Unit 3 AOS 1- Nervous system Functioning

Question 1

The Three types of Neurons

Answer 1

• Motor neurons (efferent neurons) which transmit neural messages about motor movement from the CNS to the PNS
• Sensory neurons (Also known as afferent neurons) which transmit neural messages about bodily sensations from the PNS to the CNS
• Interneurons, which transfer neural messages between sensory neurons and motor neurons. The central nervous system, including the brain and spinal cord, is made up of interneurons.

Question 2

Unconscious response

Answer 2

Automatic and involuntary actions that are performed by the body independently of the brain. Occur without conscious awareness in response to internal and external stimuli.

Question 3

Conscious response

Answer 3

Conscious responses are delibrate and voluntary actions that are intentionally initiated by the brain and performed by the body.

Involve the CNS because the brain is a component

Also involves the Somatic Nervous system

Question 4

Role of the central nervous system (CNS)

Answer 4

Is a cable of nerve tissue that extends from the brain, and connects it to the peripheral nervous system.

There are ascending tracts
and descending tracks

Question 5

Ascending tracts
(Towards the brain, they go up)

Answer 5

Transmit sensory messages from the peripheral nervous system to the brain

Question 6

Descending tracts

Answer 6

Transmit motor messages from the brain to the peripheral nervous system (PNS)

Question 7

The peripheral nervous system

Answer 7

A major division of the nervous system comprising every neuron in the body outside the central nervous system. The peripheral NS includes the somatic and the autonomic nervous system.

Question 8

Somatic nervous system

Answer 8

Transmits neural messages related to voluntary motor movement (skeletal muscles).

Question 9

What is an example of the somatic nervous system???(7 steps)

Answer 9

1) Sensory receptors
2) Sensory neurons -> Afferent pathway
3) Towards spinal cord, afferent neurons move, through ascending tracts towards brain
4) Brain reviews, interprets and initiates motor response
5) Motor muscles travels down descending spinal cord to PNS
6) Motor neurons carry message -> efferent path
7) Skeletal muscle moves

Question 10

Autonomic nervous system

Answer 10

Regulates visceral muscles, organs, and glands, and transmits neural messages to the central nervous system about their activity.

Question 11

Branches of the ANS

Answer 11

• Sympathetic
• Parasympathetic

*The sympathetic nervous system becomes dominant when a person is confronted with a threat, or stressor whereas the parasympathetic nervous system is dominant during rest and physical inactivity.

Question 12

Sympathetic response example (Heart)

Answer 12

Heart rate increases to increase blood flow, enabling high levels of physical activity

Question 13

Sympathetic response example (BREATHE)

Answer 13

Breathing rate increases and long airways expand to increase oxygenation, enabling high levels of physical activity

Question 14

Sympathetic response example (EYES)

Answer 14

Pupils dilate to allow more light to enter the eyes improving vision.

Question 15

Parasympathetic response (heart)

Answer 15

The hearts beat at a steady and regular rate that supports optimal and balanced functioning.

Question 16

Parasympathetic response (Breathe)

Answer 16

Lung airways constict, enhabling a steady and regular breathing rate.

Question 17

Parasympathetic response (eyes)

Answer 17

Pupils constrict according to external light levels, allowing an appropriate amount of light to enter her eyes for adequate vision.

Question 18

Spinal reflex

Answer 18

An unconsious response to sensory stimuli that is initiated by interneurons in the spinal cord independently of the brain.

Purpose: To protect the body from harm/injury and increase chances of survival

Question 19

Spinal cord involves three types of specialized neurons

Answer 19

• Sensory or afferent
• Interneuorn or relay neuron
• Motor or efferent

Question 20

Describing the neural pathway
1

Answer 20

The presynaptic nueron is the neuron that releases neurochemical into the neural synapse. Axon terminals are the ends of the neuron that release neurochemicals into the nueral synapse

Question 21

Describing the neural pathway
2

Answer 21

The synaptic gap is the space between presynaptic neuron and the postsynaptic neuron. In this way, despite being very close, neurons do not touch each other.

Question 22

Describing the neural pathway (3)

Answer 22

The postysynaptic neuron is the neuron that recives neurochemicals from the neural synapce. Dendrites are branched extensions of a neuron on which receptor sites are located.

