HOSA Nervous

Central Nervous System (CNS)

-consists of the brain and spinal cord (proteced by bones of the cranium and vertebrae of spinal column) -receives and processes information -regulates all bodily activities

Peripheral Nervous Systen (PNS)

-consists of 12 pairs of cranial nerves and 31 pairs of peripheral nerves -transmit nerve signals to and from the CNS

Nerves

one or more bundles of neurons that CNS communicates with other parts of the body

Tract

bundle/group of nerve fibers within the brain or spinal cord

Ascending nerve tracts

carry nerve impulses toward the brain

Descending nerve tracts

carry nerve impulses away from the brain

Ganglion

nerve centre made of a cluster of nerve cell bodies outside the CNS

Innervation

supply of nerves to a specific body part

Plexus

network of intersecting spinal nerves

Receptors

sites in sensory organs that receive external stimulation

Stimulus

anything that activates a nerve and causes an impulse

Impulse

wave of excitation transmitted through nerve fibres and neurons

Reflex

an automatic, involuntary response to some change, either inside or outside the body

autonomic nerve fibers

carry instructions to organs and glands from autonomic nervous system

sensory nerve fibers

receive external stimuli and transmits them to the brain where it is intercepted

somatic nerve fibers

convey information that controls voluntary muscular movements

Neurons

basic cells of the nervous system that allows different parts of the body to communicate, they carry impulses via an electrochemical process (brainwaves)

Afferent Neurons

Aka Sensory neurons, emerge from sensory organs and the skin to carry impulses from those organ to the brain and spinal cord

Connecting Neurons

aka associative neurons, link afferent and efferent neurons

Efferent Neurons

aka motor neurons, carry impulses away from the brain and spinal cord and toward the muscles and glands

Dendrites

root-like processes that receive impulses and conduct them to the cell body

Process

a structure that extends out from the cell body

Axon

process that conducts impulses away from the nerve cell

Myelin Sheaths

Protective covering made of glial cells. Forms white matter in brain, covers some parts of spinal cord, white fatty tissue coverings that protects the axon

Terminal end fibers

branching fibers at the end of the axon

Synapse

space between two neurons or a neurons and a receptor organ

neurotransmitters

chemical substances that transmit messages

Acetylcholine

influences muscle action (some synapses in spinal cord, neuromuscular junction)

Dopamine

involved in mood and thought disorders (within brain)

Endorphin

relieve pain (produced by brain)

Norepinephrine

affects alertness and arousal; blood pressure, heart rate, releases glucose (by an adrenal gland part of flight-or-fight response)

Serotonin

roles in sleep, hunger, pleasure recognition (in brain)

Glial cells

provides support and protection for neurons; surround neurons, supplies nutrients + oxygen, insulates one neuron from another, destroys and removes dead neurons

White matter

portion of nerve fibers that are myelinated

Gray Matter

portion of nerve fibers that are unmyelinated

the meninges

system of membranes that enclose the brain and spinal cord

Dura mater

thick, tough, outermost membrane off the meninges

epidural space

over the dura mater, contains fat and supportive connective tissues to cushion dura mater, between vertebral column walls and dura matter

subdural space

between dura mater and arachnoid membrane

arachnoid membrane

second layer of the meninges, spider web, loosely attacthed to other meninges to allow fluid flow

subarachnoid space

below arachnoid membrane and above pia mater

pia mater

third layer of meninges, nearest the brain and spinal cord, delicate connective tissue with rich supply o blood vessels

cerebrospinal fluid

colourless, watery fluid that flows throughout the brain and around spinal cord, cools and cushions these organs from shock and injury, transport nutrients + chemical messengers

cerebrum

largest and uppermost portion of the brain; thought, judgement, memory, emotion, motory and sensory functions

