L31. Urinary system

Question 1

What is the space of Disse

Answer 1

It is the sub-sinusoidal domain (basal) that has an endocrine function

Question 2

What are Kupffer cells?

Answer 2

are macrophages that patrol sinusoids and space of disse

Question 3

What is fibrosis?

Answer 3

Increased in connective tissue or eosphonic collagen fiber

-there is a decreased in blood flow in the sinosuids – leads to blockage and causes hypertension

Question 4

What 2 veins get blocked up when there is fibrosis

Answer 4

eophogeal vein and superior hemorrhoidal veins

Question 5

Describe the gall bladder

Answer 5

simple columnar epithelium - highly absorptive
Lamina propria- highly vascular, loose connective tissue
mucosa- highly folded without clearly organized vili or crypts
Prominent Muscularis: overlapping smooth muscle fibers, contractions cause persitalsis initiated by CCK
Adventitia: dense connective tissue

Question 6

How does bile enter the gall bladder

Answer 6

The sphincter of Oddi must be closed in order for bile to be backed up into the gall bladder

Question 7

Describe the sphincter of Oddi and how it is controlled

Answer 7

• it is embedded in pancreatic tissue

- smooth muscle is present and CCK mediates it’s RELAXATION

Question 8

Describe the functions of the urinary system

Answer 8

1. produce and excrete urine
2. regulate blood pressure and plasma volume
3. excrete toxic products via a duct system

Question 9

State the basic layers of a kidney

Answer 9

Capsule: dense connective tissue
Cortex
Medulla

Question 10

What is the hilum

Answer 10

It is the region where the renal artery enters and renal vein exits the kidney

Question 11

What is the function of the kidney

Answer 11

1. produces filtrate ( plasma without the proteins)
2. modifies the glomerular filtrate to make urine
3. making and modifiying of the glomerular filtrate happens in the uriniferous tubules of the kidney

Question 12

What is the renal corpuscle?

Answer 12

It is the filtrate forming protion of the nephron

Question 13

What are the tubules of the nephron?

Answer 13

They are the filtrate modifying parts of the nephron

Question 14

Trace the path of the nephron

Answer 14

renal corpuscle -> priximal tubule -> loop of Henle -> distal tubule

Question 15

What is the function of the renal corpuscle?

Answer 15

• produces glomerular filtrate in the blood releases it into the Bowman’s space
• Has a parietal and visceral layer.
• glomerular capillaries are covered in podocytes: visceral cell layers

Question 16

What is the vascular pole?

Answer 16

It is when the afferent and efferent arterioles enter and exit the corpuscle

Question 17

What does the glomerular filtration barrier consists of

Answer 17

• Fenestrated capillary endothelium
• Basement membrane
• Slit Diaphragms between the pedicels of podocytes

Question 18

What prevents movement of plasma proteins from the capillary to urinary space

Answer 18

glycoproteins and proteoglycans in basement membrane and slit diaphragms prevent the movement of plasma proteins from capillary to urinary space

Question 19

What is the function of the proximal tubule?

Answer 19

resorbs most of the NaCl and H2O through pumps and channels

Most of teh glucose is resorbed vai vesciular transport

Question 20

What is present in urine

Answer 20

ions, glucose, urea, water

Question 21

Describe the proximal tubule ( cellular machinary)

Answer 21

• simple cubodial epithelium
• has microvili for resorption
• actively resorbs through pumps and channels
• has a lot of mitochondria
• resorbs release water, glucose, ions and amino acids back to the peritubular CT (ti capillaries)
• resorbs water salt and glucose

Question 22

Describe the function of the loop of Henle

Answer 22

has descending and ascending limb
descending limb has a simple squamous epithelium with aquaporins that allow water to flow out
ascending limb is simple squamous and has many tight junctions.becomes increasingly H2O impermeable as more salt diffuses out of the tubule, as it ascends it becomes a cubodial epithelium

Question 23

What causes the medulla to be salty

Answer 23

It is due to the diffusion of salt out of the ascending limb of the loop of Henle, as that portion is impermeable to water and only salt passes through

Question 24

Describe the function of the distal tubule

Answer 24

modifies urine through the macula densa which is part of the juxtaglomerular apparatus
produces dilute high volume urine

Question 25

Describe the structure of the distal tubule

Answer 25

-simple cubodial epithelium
- water impermeable
continues to pump NaCl out of the filtrate
produces dilute high volume urine

Question 26

What is the macula densa?

Answer 26

It is the thickening of the distal tubile at the vesicular pole of the renal corpuscle

• columnar epithelial
• when there is a high urine volume stimulates the juxtaglomerular apparatus through gap junctions

Question 27

What is the function of the juxtaglomerular cells?

Answer 27

• modified pericytes of glomerular arterioles

- secrete renin into the bloodstream