Psychology Study Material: Cerebral Lobes, Membranes of the Brain

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Cerebral Lobes

  • Frontal lobe
  • Parietal lobe
  • Temporal lobe
  • Occipital lobe
Cerebral Lobes

Each lobe controls a different range of activities.

  • Each hemisphere is vertically divided by the central sulcus, a groove.
  • The lateral fissure, another groove divides each hemisphere horizontally.

Frontal Lobe

Associated with motor control and cognitive activities; reasoning, planning, decision making, problem solving, movement and speech (Broca՚s Area) .

Parietal Lobe

Associated with controlling incoming sensory information; thus, affecting movement, orientation, recognition, perception of stimuli.

Temporal Lobe

  • Associated with perception and recognition of auditory stimuli, memory & speech.
  • Wernicke՚s area: concerned with the understanding of language is located here

Occipital Lobe

Associated with visual processing.

Cranium

The brain is enclosed in the cavity of skull or cranium consisting of eight hard bones: One frontal bone, two parietal bones, two temporal bones, one occipital bone, one sphenoid bone, and one ethmoid bone.

Membranes of the Brain

Between the surfaces of the brain and the skull, there are three layers of membrane called the meanings, which completely cover the brain and spinal cord.

These three membranes are:

  • Dura Matter
  • Arachnoid
  • Pia Matter

Cerebrospinal Fluid (CSF)

  • The subarachnoid space contains a fluid called cerebrospinal fluid (CSF) , a clear, colorless fluid covering the entire surface of central nervous system.
  • The total volume of CSF is 125 - 150 ml.
  • Total production of CSF is about 400 - 500 ml/day (about 0.36ml/min) .

Association Areas

  • Areas in the cerebral cortex that are not involved in primary motor and sensory functions; rather they are involved in higher mental functions such as learning, remembering, thinking and speaking.
  • Association areas in the Frontal Lobes are concerned with judging and planning.
  • Damage may lead to intact memory but inability to plan out something. Personality
  • may also be affected.
  • Association areas of other lobes are related to other mental functions, i.e.. Temporal Lobe enables us to recognize faces; damage to this area causes inability to identify people (although facial features can be described) , and gender and approximate age too.
  • Association areas in the posterior lobes are involved in perception and memory. Damage leads to difficulty in perceiving speech.

Spinal Cord

  • Continuation of the Medulla Oblongata.
  • The spinal cord is about 45 cm long in men and 43 cm long in women and weighs about 35 - 40 grams.
  • The vertebral column (back bone) , encapsulating the spinal cord, is about 70 cm long comprising vertebra in the vertebral column.
  • The spinal cord is much shorter than the vertebral column.
  • Signals arising in the motor areas of the brain travel back down the cord and leave in the motor neurons.
  • The spinal cord also acts as a minor coordinating centre responsible for some simple reflexes like the withdrawal reflex.
  • Reflex - rapid (and unconscious) response to changes in the internal or external environment, needed to maintain homeostasis
  • Reflex arc: the neural pathway over which impulses travel during a reflex.

The components of a reflex arc include:

  • Receptor - responds to the stimulus
  • Afferent pathway -- sensory neuron
  • Central Nervous System.

Developed by: