Endocrine System

Question 0

What are the main communication pathways in the body?

Answer 0

Endocrine and nervous system

Question 1

List the main features of a control system (5)

Answer 1

Communication
Control centre
Receptor
Effector
Feedback

Question 2

What is the different between the afferent branch and the efferent branch of the nervous system?

Answer 2

Afferent is sensory input

Efferent is motor output

Question 3

What is the role of the control centre?

Answer 3

Determine a set point
Analyse the afferent input
Coordinate an appropriate response

Question 4

Name two important control centres in the brain and state what they do

Answer 4

Medulla oblongata - ventilation and cardiovascular system

Hypothalamus - control of the endocrine system

Question 5

Name some receptors

Answer 5

Chemoreceptors
Thermoreceptors
Proprioreceptors
Nocicereceptors

Question 6

What happens in negative feedback?

Answer 6

The output inhibits the effect of the control centre and the effector acts to oppose the stimulus.

Question 7

What happens in positive feedback?

Answer 7

The stimulus produces a response which increases its effect

Question 8

Give two examples of positive feedback

Answer 8

Blood clotting

Ovulation

Question 9

What is the total body water content in a 70kg male and what percentage?

Answer 9

42 litres

50-60%

Question 10

What are the three main components water is contained in? Percentages and litres?

Answer 10

Interstitial fluid - 28L, 35%
Extracellular fluid - 9.4L, 12%
Blood plasma - 4.6L, 4-5%

Question 11

What does anti-diuretic hormone do?

Answer 11

Increases permeability to water of collecting duct in kidney, increasing the reabsorption of water into the blood from the urine.

Question 12

What are hormones?

Answer 12

Chemical messengers involved in communication that travel via the bloodstream

Question 13

What are steroids derived from?

Answer 13

Cholesterol

Question 14

List the four chemical types of hormones

Answer 14

Polypeptide
Glycoprotein
Amino acid derivatives
Steroids

Question 15

Which types of hormones need to be transported by proteins?

Answer 15

Thyroid and steroids

Question 16

What is a trophic hormone?

Answer 16

A hormone whose production is controls the secretion of another hormone

Question 17

What are the six main hormones that the anterior pituitary gland secretes?

Answer 17

Growth hormone
Thyroid stimulating hormone
FSH
LH
ACTH
Prolactin

Question 18

How do hormones affect the target cell?

Answer 18

Bind to receptors in/on the cell

This triggers changes such as activity of enzymes and proteins, and affecting rate of gene expression.

Question 19

Where are hormones inactivated?

Answer 19

Liver, kidney, sometimes the target tissue.

Question 20

What can cause disorders of the endocrine system?

Answer 20

• Over/under secretion of hormones
• Production of structurally abnormal and less effective hormones
• Responsiveness of endocrine tissues may be altered by circulating abnormal proteins eg antibodies
• Physiolologically effective conc of hormones altered due to binding to circulating proteins.
• Changes in responsiveness of target tissues due to changes in receptors/post receptor events

Question 21

In the HPA axis, what is released from where?

Answer 21

CRH from the hypothalamus
ACTH from the anterior pituitary
Cortisol from the cortex of the kidneys