Central Nervous System

• The central nervous system is composed of:

  Brain

  Spinal cord
• Central nervous system - acts as an integrating command center of the nervous system by interpreting information perceived by the sensory organs and issue appropriate responses.
• 4 major regions of the brain:

  Cerebrum

  Diencephalon

  Brainstem

  Cerebellum
• • The cerebrum is the largest region of the brain.
• Cerebrum - It is the most superior part of the brain
• The cerebrum controls functions such as:

  • intelligence
  • emotions
  • learning
  • critical thinking
• Cerebrum is divided into equal halves: Cerebral hemispheres
• Corpus callosum - separates the cerebral hemispheres; thick bundle of axons
• Gyri - elevated ridges of the cerebrum
• Sulci - shallow fissures of the cerebrum
• 4 major lobes of the cerebrum:

  Frontal lobe

  Parietal lobe

  Temporal lobe

  Occipital lobe
•  Frontal - near the forehead; memory, motivation, cognition, reasoning, voluntary movement of skeletal muscles
• Parietal - top of the cerebrum (behind the frontal lobe and in front of the occipital lobe); taste, touch, reading, temperature and pressure perception
• Temporal - behind the ears; hearing, smell
•  Occipital - rear portion of the skull; vision, color recognition
•  Frontal lobe - memory, motivation, cognition, reasoning, voluntary movement of skeletal muscles
•  Parietal - taste, touch, reading, temperature and pressure perception
• Temporal - hearing, smell
•  Occipital - vision, color recognition
•  Occipital - vision, color recognition
• The cerebrum contains two cortices that are important in our sensory perceptions and motor actions. They form the cerebral cortex.
• 2 cortices of the cerebrum:

  Somatosensory cortex

  Motor cortex
• • The somatosensory cortex is located in the parietal lobe. It allows us to recognize pain, temperature, and touch. 
• • The motor cortex is located in the frontal lobe. It allows us to consciously move our skeletal muscles. 
• In the cerebral cortex, the relative amount of tissue devoted to each function is indicated by the amount of the gyrus occupied by the body part.
• Diencephalon or the Interbrain
• • The diencephalon, or the interbrain, lies atop the brain stem and almost entirely surrounded by the cerebral hemispheres. 
• Diencephalon - relays sensory information between brain regions and controls many involuntary functions.
• • The thalamus serves as a relay station for sensory impulses that pass through the sensory cortex.
• The epithalamus connects the part of the brain that controls emotions to other parts of the brain.
• • It has the pineal gland that secretes melatonin to control our sleeping patterns.
• The hypothalamus plays a role in the regulation of body temperature, water balance, and metabolism.
• Hypothalamus - center for the control fo emotions and pleasure
• • The brainstem is the stalk-like lower portion of the brain.
• the Brainstem is about the size of a thumb in diameter and is approximately 3 inches long.
• The brainstem regulates the essential survival functions such as breathing and heartbeat.
• • The midbrain is a small part of the brain stem composed of two bulging fiber tracts.
• The midbrain serves important functions in eye movements and in auditory and visual processing.
• The pons is the rounded structure below the midbrain.
• Pons - It is a message station between the cortex and the cerebellum. Without this, signals in brain would not be transmitted