Left Brain/ Right Brain

The Nervous System

What is it?  A highly complex organized system that coordinates all of the activities of the body.  This system enables the body to respond or adapt to changes that occur both inside and outside the body.

Components of the Nervous System  Brain  Spinal Cord  Nerves Nerves

NERVES  Are a combination of many nerve fibers located outside the brain and spinal cord. Their function is to relay messages to all the body muscles and glands. ( muscles power the body movements)

DIRECTIONS OF NERVE IMPULSES  Afferent (sensory) nerves carry messages from all parts of the body to the brain and spinal cord.  Efferent (motor) nerves carry messages from the brain and spinal cord to the muscles and glands.  Associative (internuncial) nerves carry both sensory and motor messages.

The Cell of the Nervous System

Neurons  The neuron is the Basic functional unit of the nervous system.  Humans have about 100 billion neurons in their brain ALONE.

3 Parts of a Neuron  Cell Body – contains the nucleus (maintains the functionality of the cell)  Dendrite – (dendritic tree) carry impulse to cell body  Axon – a single nerve fiber carries impulse away from the cell

Myelin Sheath  Axons have a lipid or fat layer called the myelin sheath.  They increase the rate of impulse transmission and insulates and maintains the axon.

 For communication between neurons to occur, an electrical impulse must travel down the axon to the synaptic terminal.

 Impulses coming from one axon “jump” the synapse to get to the dendrite of another neuron, which will carry the impulse in the right direction.

SYNAPSES  ARE spaces between the Dentrites and the Axon.

What allows for the jump across the sypnase between dentrites and axons? ….  NEUROTRANSMITTERS – located at the end of each axon allow the nerve impulses to pass from one neuron to another. These messages (impulses are able to follow many different routes.

Information is moved around the brain, from nerve cell to nerve cell, by means of chemical substances, called neurotransmitters

Parts of the Nervous System  The nervous system is broken down into 2 major parts. Central Nervous System – consists of the brain (encepha/o) and the spinal cord (spondyl/o) Peripheral Nervous System – consists of the nerves. subdivision: AUTONOMIC NERVOUS SYSTEM

AUTONOMIC NERVOUS SYSTEM TWO PARTS  Sympathetic and Parasympathetic These two systems work together to maintain a balanced state ( homeostasis )

SYMPATHETIC  In times of emergency, this system prepares the body to act in two ways: Fight or Flight by: Increasing heart rate respiration blood pressure

PARASYMPATHETIC  This system counteracts, the actions of the sympathetic system  BY slowing down the Heart Rate Respiration Rate Lowering blood pressure AND Increasing activity in the Digestive System

Central Nervous System  Consists of: Brain Spinal Cord

Brain Hemispheres  Your brain is divided into left and right hemispheres.  The right side of your brain controls the left side of your body.  The left side of your brain controls the right side of your body.

The Brain  The brain is a mass of nerve tissue well protected by membranes and the cranium.  It is made up of several sections. Cerebrum Cerebellum Diencephalon Midbrain Pons Medulla oblongata

Sections of the Brain

Cerebrum  The largest and highest section of the brain.  The outer part is arranged in folds, called convolutions, and separated in lobes.

Functions of the Cerebrum  Reasoning  Thought  Memory  Speech  Sensation  Sight  Smell  Hearing  Voluntary body movement

Functions of the Cerebellum  Muscle coordination  Balance  Posture  Muscle tone

Diencephalon  The structure that lies between the cerebrum and the midbrain.  It contains two structures: Thalmus- directs sensory impulses to the cerebrum. Hypothalmus-regulates and controls many of the functions of the body.

Midbrain  The section located below the cerebrum at the top of the brainstem.  Major Function: conducting impulses between brain parts

Pons  The section located below the midbrain and in the brain stem.  Functions: Conducting messages to other parts of the brain Certain reflex actions Assists with respiration

Medulla Oblongata  The lowest part of the brain stem.  It connects with the spinal cord.  Functions: Regulation of Heartbeat Respiration Swallowing Blood pressure

Lobes of the Brain Lobes of the brain - Creation Wiki, the encyclop edia of creation science

Spinal Cord  Continues down from the medulla oblongata and ends at the first or second lumbar vertebrae.  It is surrounded and protected by vertebrae.

