THE-NERVOUS-SYSTEM.pptx

THE NERVOUS SYSTEM ADONIS V. DELOS S ANTOS, RN, LPT - One of the smallest yet complex system - Has billions of Neurons - 2Kg. Or 3% of total body weight control communication system FUNCTIONS : (C.R.I.M.E.) Controlling muscle and glands Receiving sensory input Integrating information Maintaining...

THE NERVOUS SYSTEM ADONIS V. DELOS S ANTOS, RN, LPT - One of the smallest yet complex system - Has billions of Neurons - 2Kg. Or 3% of total body weight control communication system FUNCTIONS : (C.R.I.M.E.) Controlling muscle and glands Receiving sensory input Integrating information Maintaining homeostasis Establishing and maintaining muscle activity TERMS: 1.Neuropeptide – specialized protein messenger; mental functions 2.Neuroglia – nourishes the nerve cells in brain and spinal cord 3.Meninges – membranes that covers the brain 5. Myelinated – surrounded by myelin sheath 6. Neuron – nerve cells; receiving, transmitting impulses 7. Nerve – bundle of neuron fibers outside CNS 8. Instinct – aware of knowing something without having to discover or perceived it; immediate apprehension of the mind without reasoning 9. Stimulus – agent that directly influence an activity by exciting a sensory organ; evoking muscular contraction or glandular secretion; positive or negative; capable of exciting functional activity; produces a response in an organ or part of an organ 10. Impulse – wave excitation transmitted by nerve fibers and muscle DIVISIONS OF THE NERVOUS SYSTEM I. Central Nervous System – the control system for the entire system. - interprets incoming sensory information, issued transactions based on past and current conditions. Ex. Specific kind of Pain a. Brain – primary center for regulating and coordinating body activities (The Computer) b. Spinal cord – center of reflex action containing the conducting paths to and from the brain. (The tail of the Brain) II. Peripheral Nervous System – convey impulses to and from the brain a. Spinal Nerves – carries impulses to and from spinal cord b. Cranial Nerves – carry impulses to and from the brain; connect the brain to structures of head, neck and trunk. Spinal Nerves - Originate at the spinal cord and connected to a specific segment of the spinal cord. - Each pair of spinal nerves is connected to a segment of the cord by two pairs of attachments called roots. 31 pairs 8 Cervical – supplies the limbs, neck and diaphragm 12 Thoracic – supplies the muscle of the chest and back 5 Lumbar – supplies the lower abdomen and some parts of the lower limb 5 Sacral – supplies reproductive organs and  12 CRANIAL NERVES 1.OLFACTORY – sense of smell 2.OPTIC – for vison, visual acuity 3.OCULOMOTOR – opening of the eyelids, constriction of the pupil, upward/downward movement of the eye 4.TROCHLEAR – oblique movement of the eye 5.TRIGEMINAL – facial sensation; mastication 6.ABDUCENS – lateral movement of the eye 7.FACIAL – facial movement/facial expression, closing of the eyelids leading to production of tears 8.VESTIBULOCOCHLEAR/AUDITORY/ACOUSTIC – hearing and balance 9.GLOSSOPHARYNGEAL – sense of taste; swallowing 10.VAGUS – stimulates digestive organs, internal organ functions such as heart rate, respiratory rate; actions such as coughing, sneezing, vomiting Functional classifications of the Peripheral Nervous System: 1.Sensory Division (Afferent) – nerve fibers that convey impulses/conduct information and action potentials from sensory receptors towards the CNS a. Somatic sensory fibers - delivers impulses from skin, skeletal muscles and joints b. Visceral sensory fibers – transmits impulses from organs and blood vessels 2. Motor Division (Efferent) – carries impulses/conduct information and action potentials away from the CNS a. Somatic nervous system – voluntary; controls skeletal muscles b. Autonomic nervous system – involuntary; controls activity of smooth and cardiac muscles b.2 PARASYMPHATETIC – calming state - maintains homeostasis by seeing that normal digestion an d elimination occur and that energy is conserved - rest and digest response - lowers heart rate, blood pressure and blood flow NEURONS - basic structural and functional unit of the brain/nervous system Parts: 1. Cell Body (Perikaryon)– source of information for gene expression; metabolic central portion of the cell 2. Dendrites (Little trees) – neuron processes that conducts an action potential towards the cell body 3. Axon (Axis) – generate nerve impulses and conducts away from the cell body THE BRAIN – control center of the nervous system - weighs 3 pounds; soft, spongy, mottled, pinkish gray - protected by skull and meninges - one of the largest organs of the body with more than 100 billions of neurons - requires a continuous supply of oxygen and glucose - It consists of Brain Stem, Cerebrum, and Cerebellum. Brain Development – during the 4th week of embryonic development, 3 major vesicles are formed. a. Prosencephalon (forebrain) a.1 Telencephalon – cerebrum with basal ganglia a.2 Diencephalon – thalamus, hypothalamus b. Mesencephalon (midbrain) c. Rhombencephalon (hindbrain) c.1 Metencephalon – cerebellum, pons c.2 Myelencephalon – medulla oblongata