The Urinary System

Question 1

What does the urinary system comprise of

Answer 1

The urinary system is comprised of the kidneys, the ureters and the urethras

Question 2

What is the function of the kidneys in the urinary system

Answer 2

Filters the blood

Question 3

What is the function of the ureters in the urinary system

Answer 3

Ureters transport urine to the urinary bladder

Question 4

What is the function of the urethras in the urinary system

Answer 4

They conduct the urine to the exterior during micturition

Question 5

How much of the cardiac output does the kidneys receive

Answer 5

One fifth of the cardiac output

Question 6

How does blood enter the kidneys

Answer 6

The renal arteries

Question 7

Where do the renal arteries arise from

Answer 7

The abdominal aorta

Question 8

What is the function of the nephrons in the kidneys

Answer 8

They regulate the fluid and electrolyte balance of the blood and removes waste products

Question 9

What hormones are produced by the kidneys

Answer 9

Erythropoietin for the control of erythrocytes production and renin for the regulation of water and salt concentration

Question 10

What is the kidney made up of

Answer 10

The pale outer cortex
Darker regions of the medullary tissue

Question 11

In a healthy kidney how thick should the renal cortex be

Answer 11

At least 7mm

Question 12

How many medullary pyramids does a kidney have

Answer 12

10 to 15 medullary pyramids whose apices point towards the hilum of the kidney

Question 13

What does the cortex contain

Answer 13

The cortex contains the glomeruli of the kidney and the convoluted parts of the proximal and distal tubules
It also contains the proximal parts of the collecting ducts

Question 14

What do the medullary pyramids contain

Answer 14

They contain the straight portions of the proximal and distal tubules, the loop of Henle and the distal parts of the collecting ducts

Question 15

How does filtrate drain from each medullary pyramid

Answer 15

The filtrate is drained by up to 20 pores into a funnel-shaped calyx from where urine is collected into the widened pelvic portion of the ureter for transport to the bladder

Question 16

Where does the nephron start and end

Answer 16

The nephron starts at the glomerulus and ends at the collecting duct

Question 17

What are most of the cells in the glomerulus

Answer 17

Most cells in the glomerulus are capillary endothelial cells or mesangial cells which lie in between the capillaries

Question 18

What are the mesangial cells in the glomerulus composed of

Answer 18

They are composed of smooth muscle

Question 19

What is the function of the mesangial cells

Answer 19

They are able to reduce the filtration rate when the smooth muscle contracts and involved with the phagocytosis of the basement membrane cells

Question 20

Where to the renal artery and renal vein enter and exit the kidney

Answer 20

They enter and exit at the hilum of the kidney

Question 21

Describe the divisions of the renal artery

Answer 21

The Renal artery branches from the abdominal aorta, from this the renal artery divides into the segmental arteries which divide into the interlobar arteries which divides into arcuate arteries which divide into the interlobular arteries which divide into afferent arterioles

Question 22

Describe the structures the venous blood from the kidneys get back to the inferior vena cava

Answer 22

The blood enters the efferent arterioles then to the peritubular capillaries then to the vasa recta into the renal veins and into the inferior vena cava

Question 23

Where are straight arterioles found

Answer 23

Straight arterioles are branches of the arcuate arteries that penetrate deep into the medulla before returning blood to the arcuate veins

Question 24

Blood entering the kidneys goes where first

Answer 24

Blood entering the kidneys passes first to the glomeruli where it gets filtered

Question 25

Where does the primary filtrate pass from the glomeruli

Answer 25

The primary filtrate passes from the glomeruli to the rest of the nephron for the selective re-absorption of certain solutes

Question 26

What does a glomerulus consist of

Answer 26

A glomerulus consists of a parallel array of fenestrated capillaries ensheathed by specialised cells called podocytes