Week 9 - The Central Nervous System

Question 1

what comprises the CNS ?

Answer 1

brain + spinal cord

Question 2

what comprises the PNS ?

Answer 2

nerves and ganglia

Question 3

define forebrain

Answer 3

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

Question 4

define grey matter

Answer 4

neural cell bodies, dendrites, unmyelinated axons

Question 5

define white matter

Answer 5

myelinated axons

Question 6

define cerebrum

Answer 6

the largest and most superior structure of the CNS

Question 7

define cerebral cortex

Answer 7

a folded sheet, the outer layer covers the cerebral hemispheres

Question 8

what are the 4 lobes ?

Answer 8

• frontal
• temporal
• parietal
• occipital

Question 9

define motor cortex

Answer 9

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

Question 10

define primary motor cortex

Answer 10

motor commands to motor neurons, initiation and coordination of voluntary movements

Question 11

define pre-motor cortex

Answer 11

organisation of movements before they are initiated

Question 12

define supplementary motor area

Answer 12

preparation and control of sequential movements

Question 13

define basal ganglia

Answer 13

a set of subcortical neural nuclei strictly interconnected with the cortex and the brainstem

Question 14

what are the 2 pathways of basal ganglia connectivity ?

Answer 14

• direct pathway

- indirect pathway

Question 15

define direct pathway

Answer 15

involved in the excitation of a desired motor program

Question 16

define indirect pathway

Answer 16

inhibition of competing motor program

Question 17

define parkinson’s disease

Answer 17

degeneration of neurons in the substantia nigra

Question 18

what are the symptoms of parkinson’s disease ?

Answer 18

• shuffling gait
• tremor at rest
• slowness of voluntary movements

Question 19

define huntington’s disease

Answer 19

selective loss of striatal neurons

Question 20

what are the symptoms of huntington’s disease ?

Answer 20

involuntary, continuous movement

Question 21

define cerebellum

Answer 21

prominent structure situated at the back of the pons and concerned with motor coordination, posture and balance

Question 22

define somatosensory cortex

Answer 22

somatosensory information converges in the parietal lobe of the cerebral cortex, where it is processed to provide cohesive perceptions of your body and physical environment

Question 23

where is the primary somatosensory cortex located ?

Answer 23

located posterior to the central sulcus, on the postcentral gyrus of the parietal lobe

Question 24

define homunculus

Answer 24

representation of the body based on sensory information not size of the body part

Question 25

define primary somatosensory cortex

Answer 25

receives direct somatosensory input from the thalamus, relayed from the periphery via the spinothalamic tract

Question 26

where is the secondary somatosensory cortex located ?

Answer 26

the lateral wall of the sylvian sulcus

Question 27

define secondary somatosensory cortex

Answer 27

• important in tactile object recognition

- tactile learning and memory

Question 28

define posterior parietal cortex

Answer 28

a multisensory association area that integrates sensory information, including vision, somatosensory and auditory inputs

Question 29

define phantom limbs (clinical case)

Answer 29

representation of a missing limb in the brain leads to vivid experiences of the limb still being there

Question 30

define stroke (clinical case)

Answer 30

an event characterised by an alteration of blood flow in the CNS, resulting in neurological deficit lasting more than 24 hours