Question 23

Process of synpatic transmission

Answer 23

1) Neurochemical are produced in the axon terminals of the presynaptic neuron

2) Neurochemical are released from the axon terminals of the postsynaptic neuron into the synaptic gap

3) Neurochemicals bind to receptor sites on the dendrites of postsynaptic neurons

4) Neurochemicals affect the postsynaptic neuron either triggering or inhibiting a response

Question 24

Neuromodulators

Answer 24

Chemical molecules that have an effect on multiple postsynaptic neurons. Widespread modulatory effects

Question 25

Neurotransmitters

Answer 25

Chemical molecules that have an effect on one or two postsynaptic neurons. Enhables rapid communication between two neurons across the neural synapses.

Question 26

Seretonin

Answer 26

- Neuromodulator - Inhibitory effects on the postsynaptic neuron - Mood regulation and stabilisation - Sleep-wake cycle

Question 27

Dopamine

Answer 27

- Neuromodulator - Both excitatory and inhibitory effects on the postsynaptic neuron - Reward based learning - Motivation

Question 28

GABA

Answer 28

- Inhibitory neurotransmitter - Decreases the likelihood of the postsynaptic neuron firing an action potential - Important role in reducing anxiety

Question 29

Glutamate

Answer 29

- Excitatiry neurotransmitter - Increases likelihood of postsynaptic neuron firing an action potential - Learning and memory

Question 30

Synpatic plasticity

Answer 30

The ability of synaptic connections to change over time in responce to activity or experinece.

Question 31

Long Term Depression (LTD)

Answer 31

Long-lasting and experience-dependent weakening of synaptic connections between neurons that are not regularly coactivated. The weakening of a neural synapse involves the infrequent release of neurotransmitters into the synaptic gap by axon terminals

Question 32

Long Term Potentiation (LTP)

Answer 32

The long-lasting experience-dependent strengthening of synaptic connections that are regularly activated to high intensity stimulation.

Question 33

Sprouting

Answer 33

The ability of dendrites or axons to develop new extensions on branches. This increases the reach of the neuron and enables the formation of new synaptic connections.

Question 34

Pruning

Answer 34

The elimination of synaptic connections that are not adequately activated. When neural synapses are not used they are removed or 'pruned'. This is necessary to accommodate stronger and more essential synaptic connections.

Question 35

Rerouting

Answer 35

The ability of a neuron that is connected to a damaged neuron to create an alternative synaptic connection with an undamaged neuron. The neuron abandons its synaptic connection with the damaged neuron and forms a new synaptic connection with an undamaged neuron.

Question 36

Stressor

Answer 36

The term used to describe the stimulus (internal and external) that prompts the stress response.

Question 37

Stress

Answer 37

A psychological and physiological experience that occurs when an individual encounters something of significance that demands.

Question 38

Internal stressors

Answer 38

originate from within the individual psychological and biological processes Example: low self-esteem

Question 39

External stressors

Answer 39

- Originate from outside of the individual, external stimuli Example: exams

Question 40

Eustress

Answer 40

excited for something, feeling prepared

Question 41

Distress

Answer 41

unprepared, worried, not excited

Question 42

Acute stress

Answer 42

fight, flight or freeze

Question 43

Chronic stress

Answer 43

Sustained release of cortisol

Question 44

flight

Answer 44

An organism flees from the stressor generally because escaping the situation is the safest option. - Acitvation of sympathetic nervous system

Question 45

fight

Answer 45

organism confronts stressor. symapathetic nervous ssystem

Question 46

freeze

Answer 46

- breif activation of the parasympatehtic nervous system

Question 47

Chronic stress response

Answer 47

Chronic stress is a form of stress that endures for several months or longer. Cortisol is the stress hormone and does not demand an immediate response.

Question 48

- Alarm- shock stage of GAS model

Answer 48

- Paraysmpathetic response/activation - Momentary decrease in bodily arousal - Heart rate goes down - muscle tone decreaseed - breathing rate decreased - body reacts as if injured

Question 49

- Alarm- countershock stage of GAS model

Answer 49

Sympathetic response/activation - Increase in bodily arousal - Breathing rate increases - Muscle tone increases - Heart rate increases - Ability to deal with the stressor increases above normal

Question 50

- Resistance stage of GAS model -

Answer 50

Bodily resources are used at an increased rate to maintain the state of heightened arousal - Can do normal tasks usually

Question 51

- Exhaustion stage of GAS model

Answer 51

- By the time a person, has entered exhaustion, exposure to the stressor has been prolonged and pressistant - The body has been required to maintain the heightned physicological state for as long as the stressor has been present, which is now an extended period of time.