Cyndi's Chapter Four- Nationals

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Amyotrophic lateral sclerosis

A progressive disease that begins in the central nervous system and involves the degeneration of motor neurons and the subsequent atrophy of volantary muscle. Also called Lou Gehrig disease.

Ascending tracts

Tracts that carry sensory information to the brain.

Axon

A single enlongated projection from the nerve cell body that transmits impulses away from the cell body.

Brain

The largest and most complex unit of the nervous system, the brain is responsible for preception, sensation, emotion, intellect, and action.

Brainstem

The primitive portion of the brain that contains centers for vital functions and reflex actions, such as vomiting, coughing, sneezing, posture, and basic movement patterns.

Central nervous system

The brain and spinal cord and their coverings.

Cerebellum

The second largest part of the brain, it is involved with balance, posture, coordination, and movement.

Cerebrospinal fluid

A clear, colorless fluid that flows throughout the brain and around the spinal cord, cushioning and protecting these structures and maintaining proper pH balance.

Cerebrum

The largest of the brain divisions, it consists of two hemispheres that occupy the uppermost region of the cranium. It receives, interprets, and associates incoming information with past memories and then trasmits the appropiate motor response.

Dendrites

Branching projections from the nerve cell body that carry signals to the cell body.

Descending tracts

Tracts that carry sensory information from the brain to the spinal cord.

Dorsal root

One of two roots that attaches a spinal nerve to the spinal cord.

Epilepticus

A continous seizure

Essential tremor

A chronic tremor that does not proceed from any other pathologic condition.

Gray matter

Unmyelinated nervous tissue, particularly that found in the central nervous system

Corpus Callosum

located underneath the gray matter and functions to connect the left and right hemispheres

Monoplegia

Paralysis of a single limb or a single group of muscles.

Myelin

A white, fatty, insulating substance formed by the Schwann cells that surrounds some axons. Also produced in the central nervous system by oligodendrocytes

Neurilemma

The outer cell membrane of a Schwann cell that is essential in the regeneration of injured axons.

Neurons

Nerve cells that cinduct impulses

Sensory neurons:

known as afferent neurons are neurons that are activated by sensory input and send projections into the central nervous system that convey sensory information to the brain or spinal cord. activated by physical modalities

Motor neurons

(or motoneuron) classically applies to neurons located in the CNS that project their axons outside the CNS and directly or indirectly control muscles. Motor neuron is often associated with efferent neuron, primary neuron, or alpha motor neurons.

Interneurons

(also called relay neuron, association neuron or local circuit neuron) is a multipolar neuron which connects afferent neurons and efferent neurons in neural pathways. Like motor neurons, interneuron cell bodies are always located in the CNS.

Neurotransmitters

Chemical compounds that generate action potentials when released in the synapses from presynaptic cells

Paraplegia

Paralysis of the lower portion of the body and of both legs.

Quadraplegia

Paralysis or loss of movement of all four limbs

Schwann cell

A specialized cell that forms myelin

Spinal cord

Portion of the central nervous system that exits the skull into the vertebral column. The two major functions of the spinal cord are to conduct nerve impulses and to be a center for spinal reflexes.

Synapse

Spaces between neurons or between a neuron and a effector organ.

Tracts

Collections of nerve fibers in the brain and spinal cord with a common function

Ventral root

One of two roots that attaches a spinal nerve to the spinal cord. One of two roots that attaches a spinal nerve to the spinal cord. One of two roots that attaches a spinal nerve to the spinal cord.

White matter

Myelinated nerve fibers, particularly those found in brain and spinal tissue.

Acetylcholine

Stimulates the skeletal muscles and primarily acts on the parasympathetic nervouse system. Plentiful in the brain, the chemical is involved in memory

Catecholamines

Neurotransmitters involved in sleep, motor funtion, mood, and pleasure.

Epinephrine

Involved in the fight or flight responses such as dilation of blood vessels to the skeletal muscles and is classified as a hormone when secreted by the adrenal gland.

Norephinephrine

Causes constriction of skeletal blood vessels, is considered a "feel good" neurotransmitters, and is involved in emotional repsonses

Dopamine

Generally excitatory, is found in the brain and ANS. A feel-good neurotransmitter. Is involved in emotions and moods and int the regulation of motor control and the executive funtioning of the brain. Release is enhanced by L-dopa and amphetamines.

Histamine

Considered a stimulant, it is released by the mast cells as part of the inflammatory process. It causes itching at a cellular level and also works as a vasodilator. It also stimulates pain receptors to sensitize agains further stimulation (sunburn)

Serotonin

Works as an inhibitor in the CNS and is synthesized into melatonin and affects our biologic cycles, sleep, and moods. Feel good neurotransmitter

Cholecystokinin

Found in the brain, retina, and gastrointestianl tract, the function in the nervous system is uncertain and may be related to feel good behavior. Is a gut-brain peptide

Endorphins & Enkephalins

These endogenous morphines block the brain from feeling pain. They inhibit pain by inhibiting substance P. Morphine and herion mimic their effects. They seem to play a part in mood regulation

Gamma-aminobutyric acid

Generally inhibitory and found in the brain, this acid is the most common inhibitory neurotransmitter in the brain.

