The nervous system and the endocrine system

Question 1

Definition of the nervous system?

Answer 1

A specialised network of cells (neurons) in the human body, and is our primary internal communication system.

It makes use of electrical and chemical signals to relay information from one place to another in the body.

Question 2

What are the 2 main functions of the nervous system?

Answer 2

• Collect, process and respond to environmental stimuli
• Co-ordinate the working of different organs ans cells in the body

Question 3

What are the 2 subsystems the nervous system is divided into?

Answer 3

Central nervous system (CNS)

Peripheral nervous system (PNS)

Question 4

What is the CNS divided into?

Answer 4

Brain and spinal cord (connects brain and peripheral nervous system)

Question 5

What is the PNS divided into?

Answer 5

Somatic nervous system (voluntary functions)

Autonomic nervous system (involuntary functions)

Question 6

What is the autonomic nervous system divided into?

Answer 6

Sympathetic nervous system (arouses body to expend energy)

Parasympathetic nervous system (calms body to maintain energy)

Question 7

What is the outer layer of the brain called?

Answer 7

Cerebral cortex (3mm thick and covers brain)

Question 8

How does the brain distinguish humans from other animals?

Answer 8

The human brain is highly developed, distinguishing it from other animals as we have superior mental functions.

Very few creatures (eg. jelly fish) don’t have a brain

Question 9

What is the spinal cord?

Answer 9

It is an extension of the brain

Question 10

What does the spinal cord do?

Answer 10

It passes messages to and from the brain, and connects nerves to the PNS.

It is responsible for reflex actions eg. pulling you hand away from a hot plate

Question 11

What does the peripheral nervous system do?

Answer 11

It transmits messages via neurone to and from the CNS.

Question 12

What is the autonomic nervous system?

Answer 12

It controls vital functions in the body eg. breathing, heart rate, digestion (system operates involuntarily)

Question 13

What is the somatic nervous system?

Answer 13

It controls muscle movement and receives information from sensory receptors

Question 14

What is the endocrine system?

Answer 14

It instructs glands to release hormones directly into the bloodstream. It communicates via chemicals. It acts more slowly than the nervous system, but has widespread and powerful effects

Question 15

What are glands?

Answer 15

An organ in the body that synthesises substances such as hormones

Glands in the body produce hormones

Question 16

What does the thyroid gland produce + affects on body

Answer 16

Thyroid gland produces thyroxine.

This hormone affects cells in the heart (increases heart rate).

It also affects cells throughout body increasing metabolic rates, and it turn affects growth rates.

Question 17

What is the key endocrine gland?

Answer 17

Pituitary gland

Question 18

Where is the pituitary gland located?

Answer 18

The brain

Question 19

What does the pituitary gland do?

Answer 19

It controls the release of hormones from all other endocrine glands

Question 20

Which systems work together in stressful events?

Answer 20

Endocrine system and Autonomic nervous system

Question 21

What happens in the body during a stressful event?

Answer 21

1. A stressor is received (eg. an approaching car)
2. The hypothalamus activates the pituitary gland
3. This triggers activity in the sympathetic brand of the ANS
4. The ANS switches from a parasympathetic state (resting) to a sympathetic state (aroused)

Question 22

What is Adrenaline?

Answer 22

The stress hormone, which is released from the adrenal medulla (a part of the adrenal gland near kidneys) into the bloodstream

Question 23

What does adrenaline do?

Answer 23

It triggers physiological changes in the body (eg. increased heart rate, deeper breathing) which creates physiological arousal necessary for flight or fight responses.

Question 24

How quick are responses to threats?

Answer 24

As soon as a threat is detected, there is an acute and automatic response. This is a sympathetic response

Question 25

What happens to the body once the threat is gone?

Answer 25

The parasympathetic nervous system will kickback in, returning the body to a resting state.

The parasympathetic branch of ANS works in opposite to the sympathetic nervous system - acting like a brake to reduce the activities such as HR back to normal. This is the rest and digest phase.