F215:04:06 Organising the nervous system

Question 1

How does the nervous system co-ordinate the actions of the body?

Answer 1

Through electrical impulses

Question 2

Describe the organisation of the nervous system

Answer 2

-> Receptors and sensory neuones transmit impulses to the CNS
<- Somatic motor neurones transmit impulses to voluntary muscles

Question 3

What does the nervous system work in conjunction with and why?

Answer 3

the endocrine system

As they are both are essential in maintaining life in humans

Question 4

What are the different sub-sections of the nervous system

Answer 4

CNS

Peripheral nervous system

Question 5

What does the CNS consist of?

Answer 5

the brain and the spinal cord

its made up of grey matter and white matter

Question 6

What is the peripheral nervous system made up of?

Answer 6

neurones that carry impulses into and out of the CNS

Question 7

What is grey matter?

Answer 7

Billions of non-myelinated nerve cells

Question 8

What is white matter?

Answer 8

Longer myelinated axons and dendrons that carry impulses

Question 9

Why does white matter appear white?

Answer 9

Because of the myelin

Question 10

What do sensory neurones do?

Answer 10

They carry impulses from the many receptors, in and around the body to the CNS

Question 11

What do motor neurones do?

Answer 11

They carry impulses from the CNS to the effecter organs

Question 12

How are nerves formed?

Answer 12

Many neurones bundled together and covered in connective tissues

Question 13

How is the motor system subdivided?

Answer 13

The somatic and autonomic motor neurones

Question 14

What does the somatic and autonomic neurones make up?

Answer 14

The motor system

Question 15

What do somatic motor neurones do?

Answer 15

they carry impulses from the CNS to the skeletal muscles which are under voluntary (conscious) control

Question 16

What do the autonomic motor neurones do?

Answer 16

They carry impulses from the CNS to cardiac muscles, to smooth muscles in the gut wall and to glands, none of which are under voluntary control

Question 17

What does autonomic translate as and why?

Answer 17

self-governing

As the system operates to a large extent independently of conscious control

Question 18

What is the autonomic nervous system responsible for?

Answer 18

For controlling the majority of homeostatic mechanisms and so plays a vital role in regulating the internal environment of the body within set parameters

Question 19

What is the autonomic nervous system capable of doing beyond maintaining homeostatic conditions?

Answer 19

Controlling the heightened responses associated with the stress response

Question 20

Desrcibe the makeup of the peripheral nervous system beginning from the top of the head to the feet

Answer 20

Cerebrum
Cranial nerves
Cervical nerves (innervate the neck and arms)
Spinal cord + intercostal muscles
Lumbar and sacral nerves (innervate the legs and pelvic organs)

Question 21

What do Cervical nerves do and where are they found?

Answer 21

They innervate the neck and arms

Found in peripheral nervous system

Question 22

How does the autonomic nervous system differ from the somatic nervous system?

Answer 22

• Most Autonomic nervous systems are non-myelinated, but Somatic are mostly myelinated
• Autonomic connections to effectors always consist of at least 2 neurones (Somatic only consist of 1)
  Autonomic motor neurones occur in 2 types: sympathetic and parasympathetic

Question 23

Which of the two subdivisions of the peripheral nervous system is subdivided into two types of motor neurone and what are they known as?

Answer 23

Autonomic nervous system

Autonomic and somatic motor neurones

Question 24

What is the swelling known as where two neurones meet (potentially just autonomic- not sure)

Answer 24

a Ganglion

Question 25

What are sympathetic and parasympathetic subsystems known as?

Answer 25

antagonistic systems- because in many cases the action of one opposes the action of the other

Question 26

What rate are the impulses passing along both neurones of the para and symp systems under normal resting conditions?

Answer 26

A relatively low rate

Question 27

What leads to an altered balance of stimulation between the para and symp systems? and what does this lead to?

Answer 27

a change to internal conditions or stimulation of a stress response Leads to an appropriate response

Question 28

When is the para and symp most active?

Answer 28

para: sleep and relaxation Symp: times of stress

Question 29

How are the neurones linked in the para and symp systems?

Answer 29

para: neurones of a patheway are linked at a ganglion within the target tissues so pre-ganglionic neurones vary considerably in length Symp: Linked at a ganglion just outside the spinal cord, so the pre-ganglionic neurones are very short

Question 30

What do post-ganglionic neurones secrete in the para and symp systems?

Answer 30

para: acetylcholine as the neurotransmitter at the synpase between the neurone and the effector symp: noradrenaline at the synpase between neurone and effector

Question 31

What are the effects of action of the para and symp systens?

Answer 31

``` Para: - decreased heart rate - pupil constriction - decreased ventilation rate - sexual arousal Symp: - increased heart rate - pupil dilation - increased ventilation rate - orgasm ```

Question 32

Describe the differences between para and symp:

Answer 32

- Most active - How pathways are linked - What post-ganglionic neurones secrete - Effects of action

Question 33

What is the CNS?

Answer 33

Central nervous system | consists and of brain and spinal cord

Question 34

What is the PNS?

Answer 34

Peripheral nervous system Consists of all the sensory and motor neurones that are outside the CNS and connect the receptors and the effectors to the CNS

Question 35

Explain why the control of pupil diameter in the eye is described as an autonomic reflex

Answer 35

A reflex action involves sensory and motor neurones passing through the CNS These actions involved a stimulus and an appropriate immediate response to that stimulus Pupil diameter is controlled by autonomic neurones Where too much light enters the eye, a reflex action involving those neurones leads to constriction of the pupil by contraction of the circular muscles of the iris

Question 36

If a person exercises by running for 2 minutes, a number of autonomic responses will take place during and after the exercise List the responses

Answer 36

During exercise: -increased blood flow to muscles - Increased heart and ventilation rate - Decreased blood flow to gut - Vasodilation in skin to accommodate sweating and increased blood flow to the surface After: All the above are reversed during recovery

Question 37

If a person exercises by running for 2 minutes, a number of autonomic responses will take place during and after the exercise State whether the responses are sympathetically or parasympathetically controlled and why

Answer 37

During exercise: - Increased activity of the symp is responsible - As the cardiac, vasomotor and respiratory centres in the brain receive input from pH, temp, and stretch receptors in the carotid body, aortic body and medulla which leads to increased sympathetic output from these centres After: - Parasympathetic is responsible for returning the body back to its resting state