The Cortex and Localisation of function Flashcards Preview

Physiology and Neuroscience > The Cortex and Localisation of function > Flashcards

Flashcards in The Cortex and Localisation of function Deck (30):
1

What is grey matter?

Thin (6-8mm) folded sheet of grey matter

2

What are the grooves in the brain?

Sulci (sulcus)

3

What are the ridges of the brain?

Gyri (gyrus)

4

What makes up the white matter?

Corpus callosum
Internal capsule

5

What is the corpus callosum?

Structure that links cortex of two cerebral hemispheres

6

What is the internal capsule?

Structure that links the cortex with the brain

7

Why does folding in the brain occur?

Accommodate massive increases in area of cortex

8

How much does the cortex represent the human brain?

80%

9

How much does the cortex represent the rat brain?

30%

10

What is the Paleocortex/Archicortex?

Phylogenetically oldest part of cortex
Olfaction, emotions and memory

11

What is the Neocortex (new cortex)?

Additional sensory areas (e.g. vision)
More sophisticated motor areas

12

What do primary areas of the cortex receive?

Input (sensory) or give rise to a direct output (motor)

13

What is the association cortex?

Most recent, most expanded cortex
Responsible for most complex cognitive functions e.g. speech and language

14

How much does the association cortex take up in different mammalian brains?

5% cat brain
20% chimp brain
30% human brain

15

What was Penfield study?

Effects of electrical stimulation of the cortex in conscious patients being prepared for brain surgery
Located a region where stimulation produced muscle twitches

16

What did Penfield discover?

Mapping between areas of motor cortex and muscles of the body
Somatotopic map

17

In what way is the motor map distorted?

Face and hands (fine control) have largest representation- motor homunculus

18

What is the primary somatosensory cortex?

An are where stimulation produced sensations of numbness or tingling
Somatotopic map within stip of sensory cortex

19

What is the somatotopic map in the sensory cortex like?

Has a greater representation of body parts (tongue, face, hands) with a high degree of sensitivity and spatial discrimination represented by sensory homunculus

20

What is decussation?

Crossing of pathways from one side to another
Pathways providing connections between primary sensory and motor areas and the periphery are crossed

21

What is Broca's area aphasia?

Inability to speak while retaining comprehension of verbal and written instructions

22

Where is Broca's area?

Specfific region of the brain close to the motor cortex

23

What is Broca's areas function?

Thought to produce instructions for co-ordinated movements (of lips, tongue, mouth and larynx) for producing speech

24

When is the corpus callosum cut?

A commisurectomy is used as a treatment for intractable epilepsy

25

What are the hemispheric asymmetries for most CNS structures?

Bilateral and symmetrical

26

What do some cortical functions show?

Hemispheric asymmetry
Two hemispheres perform different functions

27

If an individual is right handed what does that mean?

Superior motor co-ordination of right hand

28

What did Sperry identify in the 1960s?

Most patients could name objects identified by feel if placed in right hand but not if held in the left

29

Where is speech predominantly functioning?

On the left hemisphere in 93% of the population

30

What is the Wada Procedure?

Injection of short-acting anaesthetic into left internal carotid artery
Selectivity anaesthetises left cerebral hemisphere
Produces paralysis and loss of sensation on right side of body
Patients remain conscious
Most (93%) lose the ability to speak