The Renal System

Question 1

What makes up the renal system?

Answer 1

2 Kidneys
2 Ureters
Urinary bladder
Urethra

Question 2

What are the function of the kidneys?

Answer 2

Maintaining homeostasis within the internal environment, by regulation of the volume and composition of body fluids

Question 3

What is Homeostasis?

Answer 3

A self-regulating process by which a living organism can maintain internal stability while adjusting to changing external conditions

Question 4

What are the key functions of the kidneys?

Answer 4

Elimination, regulation and secretion

Question 5

What other functions do the kidneys have?

Answer 5

Waste/ balance
Blood pressure
red blood cells
vitamin D

Question 6

What is renin?

Answer 6

An important enzyme in the control of blood pressure

Question 7

What is erythropoietin?

Answer 7

A hormone that stimulates the production of red blood cells

Question 8

Where are the kidneys?

Answer 8

They are on the posterior wall of the abdominal cavity: one on each side of the vertebral column at the level of thoracic and lumbar vertebrae

Question 9

How much of the cardiac output do the kidneys get?

Answer 9

25%

Question 10

What sits on the top of each kidney?

Answer 10

An adrenal gland

Question 11

How big is a kidney?

Answer 11

10cm long
6.5cm wide
3cm thick

weighs about 100-120g each

Question 12

Where do they kidneys get their blood supply?

Answer 12

The blood supply is from the aorta via the renal artery and returns to the vena cava via the renal vein

Question 13

What is the medulla?

Answer 13

The inner region of the kidney that is divided into approximately 12 pyramids, containing bundles of tubules.

Question 14

How is urine carried?

Answer 14

Urine is carried from the renal pelvis to the urinary bladder via the ureter

Question 15

What is a nephron?

Answer 15

It’s the basic functional unit of the kidney. More than 1 million nephrons per kidney

Question 16

What are the 3 stages of the renal system?

Answer 16

Filtration
Reabsorption
Secretion

Question 17

Why are glucose and amino acids not common in urine?

Answer 17

These substances are completely reabsorbed

Question 18

What do the ureters do?

Answer 18

The ureters transport urine to the bladder by peristalsis

Question 19

What happens to the bladder when it fills with urine?

Answer 19

The walls distend and it becomes a globular shape. Its capacity is approx 500-600mls although can hold more. It expands upwards and outwards when full and into the abdomen

Question 20

What lies anterior to the bladder?

Answer 20

Pubic bone separated by a space filled with fatty tissue

Question 21

What lies posterior to the bladder?

Answer 21

Cervix and ureters

Question 22

What lies lateral to the bladder?

Answer 22

Lateral ligaments of the bladder and side walls of the pelvis

Question 23

What lies superior to the bladder?

Answer 23

Body of uterus and intestines

Question 24

What lies inferior to the bladder?

Answer 24

Upper half of anterior vaginal wall and levator ani muscles

Question 25

What factors inhibit urine production?

Answer 25

Sleep and muscular activity

Question 26

What causes the structural and functional changes in the renal system?

Answer 26

the effects of progesterone on smooth muscle
the pressure of enlarging uterus
cardiovascular changes

Question 27

Describe the physiological changes in the bladder

Answer 27

As the uterus enlarges, the urinary bladder is displaced upward and fattened in the anterior- posterior position. Bladder vascularity increases and muscle tone decreases increasing capacity up to 1000 mls. Trigone elevation occurs with the increase of vascular tortuousity. The muscosa also becomes oedematous and is more vulnerable to trauma and infection. The decrease in bladder tone leads to incompetence of the junction between ureter and bladder, and there may be reflux or urine from bladder to ureters or kidneys

Question 28

What hormone is involved in the relaxation of bladder smooth muscle?

Answer 28

Progesterone

Question 29

What is renal haemodynamic?

Answer 29

Flow of blood within the kidneys

Question 30

How much does renal blood flow increase during pregnancy?

Answer 30

It increases by 35-60% by the end of the first trimester, which then decreases slightly until term. Due to the increased blood volume and cardiac output

Question 31

Describe postpartum changes?

Answer 31

Rapid and sustained loss of sodium and major diuresis during postpartum period (typically between 2nd and 5th day)
Women should pass urine 6-8 hours after birth
Urine output rises to up to 3000ml, with 500-1000 mls voided at any micturition. By the end of 1st week, urinary excretion of calcium, phosphate, vitamins, glucose return to normal.
Structural changes may take up to three months to disappear, although for most women, these are complete by 6-8 weeks