Nervous System Flashcards
nervous system
- co ordinates all activities inside and outside the body
- entire body covered with fibres called nerves
- over 100 billion nerve cells in body called neurons
3 divisions of the nervous system
- Central Nervous System
- Peripheral Nervous System (outer)
- Autonomic Nervous System
two divisions of autonomic nervous system
Sympathetic division: stimulates or speeds up activity and prepares the body for stressful situations
Parasympathetic division: operates under normal, non-stressful conditions and helps restore & slow down activity, thus keeping the body in balance
central nervous system
- brain, spinal cord, spinal nerves and cranial nerves
- controls consciousness, mental activities, voluntary functions of the 5 senses, and voluntary muscle actions including all body movement and facial expressions
peripheral (outer) nervous system
- connects outer part of the body to the central nervous system
- has sensory & motor nerves
- carries impulses to and from the central nervous system
autonomic nervous system
- controls involuntary muscle
- regulates smooth muscles, glands, blood vessels, the heart and breathing
brain
- largest and most complex nerve tissue in the body
- contained in the cranium
- controls sensation, muscles, glands, thinking and feeling
- sends telegraphic images through 12 pairs of cranial nerves
spinal cord
- originates in the brain and travels down the trunk, protected by the spinal column
- 31 pairs of nerves exit the spinal cord and supply the body
neuron
- nerve cell, the primary structural unit of the nervous system
- composed of cell body, nucleus, dendrites and an axon
dendrites: receive info from other neurons
axons: send messages away from the cell body to other neurons, glands, muscles and organs
nerves
- whitish cords made up of bundles of nerve fibers held together by connective tissue
- originate in the brain and spinal cord and branch off in all parts of the body
- transmit impulses
what are the 2 types of nerves?
- sensory/afferent
- motor/efferent
sensory nerves
afferent
-carry impulses from the sense organs to the brain, where sensation is experiences
-sensory nerve endings (receptors) are located close to the surface of the skin
motor nerves
efferent
-carry impulses from the brain to the muscles or glands to produce movement or secretion
reflex
an automatic nerve reaction to a stimulus that involves the movement of impulses from a sensory receptor along the afferent neuron to a muscle, causing a reaction
alzheimer’s
- pathology of the brain caused by atrophy of areas of the brain
- characterized by gradual and insidious progression of symptoms like confusion, memory failure, restlessness, and speech disturbances
- a client with Alzheimer’s may require a family member/advocate to help them understand the service being provided and to give consent on their behalf
epilepsy
- results from abnormal and irregular discharges of electrical activity in the brain
- individuals with epilepsy may experience sensory disturbances, seizures, abnormal behaviour and loss of consciousness
absence seizures
brief periods of unconsciousness, no convulsions
partial/focal seizures
no loss of consciousness, the person may exhibit abnormal behaviour like walking around in circless
tonic-clonic seizures
the person loses consciousness, drops to the floor and experiences convulsions
*often preceded by warning signs that the person is familiar with
clinical depression
- linked to decreased levels of neurotransmitters like serotonin and norepinephrine
- may be unipolar or bipolar (manic-depressive)
SAD: seasonal affective disorder, linked to lack of sunlight in the winter months
schizophrenia
chronic brain disorder where the person may experience delusions, hallucinations, disorganized speech, trouble thinking and a lack of motivation
panic disorder
anxiety disorder characterized by a feeling of intense fear with an increased heartrate, difficulty or increased breathing, and perspiration
obsessive-compulsive disorder `
characterized by a series of obsessions and compulsions that are extremely distressing to the sufferer and interfere with their day-to-day lives
anorexia nervosa
eating disorder characterized by an intense fear of weight gain that becomes an obsession with severely restricted food intake and excessive physical exercise
bulimia
eating disorder that consists of binge eating followed by self-induced vomiting or abuse of laxatives
multiple sclerosis
pathology of the central nervous system in which the myelin covering of the nerves in the brain, spinal cord and optic nerve are affected, causing symptoms relative to the location of the demyelination
symptoms: visual changes, numbness and spasticity of muscles, changes in gait/inability to walk, fatigue and speech disturbances
- some people have lengthy periods of remission and the disease may progress rapidly or slowly
amyotrophic lateral sclerosis (ALS)
AKA Lou Gehrig’s disease
- neurological disorder of the central nervous system that affects motor function
symptoms: weakness, spasticity or stiffness of muscles and impaired fine motor control, difficulty swallowing, speaking or breathing
spinal cord injury
-can be complete or incomplete, resulting in complete loss of movement or sensation or partial paralysis
cerebral palsy
a group of motor disorders of the central nervous system resulting in muscular incoordination and loss of muscle control caused by damage to the brain’s motor areas during fetal life, birth or infancy
*not progressive but the damage is irreversible
parkinson’s disease
a progressive, degenerative neurological disorder marked by the destruction of dopamine-producing neurons in the brain
symptoms: muscles may alternately contract and relax causing tremor, or be rigid. difficulty initiating movement, difficulty walking
