Module 5.1.5 Animal and plant responses

Question 1

What are the two main bodies of the nervous system?

Answer 1

CNS and peripheral

Question 2

What is the function of the CNS?

Answer 2

To receive and process information and coordinate the body’s response

Question 3

What is the function of the peripheral nervous system?

Answer 3

Neurones that carry action potentials to and from the CNS.

Question 4

What are the two components of the CNS?

Answer 4

Brain, spinal chord`

Question 5

What are the two neurones involved in the peripheral nervous system?

Answer 5

Motor and sensory.

Question 6

What is the function of motor neurones in the PNS?

Answer 6

Carry action potentials from the CNS to effectors (muscles and glands)

Question 7

What is the function of sensory neurones in the PNS?

Answer 7

Carry action potentials from receptors to the CNS.

Question 8

What are the two components of the motor neurone system?

Answer 8

Autonomic and somatic.

Question 9

What is the role of the autonomic nervous system?

Answer 9

Controls the involuntary activities of glands, smooth muscle and cardiac muscle. Works constantly under subconscious control. Eg heartbeat and food digestion

Question 10

What is the role of the somatic nervous system?

Answer 10

Controls the voluntary activities of body muscles. It is under conscious control eg deciding to move your arm.

Question 11

What two nervous systems are in the autonomic nervous system?

Answer 11

Sympathetic and parasympathetic.

Question 12

What involves the sympathetic nervous system?

Answer 12

If the outcome is increased activity then it involves the sympathetic nervous system. eg heart rate increase.

Question 13

What involves the parasympathetic nervous system?

Answer 13

If the outcome is a decrease in activity, a decrease in heart rate and breathing rate.

Question 14

What nervous reactions are processed by the brain?

Answer 14

All except reflex actions.

Question 15

Why is having one central control centre in the brain advantageous?

Answer 15

It provides a more rapid response.

Question 16

What is most of the brain made up of?

Answer 16

Relay neurones, most of which are non-myelinated so the tissue looks grey.

Question 17

What are the different parts of the brain?

Answer 17

Skull, cerebrum, cerebellum, medulla oblongata, spinal chord, hypothalamus, pituitary gland.

Question 18

What is the function of the cerebrum and where is it?

Answer 18

It is the outer layer of the brain and controls voluntary actions such as learning, memory, personality, language and conscious thought.

Question 19

What is the function of the cerebellum and where is it?

Answer 19

It is the part of the brain at the back and below the cerebrum. It controls unconscious functions such as posture, balance and non-voluntary movements.

Question 20

What is the medulla’s function and where is it?

Answer 20

It is found below the brain in front of the cerebellum. It is used in autonomic control such as heart rate and breathing rate.

Question 21

What is the function of the hypothalamus and where is it found?

Answer 21

It is found below the main body of the brain just above the pituitary gland. It is the regulatory centre for temperature and water balance.

Question 22

What is the function of the pituitary gland and where is it found?

Answer 22

Stores and releases hormones that regulate many body functions (AHD)

Question 23

What is the structure of the cerebrum?

Answer 23

It splits into left and right hemisphere. The left side of the brain controls the effectors on the right side of the body and vice-versa.
The two hemispheres are connected by the corpus collosum.
The outer layer is thin and is highly folded and is called the cerebral cortex.
It interprets information that it receives with respect to that stored from previous experiences.
Action potentials are sent along motor neurones to produce an appropriate response.

Question 24

What are the functions of the cerebrum?

Answer 24

Conscious thought and actions,
Emotional responses,
Intelligence, reasoning, judgement and decision making
Factual memory
Sensory areas
Association areas - compare sensory inputs with previous experience
Motor areas - send action potentials to effectors

Question 25

What is the function of the cerebellum?

Answer 25

It is involved with the control of muscular movement, body posture and balance, doesn’t initiate movement but coordinates it.
Coordinates the fine control of movements which are learned and improve with practice until they often involve much unconscious control,

Question 26

What can happen if the cerebellum is damaged?

Answer 26

A person suffers from jerky, uncoordinated movement.

Question 27

What are the cerebrum and cerebellum connected by?

Answer 27

The pons.

Question 28

What part of the body does the cerebellum receive information from?

Answer 28

Retina.
Balance organs in the inner ear.
Spindly fibres in muscles - tone of muscles and tendons.

Question 29

What does the hypothalamus control and contain?

Answer 29

Sensory receptors and controls homeostatic mechanisms.

Question 30

What two lobes does the pituitary gland consist of and what do they do?

Answer 30

Posterior lobe - linked to the hypothalamus by specialised neurosecretory cells (release of ADH)
Anterior lobe - produces it’s own hormones which are released in response to factors produced by the hypothalamus.

Question 31

What do the two centres of the hypothalamus do?

Answer 31

One is for the parasympathetic and one for the sympathetic nervous system.

Question 32

What do the functions of the hypothalamus include?

Answer 32

Controlling complex patterns of behaviours such as feeding, sleeping and aggression.

Question 33

What does the medulla do?

Answer 33

It controls the non-skeletal muscles by sending out action potentials through the autonomic nervous system.

Question 34

What are examples of the different centres of the hypothalamus?

Answer 34

Cardiac centre - regulates heart rate.
Vasomotor centre - regulates circulation and blood pressure.
Respiratory centre - regulates the rate and depth of breathing.

Question 35

What is a reflex action?

Answer 35

It is where the body responds to a stimulus without making a conscious decision to respond. This is because pathways of communication doesn’t involve the conscious parts of the brain. Reflex actions are protected and help organisms avoid damage.

Question 36

What are the main features of a reflex action?

Answer 36

Rapid
Automatic
Involuntary
Sub-conscious

Question 37

What is the path of communication in a reflex action?

Answer 37

Stimulus -> receptor -> sensory neurone -> CNS -> motor neurone -> effector -> response.

Question 38

How can the blinking reflex (or any with a relay neurone) be overridden?

Answer 38

When a relay neurone is part of the pathway, the reflex arc can be consciously overridden by inhibitory signals. This allows the person to touch their eye.

Question 39

What is the purpose of the knee-jerk reflex?

Answer 39

Used to help maintain posture and balance by causing the lower leg to straighten rapidly. Abscence may indicate an issue with nervous system.

Question 40

Does the knee jerk reflex have a relay neurone?

Answer 40

No

Question 41

Why is an inhibitory relay neurone needed for the knee jerk reflex to occur?

Answer 41

The muscles in the leg are found in antagonistic pairs. During the knee-jerk reflex, an inhibitory electrical impulse is sent, causing it to relax. This is done via a relay neurone.