Renal System

Question 1

Net Filtration Pressure (NFP)

Answer 1

pressure that determines how much water and small dissolved solutes leaves the blood

Question 2

NFP =

Answer 2

NFP = GBHP - CHP - BCOP

Question 3

Glomerular Blood Hydrostatic Pressure (GBHP)

Answer 3

mechanical pressure between the afferent and efferent arterioles (pressure inside BV pushes the blood)
- within the glomerulus, drives the plasma filtrate from the capillaries of the glomerulus into the capsular space

Question 4

Capsular Hydrostatic Pressure (CHP)

Answer 4

the pressure exerted on the plasma filtrate by the elastic recoil of the glomerular capsule

Question 5

Blood Colloid Osmotic Pressure (BCOP)

Answer 5

The osmotic force of the proteins left in the plasma
(the proteins exert an increasing osmotic “pull” on the water in the plasma filtrate

Question 6

What two forces filter fluid out?

Answer 6

Glomerular Capillary Hydrostatic Pressure
Bowmans Space Oncotic Pressure

Question 7

What two forces oppose ultrafiltration?

Answer 7

Glomerular Capillary Oncotic Pressure
Bowmans Space Hydrostatic Pressure

Question 8

What does the interaction between the podocytes and underlying capillaries do?

Answer 8

Enables filtration to take place that allows blood to be filtered (forms a filtration barrier)

Question 9

What do the cells on the Distal Convoluted Tubule do?

Answer 9

Responsible for sensing how well a nephron is performing can tell afferent arteriole to constrict or dilate - slows down blood flow in glomerular capillaries

Question 10

Podocytes

Answer 10

modifiied epithelium
visceral layer (inner)

Question 11

What are the 3 layers of filtration on the capillaries in the Glomerulus?

Answer 11

Fenestrated endothelium (no rbc, but all sizes of proteins)
Basal Lamina (Medium + small proteins)
Slit membrane between Pedicels (small proteins)

Question 12

Osmolality

Answer 12

measure of the osmotic pressure exerted by a solution across a perfect semi-permeable membrane compared to pure water
- a count of the number of dissolved particles in a set volume

Question 13

Tonicity

Answer 13

the capability of a solution to modify the volume of cells by altering their water content

Question 14

NaCL

Answer 14

low permeability

Question 15

Urea

Answer 15

high permeability
exerts not much osmotic force

Question 16

Proportions of Fluid in the body

Answer 16

1/3 Extracellular
2/3 Intracellular

Question 17

Which ions have a higher concentration in the extracellular fluid?

Answer 17

Na+, Ca2+ , Cl-

Question 18

Which ion have a higher concentration in the intracellular fluid?

Answer 18

K+

Question 19

Two types of hormanal regulation of Glomerular Filtration Rate

Answer 19

Angiotensin II
Atrial Natriuretic Peptide (ANP)

Question 20

Angiotensin II
(GFR)

Answer 20

Constricts the afferent and efferent arterioles
DECREASE IN GFR

Question 21

What stimulates secretion of ANP?

Answer 21

Stretching of atria of heart

Question 21

What stimulates Angiotension ll production?

Answer 21

Decreased BV or BP

Question 22

Atrial Natriuretic Peptide (ANP
(GFR)

Answer 22

Relaxation of mesangial cells in glomerulus increases capillary SA available for filtration
INCREASE GFR

Question 23

Neural Regulation
(GFR)

Answer 23

Constriction of afferent arterioles through activation of receptors and increased release of renin
DECREASE GFR

Question 24

What causes the release of Norepinephrine?

Answer 24

Increase in activity level of renal sympathetic nerves releases norephinephrine

Question 25

What are the two types of Renal Autoregulation?
(GFR)

Answer 25

Myogenic Mechanism
Tubuloglomerular feedback

Question 26

What triggers Tubuloglomerular Feedback?
(GFR)

Answer 26

Rapid delivery of Na+ and Cl- to the macula densa due to high systemic blood pressure

Question 27

What triggers the Myogenic Mechanism?
(GFR)

Answer 27

Increases stretching of smooth muscle fibres in afferent arteriole walls due to increased BP

Question 28

Myogenic Mechanism (GFR)

Answer 28

Stretched smooth muscle fibres contract, therby narrowing lumen of afferent arterioles
DECREASE GFR

Question 29

Tubuloglomerular Feedback (GFR)

Answer 29

Decreased release of nitric oxide (NO) by juxtaglomerular apparatus causes constriction of afferent arterioles
DECREASE GFR

Question 30

Why is urine output directly proportional to renal pressure?

Answer 30

Higher the pressure, higher the urine output
(doesn’t affect the filtration rate)