Components of the brain and their functions

 BRAIN

 

Cerebrum(forebrain)

• Large portion of brain.
• Center of conscious thought and higher mental functioning ( intelligence learning, memory ).

Cerebral cortex 

• Outer coating of cerebrum: gray matter  (nerve cell bodies ). 
• Contains convolutions ( grooves ) and elevations ( gyri) that increase brains surface area. 

Inner portion of brain

• White matter
• Location of billions of connections, due to presence of dendrites and myelinated axons

Lobes

• Frontal 
• Located at front of skull, forehead. 
• Location of higher mental processes ( intelligence, motivation, mood, aggression, planning ) site for verbal communication and voluntary control of skeletal muscle. 
• Parietal
• Between frontal and occipital lobes 
• Location of skin, taste and muscle sensations; speech center, enables formation of words to express thought and emotions, interprets textures and shapes. 
• Temporal 
• Located at sides of skull.
• Location of sense of smell and auditory interpretation, stores auditory and visual experiences, forms thoughts that precede speech. 
• Occipital 
• Located at back of skull.
• Location of eye movements integrates visual experiences. 

Hemispheres 

• Corpus callosum
• Longitudinal fissure divides brain into right and left halves
• Connects hemispheres internally

Diencephalon ( interbrain): Located between cerebral hemispheres and brainstem.

• Thalamus
• Located within cerebral hemispheres 
• Central relay point for incoming nerve messages ( switching centre),  consolidates sensory input ( especially extremes and pain), influence mood and body movements, associated with strong emotions. 
• Hypothalamus 
• Located below thalamus, at base of cerebrum 
• Regulates homeostasis, centre for body temperature regulation, hunger, peristalsis, thirst and water balance, sexual response, and sleep-wake cycle, controls heart rate and blood vessel diameter, influences pituitary gland secretions, control muscles of swallowing, urine release, link nervous and endocrine systems. 
• Limbic system 
• Consists of hippocampus and reticular formation. 
• Responding for learning, long term memory, wakefulness, and sleep. 

Cerebellum 

• Second largest part of the brain (part of hindbrain) attached to back of brainstem, below curve of cerebrum, connected via midbrain, to spinal cord and motor area of cortex. 
• Location of involuntary movement, coordination, muscle tone, balance, and equilibrium ( semicircular canals ) coordinates some voluntary muscles. 

Brainstem

• Midbrain (mesencephalon)
• Smallest and most private part of brain located atop of brainstem, below thalamus 
• Connects cerebral hemispheres with spinal cord. Acts as visual and auditory reflex centre, righting reflex located here. 
• Pons
• Between cerebrum and medulla 
• Carries messages between cerebrum and medulla, acts as respiratory center to produce normal breathing patterns. 
• Medulla (oblongata)
• Located at floor of skull below midbrain, connects brain to spinal cord. 
• Vital for life, descending nerve tracts from brain cross here to opposite side, contains centers for many body functions ( cardiac, vasomotor, and respiratory center, swallowing, coughing, and sneezing reflexes )