CNS ANATOMY AND PHYSIOLOGY PRESENATTION.pptx

CNS PRESENTATION

1. Nervous system Nervous system controls all the activities of the body. N ervous system is divided into two parts: 1. Central nervous system 2. Peripheral nervous system

2. Central nervous system (CNS) includes brain and spinal cord. It is formed by neurons and supporting cells called neuroglia. Structures of brain and spinal cord are arranged in two layers, namely gray matter and white matter. Gray matter is formed by nerve cell bodies and the proximal parts of nerve fibers, arising from nerve cell body. White matter is formed by remaining parts of nerve fibers. In brain, white matter is placed in the inner part and gray matter is placed in the outer part . In spinal cord , white matter is in the outer part and gray matter is in the inner part

3. Organization of nervous system

4. Parts of brain

5. NEUROGLIAL CELLS Neuroglia or glia (glia = glue) is the supporting cell of the nervous system. Neuroglial cells are non-excitable and do not transmit nerve impulse (action potential). So, these cells are also called non-neural cells or glial cells. CENTRAL NEUROGLIAL CELLS ASTROCYTES- 1. S upporting network in brain and spinal cord 2. Form the blood-brain barrier MICROGLIA- phagocytic cells OLIGODENDROCYTES- Provide myelination Central N S PERIPHERAL NEUROGLIAL CELLS SCHWANN CELLS- Provide myelination –Peripheral N S SATELLITE CELLS- physical support

6. CRANIAL NERVES AND FUNCTIONS Number Name Exit Modality Function 1 (CN I) Olfactory Cribriform plate Sensory (SVS) Smell 2 (CN II) Optic Optic canal Sensory (SSS) Vision 3 (CN III) Oculomotor Superior orbital fissure Motor (GSM & GVM) GSM: 4 extrinsic eye muscles and levator palpebrae superioris. GVM: pupillary sphincter 4 (CN IV) Trochlear Superior orbital fissure Motor (GSM) Superior oblique

7. 5 (CN V) Trigeminal: Ophthalmic Superior orbital fissure GSS Scalp, forehead and nose. Maxillary F. rotundum GSS Cheeks, lower eye lid, nasal mucosa, upper lip, upper teeth and palate. Mandibular F. ovale GSS SVM GSS: anterior 2/3 tongue, skin over mandible and lower teeth. SVM: muscles of mastication. 6 (CN VI) Abducens Superior orbital fissure Motor (GSM) Lateral rectus 7 (CN VII) Facial Internal acoustic meatus > stylomastoid f. Both: GSS SVS SVM GVM GSS: sensation to part of ext. ear. SVS: taste from ant. 2/3 tongue, hard and soft palate. SVM: muscles of facial expression. GVM: lacrimal, submandibular, sublingual glands and mucous glands of mouth and nose. 8 (CN VIII) Vestibulocochlear Internal acoustic meatus Sensory (SSS) Hearing and balance 9 (CN IX) Glossopharyngeal Jugular f. Both: GSS GVS SVS GVM SVM GSS: post. 1/3 tongue, ext. ear, and middle ear cavity. GVS: carotid body and sinus. SVS: taste from post. 1/3 tongue. GVM: parotid gland. SVM: stylopharyngeus 10 (CN X) Vagus Jugular f. Both: GSS GVS SVS GVM SVM GSS: ext. ear, larynx and pharynx. GVS: larynx, pharynx and, thoracic & abdominal viscera. SVS: taste from epiglottis region of tongue GVM: smooth muscles of pharynx, larynx and most of the GIT. SVM: most muscles of pharynx and larynx.

8. 11 (CN XI) Spinal accessory Jugular f. Motor (GSM & SVM) GSM: trapezius and sternocleidomastoid. SVM: a few fibres run with CNX to viscera. 12 (CN XII) Hypoglossal Hypoglossal canal Motor (GSM) Intrinsic and extrinsic tongue muscles (except the palatoglossus).

9. Sleep: S The hypothalamus regulates sleep and circadian rhythms. Energy: E The hypothalamus regulates body temperature and blood pressure. Appetite: A The hypothalamus regulates hunger and thirst. Thirst: T The hypothalamus regulates thirst and water intake