Nervous System Lecture 14 - Loc'n of Function 2(2)

Nervous System Lecture 14: The Brain (Part 4)

Overview

  • Focus on localisation of brain function.

Key Brain Areas

Primary Motor Cortex

  • Responsible for voluntary motor functions.

  • Located in the precentral gyrus.

Primary Somatosensory Cortex

  • Processes sensory information from the body.

  • Located in the postcentral gyrus.

Primary Auditory Cortex

  • Processes auditory information.

  • Important for hearing.

Primary Visual Cortex

  • Responsible for processing visual information from the eyes.

Important Historical Figures

Paul Broca

  • Known for research on Broca's area, involved in speech production.

Carl Wernicke

  • Known for research on Wernicke's area, important for language comprehension.

Stroke (Cerebrovascular Accident - CVA)

Types of Stroke

  • Transient Ischaemic Attack (TIA): Temporary blockage of blood flow.

  • Ischaemic Stroke: Blockage of blood flow usually due to a clot.

  • Haemorrhagic Stroke: Caused by bleeding in the brain.

Blood Supply to the Brain

Key Arteries

  • Common Carotid Artery: Supplies blood to the head and neck.

  • External Carotid Artery: Supplies blood to areas outside the skull.

  • Internal Carotid Artery: Supplies blood to the brain.

  • Ophthalmic Artery: Supplies blood to the eyes.

  • Anterior Cerebral Artery: Supplies blood to the frontal lobe.

  • Middle Cerebral Artery: Supplies blood to the lateral aspects of the brain.

  • Posterior Cerebral Artery: Supplies blood to the occipital lobe.

  • Basilic and Vertebral Arteries: Contribute to the posterior circulation of the brain.

Neurological Effects of Stroke

Specific Arterial Effects

  • Anterior Cerebral Artery Damage: Weakness or paralysis and sensory loss in the contralateral leg.

  • Middle Cerebral Artery Damage:

    • Weakness or paralysis, loss of sensation in the contralateral arm and face.

    • If on the left side: Possible aphasia (speech difficulties).

    • If on the right side: Hemi-inattention (neglect of the left side).

  • Posterior Cerebral Artery Damage: Visual disturbances, including scotoma (partial loss of vision).

Lateralisation of Brain Function

Hemispheric Specialisation

  • Left Hemisphere: Controls the right side of the body, involved in language and analytical tasks.

  • Right Hemisphere: Controls the left side of the body, involved in spatial and creative tasks.

Prefrontal Cortex

Function

  • Associated with complex cognitive behavior, decision making, and moderating social behavior.