The Anatomy and Physiology of The Nervous System Dr Ashwini Kalantri

Organs CNS: Brain Brain Spinal Cord Spinal CordPNS: Nerves Nerves

Brain It is one of the largest organs in the body, and coordinates most body activities. It is one of the largest organs in the body, and coordinates most body activities. It is the center for all thought, memory, judgment, and emotion. It is the center for all thought, memory, judgment, and emotion. Each part of the brain is responsible for controlling different body functions, such as temperature regulation and breathing. Each part of the brain is responsible for controlling different body functions, such as temperature regulation and breathing.

Cerebrum It is the largest section of the brain It is the largest section of the brain It is located in the upper portion of the brain and is the area that processes thoughts, judgment, memory, problem solving, and language. It is located in the upper portion of the brain and is the area that processes thoughts, judgment, memory, problem solving, and language. The outer layer of the cerebrum is the cerebral cortex, which is composed of folds of gray matter. The outer layer of the cerebrum is the cerebral cortex, which is composed of folds of gray matter. The cerebrum is subdivided into the left and right halves called cerebral hemispheres. Each hemisphere has 4 lobes. The cerebrum is subdivided into the left and right halves called cerebral hemispheres. Each hemisphere has 4 lobes.

Lobes of Cerebrum

1. Frontal lobe : Most anterior portion of the cerebrum, controls motor function, personality, and speech 1. Frontal lobe : Most anterior portion of the cerebrum, controls motor function, personality, and speech 2. Parietal lobe : The most superior portion of the cerebrum, receives and interprets nerve impulses from sensory receptors and interprets language. 2. Parietal lobe : The most superior portion of the cerebrum, receives and interprets nerve impulses from sensory receptors and interprets language. 3. Occipital lobe : The most posterior portion of the cerebrum, controls vision. 3. Occipital lobe : The most posterior portion of the cerebrum, controls vision. 4. Temporal lobe : The left and right lateral portion of the cerebrum, controls hearing and smell 4. Temporal lobe : The left and right lateral portion of the cerebrum, controls hearing and smell

Cerebellum Second largest portion of the brain Second largest portion of the brain Located beneath the posterior part of the cerebrum Located beneath the posterior part of the cerebrum Aids in coordinating voluntary body movements and maintaining balance and equilibrium Aids in coordinating voluntary body movements and maintaining balance and equilibrium Refines the muscular movement that is initiated in the cerebrum Refines the muscular movement that is initiated in the cerebrum

Brain Stem Midbrain —acts as a pathway for impulses to be conducted between the brain and the spinal cord. Midbrain —acts as a pathway for impulses to be conducted between the brain and the spinal cord. Pons — means bridge—connects the cerebellum to the rest of the brain. Pons — means bridge—connects the cerebellum to the rest of the brain. Medulla oblongata —most inferior positioned portion of the brain; it connects the brain to the spinal cord. Medulla oblongata —most inferior positioned portion of the brain; it connects the brain to the spinal cord.

Spinal Cord Runs through the vertebral canal Runs through the vertebral canal Extends from foramen magnum to 2 nd lumbar vertebra Extends from foramen magnum to 2 nd lumbar vertebra Regions Regions Cervical Cervical Thoracic Thoracic Lumbar Lumbar Sacral Sacral Coccygeal Coccygeal Gives rise to 31 pairs of spinal nerves - all are mixed nerves Gives rise to 31 pairs of spinal nerves - all are mixed nerves

Meninges Dura mater: outermost layer; continuous with epineurium of the spinal nerves Dura mater: outermost layer; continuous with epineurium of the spinal nerves Arachnoid mater: thin and wispy Arachnoid mater: thin and wispy Pia mater: bound tightly to surface Pia mater: bound tightly to surface

Nerves

Nerves

Neuron

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