Glomerular Filtration

Question 1

What are the basic renal processes?

Answer 1

Filtration
Reabsorption
Secretion

Question 2

What is glomerular filtration dependent on?

Answer 2

Hydrostatic forces favouring filtration

Oncotic pressure forces favouring reabsorption

Question 3

What factors determine whether a substance can pass across the glomerular filtration barrier?

Answer 3

Molecular size
Electrical charge
Shape

Question 4

Why is the blood arriving at the glomerulus at a high hydrostatic pressure?

Answer 4

Afferent arteriole is short and wide, offers little resistance to flow

Question 5

What is the arrangement of the efferent arteriole?

Answer 5

Long and narrow, offers a high post-capillary resistance

Question 6

What is the main factor which affects GFR?

Answer 6

Diameter of afferent and efferent arterioles

Question 7

What can change the diameter of arterioles?

Answer 7

Sympathetic VC nerves
Circulating catecholamines
Angiotensin 2

Question 8

How does autoregulation keep blood flow and GFR constant?

Answer 8

Renal vasculature has a well developed intrinsic ability to adjust its resistance in response to changes in arterial BP

Question 9

What capillaries are responsible for reabsorption?

Answer 9

Peritubular capillaries