the nervous system & the endocrine system

Question 1

what is the nervous system?

Answer 1

Consists of the central nervous system and the peripheral nervous
system, communicates using electrical signals

Question 2

what is the central nervous system (CNS)?

Answer 2

Consists of the brain and the spinal cord and is the origin of all complex commands and decisions.

Question 3

what is the peripheral nervous system (PNS)?

Answer 3

Sends information to the CNS from the outside world, and transmits messages from the CNS to muscles and glands in the body.

Question 4

what is the somatic nervous system (SNS)?

Answer 4

Transmits information from receptor cells in the sense organs to the CNS. It also receives information from the CNS that directs muscles to act.

Question 5

what is the autonomic nervous system (ANS)?

Answer 5

Transmits information to and from internal bodily organs. It is ‘autonomic’ as the system operates involuntarily (i.e. automatic). It has two main divisions: the sympathetic and parasympathetic nervous systems.

Question 6

what are the 2 functions of the nervous system?

Answer 6

To collect, process and respond to information in the environment.
To co-ordinate the working of different organs and cells in the body.

Question 7

what subsystems can the nervous system be divided into?

Answer 7

Central nervous system (CNS).
Peripheral nervous system (PNS).

Question 8

what is the CNS made up of?

Answer 8

the brain and the spinal cord

Question 9

what does the spinal cord do?

Answer 9

The spinal cord is an extension of the brain. It passes messages to and from the brain and connects nerves to the PNS. It is also responsible for reflex actions such as pulling your hand away from a hot plate.

Question 10

how does the PNS transmit messages?

Answer 10

The PNS transmits messages, via millions of neurons (nerve cells), to and from the central nervous system.

Question 11

what is the PNS divided into?

Answer 11

Autonomic nervous system (ANS)
•Somatic nervous system (SNS)

Question 12

what does the ANS govern?

Answer 12

governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses

Question 13

what does the SNS govern?

Answer 13

governs muscle movement and receives information from sensory receptors

Question 14

what is the endocrine system?

Answer 14

One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body. Communicates via chemicals.

Question 15

what is a gland?

Answer 15

An organ in the body that synthesises substances such as hormones.

Question 16

what are hormones?

Answer 16

A biochemical substance that circulates in the blood but only affects target organs. They are produced in large quantities but disappear quickly.
Their effects are very powerful.

Question 17

what is the fight or flight response?

Answer 17

The way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or, in some
cases. flee.

Question 18

what is adrenaline?

Answer 18

A hormone produced by the adrenal glands which is part of the human body’s immediate stress response system. Adrenaline has a strong effect on the cells of the cardiovascular system - stimulating heart rate, contracting blood vessels and dilating air passages.

Question 19

what does the endocrine system do?

Answer 19

The endocrine system works alongside the nervous system to control vital functions in the body. The endocrine system acts more slowly than the nervous system but has very widespread and powerful effects.

Question 20

what do hormones do?

Answer 20

Hormones are secreted into the bloodstream and affect any cell in the body that has a receptor for that particular hormone. Most hormones affect cells in more than one body organ, leading to many diverse and powerful responses.

Question 21

what is the key endocrine gland?

Answer 21

The key endocrine gland is the pituitary gland, located in the brain. It is often called the ‘master gland’ because it controls the release of hormones from all the other endocrine glands in the body.

Question 22

how does the fight or flight response activate?

Answer 22

When a stressor is perceived the first thing that happens is a part of the brain called the hypothalamus activates the pituitary gland and this triggers activity in the sympathetic branch of the autonomic nervous system. The ANS changes from its normal resting state (the parasympathetic state) to the physiologically aroused sympathetic state.

Question 23

what does adrenaline do?

Answer 23

Adrenaline triggers physiological changes in the body (e.g. increased heart rate) which creates the physiological arousal necessary for the fight or flight response.

Question 24

fight or flight: immediate & automatic

Answer 24

it happens in an instant as soon as the threat is detected, this is an acute response and an automatic reaction in the body.

Question 25

what is the parasympathetic action?

Answer 25

once the threat has passed, the parasympathetic nervous system returns the body to its resting state. The parasympathetic system acts as a ‘brake and reduces the activities of the body that were increased by the actions of the sympathetic branch.

Question 26

what biological changes are associated with the sympathetic state?

Answer 26

increases heart rate
increases breathing rate
Dilates pupils
Inhibits digestion
Inhibits saliva production
Contracts rectum

Question 27

what biological changes are associated with the parasympathetic state?

Answer 27

Decreases heart rate
Decreases breathing rate
Constrits pupils
Stimulates digestion
Stimulates saliva production
Relaxes rectum