X A&P - Chp 9 - nervous system, spinal cord, spinal nerves Flashcards
Action Potential
Electric current that spreads along membrane of neuron
Central NS comprised of
Brain and spinal cord
Peripheral NS comprised of
Cranial and spinal nerves
Dendrite
Fiber that carries impulses towards cell body
Axon
Fiber that carries impulse away from cell body
Afferent
- Sensory type
- Carries impulses towards CNS
- An outside thing Affected me. Afferent
Efferent
- Motor type
- Caries impulses away from CNS to muscle/gland
Efferent
- Motor type
- Caries impulses away from CNS
- The message from brain effected the outside
(Functional divisions)
Somatic nervous system
- Voluntary
- Skeletal muscles
Parts of Autonomic NS
- Sympathetic
- Parasympathetic
Sympathetic
- Fight or flight
- originate in spinal cord in thoracic and lumbar region (thoracolumbar)
Sympathetic
- Fight or flight
- originate in spinal cord in thoracic and lumbar region (thoracolumbar)
Somatic Nervous System
voluntary, conscious will (Skeletal Muscles)
Biofeedback
training to consciously control involuntary functions, i.e. blood pressure, heart rate
Effector
Any tissue or organ that carries out a nervous system command (muscles, glands)
Structural Division of Nervous System
- Central Nervous System (Brain, Spinal Cord)
- Peripheral Nervous System (Cranial, Spinal Nerves)
Nodes
small spaces on axon between Myelin Sheath
(Anatomic Division)
Peripheral Nervous System
- Somatic (voluntary, conscious will)
- Autonomic aka Visceral Nervous System (involuntary)
Autonomic Nervous System (visceral nervous system)
- Involuntary
- Smooth muscle, cardiac muscle, glands
- Found in soft body organs, viscera
Myelinated coated Fibers color
White, in white matter of of brain and spinal cord
Structure of Neurons
- Dendrites (receptors, conduct impulses TO cell body)
- Axons (conduct impulses AWAY from cell body, to another neuron, muscle, nerve)
Color of un-myelinated fibers
grey, grey matter
Myelin Sheath (see pic)
- insulates and protects fiber. Formed by Schwann cells, wrap around axon.
- When sheath is complete, remaining small spaces remain, Nodes.
Nerve
a fiber bundle within the PNS
interneurons (central and/or association nuerons)
relay info within CNS
Myelin Sheath (see pic)
-insulates and protects fiber. Formed by Schwann cells, wrap around axon.
Tract
a fiber bundle within the CNS
Endoneurium
coating around an individual nerve fiber
Perinuerium
coating around a fascicle
Fibers contained in a nerve
sensory, motor or a combo of both
Epineurium
coating around the entire nerve
Sensory neurons (afferent neurons)
- conduct impulses TO spinal cord.
- If you touch something it AFFECTS you
Sensory nerves (afferent)
cranial nerves containing only sensory fibers sending messages to the brain
Motor nerves
cranial nerves conducting messages AWAY from the brain
Mixed nerves
most of the cranial nerves and ALL spinal nerves and
Astrocytes
stem cells, regeneration of nervous tissue
Resting State (of nerve impluse)
inside negaticve, outside positive (polarized)
motor neurons (efferent neurons)
-conduct impulses to muscle/glands (effectors). reflex to -withdraw when you are touching something sharp/hot
Depolarization
Na+ flows inside and K+ flow out making inside more positive and outside negative
Repolarization
returning back to resting state.
