The Nervous System and Disorders By: Gabby, Stephanie, Valerie, Jamaeya, and Deja

The Nervous System What does it do? The Nervous system controls, directs, and coordinates body functions. It has two main divisions: – The Central Nervous System (CNS) This part has the Spinal Cord and the Brain – The Peripheral Nervous System This part involves all of the nerves throughout the body

The Nervous System Nerves run throughout the body and connect to our brain They carry messages or impulses to and from the brain Stimulus cause impulses – Stimulus- anything that excites or causes a body part to function, become active or respond. Reflex- the body’s response to a stimulus. They are involuntary, unconscious and immediate; uncontrollable

The Nervous System Nerves are easy damaged and take a long time to heal Some nerves have a protective end called a myelin sheath – the sheath protects, insulates, and cause nerves to conduct impulses faster

The Central Nervous System: Brain Pons Brainstem Midbrain Cerebral Cortex

Central Nervous System: Brain The Brain has three main parts: 1.Cerebrum – The largest part of the Brain – Center of thought and intelligence – Separated into two hemispheres; the right hemisphere which controls the left side of the body, and the left hemisphere which controls the right side of the body 2.Cerebellum – Regulates and coordinates body movements – Controls balance and smooth movements of voluntary muscles 3.Brainstem – Connects cerebrum to the spinal cord – Contains the midbrain, pons, and medulla

Central Nervous System: Brain Other important parts of the brain: Cerebral Cortex- the outside of the cerebrum that controls the functions such as memory, consciousness, speech, voluntary muscle movement, vision, hearing, sensation, and other activities Midbrain and Pons- relay messages between the medulla and cerebrum Medulla- controls heart rate, breathing, blood vessel size, swallowing, coughing, and vomiting.

Central Nervous System: Spinal Cord Spinal cord lies within the spinal column The cord is 17 to 18 inches long Contains pathways that conduct messages to the brain Protected by 3 layers of connective tissue called the meninges 1.Outer layer: Dura Matter 2.Middle layer: Arachnoid 3.Inner layer: Pia Matter

Central Nervous System: Spinal Cord Between the Arachnoid and Pia Matter is the arachnoid space The space is filled with cerebrospinal fluid which circulates around the brain and spinal cord The cerebrospinal fluid protects the CNS and cushions shocks that could easily injure the brain and spinal cord structure.

Peripheral Nervous System The Peripheral Nervous System has 12 pairs of cranial nerves and 31 pairs of spinal nerves Some peripheral nerves form the autonomic nervous system which controls the involuntary muscles and body functions such as the heartbeat, BP, intestinal contractions, and glandular secretions. – Divided into sympathetic nervous system which speeds up functions and the parasympathetic nervous system which slows functions.

Sense Organs: Eye Contains receptor for vision The eye has three layers: 1.Sclera- the outer, white layer of the eye 2.Choroid- second layer that has blood vessels, the ciliary muscle, and the iris. the pupil, which is in the middle of the iris, constricts (narrows) in bright light and dilates (widens) in the dark 3.Retina- the inner layer with receptors and nerve fibers of the optic nerve

Sense Organs: Ear The ear’s function is hearing and balance The ear has three parts: 1.External ear- sound waves go through here into the auditory canal, which is 1 inch into the eardrum (tympanic membrane) Glands in the auditory canal secrete a waxy substance called cerumen 2.Middle ear- small space with 3 small bones called ossicles (malleus, incus, stapes) 3.Inner ear- consists fluid that carries sound waves from the middle ear to the acoustic nerve, which carries the messages to the brain

Disorders Stroke Parkinson’s Disease Multiple Sclerosis (MS) Amyotrophic Lateral Sclerosis (ALS) Head Injuries Spinal Cord Injuries Autonomic Dysreflexia

Stroke A stroke affects the arteries that supply blood to the brain It occurs when one of these happen: – A blood vessel in the brain bursts – A blood clot blocks blood flow to the brain Warning signs: – Sudden numbness or weakness on one side of the body, sudden confusion, trouble speaking, or understanding, sudden and severe headache

Parkinson’s Disease A slow progressive disorder with no cure that affects movement S/S include – Tremors, rigid and stiff muscles, slow movements, Stooped posture and impaired balance, and a mask- like expression Treatment includes drugs to control disease, PT, ST, with normal elimination a goal People with Parkinson's need safety measures in place to prevent them from falls

Multiple Sclerosis (MS) In this disease the Myelin in the brain and spinal cord are destroyed so nerve impulses are not sent out in the normal way Symptoms are usually seen between ages of 20 and 40 Some S/S include: Blurred or double vision, muscle weakness, tingling, and fatigue Symptoms can last for a weeks or months and sometimes gradually disappear with partial or complete recovery. The person is in remission until the person has another flare up, or relapse.

Amyotrophic Lateral Sclerosis (ALS) ALS, also known as Lou Gehrig's disease, is a disease that attacks the nerve cells that control voluntary muscles. Usually strikes between years of age and is more common in men The muscles that aren’t sending messages to the brain begin to atrophy There is no cure Care plan may include ROM exercises, walkers, comfort and pain- relief measures, communication methods, Dysphagia diet or feeding tube, and Hospice care

Head Injuries These result from trauma to the scalp, skull, or the brain Traumatic Brain Injury (TBI) occurs when a sudden trauma damages the brain by bruising or tearing it. Death can occur at the time of injury or later Disabilities like cognitive problems, communication problems, behavior or mental health problems, coma, and vegetative state may occur. Rehab is required.

Spinal Cord Injuries These can permanently damage the nervous system like paralysis Rehabilitation is necessary if the person lives. Higher the injury= more functions lost – Lumbar injury usually leads to Paraplegia- legs and lower trunk affected – Thoracic injuries usually lead to paralysis below the chest (paraplegia) – Cervical injuries lead to Quadriplegia- arms, legs, and trunk affected If the person is paralyzed from the waist down, make sure to reposition pt every 2 hours to prevent pressure ulcers and try to prevent contractures.

Autonomic Dysreflexia This occurs with spinal cord injuries above the mid-thoracic level Uncontrolled stimulation of the sympathetic nerve system Left untreated, stroke, heart attack, and death are risks. Common causes are constipation, fecal impaction, full bladder, and skin disorders To be treated the bed is raised to 45 degrees or person sits upright if allowed.