Cerebral cortex

made of grey matter; outer layer of cerebrum

gyri

elevated folds of grey matter in cerebral cortex

sulci

fissures of the cerebral cortex

fissure

normally occurring deep grove

left cerebral hemisphere

controls majority of functions of right side of body

right cerebral hemisphere

controls majority of functions on left side of body

frontal lobe

controls skilled motor functions, memory, and behaviour

parietal lobe

receives and intercepts nerve impulses from sensory receptors in the tongue, skin, and muscles

occipital lobe

controls eyesight

temporal lobe

controls hearing, smell, creation, storage, access of new info

thalamus

below the cerebrum, relaying impulses to and from the cerebrum and sensory organs

hypothalamus

beow the thalamus, regulates autonomic nervous system (heart rate, respiratory rate) emotional reponse, body temp, hunger sensations, thirst sensations, sleep-wakefulness cycles, endocrine system

cerebellum

back of head, posterior portion of cerebrum, second-largest part of brain, receives msgs abt movement and position, produces smooth and coordinated movements to maintain equilibrium and sustain posture

The autonomic nervous system

controls involuntary actions of the body, maintains homeostasis within the body

Homeostasis

maintaining the constant internal environment of the body

Sympathetic nerves

prepares body for emergencies and stress aroused by fight-or-flight response (breath rate, heart rate, blood flow)

Parasympathetic nerves

returns body to normal after stress (maintains normal body functions)

Anesthesiologist

administering anesthetic agents

anesthetist

medical professional who administers anesthesia but is not a physician

neurologist

diagnoses and treats diseases and disorders of the nervous system

neurosurgeon

specializes in surgery of the nervous system

psychiatrist

specializes in diagnosing and treating chemical dependencies, emotional problems, and mental illness

psychologist

doctoral degree but not MD, evaluates and treats emotional problems and mental illness

cephalgia

pain in the head (headache)

migraine headache

throbbing pain on one side of the head, primarily affects women

cluster headache

intensely painful headaches that affect one side of the head, primarily affects men

encephalocele

congenital herniation of brain tissue through a gap in the skull

craniocele

congenital herniation of brain tissue through a gap in the skull

meningocele

congenital herniation of the meninges through a skull and spinal column defect

hydrocephalus

excess cerebrospinal fluid accumulates in ventricles

meningioma

common, slow-growing, and usually benign tumor of the meninges

meningitis

inflammation of the meninges o the brain and spinal cord

cognition

mental activites associated with thinking, learning, and memories

mild cognitive impairment

memory disorder associated with recently acquired information

dementia

slow progressive decline in mental abilities such as memory, thinking, and judgement

senile dementia

dementia of the aged

vascular dementia

form of dementia caused by a stroke or restriction of blood to the brain

encephalitis

inflammation of the brain

reye’s syndrome

potentially serious disorder in children characterized by vomiting and confusion, often follows viral illness treated with aspirin

tetanus (lockjaw)

an acute and potentially fatal infection of the CNS caused by a toxin produced by the tetanus bacteria

tourette syndrome

complex neurological disorder characterized by involuntary tics, grunts, and compulsive utterances

neurodegenerative disease

disorders with progressive loss of structure or functions of neurons

Alzheimer’s disease

group of disorders involving parts of the brain that control thought, memory, and language; leading cause of dementia; progressive deterioration that affects memory and reasoning

huntington’s disease

genetic disorder

parkinson’s disease

chronic degenerative CNS disorder characterized by fine muscle tremors, rigidity, and a slow/shuffling gait

amnesia

memory disturbance with inability to recall past experiences

concussion

violent shaking up or jarring of the brain, resulting in temporary loss of awareness and function

cerebral contusion

bruising of the brain tissue due to head injury

cranial hematoma

collection of blood trapped in tissues of the brain

traumatic brain injury

blow to the head or penetration that damages the brain

coup

injury occurring within the skull near the point of impact

contrecoup (counterblow)

injury occurs beneath the skull opposite to the area of impact

shaken baby syndrome

results from child being violently shaken (causes brain injury, blindness, factures, seizures, paralysis, death)

levels of consciousness

describe measurements of response to arousal and stimulus

altered levels of consciousness (ALOC)

decrease in LOC due to injury, disease, or substance

conscious

awake, alert, aware, responding appropriately