unit 3 AOS 1

Question 1

what are Neurons

Answer 1

Basic cell of the nervous system responsible for the reception and transmission of information throughout the nervous system

Neurons communicate with:
· Each other
· Glands
Muscles

Question 2

types of neurons?

Answer 2

· Motor neurons take information form CNS to senses

· Sensory neurons take information from the senses to CNS
 
· Interneurons (AKA relay/connector neuron) only in the CNS and allow neurons  to communicate to each other e.g. motor and sensory neurons

Question 3

The three main functions of the nervous system

Answer 3

1. Receive info (what we sense and feel)
2. Process info (what we think)
3. Coordinate a response to info (what we should do)

Question 4

what is the central nervous system?
- what does it do?

Answer 4

Compromises the brain and spinal cord

Main function: to process information received from the body’s internal and external environments and to activate appropriate responses

Question 5

central nervous system: brain (what is it and what is it responsible for?)

Answer 5

The brain is an interactive network of cells that play a vital role in processing information received through neural pathways from the body and directing actions within the body.

- responsible for virtually everything we think, feel and do

Question 6

central nervous system: spinal cord (what is it and what is it responsible for?)

Answer 6

The long, thin bundle of nerve tissue that extends from the base of the brain to the lower back; links the brain and the parts of the body below the neck.

- The spinal cord also initiates some simple motor reactions in the form of reflexes that occur extremely rapidly, independently of the brain. E.g. spinal reflexes

Question 7

central nervous system: two main functionings of the spinal cord

Answer 7

1. The spinal cord receives information from the body (via the peripheral nervous system) and sends those messages to the brain for processing.
   2. The spinal cord receives motor information from the brain and sends it to relevant parts of the body (via the peripheral nervous system) to control muscles, glands, and internal organs so that appropriate actions can be taken.

Question 8

what is the Peripheral nervous system?
- what does it do?

Answer 8

Carries information to and from the central nervous system

· It is an entire network of nerves outside the CNS

Main function: carries information to the CNS from the body’s muscles, organs and glands (about the internal environment) and from the sensory organs (about the external environment)

Question 9

what are the two sub-division of the peripheral nervous system?

Answer 9

Somatic nervous system (SNS)

Autonomic nervous system (ANS)

Question 10

peripheral nervous system: what is the Somatic nervous system (SNS)

Answer 10

A sub-division of the peripheral nervous system that carries sensory information to the central nervous system and motor information from the central nervous system.

· Sensory information: afferent (incoming information)
· Motor information: efferent (outgoing information)

• Involves in voluntary movement

Question 11

peripheral nervous system: what is the Autonomic nervous system (ANS)?

Answer 11

A self-regulating sub-division of the peripheral nervous system that connects the central nervous system to the body’s internal organs and glands, providing feedback to the brain about their activities.

• Responsible for the automatic processes that keep your body alive (e.g. breathing, heart beat and digestion) and actively involved in reaction to extreme emotions, such as fear, anger or nervousness

Autonomic = automatic; keeps us alive automatically

The ANS involves automatic (involuntary) processes

Question 12

peripheral nervous system: what are the three divisions of the autonomic nervous system

Answer 12

1. Sympathetic NS
   
   2. Parasympathetic NS
2. Enteric NS

Question 13

autonomic nervous system: what is Sympathetic NS

Answer 13

A sub-division of the autonomic nervous system that arouses the body for vigorous activity or to deal with a stressful or threatening situation.

• controls/activates arousal, “fires us up” for action.
• Release of adrenaline, heart rate increases, breathing rate increases etc.

Question 14

autonomic nervous system: what is Parasympathetic NS

Answer 14

A sub-division of the autonomic nervous system that helps to maintain the internal body environment in a steady, balanced state of normal functioning; calms or restores the body to its normal state of functioning after an extreme emotion subsides or a threat has passed.

• calms our internal functioning back down after the Sympathetic NS was dominant

Maintains a steady, stable & balanced level of normal functioning (dominates the Sympathetic NS most of the time).

Question 15

what is a Conscious response?

