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Flashcards in Physiology Deck (34):
1

What is osmolarity?

Concentration of osmotically active particles present in a solution

2

Hos is osmolarity calculated?

No. active particles * molar concentration

3

What is tonicity?

The effect a solution has on cell volume

4

Define hypertonic

Concentrated, less fluid, cell shrinkage

5

Define Isotonic

Normal

6

Define hypotonic

More water, cell lysis

7

Which is bigger ICF or ECF

ICF

8

What makes up the ECF

Most interstitial fluid but also plasma and negligible amounts of transcellular fluid and lymph

9

Name 5 methods of fluid loss in the body

Skin, lungs, sweat faeces and urine

10

Which type of nephron is more abundant?

Cortical

11

What is the main difference between the two types of nephron?

Juxtamedullary has a longer loop of Henle and has the vasa recta

12

In which structure is the glomerulus?

Bowman's capsule

13

Which cells make up the inner layer of Bowman's capsule?

Podocytes

14

What are the three filtration barriers?

Glomerular capillary endothelium
Basement membrane
Slit processes of podocytes

15

What are the four forces which comprise net filtration pressure?

Glomerular capillary BP and Bowman's capsule oncotic pressure are out
Bowman's capsule hydrostatic pressure and capillary oncotic pressure are in

16

Define GFR

Rate at which protein-free plasma is filtered from the glomeruli into Bowman's capsule per unit time

17

What is the normal GFR

Approx 125

18

How is GFR extrinsically controlled?

Baroreceptor reflex

(+BP = +GFR)

19

How is GFR intrinsically controlled?

Tubuloglomerular feedback mechanism and myogenic mechanisms

20

What is the myogenic mechanisms?

If smooth muscle is stretched in increased pressure, arteriole constricts

21

What is the tubuloglomerular feedback mechanism?

JGA
+GFR means more NaCl flows through the tubule casing constriction of arteriole

22

What is the role of the macula densa?

To sense NaCl content of tubular fluid

23

Which pressure will kidney stones increase and how does it affect GFR?

The Bowman's capsule fluid pressure
- GFR

24

Which pressure which diarrhoea increase?

Bowman's capsule oncotic pressure
-GFR

25

What effect does sever burns have on GFR?

Increase

26

What is plasma clearance?

A measure of how effectively the kidneys can clean blood

27

What is inulin clearance equal to?

GFR

28

How can RPF be measured

Using PAH as this is freely filtered and not reabsorbed

29

What is RPF

Renal plasma flow, 650ml/min

30

Name 5 substances normally reabsorbed in the prox tubule

Sugar, AAs, phosphate, sulphate and lactate

31

Name 7 substances which are secreted in the prox tubule

H+, hippurates, neurotransmitters, bile, uric acid, drugs and toxins

32

Define primary active transport

Energy required to move a substrate against its concentration gradient (Na)

33

Define secondary active transport

The carrier molecule is transported coupled to another ion (usually Na)

34

Define facilitated diffusion

Carrier mediated transport down its concentration gradient (glucose)