Nervous Control In Humans

Question 1

Describe the journey of the information of a nerve impulse

Answer 1

The information in the nerve impulse comes from the SENSE ORGAN and travels to the BRAIN and SPINAL CORD along neurones.

Question 2

What is the role of brain and nervous system?

Answer 2

To coordinate the senses and responses in the body.
This enables you to react to your surroundings (as it detects stimuli - change in internal or external environment) and coordinate your behaviour. It does that by sending impulses through the PERIPHERAL NERVOUS SYSTEM to the CENTRAL NERVOUS SYSTEM.

Question 3

What does the nervous system consist of?

Answer 3

• CENTRAL NERVOUS SYSTEM (brain + spinal cord) -> coordinates a response to the stimulus and sends impulses to effector organs that carry out the response. ex : muscular movement or release of hormones
• PERIPHERAL NERVOUS SYSTEM (matching sets of nerves on euther side of the brain = cranial and spinal nerves)

Question 4

What are Cranial nerves ?

Answer 4

Cranial nerves link the brain to the organs in the head and some in thorax and abdomen

Question 5

What is the spinal nerve?

Answer 5

Spinal nerves are responsible for the remaining organs in the abdomen and thorax and limbs

Question 6

3 types of neurones

Answer 6

Motor neurone (or effector)
Sensory neurone
Relay neurone (or bipolar, or connector)

Question 7

Draw diagram of motor neurone

Answer 7

—check book

Question 8

Draw diagram of sensory neurone

Answer 8

—see book

Question 9

Draw diagram of relay neurone

Answer 9

—see book

Question 10

Give examples of reflex actions

Answer 10

• blinking (changing size of pupil)
• withdrawing hand from a hot object
• salivary gland releasing saliva when food is in the mouth
• sneeze reflex when particles enter airways

Question 11

Definition of reflex action

Answer 11

A means of automatically and rapidly integrating and coordinating stimuli with the responses of effectors (muscles and glands)

Question 12

What are voluntary actions?

Answer 12

Actions that require a conscious decision

Question 13

Examples of voluntary actions

Answer 13

Picking up pen

Running

Question 14

What are involuntary actions? + examples

Answer 14

Other actions that are too important to be left to our conscious decision- making process and so our nervous system carries them out without conscious input
Ex blinking
Breathing
Heart beating

Question 15

Definition of synapse

Answer 15

Junction between 2 neurones which ensure impulse travels in one direction in a reflex arc

Question 16

Describe how a synapse works

Answer 16

The neurone carrying the message produces chemicals know as NEUROTRANSMITTERS in the synapse and they diffuse accross to the receiving neurone where they trigger a new impulse?

Question 17

Explain how drugs and toxins affect how synapses work

Answer 17

Some drugs and toxins affect how impulses pass from one neurone into another.
Some stop the impulse which passes accross the synapse, leading to paralysis.
Others stimulate the synapse so that once an impulse crosses the gap, the impulse is repeated over and over again (spasm).

Question 18

Definition of nerve impulse

Answer 18

An electrical signal that passes along nerve cells called neurones.