Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
56 Cards in this Set
- Front
- Back
3 main functions of the nervous system
|
1-sensory
2-integrative 3-motor |
|
types of channels @ ea. part of the neuron
|
1. @ the dendrites & cell body: chemically gated channels
2. along the axon: voltage-gated Na+ and K+ channels 3. @ axon terminals/end bulbs: voltage-gated Ca2+ channels |
|
sensory neurons
|
aka afferent (upward); carry info from lower to higher levels in the SC or from cranial or spinal nerves to the brain and SC
|
|
interneurons
|
nexus b/w neurons, their axons extend for short distances contacting neurons in brain, SC or ganglia
|
|
motor neurons
|
aka efferent; carry info from the brain toward the SC and/or from the brain and SC to cranial nerves and spinal nerves
|
|
synapse
|
junction b/w 2 neurons or b/w a neuron and an effector cell
- includes presynaptic (sends signal) and postsynaptic (receives impulse) terminals |
|
gap junction
|
electrical synapse
|
|
synaptic cleft
|
chemical synapse
|
|
electrical synapse characteristics
|
-ionic current spread to next cell thru gap junctions
-faster, 2-way transmission [pre-> post or post->pre] -capable of synchronizing groups of neurons -ex: heart |
|
chemical synapse characteristics
|
- 1-way transmission from pre to postsynaptic neuron
-neurons/cells involved do not touch (separated by synaptic cleft) -there are more of these types of synapses -can't synchronize |
|
events in a chemical synapse
|
1. nerve impulse arrives
2. nerve impulse causes a change in impulse/ opens voltage-gated calcium channels 3. exocytosis of neurotransmitter ((ca2+ rushes in, ca2+ causes vesicles to dump their contents into synaptic cleft)) 4. CA2+ causes vesicles 2 dump their contents (neurotransmitters) into synaptic cleft 5. neurotransmitter binds to the specific channels 6. na, k gates open, Na+ rushes in 7. post-synaptic potential: if there's enough Na+ to create nerve impulse |
|
botulinum toxin
|
blks release of neurotransmitter at the NMJ
muscle contraction can't occur |
|
curare
|
plant poison from poison arrows
causes muscle paralysis blocks ACh receptors used to relax muscles during surgery |
|
neurotransmitter effects can be modified via
|
-synthesis
-release -removal -receptor sight (blocked or activated) |
|
common neurotransmitters
|
ACh
AAs Amines (Ep, Norep, Dop, Ser) ATP NO Neuropeptides (endorphins,etc) |
|
Divisions of NS
|
2 Main: Central & Peripheral
CentraL: B & SC Peripheral: Somatic & Autonomic Autonomic: Sympathetic, Parasympathetic, Enteric |
|
Tracts of the SC
|
are highways for sensory &motor info
sensory/ascending ____s: conduct nerve impulses toward the brain motor/descending ____s: conduct impulses down the cord Sometimes ____s receive & integrate incoming & outgoing info |
|
Somatic NS
|
sensory neurons to CNS & motor neurons to skeletal muscle
1 neuron in pathway motor neurons innervate SKELETAL muscle to produce: conscious, voluntary mvmts effect of a motor neuron is always excitation (to stop, withdraw excitation) |
|
Autonomic NS
|
operates via REFLEX ARCS
2 neurons in pathway (pre and postganglionic) - pre- myelinated - post- unmyelinated continual flow of sensory input from receptors in organs & motor output to the same organs [constant info bk and frth] not aware of responses (control center is in lower regions of brain) HYPOTHALAMUS is major control center --> autonomic tone: regs balance b/w symp and parasymp activity Dual innervation (input from symp and parasymp) of most organs |
|
Hypothalamic Control of ANS
|
input: emotions and visceral sensory info (smell,taste,temp, osmolarity of blood,etc)
output: to nuclei in brainstem & SC post&lat: control SYMPNS to inc <3rate, inhibit GI tract, inc temp (deal w/stress) med&ant: control PARASYMNS to dec <3rate, lower BP, inc GI tract secretion & mobility |
|
Adrenergic
|
postganglionic
neuron: releases NE receptor: receives NE |
|
Cholinergic Neuron
|
preganglionic
releases ACh |
|
Nicotinic
|
preganglionic
receives ACh excitation |
|
Muscarinic
|
Postganglionic
receives ACh excite or inhibit |
|
all preganglionic neurons....
|
are cholinergic...release ACh to NICOTINIC receptors (cause excitation)
|
|
all postganglionic neurons...