Functions of the Spinal Cord  Responsible for many reflex actions and for carrying messages to and from the brain to the nerves that go to the organs and glands.

MENINGES There are three membranes that cover and protect the brain and spinal cord. 1. Dura mater – outer layer 2. Arachnoid membrane – delicate and web-like 3. Pia mater – closely attached to the brain and spinal cord; contains the blood vessels that nourish the nerve tissure.

VENTRICLES There are FOUR hollow spaces that connect with each other and with the space under the arachnoid membrane. The ventricles are filled with a fluid called: CEREBR0SPINAL FLUID This fluid serves as a shock absorber  Carries nutrients, removes metabolic waste  Absorbed into the blood vessels of the dura mater, returned to the bloodstream via the arachnoid villi

DISEASES AND ABNORMAL CONDITIONS  Cerebral palsy – a disturburbance in voluntary muscle action and is caused by brain damage (due to lack of oxygen, birth injuries, prenatal rubella(german measles), and infections.  Cerebrovascular accident (CVA) (stroke) – cerebral hemorrhage due to an aneurysm or occlusion or thrombus.

 Encephalitis – inflammation of the brain due to virus or bacterium or chemical agent.  Epilepsy – or seizure syndrome; abnormal electrical impulses in the neurons of the brain.  Hydrocephalus – an excessive accumulation of cerebrospinal fluid in the ventricles and sometimes, in the subarachnoid space of the brain.

 Meninigitis – inflammation of the meniges of the brain and/or spinal cord due to bacterium, virus, fungus, or toxins (lead, arsenic, mercury)  Multiple sclerosis – (MS) chronic, progressive, disabling, condition due to degeneration of the myelin sheath in the CNS.  Neuralgia – nerve pain due to inflammation, pressure, toxins and other diseases.

 Paralysis – results from a brain or spinal cord injury that destroys neurons and results in a loss of function and sensation below the level of injury. Hemiplegia – one side of the body Paraplegia – lower extremities Quadriplegia – upper and low extremities  Parkinson’s disease – chronic, progressive condition involving degeneration of brain cells; includes tremors

 Shingles (herpes zoster) – acute inflammation of nerve cells caused by herpes virus; which also causes chicken pox.

RELATED CAREERS  Acupressurist  Acupuncturist  Anesthesiologist  Chiropractor  Diagnostic imager  Doctor of Osteopathic Medicine  Electroencephalographic Technologist  Electroneurodiagnostic Technologist  Mental Health Technicians

 Neurologist  Neruosurgeon  Physical Therapist  Polysomnographic Technologist  Psychiatrist  Psychologist

Medical Terminology Root word: myel/o denotes spinal cord or bone marrow Myelocelehernail protrusion Poliomyelitisgray; inflammation Myelomalaciasoftening Myeloplegiaparalysis Myelogenousproduce/create

 Root Word: encephal/o denotes brain (inside) combined with cephal/o: head Encephalitis inflammation Encephalogrampicture-tracing x-ray Encephalopathicdisease; pertaining to Encephalomatumor Encephalomalaciasoftening

Psychiatrics treatment Psychastheniawithout, strength Psychologyscience, study of Psychosomaticbody, pertaining to Psychophylaxisprotection, prevention

Root Word: algia,algesia; denotes pain or ache Cephalalgiahead Neuralgianerves Arthralgiajoint Otalgiaear Hyperalgesiaabove,excess Analgesic without, pertaining to Gastralgiastomach Myalgiamuscle Kinesalgiamovement Costalgiarib

Root Word: neur/o, denotes the nerves or nervous system Neruobiologylife, study of Neuritisinflammation Neuromatumor, swelling Neuropathydisease Neruosisdisease condition

Root Word: cephal/o, denotes cranium (head) Cephalocelehernia Cephaloplegiaparalysis Cephalometermeasure Cephalicpertaining to Cephalocaudaltail, pertaining to

Medical Abbreviations Letter OMeaning O 2 oxygen ob or obsobstetrics odoverdose ointointment OJorange juice OOBout of bed

oppopposite ORoperating room Ordorderly OrthOrthopedics osmouth OUeach eye ozounce