Functional Area Of Cerebral Cortex: Parietal Lobe

Question 1

Parietal lobe

Answer 1

1. Main sensory area (3,1,2)
2. Parietal (sensory) association area
3. Supramarginal gyrus (40)
4. Angular gyrus (39)
5. Paracentral lobule (see frontal lobe)

Question 2

Main sensory area 312 site

Answer 2

Postcentral gyrus and extends in posterior part of Paracentral lobule

Question 3

Main sensory area 312 functions

Answer 3

1. Gives 20% pyramidal tract
2. Receive general somatic sensations from opposite 1/2

Question 4

Main sensory area 312 representation

Answer 4

1. Represented upside down
2. Lower 1/3 receives general sensations from head
3. Upper 2/3 receives general sensations from body below head

Question 5

Main sensory area 312 lesion

Answer 5

Contralateral hemianaesthesia

Question 6

Parietal association area site

Answer 6

Remaining part of parietal lobe and adjoining part of occipital and temporal lobes

Question 7

Parietal association area function

Answer 7

1. Associating visual, auditory, and tactile sensations so that one can know meaning of sensations he feels (recognition of structures)

Question 8

Parietal association area lesion

Answer 8

Tactile agnosia (asterognosis) where patient cannot identify objects he feels

Question 9

Supramarginal gyrus 40 site

Answer 9

Lies in inferior parietal lobule surrounding upturned posterior end of lateral fissure posterior ramus

Question 10

Supramarginal gyrus 40 functions

Answer 10

Contains 2nd (sensory) speech wernicke area in dominant hemisphere, responsible for understanding spoken and written words and thoughts formation then sending it to Broca’s area for execution

Question 11

Supramarginal gyrus 40 lesion

Answer 11

Sensory aphasia (inability to understand spoken or written words)

Question 12

Angular gyrus 39 site

Answer 12

Lies in inferior parietal lobule surrounding upturned posterior end of superior temporal sulcus

Question 13

Angular gyrus 39 functions

Answer 13

1. Contains rest of 2nd speech wernicke area
2. Contains reading and writing centers

Question 14

Angular gyrus 39 lesion

Answer 14

Alexia and agrahia (inability to read and write)