|
are adrenergic...release NE to ADRENERGIC receptors (SNS) or ACh to MUSCARINIC receptors (PNS)
|
|
Sympathetic Responses
|
f or f= prepares for acute stress or phys activity
response caused by phys or emotional stress (E situations: emergency, embarrassment, excitement, exercise) pupils dilate, airways dilate, respiratory rate inc, inc HR, inc force of contraction & BP, blood flow to skeletal & cardiac muscle; inc blood glucose levels inc BP and mental activity dec bloodflow to nonessential areas some organs have ONLY sympathetic innervation (sweat glands, adrenal medulla, arrector pili, many bvs) --controlled by reg of the "tone" of the sympathetic sys NE- major neurotransmitter |
|
Parasympathetic Responses
|
rest and digest
conserve& restore energy dec'd HR, diam of airways and coronary vessels normally dominate over sympathetic impulses SLUDD responses: salavation, lacrimation, urination, digestion & defecation ACh major neurotransmitter |
|
Enteric NS
|
supports digestion & metabolism
innervates the viscera (GI tract, pancreas, gall bladder) butterflies in stomach involuntary body processes 2 neurons in pathway |
|
Reflex
|
Fast, predictable, automatic response to changes in env to help maintain homeostasis
simplest type of pathway lvl of brain involvement varies how ANS operates some inborn, some learned |
|
Gray matter
|
dendrites & cell body
integration center for reflexes |
|
White matter
|
axons
highways for nerve impulse propagation |
|
Components of Reflex Arcs
|
1. Sensory Receptor
- produces a generator or receptor potential 2. Sensory Neuron - axon conducts impulses from receptor to integrating cntr 3. Integrating Center 4. Motor Neuron - axon conducts impulses from integrating center to effector 5. Effector -muscle or gland that responds to motor nerve impulses |
|
muscle spindle
|
purpose- sense muscle LENGTH
neurons "report" stretch to CNS helps CNS to give info ab bodys position muscles contract (reflex) to resist further stretching |
|
patellar stretch reflex
|
ex of how muscle spindle works
1. stretching stimulates sensory receptor (muscle spindle) 2. sensory neuron excitd 3. integrating center, sensory neuron activates motor neuron 4. motor neuron excited 5. effector- contraction relieves stretching of the same muscle |
|
golgi tendon organs (GTO)
|
Sense changes in muscle TENSION
Located close to tendon & muscle attachment Inhibit agonist muscle contraction & excite antagonist muscles to prevent injury i.e. quad vs. hamstring (stop contracting of quad, strt contracting of hamstring) |
|
4 pts of the brain
|
1. brain stem
2. cerebellum 3. diencephalon 4. cerebrum |
|
midbrain
|
relays motor output from cerebral cortex to pons; sends sensory input from spinal cord to thalamus
|
|
pons
|
relays impulses from one side of the cerebellum to the other, relays impulses frm medulla to midbrain; also regulates breathing
|
|
medulla oblongata
|
relays sensory input and motor output between brain and spinal cord; consciousness & arousal; regulates heartbeats, blood vessel diameter & breathing
|
|
brain stem
|
composed of midbran, pons, and medulla oblongata
regulates basic vital signs/primitive functions acts as a relay station between the spinal cord & brain |
|
cerebellum
|
compares intended to actual movements
coordinator (strings together series of movements into 1 complex motor movement) regulates posture & balance |
|
thalamus
|
relays sensory input to cerebral cortex
helps to plan and control movements perceives touch, pressure, pain, temperature |
|
hypothalamus
|
controls & integrates ANS & pituitary gland
emotion & behavior; body temp; eating & drinking; sleep, ADH &oxytocin |
|
epithalamus
|
pineal gland which secretes melatonin (regulate sleep-wake cycle)
|
|
cerebrum
|
sensory areas: perceive sensory info
motor areas: plan & initiate muscular movements association areas: memory, personality, intelligence basal ganglia: coordinate gross movements & muscle tone (works w/ cerebellum) limbic system: emotion, survival [instinctual] -amygdala- fear |
|
basal ganglia
|
parts: globus pallidus, putamen, caudate nucleus
part of the cerebrum associated w/ sustained and repetitive movements |
|
putamen & caudate nucleus
|
parts of the basal ganglia that receive sensory & motor input from the cerebral cortex
|
|
globus pallidus
|
pt of the basal ganglia; gives output, sends feedback signals to motor cortex via thalamus
|
|
Summary of Integration Centers
|
SC: simple motor reflexes
Lower Brain Stem: more complex subconscious motor reactions such as postural control Cerebellum: subconscious control of movement such as those needed to coordinate multiple movements Thalamus: conscious distinction among sensations such as feeling hot, cold, tired Cerebral cortex: perceive sensory info; conscious movements |
|
Primary Motor Cortex
|
pt of the ceerbrum
plans & initiates voluntary movement; starts movements |
|
Cerebellum
|
necessary to produce movement
intentions vs. actual movements posture & balance, corrections, fast & complex movements |
|
engrams
|
memorized motor patterns stored in the brain
make program in brain i.e. for how to ride a bike actually changes the structure of the brain |
|
learning
|
ability to acquire new information or skills via instruction or experience
|
|
memory
|
info acquired via learning is stored & retrieved
must produce structural & functional changes limbic system, hippocampus, amygdala, diencephalon, primary somatosensory & primary motor areas ==> all help to acquire memory |
|
types of memory
|
immediate: few seconds (where, what)
short-term: seconds to mins (phone #) long-term: days to yrs (retrieve anytime) Motor skill memories: basal ganglia, cerebellum, cerebral cortex [[call upon these to do a motor skill related to memory]] |