Ns

Question 1

What are changes in the environment called?

Answer 1

Stimuli

Stimuli are detected by receptors.

Question 2

What cells detect stimuli?

Answer 2

Receptors

Receptors are specialized cells that respond to environmental changes.

Question 3

What are the components involved in the response to stimuli?

Answer 3

Effectors

Effectors are organs or cells that carry out the response.

Question 4

How do receptors and effectors communicate?

Answer 4

Using electrical impulses

The communication involves nervous coordination.

Question 5

What is an electrical impulse?

Answer 5

An electrical signal that passes along nerve cells called neurons

Electrical impulses are crucial for nervous coordination.

Question 6

What are the three types of neurons?

Answer 6

• Sensory neurone
• Relay neurone
• Motor neurone

Each type of neuron has a specific role in the nervous system.

Question 7

What does a sensory neurone do?

Answer 7

Carries impulses from receptor to CNS

The CNS includes the brain and spinal cord.

Question 8

What is the role of a relay neurone?

Answer 8

Carries impulses within the CNS

Relay neurones connect sensory and motor neurones.

Question 9

What does a motor neurone do?

Answer 9

Carries impulses from CNS to effector

Effectors can be muscles or glands.

Question 10

What are the main components of a neurone?

Answer 10

• Cell body
• Axon
• Dendrites

Each component has a specific function in impulse transmission.

Question 11

What does the cell body of a neurone contain?

Answer 11

• Nucleus
• Cytoplasm
• Ribosomes
• Mitochondria

These organelles are essential for the neurone’s functioning.

Question 12

What is the function of the axon?

Answer 12

Carries impulses away from the cell body

The axon transmits signals to other neurons or effectors.

Question 13

What do dendrites do?

Answer 13

Receive impulses from other neurons and pass them down towards the cell body

Dendrites are crucial for communication between neurones.

Question 14

What adaptation do motor neurones have for transmitting impulses?

Answer 14

Long axon

A long axon allows for the transmission of impulses over long distances.

Question 15

Why do neurones contain many mitochondria in the cell body?

Answer 15

To provide energy for the transmission of electrical impulses

Mitochondria are the powerhouses of the cell.

Question 16

What is the central nervous system composed of?

Answer 16

Brain and spinal cord

The CNS processes information and coordinates responses.

Question 17

True or False: The effector can only be a muscle.

Answer 17

False

Effectors can also be glands.

Question 18

Fill in the blank: The _______ carries impulses from the CNS to the effector.

Answer 18

[Motor neurone]

Question 20

What are the two main components of the human nervous system?

Answer 20

CNS (central nervous system) and PNS (peripheral nervous system)

CNS consists of the brain and spinal cord, while PNS consists of cranial nerves and spinal nerves.

Question 21

What does the CNS consist of?

Answer 21

Brain and spinal cord

The CNS is responsible for processing and integrating information.

Question 22

What does the PNS consist of?

Answer 22

Cranial nerves and spinal nerves

The PNS links the brain and spinal cord with other organs in the body.

Question 23

Which type of neurones are found only within the CNS?

Answer 23

Relay neurones

Relay neurones play a crucial role in transmitting signals within the CNS.

Question 24

Which types of neurones are found within the PNS?

Answer 24

Sensory and Motor neurones

Sensory neurones carry signals to the CNS, while motor neurones carry signals away from the CNS.

Question 25

What is a reflex action?

Answer 25

Automatically and rapidly occurring response to stimuli ## Footnote Reflex actions do not require conscious thought and are controlled by the spinal cord.

Question 26

Give examples of reflexes.

Answer 26

* Withdrawal reflex * Iris reflex * Knee jerk * Blinking * Coughing * Sneezing ## Footnote These reflexes demonstrate the body's immediate response to stimuli.

Question 27

What is a reflex arc?

Answer 27

The neural pathway that mediates a reflex action ## Footnote A reflex arc includes a receptor, sensory neurone, relay neurone, motor neurone, and effector.

Question 28

What triggers a withdrawal reflex?

Answer 28

Pain receptor ## Footnote The withdrawal reflex is a protective response to avoid injury.

Question 29

What is the difference in speed between reflex actions and voluntary actions?

Answer 29

Reflex actions are faster than voluntary actions ## Footnote Reflex actions are involuntary and do not involve thinking, while voluntary actions require conscious thought and are slower.

Question 30

What controls voluntary actions?

Answer 30

The brain ## Footnote Voluntary actions involve conscious thought and decision-making.

Question 31

What controls involuntary actions?

Answer 31

The spinal cord ## Footnote Involuntary actions occur without conscious control.

Question 32

Fill in the blank: The PNS links the brain and spinal cord with other _______.

Answer 32

[organs] ## Footnote This connection is essential for communication between the CNS and the rest of the body.

Question 33

True or False: Reflex actions involve thinking.

Answer 33

False ## Footnote Reflex actions are involuntary and do not require conscious thought.

Question 34

What is the role of motor neurones in the reflex arc?

Answer 34

To make the muscle contract ## Footnote Motor neurones transmit impulses from the CNS to effectors, such as muscles.

Question 35

What is the role of sensory neurones in the reflex arc?

Answer 35

To carry signals from receptors to the CNS ## Footnote Sensory neurones are crucial for detecting stimuli and initiating reflex actions.

Question 36

What is a synapse?

Answer 36

A junction between two neurons ## Footnote A synapse consists of the endings of two neurons and the synaptic cleft.

Question 37

What is the tiny gap between two neurons called?

Answer 37

Synaptic cleft ## Footnote The synaptic cleft is the space that separates the endings of two neurons.

Question 38

List the steps of how impulses are transmitted across a synapse.

Answer 38

* Impulse arrives at the end of the neuron * Vesicles containing neurotransmitter move towards the membrane * Vesicles fuse with the membrane * Neurotransmitter is released * Neurotransmitter moves by diffusion across synaptic cleft * Neurotransmitter binds to receptors on other neurone surface * Resulting in an impulse in the next neurone

Question 39

What happens when a neurotransmitter binds to receptors on the other neurone's surface?

Answer 39

It results in an impulse in the next neurone ## Footnote This process is facilitated by the complementary shapes of neurotransmitters and receptors.

Question 40

Why is the synapse important?

Answer 40

It ensures that impulses travel in one direction only ## Footnote This is because vesicles are located on one side of the synapse and receptors are found only on the other side.

Question 41

Fill in the blank: A synapse is made up of the endings of two neurons and the _______.

Answer 41

synaptic cleft

Question 42

True or False: Neurotransmitters and receptors have complementary shapes.

Answer 42

True

Question 43

What is the role of vesicles in the synapse?

Answer 43

To contain and release neurotransmitters ## Footnote Vesicles move toward the membrane when an impulse arrives.

Question 44

What structure is found at the end of the axon in a synapse?

Answer 44

Synaptic bulb ## Footnote The synaptic bulb contains neurotransmitter vesicles.