Introduction to Neuroanatomy PDF

Suez Canal University Faculty Of Medicine Presented By Dr. Bassma M. Dessouki Lecturer of Anatomy & Embryology Depart. *The Nervous System is divided into:- Nervous System Central Nervous Peripheral System...

Suez Canal University Faculty Of Medicine Presented By Dr. Bassma M. Dessouki Lecturer of Anatomy & Embryology Depart. *The Nervous System is divided into:- Nervous System Central Nervous Peripheral System Nervous (CNS) System 1. The Brain. 1. Somatic Component. 2. The Spinal 2. Autonomic Component. Cord. *The (CNS) is consists of:- 1. The Brain. 2. The Spinal Cord. *The CNS is protected by: 1. The Skull & the vertebral column. 2. CSF: Cerebrospinal fluid. 3. Meninges *The CNS is enclosed in 3 coverings called meninges:- 1. The Dura Matter. 2. The Arachnoid Matter. 3. The Pia Matter. *Subdivisions of the brain:- 1. The Cerebrum. 2. The Cerebellum. 3. The Brain stem Midbrain Medulla Oblongata Pons 4. The Diencephalon Thalamus Hypothalamus *It is the upper & largest part of the brain. *It is divided incompletely into right & left cerebral hemispheres *It is formed of 2 cerebellar hemispheres united by a median vermis. *It lies below the posterior portion of the cerebrum. 1. Midbrain 2.Pons 3. Medulla Oblongata 1. Midbrain:- * It extend between the diencephalon above & the pons below. * It is the shortest part of the brain stem. * It contains a narrow canal called aqueduct of midbrain. 2. Pons:- * It extends between the midbrain above & the medulla oblongata below. * It lies in front of the cerebellum. 3. Medulla Oblongata:- * It is the lowest part in the brain stem. * It is continuous above with the pons & below with the spinal cord. * It contains a number of vital centers for regulating of breathing, heart beat & blood pressure. * It lies above the midbrain & between the lower parts of the cerebral hemispheres. 1. The Thalamus * It is an ovoid mass of grey matter in the middle of the cerebrum. * It is located on each side of the 3rd ventricle. 2. The Hypothalamus 2. The Hypothalamus * It lies below the thalamus immediately above the pituitary gland. * It forms the floor of the 3rd ventricle. *Site: in the upper 2/3 of the vertebral canal. It is continuous above with the medulla. *It contain a narrow central canal called the central canal. *This canal is contain cerebro-spinal fluid (C.S.F) & is continuous above with the cavity of the 4th ventricle. *The Spinal Cord is formed of: 1. Outer white matter. 2. Inner grey matter: H-shaped. *Spinal Nerves: 31 pairs of spinal nerves arise from the spinal cord. *They are 31 pairs distributed as follows: 8 cervical pairs. 12 thoracic pairs. 5 lumbar pairs. 5 sacral pairs. 1 coccygeal pair. *Each nerve is formed by the union of: 1. A ventral root & 2. A dorsal root. *Each spinal nerve is divides into: 1. A ventral (anterior) ramus & 2. A dorsal (posterior) ramus. Olfactory n. (I) Sense of smell. Optic n. (II) Sense of vision. Oculomotor n. (III) Motor to the eye. Trochlear n. (IV) Motor to the eye. Trigeminal n. (V) Sensory to eye, face, nasal cavity, mouth cavity & motor to muscles of mastication. Abducent n. (VI) Motor to the eye. Facial n. (VII) Taste, motor for muscles of facial expression Vestibule-cochlear (VIII) Hearing, sense of balance. Glosspharyngeal n. (IX) Taste, sensory to pharynx & middle ear. Vagus n. (X) Taste, Motor & sensory to larynx, pharynx, thoracic & abdominal organs. Accessory n. (XI) Motor larynx, pharynx, sternomastoid m. & trapizus Hypoglossal n. (XII) Motor to muscles of tongue. *The motor & sensory neurons supplying the viscera are collectively called autonomic nervous system. *It is classified into 2 main components:- 1. The Sympathetic nervous system: arises from the thoracic & lumbar regions of the spinal cord. It prepares the body for urgent activity (fright, fight). 2. The parasympathetic nervous system: arises from some cranial nerves & from sacral region of the spinal cord. It regulates the normal functions of the organs it supplies.