Central Nervous System (Part 1 - Motor System Focused)

Question 1

state what it is meant by the key term - nervous system

Answer 1

the nervous system comprises all of the nervous tissue in the body

Question 2

state what it is meant by the key term - CNS

Answer 2

the CNS is the ‘control centre’ for human movement; integrating information for coherent action

Question 3

all CNS elements contain what 2 things ?

Answer 3

1. grey matter - neural cell bodies, dendrites, unmyelinated axons
2. white matter - myelinated axons

Question 4

what does the CNS do with afferent information

Answer 4

basic afferent information is processed into meaningful perceptions within the CNS

Question 5

what does the CNS have control over

Answer 5

the CNS has control over the body systems that govern our movement

Question 6

what does the forebrain consist of ?

Answer 6

the forebrain consists of elements you would most readily associate with cognition, our ability to think, plan, feel and act

Question 7

state 2 facts about general brain structure

Answer 7

1. makes up approx. 2% of total body weight (130-150g)

2. consists of approx. 86 billion neurones

Question 8

what percentage of the brain consists of the cerebrum ?

Answer 8

85%

Question 9

what are the two major cell types within the CNS

Answer 9

1. pyramidal cells - major output cells

2. non-pyritical cells - major input cells

Question 10

state 3 facts about the Cerebrum

Answer 10

1. the largest and most prominent brain structure
2. includes the cerebral cortex, basal ganglia and other structures
3. consists of 2 hemispheres and is connected by the corpus collosum (bundle of fibres)

Question 11

state what it is meant by the key term - cerebral cortex

Answer 11

the cerebral cortex is a folded sheet (2-4 mm) of grey matter; the outer layer covering the cerebral hemispheres

Question 12

what does the cerebral cortex consist of ?

Answer 12

gyri (crest of folded tissue) and sulci (grooves that divide gyri)

Question 13

each hemisphere is divided into 4 lobes, what are the names of these lobes ?

Answer 13

1. frontal
2. temporal
3. parietal
4. occipital

Question 14

state a general fact about the 4 lobes

Answer 14

Each lobe receives input from different sensory systems involved in different processes. However, there is significant cross talk between lobes

Question 15

state what it is meant by the key term - motor cortex

Answer 15

the motor cortex is the area in the frontal lobe, anterior to the central sulcus, fundamental for voluntary motor control and deciding/planning actions

Question 16

state what it is meant by the key term - Broca’s area

Answer 16

a region of the prefrontal cortex concerned with the production of speech

Question 17

what does damage to the Broca’s area do ? (2 points)

Answer 17

1. Damage in this area causes Broca’s aphasia

2. characterised by hesitant and fragmented speech with little grammatical structure

Question 18

state what it is meant by the key term - frontal eye field (FEF)

Answer 18

the frontal eye field (FEF) is the area in dorsolateral prefrontal cortex that signals the location of targets and controls the execution of goal-directed movements of the eyes

Question 19

state what it is meant by the key term - primary motor area

Answer 19

sends motor commands to motor neurones; initiation and co-ordination of voluntary movements

Question 20

state what it is meant by the key term - pre-motor area

Answer 20

concerned with the organisation of movements before they are initiated

Question 21

state what it is meant by the key term - supplementary motor area

Answer 21

concerned with the preparation and control of sequential movements

Question 22

what does the primary motor area contain ?

Answer 22

the primary motor area has large pyramidal neurones

Question 23

what proportion of the motor cortex is related to hand movement ?

Answer 23

1/3 of the motor cortex is concerned with hand movement

Question 24

state 2 additional facts about the motor cortex as a whole

Answer 24

1. has both dorsal and ventral promotor areas

2. has somatotopic organisation

Question 25

state what it is meant by the key term - basal ganglia

Answer 25

basal ganglia are a set of subcortical nuclei that are strictly interconnected with the cortex and the brainstem

Question 26

what are the 5 types of basal ganglia (stop going stupidly slowly nan)

Answer 26

1. striatum (caudate and putamen)
2. globus pallidus
3. substantia nigra
4. subthalmic nucleus
5. nucleus accumbens

Question 27

the basal ganglia play an important role in what 4 things ?

Answer 27

1. control of voluntary movements
2. motor learning
3. cognition
4. emotion

Question 28

state, and explain, what the two pathways in the basal ganglia are

Answer 28

1. direct pathway - involved in the excitation of a desired motor programme
2. indirect pathway - involved in the inhibition of competing motor programmes

Question 29

explain what the basal ganglia and motor cortex form

Answer 29

form a process loop, whereby basal ganglia enable the desired MP represented in the motor cortex to be excited via the direct pathway and inhibits competing MP’s via the indirect pathway

Question 30

the appropriate motor programme is selected via the basal ganglia and motor cortex based on the integration of what 3 parameters ?

Answer 30

1. motor planning
2. sensory information
3. predicted consequences of action based on previous experiences

Question 31

state what it is meant by the key term - Parkinson’s disease

Answer 31

Parkinson’s disease is the degeneration of neurones in the substantia nigra

Question 32

explain how Parkinson’s disease works (3 points)

Answer 32

1. loss of dopaminergic neurones in the substantia nigra
2. imbalance in pathways occur, and it deteriorates the ability to choose the correct motor programme
3. loss of dopaminergic pathway tips balance towards indirect pathway, reducing the excitatory activity in the motor cortex, reducing voluntary movements

Question 33

state the 4 symptoms of Parkinson’s disease

Answer 33

1. increased likelihood of falling, suffering gait, tremor at rest
2. bradykinesia (slowness of voluntary movements)
3. akinesia (difficulty in initiating movements)
4. hypometria (inadequate amplitude of movements)

Question 34

state what it is meant by the key term - bradykinesia

Answer 34

slowness of voluntary movements

Question 35

state what it is meant by the key term - akinesia

Answer 35

difficulty in initiating movements

Question 36

state what it is meant by the key term - hypometria

Answer 36

inadequate amplitude of movements

Question 37

state what it is meant by the key term - Huntington’s disease

Answer 37

Huntington’s disease is the selective loss of stratal neurones

Question 38

explain how Huntington’s disease works

Answer 38

balance is tipped in favour of the direct pathway, without normal inhibitory response of the thalamus, random firing causes inappropriate execution of motor programmes

Question 39

state and explain the major symptom of Huntington’s disease (2 points)

Answer 39

1. cuneiform movements/dyskinesia - continuous movement of the body, especially of the extremities and the face
2. resemble adaptive movements, but occur involuntarily and incoherently

Question 40

state what it is meant by the key term - cerebellum

Answer 40

the cerebellum is the prominent structure situated at the back of the pons (brainstem) and is concerned with motor co-ordination, posture and balance

Question 41

what does the cerebellum play a key role in ?

Answer 41

the execution of smooth and accurate movements

Question 42

what is the cerebellum also known as ?

Answer 42

the ‘little brain’

Question 43

state 2 structural facts about the cerebellum

Answer 43

1. accounts for approx. 10% of brain volume

2. accounts for > 50% of the brains neurones

Question 44

state 4 cerebellum functions

Answer 44

1. maintenance of balance and posture
2. coordination of voluntary moments
3. motor learning
4. cognitive functions

Question 45

what does the cerebellum really do ?

Answer 45

modifies motor programmes of the descending pathway to make movements more adaptive and accurate

Question 46

what is damage to the Broca’s area called ?

Answer 46

Broca’s aphasia