Glutamate (glutamic acid)

Generally excitatroy an dfound in the CNS, is thought to be responsible for as much as 75% of the excitatory signals to the brain

Somatostatin

Generally inhibitory, it inhibits the release of growth hormone and is a gut-brain peptide

Substance P

Is excitatory and is found in the brain, spinal cord, sensory pain pathways, and gastroinstestinal tract. Transmits pain information Is excitatory and is found in the brain, spinal cord, sensory pain pathways, and gastroinstestinal tract.

Vasoactive Intestinal Petide

Found in the brainstem, some ANS and sensory fibers, retina, and gastrointestinal tract; the function of this peptide iin the nervous system is uncertain.

Depolarization

is a decrease in the absolute value of a cell's membrane potential. Thus, changes in membrane voltage in which the membrane potential becomes less positive or less negative are both depolarizations. In neurons and some other cells, a depolarization large

Membrane potential

when a neuron is positively charged on the outside of the cell membrane and negatively charged on the inside.

Refractory Period

the brief period after inhibition when the neuron recovers.

Parietal lobe

primary area of the brain that would process the pain/pleasure aspect of massage

Ventricles

Four pockets or spaces in the brain

Right hemisphere

Contains sensory and motor pathways for the left side of the body

Left hemisphere

Contains sensory and motor pathways for the right side of the body

Frontal lobe

Responsible for personality, judgment, planning, and speech; contains the motor cortex

Motor cortex

Initiates movement of skeletal muscles

Sensory cortex

Detects general sensory impulses from the skin

Temporal lobe

Contains auditory and olfactory areas, stores memories of auditory and visual experiences

Occipital lobe

Contains visual area for interpreting impulses from the eye

Insular lobe

Integrates cerebral activities, may also assist in memory

Integrative functions

activities that occur in the cerebrum after sensory signals are received and before motor responses are sent

Reticular Activating System

consists of centers in the brainstem that receive impulses from the spinal cord and relay them to the thalamus

Limbic system:

located on the interior of the cerebrum and is important in our emotional responses, including fear, rage and pleasure

Engrams:

structural traces in the cerebral cortex that involves protein synthesis and physical brain changes that support long term memory

Medulla oblongata

brain area that functions to regulate vital life functions such as heart rate, blood pressure and breathing

Peripheral nervous system

All of the nervous system except CNS

Somatic nervous system

Nerves that control skeletal muscle contractions

Autonomic nervous system

Nerves that control smooth muscle, cardiac muscle, internal organs, and glands

Sympathetic nervous system

Prepares the body for stress, the "fight or flight system"

Parasympathetic nervous system

Prepares the body for rest, the "rest and digest system"

Meninges

Three layers of tissue that surround the CNS

Dura mater

Thickest, most external layer of meninges

Arachnoid membrane

Delecate web-like middle layer of meninges

Pia matter

Thin, vascular, innermost layer of meninges

Thalamus

Sorts out incoming sensory impulses (except smell) and directs them to the proper areas of the cerebral cortex, also filters stimuli

Hypothalamus

Controls pituitary, regulates water and eletrolyte balance, hunger, temperature, sleep, sexual response, and emotions

Dorsal horns

Gray matter in the spinal cord that extends posteriorly

Ventral horns

Grey matter in the spinal cord that extends anteriorly

Reflex arc

Route followed by nerve impulses to provide protective response to potentially harmful stimulus

Receptor organ

Organ that contains dendrites and receives stimulus

Effector organ

Organ that produces or carries out a response

How many cranial nerves are there?

How many pairs of spinal nerves are there?

How many pairs of cervical nerves are there

How many pairs of thoracic nerves are there?

How many pairs of lumbar nerves are there

How many pairs of sacral nerves are there

How many pairs of coccygeal nerves are there?

Dorsal root

Nerve root that protrudes posteriorly from the spinal cord

Dorsal root ganglion

Collection of sensory nerve cell bodies outside of the dorsal

Ventral root

Nerve root that protrudes anteriorly from the spinal

Dermatome

Sensory area of the skin innervated by a particular spinal nerve

Nerve plexus

Network of interconnecting nerves

Cervical plexus

Nerve roots C1-C4 and part of C5; Provides sensory innervation for skin around the head, neck, and shoulders along with motor innervation for some of the muscles

Brachial plexus

C5-T1 and sometimes portions of C4 and/or T2; Provides sensory and motor innervation for the upper extremity and some neck muscles, gives rise to the axillary nerve, musculocutaneous nerve, radial nerve, median nerve, and ulnar nerve Lumbosacral plexus

Nerve roots L1-S4

Provides sensory and motor innervation for the lower extremities and gives rise to the obturator nerve, femoral nerve, and sciatic nerve Special sensory Smell, taste, vision

General sensory

Pain, touch, temperature

Somatic motor

Voluntary movement

Visceral motor

Involuntary movement

Transmissions on nerve cells are ____ way

Microglia

Clean up dead cells

Oligodendrocytes

Produce myelin which coats nerves

Afferent nerves