Study of Nervous System

STUDY OF NERVOUS SYSTEM AIM: To study nervous system using specimen and models. NERVOUS TISSUE The majority of the nervous system is tiresve made up of twe classes of colles irontons and neuroglia NEURONS Neviens, also known as nowe celle, communicate within the body by transmiting electrochemical signals. Neurons lok quite different from other celle in the body due to the many long cellular processes that ortend from their contral cell body. NEUROGLIA: Naraglia, ales known as glial cells, act as the helper cells of the nervous system. Each neutron in the body is surrounded by anywhere from 6 to 60 newroglia that protect feed and insulate the neutron. BRAIN: The brain, a soft wrinkled ngan that weighs about 3 pounds, is located inside the cranial cavity where the bones of the skull surovound and protect it. The approximately 100 billion naron f the brain form the main control centre of the body The brain and spinal, I cond. Together form the central novous system, where information is processed and responses originate. SPINAL CORD The spinal cord is a long, thin mass of bundled nevrons that carriel information through the vertebral cavity of the spine beginning of the medulla oblongata of the brain on ite superior and and continuing inferiorly to the lumbar region of the spine. NERVES Nerves are bundles of avons in the peripheral nervous system that acts as information highuny to cavery signals between the brain and spinal card and the rest of the body. CRANIAL NERVES Extending, from the inferich side of the brain are 12 pairs of cranial nerves, fach cranial nerve pair is identified by a Roman numeral I to 12 based upon ite location along the anterior-posterior axis of the brain bach nowe ales has a descriptive name that identifies ite banction or location. SPINAL NERVES Extending from the left and right sides of the spinal cord are 31 pairs of spinal nerves. The spinal nerves are mixed nerves that carry both sensory and motor signals between the spinal cord and specific regions of the hady.. CEREBROSPINAL FLUID: The space surrounding the organs of the CNS is filled with a clear fluid known as corebrofluid CSF is formed from blood plasma by specific structures called choroid plexcuses. The choroid plexures contain many capillaries lined with epithelial tissue that filters the blood plaema and allows the filtered fluid to enter the space around the brain CSF absorbs shal between the brain and skull and between the spinal cord and vertebral FUNCTIONS OF THE NERVOUS SYSTEM SENSORY: The sensory function of the nervous system involves collecting information from sensory receptors that monitor the body's internal and external conditions. INTEGRATION: The process of integration is the processing of the many sensory signals that are passed into the CNS at any given time. MOTOR One the networks of inter neurons in the CNS evaluate sensory information and decide on an action, they stimulate efferent neurons. DIVISIONS OF THE NERVOUS SYSTEM CENTRAL NERVOUS SYSTEM The brinin and spinal cord together form the central nowous system, in CNS. The CNS acto as the control centre of the body by providing its processing, memary and regulation systems PERIPHERAL NERVOUS SYSTEM The peripheral nervous system includes all of the parte of the nervous system outride of the brain and spinal cord. These part include all the cranial and spinal nerves, ganglion and seedy receptors. SOMATIC NERVOUS SYSTEM The somatic nervous system is a division of the PNS that includes all of the invduntar fferent neurons. The SNS is the only consciously controlled part of the PNS and is responsible for stimulating skeletal murces in the body. AUTONOMIC NERVOUS SYSTEM SYMPATHETIC: The sympathetic division forms the body's "fight or flight" response to stress, danger. excitement, exercise, emotions and embarrassment. PARASYMPATHETIC: The parasympathetic division forms the body's "rest and digest" response when the body is Prelaxed, resting or feeding. ENTERIC NERVOUS SYSTEM The enteric nervous system is the division of the ANS that is responsible for regulating digestion and function of the digestive organs.