Answer 15

a reaction to a sensory stimulus that involves awareness; usually voluntary, goal-directed and with some degree of control over it; compare with unconscious response

Question 16

what is an Unconscious response?

Answer 16

a reaction to a sensory stimulus that does not involve awareness; involuntary, unintentional, automatic and we cannot ordinarily control its occurrence; compare with conscious response

Spinal reflex
an unconscious, involuntary response to certain stimuli, initiated within the spinal cord and controlled solely by neural circuits; also called reflex arc

Question 17

autonomic nervous system: what is Enteric NS

Answer 17

The ENS has extensive, two-way connections with the CNS, and works together with the CNS to control the digestive system in the context of local and whole body physiological demands. For example, the ENS and brain interact in controlling stomach secretions and voluntary bowel movements.

Ens activity is influenced by:
- External factors (hunger, diet, mood..etc)
- Microbiota (the bacteria and trillions of other microscopic organisms that live in the gastrointestinal tract)

Question 18

Unconscious response?: what is spinal reflex

Answer 18

an unconscious, involuntary response to certain stimuli, initiated within the spinal cord and controlled solely by neural circuits; also called reflex arc

Simple motor reactions in the form of reflexes that occur extremely rapidly, independently of the brain

Withdrawal reaction = adaptive response (aids survival)

The spinal reflex demonstrates that a response to a particular sensory stimulus can have both an unconscious and conscious component, one occurring before the other.

Question 19

role of neurotransmitters

Answer 19

Neurons communicate with one another where they meet (but do not touch) at the synapse. The presynaptic neuron releases neurotransmitters from the terminal buttons into the synaptic gap. The neurotransmitters are then received by the dendrites in the postsynaptic neuron.

Question 20

what is a neurotransmitter

Answer 20

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

Question 21

what is Neural synapse

Answer 21

the site where communication typically occurs between adjacent neurons

Question 22

what is Synaptic gap

Answer 22

the tiny space between the axon terminal of a presynaptic neuron and the dendrite of a postsynaptic neuron

Question 23

Excitatory effect of neurotransmitters

Answer 23

when a neurotransmitter stimulates or activates a postsynaptic neuron to perform its functions

Question 24

Inhibitory effect of neurotransmitters

Answer 24

when a neurotransmitter blocks or prevents a postsynaptic neuron from firing and therefore performing its functions

Question 25

what two effects do neurotransmitter typically have

Answer 25

Excitatory effect Inhibitory effect

Question 26

Excitatory neurotransmitter: Glutamate (glu)

Answer 26

The primary excitatory neurotransmitter for information transmission throughout the brain - plays crucial roles in the growth and strengthening of synaptic connections during learning an memory formation. - Glu is the second most abundant neurotransmitter in the brain and involved in most aspects of normal brain function, including perception, learning, memory, thinking and movement. ◊ Glu enhances information transmission by making postsynaptic neurons more likely to fire

Question 27

Inhibitory neurotransmitter: Gamma-amino butyric acid (GABA)

Answer 27

The primary inhibitory neurotransmitter in the CNS. - Maintains neurotransmission at optimal levels my making postsynaptic ('receiving') neurons less likely to fire (Calming neurotransmitter)

Question 28

what does too much and not enough of glutamate do

Answer 28

Too much - too much glutamate in the brain can cause nerve cells to become overexcited Not enough - can result in poor communication, mental health and physical development delays

Question 29

what does too much and not enough of GABA do

Answer 29

Too much - can result in central nervous system depression Not enough - anxiety and mood disorders

Question 30

Role of neuromodulators

Answer 30

A neurotransmitter that can influence the effects of other neurotransmitters; also called modulator neurotransmitter - Neuromodulators influence the activity of multiple neurons at the same time

Question 31

Dopamine

Answer 31

A neurotransmitter or a neuromodulator that plays a key role in motivation, reward, pleasure, and movement. It helps regulate mood, attention, learning, and motor control. Imbalances in dopamine levels are linked to conditions such as Parkinson’s disease, schizophrenia, and addiction.

