Physiology

Question 1

What are the major components of the plasma membrane?

Answer 1

Phospholipid molecules
Proteins
Cholesterol

Question 2

What is the function of cholesterol in the lipid membrane?

Answer 2

To stiffen the membrane and give it rigidity

Question 3

What are the different kinds of membrane proteins and their functions?

Answer 3

Peripheral proteins; receptor proteins

Intergral proteins; intracellular signalling, membrane transporters

Question 4

What cells do tight junctions occur in? What is their function?

Answer 4

Epithelial cells, to prevent diffusion of molecule if tight or allows some molecules through if leaky

Question 5

What cells do desmosomes occur in? What function?

Answer 5

Skin, heart, uterus, to provide mechanical stability under stress

Question 6

What cells contain gap junctions? What is their function?

Answer 6

The heart, allows signal transmission rapidly between cells

Question 7

Define blood pressure

Answer 7

The intraluminar pressure exerted on the blood vessel wall

Question 8

What is pulse pressure and what are the normal parameters of this?

Answer 8

It is the difference between systolic and diastolic pressures usually 30-50mmhg

Question 9

What is MAP and what is its usual range>

Answer 9

Average of systolic and diastolic blood pressure, 70-105mmhg

Question 10

How can MAP be estimated?

Answer 10

diastolic pressure +1/3pulse pressure

systolic pressure + 2xdiastolic pressure/3

Question 11

Which nerve carries signals from the baroreceptors to the medulla?

Answer 11

Herings nerve (branch of glossopharyngeal )

Question 12

What are the components of ficks law of diffusion?

Answer 12

Magnitude of concentration gradient
Surface membrane diffusing over
Solubility of substance in lipid
Molecular weight (e.g small molecule or not)
Distance of diffusion

Question 13

What is the relationship between osmolarity and concentration of solute?
What is the mormal osmolarity of a RBC?

Answer 13

The greater the osmolarity the more solute contained in the solution

300mOsm

Question 14

Describe the ATP na/k pump

What does it physiologically maintain?

Answer 14

Transports two potassium ions intracellularly and 3 sodium ions extracellularly requires phosphorylation

Establishes concentration gradient of cell
Regulates cell volume
Maintains membrane potential

Question 15

Define hyperthermia

Answer 15

Body temperature above 40º

Question 16

Define hypothermia

Answer 16

Core temp below 35º

Question 17

What is the control centre for body temperature? What do its components control?

Answer 17

Hypothalamus

POsterior cOld

Anterior heAt

Question 18

Is sodium or potassium more permeable to the cell membrane?

Answer 18

Potassium is more soluble

Question 19

What is the Nearnst equation

Answer 19

The equilibrium membrane potential

E= 61log10 ([ion outside]/ [ion inside])

Question 20

What is the GHK equation? What does it calculate

Answer 20

E= 61log10 ([ion + ion outside]/ [ion +ion inside])

Question 21

What are some naturally occurring anti-coagulants?

Answer 21

Serine protease inhibitors e.g thrombin and trypsin

Protein C and S; two vitamin K-dependent plasma proteins