The Nervous System
Organization of the Nervous System Structural Classification Structural Classification Functional classification Functional classification
Structural Classification Central nervous system (CNS) consists of brain and spinal cord. Central nervous system (CNS) consists of brain and spinal cord. Peripheral nervous system (PNS) consists of spinal and cranial nerves. Peripheral nervous system (PNS) consists of spinal and cranial nerves.
Functional classification The sensory, or afferent. The sensory, or afferent. The motor, or efferent. The motor, or efferent.
The somatic nervous system voluntary nervous system voluntary nervous system The autonomic nervous system involuntary nervous system involuntary nervous system Sympathetic and parasympathetic Sympathetic and parasympathetic
Functional anatomy of the brain Cerebral hemispheres. Cerebral hemispheres. Diencephalon. Diencephalon. Brain stem. Brain stem. Cerebellum. Cerebellum.
Cerebral Hemispheres The most superior and largest part of the brain. The most superior and largest part of the brain. The entire surface of the cerebral hemispheres have elevated ridges of tissue called gyri,separated by shallow grooves called sulci The entire surface of the cerebral hemispheres have elevated ridges of tissue called gyri,separated by shallow grooves called sulci Fissures are the deeper grooves which separate large regions of the brain Fissures are the deeper grooves which separate large regions of the brain
The cerebral hemispheres are separated by a single deep fissure the longitudinal fissure The cerebral hemispheres are separated by a single deep fissure the longitudinal fissure Other fissures divide each cerebral hemispheres into number of lobes(frontal, pariatal, temporal and occipital) Other fissures divide each cerebral hemispheres into number of lobes(frontal, pariatal, temporal and occipital) Somatic sensory area is located in the parietal lobe posterior to the central sulcus Somatic sensory area is located in the parietal lobe posterior to the central sulcus The body represented upside-down manner The body represented upside-down manner The visual area is located in the in the posterior part of the occipital lobe The visual area is located in the in the posterior part of the occipital lobe
The auditory is located in the temporal lobe The auditory is located in the temporal lobe The olfactory area is found deep inside the temporal lobe The olfactory area is found deep inside the temporal lobe The primary motor area is anterior to the central sulcus in the frontal lobe. The primary motor area is anterior to the central sulcus in the frontal lobe. Broca ’ s area is found at the base of the precentral gyrus Broca ’ s area is found at the base of the precentral gyrus Speech area is located at the junction of the temporal, parietal, and occipital lobes. Speech area is located at the junction of the temporal, parietal, and occipital lobes.
The cell bodies of neurons are found only in the outermost gray matter of cerebrum,the cerebral cortex The cell bodies of neurons are found only in the outermost gray matter of cerebrum,the cerebral cortex The deeper cerebral white matter is composed of fiber tracts carrying impulses to or from the cortex. The deeper cerebral white matter is composed of fiber tracts carrying impulses to or from the cortex.
Diencephalon The major structures of diencephalon are the thalamus, hypothalamus and epithlamus The major structures of diencephalon are the thalamus, hypothalamus and epithlamus
Brain stem Midbrain,pons,and medulla oblongata Midbrain,pons,and medulla oblongata
cerebellum. It has two hemispheres and a convoluted surface. Precise timing for skeletal muscle activity..
Protection of the central nervous system Bone (skull and vertebral column) Bone (skull and vertebral column) Membranes (meninges) Membranes (meninges) Watery cushion (CSF) Watery cushion (CSF) Blood brain barrier Blood brain barrier
meninges Dura mater … double-layered membrane Dura mater … double-layered membrane periosteal layer periosteal layer meningeal layer meningeal layer Folding of meninges Folding of meninges Falx cerebri Falx cerebri Tentorium cerebelli Tentorium cerebelli
Arachnoid mater Arachnoid mater Pia mater..delicate pia mater Pia mater..delicate pia mater The subarachnoid space contain cerebrospinal fluid ( C.S.F). The subarachnoid space contain cerebrospinal fluid ( C.S.F).
C.S.F Watery similar in it ’ s makeup to blood plasma, from which it forms. Watery similar in it ’ s makeup to blood plasma, from which it forms.
Spinal cord It extends from the foramen magnum of the skull to the 1 st and 2 nd lumbar vertebra It extends from the foramen magnum of the skull to the 1 st and 2 nd lumbar vertebra The spinal is protected by meninges which is extend well beyond the end of spinal cord. The spinal is protected by meninges which is extend well beyond the end of spinal cord. 31pairs of spinal nerves 31pairs of spinal nerves Cauda equina Cauda equina Cervical and lumbar enlargement Cervical and lumbar enlargement
Gray mater of the spinal cord Butterfly – H Butterfly – H Posterior or dorsal horn Posterior or dorsal horn anterior or ventral horn and lateral horn Gray mater surrounds the central canal Gray mater surrounds the central canal Dorsal root, dorsal root ganglion, ventral root Dorsal root, dorsal root ganglion, ventral root
White mater of the spinal cord Posterior, lateral, and anterior columns Posterior, lateral, and anterior columns