Some Bioscience

Question 1

Describe anastomosis

Answer 1

A point of convergence between two vessels other than capillaries.

1. Arteriosvenous (shunt), to reduce heat loss by bypassing exposed surfaces, e.g. ears and fingers.
2. Venous, for alternate routes of drainage from organs.
3. Arterial, in joints where limb movement may temporarily compress an artery, AKA collateral route.

Question 2

Baroreceptor pathway

Answer 2

Receptors: carotid sinus (glossopharengeal nerve) and aortic arch (vagus nerve)

Control centre: medulla oblongata

Effectors:
Sympathetic - blood vessels and right atrium.
Parasympathetic - right atrium.

Question 3

Glucose response pathway

Answer 3

Stimulus: rise in blood glucose concentration.

Receptor: beta cells.

Control centre: pancreas.

Effector: beta cells release insulin.

Response: glucose uptake my cells, leading to decrease in blood glucose.

Question 4

Bladder receptor pathway

Answer 4

Receptor - stretch receptors (afferent signals).

Control centre - spinal cord.

Effector - detrusor muscles and sphincters.

Response:
To release - excite detrusor muscles and relax internal urethral sphincter. For voluntary control - mictrition centre in brain.
To hold - external urethral sphincter contracts.

Question 5

Chemoreceptor trigger zone (CTZ)

Answer 5

Located on the floor of the fourth ventricle.
Morphine can directly stimulate CTZ and initiate vomiting.
Motion can stimulate CTZ via receptors in the inner ear.
Projectile vomiting is spontaneous and does not follow nausea or retching.

Question 6

Outline the nervous system pathways.

Answer 6

CNS (brain and spinal cord)
—>
PNS (the rest)
—> sensory (receptors moving toward CNS)
—> motor (CNS toward effectors)
—> somatic (skeletal muscle)
—> visceral (cardiac and smooth)
—> sympathetic
—> parasympathetic

Question 7

Name each region of the brain and it’s basic function.

Answer 7

Frontal lobe - cognitive functions and voluntary movement.

Motor cortex - plan, control and execute voluntary movement.

Central sulcus - separates lobes.

Sensory cortex - receives sensory input.

Parietal lobe - temperature, taste, touch and movement.

Occipital lobe - vision

Temporal lobe - processes memories, integrates with sensations.

Longitudinal fissure - divides hemispheres.

Question 8

Name the 4 physiological processes in birth transition

Answer 8

1. Disruption of feto-placenta circulation
2. The lungs change from being fluid filled to being air filled
3. The pulmonary blood flow increases to assist pulmonary oxygenation
4. The intracardiac and extracardiac shuts close

Question 9

Outline the pathophysiology of fractures

Answer 9

1. Fracture of the bone
2. Blood supply to area interrupted
3. Haemorrhage of surrounding tissue
4. Clot formation
5. Bone tissue begins to die
6. Inflammatory response lead to swelling
7. Blood flow to bone increased
8. Bone forming cells activated, leading to osteoblasts
9. Remodelling occurs, osteoclasts and osteocytes

Question 10

Name the 4 different tissue types

Answer 10

Epithelia
Connective
Nervous
Muscle