end of the loops of henle. thick ascending limb. starts in the medulla and ascends into the cortex. reabsorbs electrolytes. simple cuboidal epithelial cells. has unclear borders between the cells and noticeably lighter staining

Question 19

what is the macula densa

Answer 19

this is the area at the junction between the thick ascending lumb and the distal convoluted tubule. it has tightly packed cells and faces the arterioles. the cells have taller bodies and prominent nuclei.

Question 20

describe the distal convoluted tubule

Answer 20

has shorter microvilli and lighter staining compared to proximal convoluted tubules. it reabsorbs sodium and chloride to make urine hypotonic

Question 21

what does the collecting duct do

Answer 21

this drains urine from the nephron into the minor calyx at the apex of a renal pyramid and can also regulate electrolyte and fluid balance.

Question 22

what are mesangial cells

Answer 22

large cells with irregular, dark nuclei found in the glomerulus
has contractile properties to regulate the amount of blood flowing to the glomerular capillaries. it is also involved in immune defense and repair of the glomerulus

Question 23

what do the walls of the collecting duct consist of

Answer 23

simple cuboidal or columnar epithelial cells with well defined borders. it is lightly stained as it is not very eosinophilic

Question 24

how does the collecting duct regulate electrolyte and fluid balance

Answer 24

by reabsorbing water from the filtrate as needed as well as secreting or absorbing various electrolytes

Question 25

what does the macula densa do

Answer 25

it can detect changes in the sodium chloride levels in the tubule to trigger an autoregulatory response to maintain normal blood pressure and volume