Stress

Question 1

Where does the hypothalamus stimulate to provide a short term fight or flight response?

Answer 1

Sympathetic division of the ANS and adrenal medulla

Question 2

What does the sympathetic nervous system do?

Answer 2

Nerve endings release noradrenaline
Increased heart rate and increased stroke volume - increase cardiac output increased MABP
Blood vessels constrict - increased blood pressure
Blood diverts from non essential organs to skeletal muscle, brain and heart

Question 3

What do preganglionic nerve endings in the adrenal medulla release?

Answer 3

Catecholamines (adrenaline and noradrenaline)

80-90% adrenaline stored in granules

Question 4

Where are the adrenal glands located?

Answer 4

Adrenal medulla above kidney inner region, outer region adrenal cortex

Question 5

what does adrenaline stimulate

Answer 5

Increased glycogenolysis - increases blood glucose and increased gluconeogenesis - increases blood glucose

Question 6

What does noradrenaline do?

Answer 6

Causes vasoconstriction

Question 7

What does adrenaline do?

Answer 7

Vasodilation in skeletal muscle, more potent on heart and metabolic activities

Question 8

What do both adrenaline and noradrenaline do?

Answer 8

Inhibit insulin release and stimulate glucagon - increased glucose

Question 9

What is pheochromocytoma?

Answer 9

Adenoma of adrenal medulla causing hypertension, increased heart rate, increased blood glucose, sweating

Question 10

Can someone live without an adrenal medulla?

Answer 10

Yes but not cortex

Question 11

What does cortisol do?

Answer 11

Long lasting response to stress, can also stimulate tissue repair

Question 12

What does cortisol secretion reflect?

Answer 12

Corticotropin releasing hormone and adrenocorticotropic hormone in anterior pituitary gland

Question 13

What does cortisol do?

Answer 13

More gluconeogenesis less glucose utilisation so increased blood glucose.
Increased mobilisation of fatty acids, more triglyceride breakdown and more used for energy - sparing glucose, more protein catabolism

Question 14

What are the effects of cortisol?

Answer 14

Increased vasoconstriction, enhances sympathetic response, increased heart rate, decreased inflammatory response, decreased immune response, less ACTH and less CRH secretion

Question 15

What is cushings disease

Answer 15

Hypersecretion of cortisol as there is a tumour in the adrenal cortex, swelling of face, increased blood pressure, thin limbs, decreased immune response

Question 16

What is Addison’s disease?

Answer 16

Hyposecretion of cortisol caused by damage of adrenal cortex, less blood pressure, hypoglycaemia

Question 17

What causes fainting?

Answer 17

Decreased vagal output, less CO, venous return, peripheral resistance, decreased atrial pressure less cerebral blood flow

Question 18

What are the three factors that control stroke volume in the heart?

Answer 18

• Ventricular contractility
• End diastolic volume
• Afterload

Question 19

Describe Starling’s law of the heart

Answer 19

When the rate at which blood flows into the heart (venous return) changes, the heart will automatically adjust its output to match the inflow

Question 20

Describe what is meant by after load and its effect on the heart

Answer 20

The load at which arterial pressure places on the myocardium after the heart starts to contract