lobes&Functions

1. Frontal Lobe

-General Functions: Memory formation, decision making, reasoning, personality, emotions, goal attainment.

   -Lesion: Personality and behavioral changes, impaired logical reasoning, poor judgment/decision-making (e.g., Phineas Gage case).

* ⭐️⭐️⭐️Area 4 (Primary Motor Cortex - Precentral Gyrus):

   * Function: Direct control of voluntary motor movements across specific body parts

  ⭐️* Lesion: Contralateral flaccid paralysis/paresis (progressing to spasticity/upper motor neuron signs).

* Area 6 (Premotor Cortex & Supplementary Motor Area):

   * Function: Motor planning, elaboration of thoughts, and coordination of complex movement sequences.

   * Lesion: Motor apraxia (inability to carry out purposeful movement despite normal strength).

* Area 8 🧐(Frontal Eye Field):

   * Function: Controls voluntary conjugate horizontal eye movements to the opposite side.

   * ⭐️Lesion: Conjugate eye deviation toward the side of the lesion (inability to gaze toward the opposite side).

⭐️⭐️Areas 44 & 45 (Broca’s Area - Dominant Left Frontal Lobe):

   * Function: Word formation, speech production, motor pattern planning for individual word expression.

 ⭐️  * Lesion: Expressive (Broca’s/motor) aphasia — non-fluent speech, slow/labored utterance, decreased motor ability to form words, but preserved comprehension.

🛑Arcute fasciculus!🛑

* Prefrontal Association Area (Anterior Pole of Frontal Lobe):

   * Function: Planning complex patterns of movement, personality development, social behavior, deep/abstract/logical thinking, working memory (comparing inputs with stored knowledge for future plans).

🛑Uncinate fasciulus(regulation of behavior)

2. Parietal Lobe

* General Functions: sensations and awareness of body parts in space

Lesion in parietal lobe =loss ability to recoginze shapes of objects(develops sensory inattention on oppsite side)

* Areas 3, 1, 2 (Primary Somatosensory Cortex - Postcentral Gyrus):

   * Function: Processing tactile, pain, thermal (warmth/cold), and proprioceptive inputs (arranged as the sensory homunculus).

   *⭐️ Lesion: Contralateral loss of sensory discrimination, tactile localization, two-point threshold, and contralateral sensory inattention.

* Area 43 (Primary Gustatory Cortex):Taste

* Areas 5 & 7 (Somatosensory Association Cortex):

   * ⭐️Function: Integrates and interprets sensory inputs relative to body position/orientation in space, stereognosis, visuo-motor coordination.

   *⭐️ Lesion: Astereognosis (inability to recognize complex shapes/objects by palpation/touch) and hemispatial neglect syndrome.

3. Temporal Lobe(Hearing)

* General Functions: Hearing, organization/comprehension of language, information retrieval (memory formation).

* ⭐️Areas 41 & 42 (Primary Auditory Cortex)

* ⭐️Area 22 (Wernicke’s Area - Superior Temporal Gyrus, Dominant Left Hemisphere):

   * Function: Language comprehension, intelligence, higher intellectual functions, word organization.

4. Occipital Lobe(vision)

* Area 17 (Primary Visual Cortex - Calcarine Sulcus):Vision

 Lesion: Contralateral homonymous hemianopia (with macular sparing in PCA infarctions sparing MCA territory).

Pre-Frontal association area

Personality characteristics

⭐️Working memory→

lesion lead to change in personality and behavior

Parieto-Occipitotemporal association areas

1-Language Comprehension(Wernicke’s)

2-coordinate visual,auditory and body surroundings

3-Reading(Angular Gyrus)

4-Naming Objects

* Hemispheric Specialization:

 -No functional area acts alone!Conscious behavior involves the entire cortex!

  *⭐️ Left (Dominant/Categorical Hemisphere in ~90%): Language, speech, reading, writing, mathematics, logic, decision-making.

