part 2

Question 1

Where is cortisol released from?

Answer 1

Adrenal cortex

Question 2

What is the stress response in humans referred to as?

Answer 2

General adaptation syndrome (GAS)

Question 3

GAS is divided into three phases which incorporate short-term and long-term stress:

Answer 3

1. Alarm phase (Fight or Flight): Immediate sympathetic response to increase mental alertness and energy use by all cells and enhancing cardiovascular and respiratory functions
2. Resistance phase: Long-term metabolic adjustments involving the mobilisation of energy stores and the release of mineralocorticoids, glucocorticoids, glucagon and growth hormone. Thyroid hormones are also released to enhance cellular metabolism.
3. Exhaustion phase: This can be triggered by exhaustion of lipid reserves, infections, muscle wasting, ulceration of the gastrointestinal tract, failure to maintain fluid and electrolyte balance, cardiovascular damage, and/or failure of endocrine cells in the adrenal cortex and the pancreas.

Question 4

The pancreatic hormone that causes blood glucose levels to fall is ?

Answer 4

Insulin ( facilitates cellular uptake of glucose form the blood )

Question 5

An individual suffering from untreated diabetes mellitus will exhibit ?

Answer 5

polydipsia (excessive thirst), polyphagia (excessive hunger), polyuria (excessive urination).

Question 6

During short-term stress, epinephrine is released to:

Answer 6

Increase cardiac output

(Is released to complement the sympathetic nervous system response. This results in enhanced metabolic rate, bronchodilator, glycogenolysis and increased heart rate and blood pressure. An increase in heart rate results in an increased cardiac output.)

Question 7

The main hormone released during the long-term stress response is:

Answer 7

Cortisol

(glucocorticoid and mineralocorticoids are released during the long term stress response)

Question 8

During the alarm phase of the general adaptation syndrome

Answer 8

energy reserves are mobilised (The alarm phase is “Fight or Flight” response therefore glycogen and lipid storage will be mobilised to release glucose for energy purposes.)

Question 9

Growth hormone is released during the resistance phase of the general adaptation syndrome. true or false?

Answer 9

true

Question 10

The exhaustion phase of the general adaptation syndrome is characterised by an ability to maintain fluid and electrolyte homeostasis and maintain energy requirements. True or false?

Answer 10

false

Question 11

most important effect of cortisol?

Answer 11

is to stimulate conversion of amino acids and fatty acids to glucose to “save” glucose for the brain (Glucocorticoid)

Question 12

Cortisol is released from the adrenal cortex which then initiates the following responses:

Answer 12

• Stimulates lipolysis and gluconeogenesis
• Releases amino acids from skeletal muscle
• Vasoconstricts blood vessels of non-essential organs
• Inhibits inflammation and the immune response.

Question 13

when does long term stress initiate?

Answer 13

is initiated at least 30 mins after exposure to stressors.

(The hypothalamus stimulates release of major glucocorticoid – cortisol. Severe pain and prolonged exercise typically cause the secretion of cortisol.)

Question 14

what does the short term stress stimuate in NS

Answer 14

During ‘fight or flight’, the hypothalamus stimulates the sympathetic nervous system and the adrenal medulla.

Question 15

Sympathetic responses in short term include:

Answer 15

• Increases in cardiac output, ventilation and sweating

-Changes in BP and redirecting blood flow to vital tissues and skeletal muscle

Question 16

what are the stress response steps

Answer 16

The hypothalamus directs the stress response via the following steps:

1. Stimuli activates receptors
2. Nerve impulses sent to hypothalamus
3. Nervous system and endocrine system activated
4. Stress response occurs to try to maintain homeostasis and enable the body to cope

Question 17

state the process of homeostatic regulation of glucose is as follows

Answer 17

1. Low blood glucose (hypoglycemia) stimulates alpha cells to secrete glucagon
2. Glucagon acts on liver cells to convert glycogen into glucose and form glucose from lactic acid and certain amino acids
3. Glucose released by liver cells raises blood glucose level to normal
4. If blood glucose continues to raise, hyperglycemia inhibits release of glucagon
5. High blood glucose (hyperglycemia) stimulates beta cells to secrete insulin
6. Insulin acts on various body cells to accelerate facilitated diffusion of glucose into cells, speed conversion of glucose into glycogen, increase uptake of amino acids and increase protein synthesis, and speed synthesis of fatty acids
7. Blood glucose levels fall
8. If blood glucose continues to fall, hypoglycemia inhibits release of insulin

Question 18

there is a good table to look at in 5.5 and shows the the typical symptoms seen in an individual suffering from untreated diabetes mellitus

Question 19

where is Epinephrine released from?

Answer 19

adrenal medulla is a specialised sympathetic ganglion

Question 20

what is the function of Epinephrine?

Answer 20

enhancing sympathetic response and mobilising carbohydrate and fat storage.

(Epinephrine is also secreted in response to mild hypoglycaemia, moderate hypoxia and fasting. Metabolic effects of epinephrine include liver glycogenolysis, lipolysis, gluconeogenesis, and increased metabolic rate)