Chapter 2: Nervous System Functioning Part 2

Question 1

What are the 2 types of effects on neurotransmitters?

Answer 1

• Excitatory effect

- Inhibitory effect

Question 2

What is the excitatory effect of neurotransmitters?

Answer 2

It stimulates or activates presynaptic neurons to perform their functions.

Question 3

What is the inhibitory effect of neurotransmitters?

Answer 3

It blocks or prevents presynaptic neurons from firing.

Question 4

What is glutamate (Glu)?

Answer 4

It is the primary excitatory neurotransmitter in the CNS, which enhances info transmission by making postsynaptic neurons more likely to fire.

Question 5

What is glutamate associated with and what are the consequences when there is the wrong amount (give an example)?

Answer 5

• The release of Glu is associated with enhanced learning and memory.
• When there is too much or too little of Glu it can harm neurons and brain functioning (Eg. Abnormally high concentrations of glutamate can result in over-excitation of receiving neurons)

Question 6

What is gamma-amino butyric acid (GABBA)?

Answer 6

It is the primary inhibitory neurotransmitter in the CNS, which works to make postsynaptic neurons less likely to fire.

Question 7

What roles do GABBA and Glu play in the CNS?

Answer 7

They play important roles in regulating CNS arousal

Question 8

Give an example of the consequences of low levels of GABBA:

Answer 8

It can lead to anxiety symptoms such as those experienced by people with phobias

Question 9

What is GABBA able to counterbalance?

Answer 9

The inhibitory action of GABBA is able to counterbalance the excitatory activity of glutamate and vice versa.

Question 10

Describe the lock-and-key process of neurotransmission:

Answer 10

Because each neurotransmitter has a chemically distinct shape, when one is released by a presynaptic neuron it searches for the correctly shaped receptor site on the dendrites of the postsynaptic neuron to bind to.
-Like a key in a lock, a neurotransmitter’s shape must perfectly match the shape of the receptor site

Question 11

What is the effect of binding in the lock-and-key process?

Answer 11

Binding ‘unlocks’ the postsynaptic neurons’ responses so that neurotransmitters can cause changes to the neuron, resulting in either an excitatory or inhibitory effect.

Question 12

What is Parkinson’s disease and why is it called a neurodegenerative disease?

Answer 12

A chronic and neurodegenerative condition that affects both motor and non-motor functions. It is neurodegenerative because the loss of neurons worsens over time.

Question 13

List 4 key motor symptoms of Parkinson’s:

Answer 13

• Tremors
• Slowness of movement (Bradykinesia)
• Muscle rigidity
• Postural instability

Question 14

List 2 key non-motor symptoms of Parkinson’s:

Answer 14

• Speech impairment

- Mental illnesses (Eg. Depression, anxiety)

Question 15

What are tremors?

Answer 15

The continuous involuntary shaking of the body.

Question 16

What is muscle rigidity?

Answer 16

Muscles seem unable to relax and are tight, even when at rest.

Question 17

What is postural instability?

Answer 17

Involves difficulty maintaining an upright posture and a steady balanced position.

Question 18

What is speech impairment?

Answer 18

Problems with verbal fluency, which can reduce the volume, clarity, and speed of speech.

Question 19

What is the effect of dopamine in Parkinson’s?

Answer 19

• Parkinson’s causes a degeneration of the neurons in the substantia nigra, which produces dopamine neurotransmitters
• Because dopamine is responsible for the smooth, coordinated functioning of the body’s muscles and movements when at rest or during periods of activity, those with Parkinson’s experience a reduction in these functions since there are fewer messages sent to the motor cortex.

Question 20

What is the fight-flight-freeze response?

Answer 20

Is initiated by the sympathetic nervous system and prepares the body to confront a stressful situation to optimise the chance of survival.

Question 21

What are the types of neurons in the spinal cord and what is their function?

Answer 21

Interneurons communicate messages between sensory and motor neurons at the spinal cord.

Question 22

Give 3 examples of physiological stress reactions:

Answer 22

• Headaches
• Stomach ulcers
• Colds/flu

Question 23

Give an example for each of the 3 types of psychological stress reactions:

Answer 23

Behavioural: Changes to sleeping patterns
Emotional: Irritability
Cognitive: Decreased concentration