Endocrine System

Question 1

Key Features of ES

Answer 1

1) Works alongside nervous system to control vital functions in body through action of hormones.
2) Made up of glands that secrete hormones.
2) Works slower than NS (by secs) but has widespread & powerful effects.

Question 2

Glands

Answer 2

1) Glands - organs in body that produce hormones.
2) Key endocrine gland is Pituitary Gland - located in brain, called ‘master gland’ since it controls release of hormones from all other endocrine glands in body.

Question 3

Pituitary Gland

Answer 3

1) Referred to as the “master gland” because its messenger hormones control all the other glands in the endocrine system.
2) Also secretes growth hormone, endorphins for pain relief, and a number of important hormones that regulate fluid levels in the body.

Question 4

Hormones

Answer 4

Chemical messenger

1) Secreted in bloodstream & affect any body cell that has a receptor for a particular hormone.
2) Hormones are slower to take effect and longer lasting than neurotransmitters.
3) Hormones are involved in regulating bodily functions - Imbalances in hormones are related to a number of disorders.
4) They are controlled by the pituitary gland.

Question 5

Thyroid/ Adrenal/ Pancreas

Answer 5

Thyroid Gland:
1) Located in back of neck - Releases thyroxine that regulates growth, metabolism, and appetite.

Adrenal glands:
2) On top of the kidneys - Secrete adrenaline/noradrenaline involved in the stress response.

Pancreas:
3) Organ that secretes hormones that regulate blood sugar levels: insulin, which lowers levels, and glucagon, which raises them.

Question 6

Autonomic Nervous System

Answer 6

1) Endocrine system often works with the ANS, e.g. during stressful events (fight or flight response).
2) Stressor perceived by hypothalamus which activates pituitary.
3) Sympathetic Nervous System is now aroused.
4) Adrenaline is released from adrenal medulla into bloodstream –> delivers the aroused state causing changes in target organs e.g. increased heart rate, pupil dilation, inhibited saliva production –> This is called fight or flight response.
5) Immediate & automatic response - as soon as threat is perceived.
6) Parasympathetic Nervous System (rest & digest) takes over once threat has passed –> returns body to resting state, acts as a ‘brake’ & reduces activities of body that were increased by actions of sympathetic branch.

Question 7

Sympathetic State

Answer 7

During Adrenaline Rush:
- Increases Heart Rate
- Increases Breathing Rate
- Dilates Pupils
- Inhibits Digestion
- Inhibits Saliva Production
- Contracts Rectum

Question 8

Parasympathetic State

Answer 8

Rest & Digest:
- Decreases Heart Rate
- Decreases Breathing Rate
- Constricts Pupils
- Stimulates Digestion
- Stimulates Saliva Production
- Relaxes Rectum