Endocrine System

Question 1

What is the definition of Homeostasis?

Answer 1

The regulation of a constant internal environment to maintain optimum conditions

Question 2

Give three examples of what homeostasis regulates

Answer 2

Blood glucose levels, body temperature, CO2 levels

Question 3

Defines ‘Synapse’

Answer 3

The gap where the ends of two neurons meet

Question 4

How does a synapse work?

Answer 4

An electrical impulse arrives at the terminal of the first neuron, and causes the release of neurotransmitter chemicals into the synapse. They cross the synapse and bind to the receptor sites on the next neuron. The receptor site are specific to a single neurotransmitter, and will create a nerve impulse when they fully bind.

Question 5

Where are the 6 major glands in the endocrine system?

Answer 5

Pituitary gland - brain
Thyroid gland - throat
Adrenal gland - above kidney
[Pancreas]
[Ovary]
[Testis]

Question 6

What does the Pituitary gland produce?
What do the hormones do?

Answer 6

FSH (follicle stimulating hormone) - matures egg in ovaries, stimulates Oestrogen
LH (luteinizing hormone) - trigger ovulation, stimulates Progesterone

Question 7

What does the Thyroid gland produce? What does the hormone do?

Answer 7

Thyroxine - stimulates the rate of metabolism, triggered by TRH from Hypothalamus

Question 8

What does the Adrenal gland produce? What does the hormone do?

Answer 8

Adrenaline - prepares body for ‘fight or flight’ response: increases heart and breathing rate, causes vasodilation

Question 9

What does the Pancreas produce? What do the hormones do?

Answer 9

Insulin - causes cells to absorb glucose, converts glucose into glycogen
Glucagon - causes cells to release glucose, converts glycogen into glucose

Question 10

What do the Ovaries produce? What do the hormones do?

Answer 10

Oestrogen - builds and thickens uterus lining, stimulates production of LH, inhibits production of FSH
Progesterone - maintains uterus lining, inhibits production of LH

Question 11

What do the Testes produce? What does the hormone do?

Answer 11

Testosterone - stimulates production of sperm

Question 12

Describe the sequence of the reflex arc

Answer 12

Stimulus - receptor - sensory neuron - relay neuron - motor neuron - response

Question 13

Define a reflex

Answer 13

A fast and automatic response to a stimulus that may be harmful to the organism.

Question 14

What day is ovulation in the menstrual cycle?

Answer 14

Day 14