Functional Areas Of Cerebral Hemispheres: Frontal Lobe

Question 1

Frontal lobe

Answer 1

1. Motor area (4)
2. Premotor area (6)
3. Frontal eye field (8)
4. Brocas (primary or motor speech) area (44)
5. Prefrontal (frontal association) area
6. Frontal lobe medial surface
7. Frontal lobe orbital surface
8. Paracentral lobule

Question 2

Motor area 4 site

Answer 2

Lies in Precentral gyrus and extends in anterior part of Paracentral lobule

Question 3

Motor area 4 function

Answer 3

Gives 40% of pyramidal tract (cortico-spinal and corticonuclear fibers) being motor area for highly skilled movements opposite 1/2

Question 4

Motor area 4 sensation

Answer 4

Motor area for all body except eye

Question 5

Motor area 4 representation

Answer 5

Represented upside down (motor area of lower part of lower limb and perineum lies in anterior part of Paracentral lobule)

Question 6

Motor area 4 lesion

Answer 6

Leads to contralateral hemiplegia

Question 7

Premotor area 6 site

Answer 7

In front and parallel to motor area 4

Question 8

Premotor area 6 functions

Answer 8

1. Give origin to 40% of pyramidal tract
2. Storage of programs of skilled movements learned by experience
3. Extrapyramidal function by controlling postural adjustment of proximal girdle muscles and inhibition of muscle tone

Question 9

Premotor area 6 lesion

Answer 9

Leads to:
1. Motor apraxia (impaired performance of voluntary movements in spite of absence of paralysis
2. Loss of postural stability of proximal girdle muscles and muscle spasticity

Question 10

Frontal eye field 8 site

Answer 10

Posterior part of middle frontal gyrus

Question 11

Frontal eye field 8 function

Answer 11

1. Lateral conjugate movements of both eyes to opposite side
2. Being responsible for accommodation reflex

Question 12

Frontal eye field 8 lesion

Answer 12

1. Loss of conjugate movements of both eyes to opposite side (lateral deviation of both eyes to same side)
2. Loss of accommodation reflex

Question 13

Brocas area 44 site

Answer 13

Posterior part of inferior frontal gyrus in dominant hemisphere

Question 14

Brocas area 44 function

Answer 14

1. Words formation
2. Coordinates movements of the tongue, lips, and larynx

Question 15

Brocas area 44 lesion

Answer 15

Motor aphasia (patient unable to express his idea in form of speech in absence of paralysis)

Question 16

Prefrontal area site

Answer 16

Remaining part of frontal lobe lateral surface

Question 17

Prefrontal area function

Answer 17

1. Receive association fibers from other sensory area
2. Determines personal reactions of individual so responsible for control of conduct, behavior, and emotions

Question 18

Prefrontal area lesion

Answer 18

Leads to personality changes

Question 19

Frontal lobe medial surface

Answer 19

Related to emotional behavior

Question 20

Frontal lobe orbital surface

Answer 20

Related to control of autonomic (visceral) activities

Question 21

Paracentral lobule site

Answer 21

On medial surface of hemisphere

Question 22

Paracentral lobule functions

Answer 22

1. Motor and sensory area of leg, foot, and perineum
2. Also concerned with voluntary control of defecation and micturation reflexes