8.2.1 Consciousness Flashcards

1
Q

What is consciousness?

A

Awareness of both external world and internal states

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is arousal?

A

Emotional state associated with a goal or avoidance of something noxious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What neural components are required for consciousness?

A

Cerebral cortex

Reticular formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of the cerebral cortex in conciousness?

A

Site where conscious thoughts arise, receives many inputs, including from reticular formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the function of the reticular formation?

A

Keeps the cortex awake, receives many inputs, including from the cortex and sensory systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How are the cerebral cortex and reticular formation connected?

A

Connected by reciprocal excitatory projections

Forms a positive feedback loop, seen when there is a binary outcome e.g. sleep/awake, ovulating/not ovulating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 3 major relay nuclei from the reticular formation to the cortex?

A

Basal forebrain nuclei

Hypothalamus

Thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of projections does the reticular formation send to the cerebral cortex?

A

Cholinergic, excitatory projections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Outline the Basal forebrain nuclei projections

A

First order sensory neurones synapse with second order

Second order decussate and arise to the reticular formation

Reticular formation sends projections to the basal forebrain nuclei

Basal forebrain nuclei send ACh excitatory projections to the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Outline the Hypothalamus excitatory fibre projection to the cortex

A

First order sensory neurones synapse with second order

Second order decussate and arise to the reticular formation

Reticular formation sends projections to the Hypothalamus

Hypothalamus sends histaminergic excitatory projections to the cortex

Hence why anti-histamines have a sedative effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Outline the Thalamus excitatory fibre projection to the cortex

A

First order sensory neurones synapse with second order

Second order decussate and arise to the reticular formation

Reticular formation sends projections to the Thalamus

Thalamus sends glutamatergic excitatory projections to the cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where else does the reticular formation also send projections?

A

Down the cord, responsible for maintaining muscle tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the reticular activating system?

A

Large part of the reticular formation devoted to arousal

Contains the fibre projections from the reticular formation to the basal forebrain, hypothalamus and thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is consciousness assessed?

A

Glasgow coma scale

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 3 parts used by the GCS to assess conciousness?

A

Eyes- 4(eyes 4 letters so 4)
Motor response- 6(muscle 6 letters so 6)
Verbal response- 5 (voice 5 letters so 5)

Score out of 15 (higher the better)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is an electroencephelogram?

A

Used to measure the activity of neurones in a particular region of the cortex

High temporal resolution as EEG works very fast

Poor spatial resolution as limited by the number of electrodes

17
Q

What is an electroencephalogram used for?

A

Detecting neuronal synchrony and evidence of normal cerebral function

18
Q

When does neuronal synchrony occur?

A

Occurs commonly in the brain during both physiological and pathological processes e.g. sleep and epilepsy