Electric impulse moves _____ over myelinated cells
faster
Saltatory conduction
the way current jumps from node to node in myelinated cells
Presynaptic cell
axon of a cell
Astrocytes
- stem cells, regeneration of nervous tissue
- form blood brain barrier
postsynaptic cell
dendrite of a cell
Synaptic cleft
gap that neurotransmitters send messages over
Enlarged axon ending
terminal knobs/end bulb
After neurotransmitter released, may be removed by
- Slowly diffuse away
- destroyed rapidly by enzyme in synaptic cleft
- re uptake
- taken by neuroglial cells, astrocytes
Common Neurotransmitters
epinephrine (adrenaline) Norepinephrine (noradrenaline) Acetylcholine Serotonin (brain) Dopamine (brain) GABA (brain)
Spinal Cord structure (see pic)
Inner grey matter (dorsal and ventral horns give H shape)
outer white matter
Grey commissure
bridge of gray matter that connects the R and L horns
Central Canal contains
Cerebro Spinal Fluid - in spinal cord
Ascending tracts
impulses transmitted TO brain through white matter
Descending tracts
impulses transmitted FROM brain through gray matter to PNS
How many spinal nerves
31 pairs
Cauda Equina
bundle of nerve roots in sacral region meet (horses tail)
Each nerve connected to spinal cord by
Dorsal and ventral roots
ganglion
any collection of nerve cell bodies located outside the CNS
Ventral Root
contains motor fibers that supply muscles and glands
EFFECTORS
located in Ventral horn
Plexus (see pic)
-branching network of vessels or nerves
Cervical Plexus (see pic)
-supplies motor impluses to
neck muscles.
-receives sensory impulse from neck and back of head
-Phrenic nerve activates diaphragm, in this plexus
Brachial Plexus (see pic)
branches to
shoulder, arm, forearm, wrist and hand
Lumbosacral Plexus
- supplies nerves to pelvis and legs
- Femoral nerve (to thigh)
- Sciatic nerve (dorsal down butt to thigh, 1” thick then branches to leg and foot)
Dermatomes (see pic, rainbow man)
regions supplied by single spinal nerves
Reflex Arc
pathway through nervous system from stimulus to response
Sensory Neuron
- cell transmits impulse TO CNS
- enter dorsal horn of SCord gray matter
CNS
where impulse coordinated and response organized
Disorders of Spinal Cord
Multiple Sclerosis
Amyotrophic Sclerosis
Poliomyelitis
Disorder of Spinal Nerves
Neuritis
Sciatica
Herpes Zoster (Shingles)
Neuropathy
any disease of the nerve
Innervate
nerve tissue going to an area and providing it with nervous signals
3 types of Nerves
- Afferent (sensory neurons message TO CNS)
- Efferent (motor neurons TO muscles/glands)
- Mixed
Hyponatremia
low sodium
Hypernatremia
high sodium
Hypokalemia
low K
Hyperkalemia
high K
Nodes
spaces on axon between myelin sheath
lack of Seratonin causes
- Depression
- Seratonin gets reuntaken to be used again
- Depression meds inhibit axon from reuptaking seratonin so it lingers in the sysnapse to promote feeling of well being
mono synaptic reflex arc
body reacts before brain even realizes it
Meninges of Brain
- Pia Mater (closest to brain)
- dura mater (outermost layer, like canvas
- Aarachnoid layer (weblike, full of capillaries)
Folds and Bumps of brain tissie
Sulci (inner folds)
Gyri (bumps)
Sympathetic Nervous System
neurotransmitter
Fight or Flight
Epinephrine/Nor Epinephrine
Adrenaline/Nor Adrenaline
Autonomic nervous system controlled by
Hypothalamus
Medulary Hormones
Catecholamines (from adrenal medula)
Sympathetic NS activates
And what neurotransmitter
Fight or flight
Epinephrine (norepinephrine )
Depolarization and Re polarization only happen where?
Nodes of Ranvier
Parasympathetic NS activate
And neurotransmitter
Rest & Digest
Acetylcholine
Cystic Fibrosis
thick mucous secretions. Very salty
See chart of sympathetic vs parasympathetic
See pic of notes
Multiple Sclerosis
scar tissue preventing conduction on schwann cells
Phagocyte Glial Cell
Microglia
Neurotransmitter for affectors
Acetocholine
Sympathetic Nervous System
- neurotransmitter
- receptors
- Epi/Nor Epi
- Alpha (mostly on blood vessels) & Beta (mostly on heart)
Alpha Blocker
- blocks effects of epinephrine on blood vessels. stops from constrict blood vessels
- adrenurgic antagonist
Beta Blocker
-blocks effects of Epi on heart.
Alpha & Beta Adrenergic part of what NS and what neurotransmitter
- Sympathetic NS
- Epinepherine
Cholinergic receptors
-what NS, what neurotransmitter
- Parasympathetic NS
- acetocholine
2 types of Cholinergic receptors
Moscarinic
Nicotonic