   * ⭐️Right (Non-Dominant/Representational Hemisphere):body language and emotions

Corpus Callosum:Rosturm,Genu→Frontal lobe

body&Splenium→Occupital lobe

Lesion in the splenium leads to post disconnection syndrome of alexia without agraphia,يقدر يكتب ويتكلم بس مايقدر يقرا

Alexia(مايقدر يقرا او يفهم المكتوب)

Agraphia يقدر يكتب ويتكلم بس

White matter

1-Internal capsule(between thalamous and basal ganglia)

Projection fibers between Caudate nucleus, thalamus and lentiform

Formed of

• Anterior limb by lenticulostruate of MCA and Recurrent of ACA

• Genu(corticobulbar⭐️)lenticulostruate by MCA

• Lesion→Damage of corticonuclear fibers,Facial+hypoglossal+ambigus nuclei

• Posterior limb by lenticulostruate and anterior choroidal of ICA

• Lesion→Contralateral hemiplegia/Hemiparesis affecting upper and lower limbs

• and Hemianaesthesia

• Retrolenticular(⭐️Optic radiation)

• Sublenticular(⭐️Auditory radiation)

long association fibers:

🔴bilateral lesion in inferior longitudinal fasciculus(CO poison)leads to

Agonsia of obj

Prosopagnosia of faces

عدم القدرة على التعرف مع العلم النظر لايوجد به مشكلة

Unicinate fasciculus(Regulate behavior)

Arcuate fasciculus(Languge)

Connecte Brocas to Wernicks

CEREBRAL CORTEX LAYERS

1.The incoming sensory signal excites neuronal layer

IV first; then the signal spreads toward the surface of

the cortex and also toward deeper layers.

2.Layers I and II & III perform most of intracortical

association function.

3.The neurons in layers II and III making short

horizontal connections with adjacent cortical areas.

4.The neurons in layers V and VI send output signals

to brain stem ,spinal cord (V) & thalamus (VI)

Tagme3at

تجميعات محاضرة Functions of cerebral hemispheres:

-444-

-A patient lost his sense of interpretation of objects which lobe is affected ?

A. Frontal

B. Temporal

C. Parietal

D. Occipital

Answer: C

-Which of the following will be lost if there is a lesion in the prefrontal

association area?

A. Motivational drive

B. Facial recognition

C. Processing of visual language

D. Personality characteristics

Answer: D

- 443 -

1. Which neuronal layer sends output signals to the brainstem and spinal cord?

A. l

B. lll

C. V

D. lV

Answer: C

2. The smell pathway ends at what lobe?

A. Frontal

B. Temporal

C. Parietal

Answer: B

في التجميعات A خطأ

The olfactory bulb is in the frontal lobe

But the primary olfactory cortex is in the temporal lobe

3. A patient is suffering from language comprehension, which of the following is affected?

A. Superior temporal gyrus

B. Inferior frontal gyrus

C. Inferior parietal gyrus

Answer: A

- 442 -

4. In which of the following areas is the skilled motor pattern of speech initiated?

A. Broca’s area

B. Premotor cortex

C. Angular gyrus

D. Primary motor cortex

Answer: A

- 439 -

5. Which cortical area is associated with the initiation of skilled motor pattern for controlling the muscles of speech?

A. Broca’s area

B. Pre-motor area

C. Primary motor cortex

D. Wernicke’s area

Answer: A

6. The pathway for taste fibers ends in which lobe?

A. Parietal

B. Frontal

C. Occipital

D. Temporal

Answer: A

Remember:

Sensation of smell 👃: 1ry Olfactory cortex , Temporal lobe

Sensation of taste 👅: 1ry Gustatory cortex, Parietal lobe

7. Which of the following is the function of the prefrontal association area?

A. Motivational drive

B. Facial recognition

C. Processing of visual language

D. Personality characteristics

Answer: D

8. Which of the following represent actions controlled by the right cerebral hemisphere if the individual is right handed?

A. Reading and writing

B. Mathematics

C. Interpretation of body language

D. Speech

Answer: C

سؤال مو متأكدة اذا تبع المحاضرة بس بحطه احتياط:

🧠. A 67-year-old female experienced a stroke in the posterior superior temporal gyrus. Which neurological deficit will be seen?

A. Fluent aphasia

B. Loss of short-term memory

C. Afluent aphasia

D. Prosopagnosia

Answer: No answers were found

A, Wernicke’s area is in the posterior superior temporal gyrus

#physiology

#تجميعات