Hormonal Communication - Module 5

Question 1

What is an endocrine gland?

Answer 1

A gland that secretes hormones directly into the bloodstream

Question 2

What is an exocrine gland?

Answer 2

A gland that secretes chemicals through ducts and into organs e.g digestive system

Question 3

Why is it important that the pituitary gland and the hypothalamus are close together?

Answer 3

So hormonal and neuronal communication are coordinated

Question 4

What are the two types of hormone?

Answer 4

1. Steroid hormones
2. Non steroid hormones

Question 5

How do steroid hormones function?

Answer 5

Are they are LIPID soluble they enter the cell membrane and form hormone receptor complexes acting as transcription factors for genes

Question 6

How do non steroid hormones function?

Answer 6

As they are HYDROPHILIC they cannot get through the cell membrane so they bind to cell surface receptors and cause a cascade of reactions

Question 7

Describe the structure of the adrenal gland

Answer 7

Adrenal cortex is the outer layer of the
Adrenal medulla is the inner layer

Question 8

What is the role of the adrenal medulla?

Answer 8

To secrete adrenaline and noradrenaline

Question 9

What is the role of noradrenaline?

Answer 9

To aid adrenaline, dilating pupils and relaxing airways/blood vessels

Question 10

What is the role of adrenaline?

Answer 10

To raise heart rate and blood glucose concentrations

Question 11

What is the role of the adrenal cortex?

Answer 11

To secrete hormones such as glucocorticoids, minerlocorticoids, androgens

Question 12

What is aldosterone?

Answer 12

Mineralocorticoid which maintains salt water blood balance

Question 13

What are androgens?

Answer 13

Release of small amounts of sex hormones

Question 14

What does cortisol control?

Answer 14

Metabolism

Question 15

How does the hormonal response differ to the neuronal response?

Answer 15

It is slower and less specific however the effects tend to last longer

Question 16

When is the medulla of the adrenal gland activated?

Answer 16

When the sympathetic nervous system is stimulated

Question 17

What is the fight or flight response?

Answer 17

When danger is detected the body automatically triggers a series of physical responses

Question 18

List 5 physiological responses of the fight or flight response

Answer 18

1. Increased HR to allow more oxygen to muscles
2. Pupils dilate for better vision
3. Non essential systems shut down
4. Blood glucose levels rise for respiration
5. Smooth muscles airways relax to allow more oxygen in

Question 19

What detects a threat?

Answer 19

Autonomic neuronal system

Question 20

Once a threat is detected, the hypothalamus is informed.
What is the sympathetic nervous system response?

Answer 20

Sympathetic nervous system;
1. Sends impulses to glands and smooth muscles
2. Sends signals to adrenal medulla to secrete adrenaline and noradrenaline

Question 21

Once a threat is detected, the hypothalamus is informed.
What is the response from the adrenal cortical system?

Answer 21

1. The pituitary gland releases ACTH
2. And the adrenal cortex releases a further 30 hormones to be secreted into the blood stream

Question 22

What type of hormone is adrenaline?

Answer 22

Non steroid hormone - so it binds to cell surface receptors and triggers a cascade of reactions inside the cell

Question 23

Describe the cascade of reactions caused by adrenaline

Answer 23

1. Adrenaline binds to surface activating ADENYLYL CYCLASE
2. Adenylyl cyclase triggers conversion of ATP to cAMP on the inside of surface membrane
3. Increase in cAMP activation specific protein kinases enzymes and activate more enzymes (cascade) including the enzyme converting glycogen to glucose

Question 24

What does Adrenalin trigger liver cells to do?

Answer 24

Glycogenolysis - glycogen to glucose

Question 25

What part of the brain is responsible for changes in HR?

Answer 25

Medulla oblongata

Question 26

How is heart rate increased in a centre in the brain?

Answer 26

Impulses are sent to SAN through sympathetic nervous system through the accelerator nerve

Question 27

How is heart rate decreased in a centre in the brain?

Answer 27

Impulses are send through the parasympathetic nervous system through the vagus nerve

Question 28

What are the 2 receptors that provide information affecting heart rate?

Answer 28

1. Baroreceptors
2. Chemoreceptors

Question 29

What do baroreceptors do?

Answer 29

They detect changes in blood pressure and are present in the aorta, vena cava and carotid artery

Question 30

What is a caratoid artery?

Answer 30

Main artery in neck providing blood for the brain

Question 31

What does a chemoreceptor do? Provide a specific example

Answer 31

Chemoreceptors detect chemical changes in the blood

E.g sensitivity to pH means that if pH decreases it will stimulate an increase in heart rate as it will be caused by increase levels of CO2 meaning the faster the blood flows the faster CO2 is exhaled

Question 32

What is hyperglycaemia?

Answer 32

Very high blood glucose

Question 33

What is hypoglycaemia?

Answer 33

Very low blood glucose

Question 34

How is type 1 diabetes treated?

Answer 34

Using insulin injections, insulin pump, islet cell transplant and pancreas transplant

Question 35

What increases the risk of type 2 diabetes?

Answer 35

Obesity, sedentary lifestyle, high sugar diet

Question 36

How is type 2 diabetes treated?

Answer 36

Life style changes
Weight loss, regular expertise, change in diet