Vocab Flashcards
PNS- peripheral nervous system
Nerves on the peripheral parts of the body
CNS - central nervous system
Nerves in the brain & spinal cord
ANS - autonomic
- controls nerves you don think about
- heart rate
- contractions of stomach & intestines
- secretion if chemical compounds by glands
Neuron
- Nerve cell
- no mitosis
- conduct impulses
Glia cells
- act as “glue”
- Support cells
- mitosis
- holds functioning neurons together & protects them
Schwann cells
- found in PNS
- wrapped around ONE axon
- form of glia cell
- form myelin sheaths
SNS - somatic
•Controls nerves you think about
Aka voluntary
Astrocyte
- large glia cells that look like stars
* branches attach to neurons and small blood vessels holding them together
Blood brain barrier (BBB)
- It’s the 2 layer structure in astrocytes
* separates the blood tissue and nervous tissue to protect brain tissue from chemicals in blood
Microglia
- in degenerating brain tissue, they enlarge & move about
- act as microbe eating scavengers
- digest microbes into cytoplasm
- clean up cell damage
Oligrodendrocytes
- Found in CNS
- hold nerve fibers together
- produce myelin sheath that surround nerve fiber
- wrap around several axons
Sensory/ afferent neurons
• transmits impulses to CNS
Motor/efferent neurons
•Transmits Impulses to PNS
Interneuron
•conduct impulses from sensory to motor neurons
Myelin
•white fatty substance formed by Schwann cells that wrap around some axons outside of CNS
Nodes of ranvier
•Spaces between Schwann cells
Glioma
•Brain tumor developed from glia cells
Cell body
•Main part of a neuron in which dendrites and axons extend
Axon
•transmit impulses from cell body away
Dendrites
•processes impulses to cell body
Neurilemma
- outer cell membrane of a Schwann cell
- plays essential part in regenerating of injured axons
- CNS has no neurilemmas
Tracts
•bundles of axons in CNS
White matter
Nerves covered w white myelin
Grey matter
Tissue made up of cell bodies and unmyelinated axons and dendrites
Endoneurium
• thin wrapping of fibrous connective tissue over axon
Fascicles
Groups of endometrium aka wrapped axons
Perineurium
Layer on top of fascicles aka group of endometrium
Epineurium
Tough fibrous sheath that covers the whole nerve
Action potential
•route made up of neurons that conduct impulses
Reflex arc
- allow impulse conduction in only one direction
* a 2 neuron arc consists of sensory and motor neurons
Receptors
•beginning of dendrites of sensory neurons
Ganglion
A groups of nerve cell bodies located in PNS
Synapse
Space separating axon ending from one neuron to another neurons dendrites
Effector
- Organ that puts nerve signals “into effect”
* effectors are muscles or glands
Reflex
- the response to impulse conduction over a reflex arc
* “knee jerk” response
Withdrawl reflex
•a 3 neuron arc reaction
- include sensory, motor, and interneurons
• a reflex that causes muscles to pull away
Polarization
A positive charge on outside & negative on inside
Depolarization
Inside is positive & outside is negative
Saltatory conduction
Impulse that jumps around the gaps in the myelin sheath on axons
Presynaptic conduction
Where the impulse is first transmitted
Postsynaptic
Where the impulse it transmitted to
• aka the second neuron the impulse is transmitted to
Synaptic knob
•a tiny bulge at the end of a branch on the axon of a presynaptic neuron
Synaptic cleft
Space between synaptic knob & the plasma membrane of a postsynaptic neuron
Neurotransmitter
Chemicals by which neurons communicate
Acetylcholine
Released at some of the synapses in the spinal cord and neuromuscular junctions
Norepinephrine
- Hormone secreted by adrenal medulla
* release my sympathetic nervous system (SMS)
Dopamine
Chemical neurotransmitter
Serotonin
A neurotransmitter
Catechism ones
- A group in which the compounds ; norepinephrine, dopamine, & serotonin belong to
- plays role in sleep, motor function, mood, and pleasure recognition
Endorphins
- influence pain & perception
- a natural pain killer
- in CNS
Enkephalins
Natural painkiller in CNS
Nitric oxide
Diffuses directly across the plasma membrane of neurons
Brainstem
Consists of the
•medulla oblongata
•pons
•midbrain
Medulla oblongata
Consists of grey and white matter
Reticular formation
Bits of grey and white matter mixed closely
In the medulla
Pons
Consists of white matter and scattered bits of grey
In the brain stem
Midbrain
Located above pons
Cerebellum
- Second largest part of human brain
- arbor vitae
- plays part in movement
Arbor vitae
- inside cerebellum
* “living tree”
Diencephalon
- located between midbrain & cerebrum
* consists of hypothalamus and thalamus
Hypothalamus
- located below thalamus
* controls all internal organs
Antidiuretic hormone
Affects the volume of urine excreted
Thalamus
- above hypothalamus
- it produces and controls sensations
- plays a part in the arousal mechanism
Pineal body
- resembles a small pine nut
* receives sensory info
Cerebrum
•largest and uppermost part of the brain
Gyri
Ridges in the cerebrum
Higher point
Sulci
Deepest part of the ridged in cerebrum
Corpus callosum
Connects two fissures in the brain (left and right halves )
Cerebral cortex
Surface of cerebrum
Basal nuclei
Produces automatic movements and postures
Cerebral vascular accident
An injury that causes a hemorrhage of blood flow through the cerebral blood vessels.
Victim can’t move the opposite side of body
Spinal tract
Bundles of myelinated nerve fibers
Anesthesia
Loss of sensation
Paralysis
Loss of ability to make voluntary movements
Meninges
Tough fluid containing membrane covering brain and spinal cord
Dura mater
Tough outermost layer in spin cord
Pia mater
Covers innermost membrane I’m spinal cord
Cerebrospinal fluid
Fluid between the meninges (pia & arachnoid)
Ventricles
Irregular shapes of the brain
Choroid plexus
Brain capillary where cerebral spinal fluid is filtered
Hydrocephalus
Condition in which the cerebrospinal fluid goes on the brain
Spinal nerves
Connect to brain and spinal nerves
Plexus
When never fibers from several spinal nerves are reorganized to form a single peripheral nerve
Aka “braided” branching
Dermatomes
Skin surface that is supplied by a single spinal nerve
Sympathetic nervous system
- ANS
- produce changes in our bodies when we have strong emotions
- fight or flight response
- located in thoraculumbar system
- makes a heart beat faster
- several organs effected
Autonomic neurons
Motor neurons that make up ANS
Ganglia
“Junction boxes” that are terminated by axons
Preganglion neuron
Conduct impulses between spinal cord and ganglion
Autonomic/visceral effectors
Tissues to which autonomic neurons conduct impulses
•ex. Cardiac and smooth muscle etc.
Sympathetic ganglion neurons
Synapses w postganglionic neurons
Sympathetic post ganglionic neurons
Travel in spinal nerves to blood vessels sweat glands and arrector pili hair muscles all over body
Fight or flight response
Sympathetic control
Parasympathetic nervous system
- located in cranial sacral system
- stimulation frequently involves response by only one organ
- calms a person down
- one organ effected
Cholinergic fibers
Axons that release acetylcholine
Adrenergic fibers
Sympathetic postganglionic neurons