Chapter 2: Nervous System Functioning Part 1

Question 1

What is the Central Nervous System comprised of and what is its main function?

Answer 1

• Consists of the brain and spinal cord

- Processes information received from the body’s internal and external environments to activate appropriate responses.

Question 2

What is the role of the brain in the CNS?

Answer 2

It acts as a control centre to organise , integrate and interpret information from the body via the PNS.

Question 3

What is the role of the spinal cord in the CNS? Give an example of both sensory information received:

Answer 3

-Connects the brain to the PNS
-Receives sensory info from the body (via the PNS) then sends the messages to the brain for processing.
Eg. Seeing a plate fall
-Receives motor info from the brain which it sends to relevant parts of the body (via the PNS) to control muscles, glands and internal organs to take appropriate action.
Eg. Holding your hands out to catch it

Question 4

What is the Peripheral Nervous System and what is its function?

Answer 4

• Consists of the entire network of nerves located outside the CNS
• Carries info from the sensory and internal organs to the CNS and transmits info from the CNS to the muscles, organs, and glands.

Question 5

What is the role of sensory neurons in the PNS?

Answer 5

Are afferent (ascending) and deliver sensory info to the brain for processing.

Question 6

What is the role of motor neurons in the PNS?

Answer 6

Are efferent (descending) and carry messages to muscles to initiate a response.

Question 7

What is the role of interneurons in the PNS?

Answer 7

Connect sensory and motor neurons

Question 8

What is the PNS divided into?

Answer 8

The Somatic and Autonomic nervous systems

Question 9

What is the Somatic Nervous System also known as and why?

Answer 9

The Skeletal Nervous System since it connects the CNS with muscles connected to bones that control voluntary movements.

Question 10

What is the process of the SNS?

Answer 10

Messages are sent from sensory receptors via sensory neurons to CNS and back to skeletal muscles via motor neurons.

Question 11

What is the role of neurotransmitters in the SNS? Give an example:

Answer 11

Are chemicals that are released to assist the transmission of a message from a neuron to a muscle.
Eg. The release of a neurotransmitter onto a muscles causing it to expand or contract

Question 12

What is the Autonomic Nervous System responsible for? Give some examples:

Answer 12

Connects the CNS to internal organs and glands (visceral muscles) and their functions (eg. Breathing, digestion, heart rate), which are generally involuntary as they are self-regulating.

Question 13

When is the Autonomic Nervous System activated?

Answer 13

During fear, anger, and excitement at intense levels.

Question 14

What is the function of the Sympathetic Nervous System? Give an example:

Answer 14

Generally increases activity when an individual is in a stressful or threatening situation.
Eg. About to make a speech at assembly

Question 15

What are the two branches of the Autonomic Nervous System?

Answer 15

Sympathetic and Parasympathetic Nervous Systems

Question 16

What is the function of the Parasympathetic Nervous System? Give an example:

Answer 16

Generally decreases activity as it calms the body to return to its normal state, and maintains homeostasis in the absence of a threat.
Eg. Doing yoga

Question 17

What is a conscious response and give an example:

Answer 17

A reaction to a sensory stimulus that requires awareness, which is usually voluntary and goal-directed.
Eg. Going outside when it is cold and consciously deciding whether or not to wear a jacket.

Question 18

What is an unconscious response and give an example:

Answer 18

A reaction to a sensory stimulus that does not require awareness, which is involuntary and automatic.
Eg. The ANS unconsciously regulating the pumping of blood to the heart.

Question 19

What is the Spinal Reflex and what is it also called and why? Give an example:

Answer 19

An unconscious, involuntary and automatic response to specific stimuli which occurs independently of the brain.

• Is also called the Reflex Arc because the response is ‘reflected back’ from the spinal cord without input from the brain before conscious perception occurs.
• Eg. Removing your hand from a hot or sharp object

Question 20

What are the benefits of the Spinal Reflex and why is it thought to be adaptive?

Answer 20

• It enables a faster reaction time (a fraction of a second before info reaches the brain).
• Is thought to be adaptive because it saves time in potentially harmful situations, thus increasing the chance of survival.

Question 21

What is a neuron?

Answer 21

Is an individual nerve cell that is specialised to receive, prosses and/or transmit info.

Question 22

What is the function of dendrites?

Answer 22

Receives info from other neurons.

Question 23

What is the function of axons?

Answer 23

Transmits neural info to other neurons.

Question 24

What are axon terminals?

Answer 24

Send messages to other neurons

Question 25

What is myelin?

Answer 25

A white, fatty substance that surrounds and insulates the axon, which provides protection and allows for faster transmission.

Question 26

What is a neurotransmitter?

Answer 26

A chemical substance produced by a neuron that carries a message to other neurons or cells in muscles, organs or other tissue.

Question 27

What is the role of neurotransmitters in presynaptic neurons?

Answer 27

The neurotransmitter binds itself to receptor sites of postsynaptic neurons that are specialised to receive that specific neurotransmitter.

Question 28

What is a synaptic gap?

Answer 28

The tiny gap between the terminal buttons of a presynaptic neuron, which releases neurotransmitters, and the dendrites of a postsynaptic neuron, which receives neurotransmitters.

Question 29

What is a synapse?

Answer 29

The area where communication occurs between presynaptic and postsynaptic neurons.