Homeostasis & Biological Signalling

Question 1

What does MEF (matter energy and fields) require in a living cell?

Answer 1

Substrate supply system, Product distribution system, Waste removal system, Stable controlled physicochemical environment, Reliable and responsive control systems that monitor and adjust when required

Question 2

What is entropy?

Answer 2

A measure of disorder

Question 3

How are signalling molecules classified?

Answer 3

Endogenous: within body – our reference signalling molecules OR Exogenous I: natural – plant based, morphine, aspirin OR Exogenous II: synthetic – man made

Question 4

What are the parameters under homeostatic control?

Answer 4

temp (37, just right for homeotherms), pH, O2, CO2, H2O, Na, K, Ca2+, Cl-, glucose

Question 5

What is the most common painkiller?

Answer 5

paracetamol

Question 6

What is in a control system?

Answer 6

SYSTEM NEEDING CONTROL, SENSOR - detect physiological parameter produce signal related to parameter = SO, SET POINT/comparator = SP to compare against sensor signal, DIFFERENCE ERROR SIGNAL - provide ‘-ve feedback’ signal equivalent to difference SP -SO, CONTROLLER - amplified signal to bring system back to set point, EFFECTOR - components to bring about change, SIGNAL TRANSMISSION ROUTES

Question 7

At what temp do you get hyperthermia?

Answer 7

38-40C

Question 8

At what temp do you get hypothermia?

Answer 8

34-36C

Question 9

Why does the body have a set point of 37C?

Answer 9

most proteins operate optimally at this temp, reduces rate of thermal degradation/denaturation

Question 10

What are the temperature limits of a normal dynamic system?

Answer 10

34-40C

Question 11

What are the normal ranges for Na+, K+, Ca2+, glucose

Answer 11

Na+ 135-145mM

K+ 3.5-5mM

Ca2+ ~1.2mM

Glucose 4-6mM

Question 12

What are the clinical consequences of high and low Na+?

Answer 12

Hypernatremia: dehydration, comatosed, diabetes insipidus

Hyponatremia: headaches, nausea, poor balance, cerebral edema

Question 13

What are the clinical consequences of high and low K+?

Answer 13

Hyperkalemia: palpitations, muscle pain, muscle weakness, or numbness

Hypokalemia: feeling tired, leg cramps, weakness, constipation, bradycardia

Question 14

What are the clinical consequences of high and low Ca2+?

Answer 14

Hypercalcemia: no symptoms, or agitation, gritty eyes, abdominal pain

Hypocalcemia: muscle twitching and spasms

Question 15

What are the clinical consequences of high and low glucose?

Answer 15

Hyperglycemia: diabetes, kidney damage, neurological damage, cardiovascular damage

Hypoglycemia: trouble talking, confusion, loss of consciousness, seizures, or death