Flashcard set 4

Question 1

What causes more O2 than usual to dissociate from haemoglobin?

Answer 1

• rise in body temp
• bohr effect
• diphosphoglycerate
• a drop in PO2

Question 2

What is the function of the ear canal/ auditory meatus?

Answer 2

amplifies sounds in frequency range of speech

Question 3

What is lateral inhibition?

Answer 3

increases contrast and sharpness of stimulus

Question 4

What causes the amplification phase in blood clotting?

Answer 4

thrombin

Question 5

How are the optics of the eye adjusted for closer vision?

Answer 5

• lens changes shape by ciliary muscles contracting
• zonulas slackening
• lens becomes round for closer vision

Question 6

Order of blood travelling

Answer 6

vena cava -> right atrium -> right ventricle -> pulmonary artery -> lungs -> left atrium -> left ventricle -> aorta -> body -> vena cava

Question 7

What happens in the SA nodal cell vs the ventricular muscle cell in terms of ionic channels

Answer 7

SA node:

• at -60mv K+ close and Na+ open
• at -40mv Ca2+ open
• at 0mv Ca2+ and K+ open

Ventricular muscle cell:

• Na+ open after -40mv and close at -20mv
• 0mv (plateu) Ca2+ open and fast K+ close
• at -40mv Ca2+ close and slow K+ open

Question 8

What do aggregated platelets secrete?

Answer 8

• platelet derived growth factor beta (forms scar tissue)
• 5-HT (serotonin)
• ADP
• Thromboxane A2

Question 9

What do the ABO enzymes do?

Answer 9

• FUT-1 = encoded by H gene
• A transferase = adds N-acetylgalactosamine
• B transferase = adds galactose

Question 10

The respiratory volumes

Answer 10

Vital capacity = vol. of total inspiration and expiration
Tidal vol. = vol. of inspired or expired air during normal breathing
Residual vol. = vol. remaining in lung after maximal expiration
Inspiratory reserve vol. = maximal vol. of air inspired over a tidal vol.
Total lung capacity = total vol. in the lungs after maximal inspiration

Question 11

Final formation of blood clot

Answer 11

Thrombin (factor IIa) Factor XIIIa
Fibrinogen——————————->Fibrin monomer———————-> Fibrin polymer
Ca2+

Question 12

What happens from rest -> exercise?

Answer 12

• systolic pressure increases
• diastolic pressure increases
• mean arterial pressure increases
• total peripheral resistance decreases

Question 13

Heart conditions shown on ECG

Answer 13

• atrial fibrillation = many indistinct waves in between QRS complex
• myocardial infraction = S-T segment elevation (t wave starts from s wave)
• first degree atrioventricular heart block = prolonger P-R interval

Question 14

Venous return is maintained by?

Answer 14

• venous pressure
• valves
• respiration
• skeletal muscle contraction

Question 15

Areas of the somatosensory cortex and what info do they take in?

Answer 15

3A = body positioning 
3B = dense info from thalamus
3B-1 = texture
3B-2 = size and shape
5-7 = posterior parietal cortex

Question 16

Control of behaviours by higher brain centres?

Answer 16

Dorsalmedial nucleus: FEEDING behaviour

• increase b.p
• increased intestinal mobility
• increased intestinal blood supply
• decreased blood supply to muscle

Ventromedial nucleus: DEFENSE BEHAVIOUR

• increased b.p
• decreased intestinal mobility
• decreased intestinal blood supply
• increased blood supply to muscle

Question 17

If a foetus is Rh+ and mother is Rh- what is the clinical solution?

Answer 17

give the mother anti-D immunoglobulin to remove the Rh+ve blood in the mothers circulation in the 3rd trimester.

Question 18

What is pneumothorax?

Answer 18

when air enters the pleural cavity between the pleural membranes

Question 19

What is the difference between afferent and efferent neurons?

Answer 19

Afferent neurons: send info from muscle/skin/organ to CNS

Efferent neurons: send infor from the CNS to muscle