Endocrine System

Question 1

What is the endocrine system?

Answer 1

A network of glands throughout the body that secrete chemical messengers called hormones

Question 2

How do hormones travel?

Answer 2

Via the bloodstream

Question 3

Name all the glands within the endocrine system.

Answer 3

Pituitary gland
Pineal gland
Thyroid gland
Adrenal glands
Pancreas
Ovaries (female)
Testes (male)

Question 4

What is the hypothalamus?

Answer 4

In the brain
Links the nervous system to the endocrine system via the pituitary gland

Question 5

What is the hormone and hormone function of the pituitary gland?

Answer 5

Hormone: ACTH, TSH, LH, FSH
Hormone function: releases hormones to activate other glands in the endocrine system to release hormones

Question 6

What is the hormone and hormone function of the pineal gland?

Answer 6

Hormone: melatonin
Hormone function: regulates the sleep-wake cycle

Question 7

What is the hormone and hormone function of the thyroid gland?

Answer 7

Hormone: thyroxine
Hormone function: regulates the body’s metabolic rate

Question 8

What is the hormone and hormone function of the adrenal glands?

Answer 8

Hormone: cortisol, adrenaline
Hormone function: both hormones are involved in the body’s fight or flight response
Cortisol increase blood sugar, adrenaline increases heart rate and respiration

Question 9

What is the hormone and hormone function of the pancreas?

Answer 9

Hormone: insulin
Hormone function: regulates blood sugar levels via absorption of glucose

Question 10

What is the hormone and hormone function of the ovaries?

Answer 10

Hormone: oestrogen and progesterone
Hormone function: maintenance of reproductive organs and regulation of the menstrual cycle

Question 11

What is the hormone and hormone function of the testes?

Answer 11

Hormone: testosterone
Hormone function: sperm development
Higher levels have been associated with periods of sexual activity and aggression

Question 12

Explain the process of the fight or fight response.

Answer 12

1. A person enters a stressful or dangerous situation
2. The amygdala send a distress signal to the hypothalamus
3. The hypothalamus activates the SAM pathway (this runs to the adrenal medulla and the SNS)
4. The SNS stimulates the adrenal medulla
5. The adrenal medulla secretes adrenaline and noradrenaline into the bloodstream
6. Adrenaline then causes physiological changes to prepare fight or flight

Question 13

What are some physiological changes caused via adrenaline?

Answer 13

Increased heart rate - increase blood flow to organs and increase movement of adrenaline around the body
Increased breathing rate - increased oxygen intake
Pupil dilation - increase light to eyes which enhances vision
Sweat production - regulates temperature
Reduce non-essential functions - increases energy for functions essential for survival

Question 14

Does fight or flight give a complete account of the stress response?

Answer 14

Gray (1988) proposes that before confronting or fleeing a stressor, most animals (including humans) display a freeze response
By freezing the animal is hyper-vigilant, alert to the slightest signs of danger
This has an adaptive advantage as new info is sought allowing the best possible response to be made for a threat

Question 15

Is there a genetic basis to sex differences in the fight or flight response?

Answer 15

• SRY gene promotes aggression = only present on male Y chromosome
• Females don’t have the Y chromosome + action of oestrogen and oxytocin may prevent fight or flight response
• Women’s responses may have evolved in context of being primary caregivers, where fight or flight could’ve put their offspring in danger
• Von Dawans et al. (2012) found, however, that both genders acute stress increased cooperative and friendly behaviour