Question 32

Serotonin

Answer 32

A neurotransmitter that plays a crucial role in regulating mood, emotions, sleep, appetite, and overall well-being. It is often associated with feelings of happiness and calmness. Low serotonin levels are linked to conditions such as depression and anxiety, while balanced levels contribute to emotional stability and relaxation.

Question 33

Effects on brain activity (inhibitory and/or excitatory effects) - dopamine

Answer 33

although primarily an excitatory neurotransmitter, dopamine can have either an excitatory effect at one location or an inhibitory effect at another, depending on the type of receptors that are present. Sends messages to the brain about voluntary movement

Question 34

Effects on brain activity (inhibitory and/or excitatory effects) - serotonin

Answer 34

serotonin only has inhibitory effects, so it does not stimulate brain activity. Its inhibitory effects can help counterbalance excessive excitatory effects of other neurotransmitters, as GABA does with glutamate.

Question 35

too much or too little of dopamine

Answer 35

Too little If too little dopamine is produced then the brain will receive voluntary movements slower. - can result in a condition of extreme muscle rigidity, or ‘stiffness’, that makes it difficult for a person to move Too much Hallucinations and delusions Too much dopamine can lead to addicting behaviours, since dopamine provides rewards, too many rewards can lead to addiction. E.g. eating something unhealthy has an award - can lead to overeating

Question 36

too much or too little of serotonin

Answer 36

Too little Reduced levels of serotonin in the brain have also been associated with a number of anxiety disorders, particularly obsessive-compulsive disorder (OCD) Too much Impulse decisions, restlessness, high blood pressure, increased heart rate the presence of an excessive amount of serotonin may cause serotonin syndrome, which can be life threatening in some people.

Question 37

memory

Answer 37

the expression of what you have acquired

Question 38

Learning

Answer 38

the acquisition of skill or knowledge

Question 39

Synaptic plasticity

Answer 39

The ability of a synapse to change over time through use or disuse - Synaptic plasticity enables a flexible, efficient and effectively functioning nervous system It is also the biological basis of learning and memory

Question 39

Hebbian learning

Answer 39

Donald Hebb is credited with the idea that learning involves the establishment and strengthening of neural connections at the synapse. Hebb proposed that learning results in the creation of cell assemblies, or interconnected groups of neurons that form networks or pathways Neurons that fire together, wire together

Question 40

Changes in synaptic connections occur in 3 ways:

Answer 40

sprouting, rerouting and pruning

Question 41

sprouting

Answer 41

new pathways form Growth of nerve cells endings an axons or dendrites enables new links to be made

Question 42

Rerouting

Answer 42

pathways go around Entirely new neural pathways are formed

Question 43

Pruning

Answer 43

use it or lose it Synapse not frequently used to decay and disappear

Question 43

Long term potentiation (LTP)

Answer 43

increased strength The long lasting strengthening of synaptic connections, resulting in enhanced or more effective neurotransmission across the synapse - Occurs after repeated strong stimulation - Enables postsynaptic neurons to be more easily activated · Increased transmission efficiency · Increased memory storage information · Decreased likelihood that learning will be forgotten · Rote memorisation works

Question 44

Long term depression (LTD)

Answer 44

decreased strength The long lasting decrease in the strength of synaptic connections and transmission and neuronal response - Allows for the elimination of unused synapses through pruning unimportant or unwanted connections - Ability to adapt and correct problem solving strategies / physical skills etc.

Question 45

What is stress?

Answer 45

A state of physiological and psychological arousal produced by internal or external stressors, perceived as challenging or exceeding one's ability to cope.

Question 46

What is a stressor?

Answer 46

Any stimuli that produces stress.

Question 47

What is an internal stressor?

Answer 47

A stressor that originates within the individual. ## Footnote Example: low self-esteem.

Question 48

What is an external stressor?

Answer 48

A stressor that originates outside the individual from situations and events in the environment. ## Footnote Example: school work.

Question 49

Acute stress

Answer 49

Stress that produces a high level of arousal over a short period of time

Question 50

Chronic stress

Answer 50

High level of arousal that persist over a long period of time and results in a number of physiological and psychological responses which may be short term or long lasting