histology

Question 1

what is the role of the urinary tract?

Answer 1

• maintains water and electrolyte homeostasis, body fluid osmolarity and acid base balance
• excrete toxic metabolic waste products (mainly urea and creatinine)
• acts as an endocrine gland, producing renin and erythropoietin

Question 2

what is the kidney covered in?

Answer 2

-thin but strong collagenous capsule

Question 3

what is contained in the hilum of the kidney?

Answer 3

-ureter, renal artery and renal vein

Question 4

what is considered a lobe of the kidney?

Answer 4

-each medullary pyramid and its associated cortisol tissue is considered a lobe of the kidney

Question 5

what is this?

Answer 5

renal cortex

Question 6

what is this?

Answer 6

renal papillae

Question 7

what is this?

Answer 7

Calices

-top arrow is the minor calyx and bottom arrow is the major calyx

Question 8

what is this?

Answer 8

renal pelvis

Question 9

what is this?

Answer 9

Medulla containing renal pyramids

Question 10

what is at each tip of the medulla in the kidney?

Answer 10

at the tip of each medulla is a minor calyx

Question 11

where are medullary rays found?

Answer 11

-in the cortex

Question 12

what is the kidney capsule continuous with?

Answer 12

-the capsule is continuous with the connective tissue that lines the renal sinus

Question 13

histological slide of cortex and medulla

Answer 13

Question 14

what is a nephron?

Answer 14

-basic functional unit of the kidney

Question 15

what are nephrons composed of?

Answer 15

-renal corpuscle nd renal tubules

Question 16

what is the renal corpuscle responsible for

Answer 16

-produce and collect glomerular filtrate

Question 17

what is the renal corpuscle made of?

Answer 17

-made of knotted ball of capillaries called the glomerulus and then there is a gap and it is surrounded by simple squamous epithelium (Bowman’s capsule)

Question 18

what supplies the capillaries in the renal corpuscle?

Answer 18

-an afferent arteriole and drained by an efferent arteriole

Question 19

what two cell layers separate the blood from the glomerular filtrate?

Answer 19

-the capillary endothelium and specialised epithelium which lie on top of the glomerular capillaries (these epithelial cells are called podocytes)

Question 20

what is the role of mesangial cells?

Answer 20

• produce a connective tissue core called the mesangium

- support and removal of debris

Question 21

where do the afferent and efferent arterioles enter and leave Bowman’s capsule?

Answer 21

• opposite the beginning of the renal tubule

- thus there is a vascular and urinary pole

Question 22

summary slide

Question 23

what are the 3 components of glomerular filter?

Answer 23

• fenestrated endothelium of capillary wall
• the thick basement membrane (shared by endothelium and podocyte)
• the filtration slits between the pedicels (small arrows)

Question 24

what is the role of the proximal convoluted tubule?

Answer 24

• reabsorption of water, proteins, amino acids, carbohydrates and glucose
• 70% of sodium (active transport) and water (diffusion) is reabsorbed
• almost all glucose and amino acids reabsorbed (by co-transporters)

Question 25

what is the role of the renal corpuscle?

Answer 25

-production and collection of glomerular filtrate

Question 26

electron micrograph of proximal convoluted tubule

Question 27

what is the role of the loop of Henle?

Answer 27

-the creation of a hyperosmotic environment in the medulla

Question 28

what is the role of the distal convoluted tubule?

Answer 28

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

Question 29

where is the loop of Henle located?

Answer 29

in nephrons in the medulla

Question 30

what is the loop of henle made up of?

Answer 30

• a thick descending limb
• a thing descending limb which makes a hairpin turn and begins the journey back out of the medulla as the thin ascending limb which then transitions to a thick ascending limb

Question 31

what are the thick limbs of the loop of Henle lined with?

Answer 31

-simple cuboidal epithelium

Question 32

what are the thin limbs of the loop of Henle lined with?

Answer 32

simple squamous epithelium

Question 33

what are vasa recta?

Answer 33

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

Question 34

distal convoluted tubule cell

Question 35

what controls the reabsorption of sodium in the distal convoluted tubules?

Answer 35

-aldosterone which is secreted from the adrenal corte

Question 36

is the collecting duct part of the nephron?

Answer 36

no

Question 37

what are in the medullary rays?

Answer 37

-collecting ducts, along with the straight segments of the proximal and distal tubules are gathered together in parallel bundles to the surface of the kidney and called medullary rays

Question 38

what effect does ADH have on the collecting duct?

Answer 38

-increases the permeability of the collecting duct allowing more water to pass in

Question 39

what are almost all conducting parts of the urinary tract lined with?

Answer 39

-special epithelium called transitional epithelium or urothelium

Question 40

what are umbrella cells?

Answer 40

-domed, thick, and inflexible cells at the luminal surface

Question 41

what is the ureter lined with?

Answer 41

transitional epithelium

Question 42

bladder histology slide

Question 43

what type of epithelium is the penile urethra lined with?

Answer 43

-stratified columnar epithelium which then becomes stratified squamous near the tip of the penis

Question 44

what is the membranous urethra lined with?

Answer 44

-transitional epithelium changed to stratified columnar epithelium

Question 45

what is the prostatic urethra lined with?

Answer 45

transitional epithelium

Question 46

what is the female urethra lined with?

Answer 46

initially lined by transitional epithelium which transitions to stratified squamous near its termination