histology

Question 1

functions of the kidney and urinary tract

Answer 1

• maintain water and electrolyte homeostasis, body fluid osmolarity and acid-base balance
• excrete toxic metabolic waste products
• act as an endocrine gland, producing renin and erythropoietin

Question 2

what is the kidney covered in

Answer 2

capsule of dense collagen fibres

Question 3

what is the hilum

Answer 3

site of entry of renal artery and exit of renal vein and ureter

Question 4

what are the lobes of the kidney

Answer 4

each medullary pyramid and its associated cortical tissue

Question 5

label this

Answer 5

Question 6

what is the renal sinus filled with

Answer 6

adipose tissue

Question 7

what part of the kidney is this

Answer 7

the capsule

Question 8

what are nephrons composed of

Answer 8

renal corpuscle

renal tubules

Question 9

what does the renal corpuscle do

Answer 9

production and collection of glomerular filtrate

Question 10

what is the renal corpuscle formed from

Answer 10

a tuft of capillaries called the glomerulus and the cup of simple squamous epithelium at the blind end of the nephron which the capillaries invaginate into (bowman’s capsule)

Question 11

what are podocytes

Answer 11

specialised epithelium which lies on top of the glomerular capillaries

Question 12

what are the two pores of the renal corpuscle

Answer 12

vascular pole

urinary pole

Question 13

what holds the capillaries together in the renal corpuscle

Answer 13

mesangial cells

Question 14

what are the three components of the glomerular filter

Answer 14

• fenestrated endothelium of the cell wall
• thick basement membrane
• filtration slits between pedicels

Question 15

function of proximal convoluted tubule

Answer 15

reabsorption of water, proteins, amino acids, carbs and glucose

Question 16

what happens in proximal tubule

Answer 16

• 70% of sodium and water is reabsorbed

- almost all glucose and amino acids reabsorbed

Question 17

what is the medulla made up of

Answer 17

• paralelle tubules
• loops of henle
• collecting ducts
• a looping vascular network

Question 18

function of loop of Henle

Answer 18

creation of hyperosmotic environment in medulla

Question 19

what does the loop of Henle consist of

Answer 19

• thick descending limb
• thin descending limb which makes the loop
• thick ascending limb

Question 20

what are the thick limbs lined with

Answer 20

simple cuboidal epithelium

Question 21

what are the thin limbs lined with

Answer 21

simple squamous epithelium

Question 22

what is the vasa recta

Answer 22

loops of thin walled blood vessels that dip down into the medulla from above and then climb back up to the cortex

Question 23

role of the distal convoluted tubule

Answer 23

acid-base and water balance
(absorption of water, Na and bicarbonate)
(excretion of K and H ions)

Question 24

what is absorption of sodium in the DCT controlled by

Answer 24

aldosterone

Question 25

where is aldosterone secreted

Answer 25

adrenal cortex

Question 26

what does resorption of sodium in the DCT do

Answer 26

results in greater sodium and water retention therefore it increases blood pressure

Question 27

is the collecting duct part of the nephron

Answer 27

no

Question 28

what are the medullary rays

Answer 28

the proximal and distal tubules are gathered together in parallel bundles running perpendicular to the surface of the kidney and called medullary rays

Question 29

what increases the permeability of the collecting duct for water

Answer 29

vasopressin from the posterior pituitary

ADH

Question 30

permeability of collecting duct in the presence of high ADH

on a hot day for example

Answer 30

permeability is high

• high salt content in surrounding tissue
• water passes out of the lumen
• concentrated urine results

Question 31

what are almost all of the conducting parts of the urinary tract lined by

Answer 31

transitional epithelium (uroepithelium)

Question 32

what are umbrella cells

Answer 32

cells at the luminal surface of the urinary tract

Question 33

what is the lumen of the ureter lined by

Answer 33

transitional epithelium

Question 34

what is the penile urethra lined with

Answer 34

stratified columnar epithelium then at the tip becomes stratified squamous