Final Flashcards
Lose control of limbs, then trunk
Immune response after a viral infection
Reversible demyelinated
Guillain-Barre
Neuron at rest
Sodium and chlorine high outside the axolemma
Potassium and proteins high inside the axolemma
Resting potential of neuron
-70mV
How do we maintain unequal charge?
Channels
Sensory movement
Afferent divisions of PNS
10 million
Collect info, about internal body environment
Visceral sensory neurons
Collect info, about external environment and body position
Somatic sensory movement
Exterceptors
Monitor touch, pressure, temp. Sight, smell, hearing
Monitor joints and muscles
Proprioceptors
Monitor digestion, urinary, reproductive, pain, taste
Interceptors
Receptors deliver..
Info to the CNS for processin
Efferent division of PNS
Send directions from CNS to muscle and glands
Motor neurons
Smooth m., cardiac glands, fat
Visceral motor neurons
Skeletal m.
Somatic motor neurons
Most located in CNS-pyramidal and parkinje
20 billion in body
Interneurons
The middle men
A) distributes sensory info
B) coordinate motor signals- the more complex the action, more Interneurons we involved
Association cells
Most numerous in CNS
Directs growth of neurons
Composed of BBB
astrocytes
Make and circulate CSF
Ependymal cells
Oligodendrocytes
Myelinate the CNS making internodes
Gaps in myelin called “modes of Ranvier”
Police force of CNS
Garbage chewers
Microglia
Monitor environment of cell
Like astrocytes in CNS by function
Satellite cells
Myelinated axons in PNS
Act like Oligos in CNS
Important in Wallerjam degeneration
Schwann cell
Passive, always open, maintains resting potential
Leak channels
Active, restores resting potential, ejects 3 NA+ for every 2 K+ brought in
NA/K ATPASE pump
Active, open in response to stimulus. Changes the resting potential= depolarizers, repolarizes the cell
Gated channel
Occurs in most membranes
Weak- diminishes w/ distance
Depolarize, no threshold reached
Usually does not turn into action potential unless received lad to axon hillock
Graded
Occurs in exciteable in cells Strong stimulus Excited the entire length of the cell Depolarize to threshold Action potential form
Action potential
Single synapse, repeated stimuli
Temporal summation
Spatial summation
Multiple synapses, stimulatianous stimuli
If threshold is reached, action potential will be generated and passed along axon
All or none principle
Differences in the speed of AP
Propagation
Unmyelinated axons, ap runs in small steps as signals continue to be repeated
Continuous
Myelinated axons, a.p. Signal conducts only at the nodes of Ranvier, leaping over the internodes
Saltatory
Largest diameter, myelinated ap travels over 300 mph
Type A fibers
Medium diameter, myelinated ap travels at 40 mph
Type B fibers
Smallest diameters, Unmyelinated, ap travels at 2 mph
Type C fibers
So we have an ap now what?
Release of neurotransmitter from synaptic bulb
NTs have ethier excitatory or inhibitory effects in body.
1st discovered, excitatory at NMJ
Acetylcholine
Inhibitory in motor cortex
Prevents overstimulation of muscles
Induces hyper polarization
If receptors are destroyed then causes ridged/ stiff muscles
Dopamine
Receptors are destroyed then causes rigid / stuff muscles
Parkinson’s disease
Excitatory in Limbic system
Causes depolarization and ap to occur
Dopamine
Blocks the re-uptake of dopamine- you get high
Cocaine
Excitatory, make you feel “happy”
Lack of it, can cause depression
SSRI such as Zoloft, Prozac help
Serotonin
Sits in receptors, rush of happy, then total crash
Ecstasy
Inhibitory
Reduces anxiety
GABA
Excitatory
Lowers threshold values
Increases amount of ACh released as reduces adenosine Ca NT which makes drowsiness
Caffeine
Excitatory bind to ACh receptors
Nicotine
Excitatory, released when you need to feel pain
Substance P
Released from knob with NTs
Can modify the action of NTS
Neuromodulators
Moraine/opium block substance P release, temp. Pain relief ex) morphine pill, OxyContin
Opioids
Hits in 30s Myelin hardens Common to optic nerve, brain cord Episodic and progressive More common in colder climates
Multiple Sclerosis
Outer gray layer of the brain
Cerebral cortex
Large white matter tract that allows communication of hemispheres
Corpus callosum
Elevated areas of cortex, increases surface area
Gyri
Shallow depression between gyri
Sulci
Deep grooves, the longitudinal seperatss L/R hemi
Fissure
Chunks of gray matter in each hemi, continued movements once started
Basal nuclei
Basal nuclei work unchecked, so voluntary movements are extremely difficult to start and continue and no treatment
Parkinson’s disease
Coordination of involuntary movement, posture, balance
Cerebellum
Outer gray matter in the cerebellum
Cerebellar cortex
Tree of life, large whitest get tract
Arbor vitae
Vital functions, connection to other brain areas
Brain stem
Alertness
Mesencephalon aka midbrain
Body reflex to visual stimuli like a flash of bright light
Superior collicilus
Body reflex to loud noises
Inferior collicilus
Modified breathing, connects CBL to rest of brain
Pons
Digestion, blood pressure, heart rate, sets rate of breathing, also links brain with spinal cord
Medulla oblongata
Link between the cerebrum and the brainstem
Dicephalon
Post office of the brain
Thalamus
Body temp, hormone release, hunger+thirst
Hypothalamus
Pituitary gland
Hypophysis
Sleep/wake cycles, melatonin released when no light, so you get sleep
Pineal gland
Emotional system
Limbic system
Learning, memory, and emotion, looks like a sea horse
Memory storage and retrieval
Concerts short term mem to long
Hippocampus
Links emotion with memory, emotional learning , controls fight or flight response
Amygdala
Reticular activating system
RAS FILTERING SYSTEM
4 chambers in the brain
Ventricles
What are the laterals divided by
Septum pellueidum
How is a brain protected
Bones, meninges, cerebrospinal fluid
Outermost layer of menu he- 3 places where it folds on itself to cover gaps
Dura mater
Places where dura mater folds on itself
Falx cerebri, falx cerebelli, tentoriun cerebelli
Veins found in meninges
Subdural space
Intermediate layer, looks like spider webs
Arachnoid layer
Subarachnoid space
CSF found here
Innermost layer lies directly on the brain
Pis mater
Made by choroid plexus
Cerebrospinal fluid
Layer of ependymal cells lining the 3rd ventricle
Choroid plexus
Cerebrospinal fluid drained by this Into the veins
arachnoid granulations
CSF production norm or increased, but absorption does not occur or is slow
Hydrocephalus
What do adults and infants do to drain excess fluid
Shant
Layer of endothelial cells that surrounds brain capillaries
Blood brain barrier
BBB Alows
Polygon, glucose, alcohol, carbon dioxide, steroids, anesthesia
BBB DENIES
Most hormones Most neurotransmitters Most bacteria and viruses Antibiotics Penicillins and tetracyclines
Needs to regulate water/ nutrient content in blood
Hypothalamus
To detects poisons in blood
Vomit center
Blood supply cut off to brain- caused by a clot or aneurysm
Stroke
Strokes are mostly seen in
Wernicke’s area
Broca’s area
Incoming speech
Understanding of words
Sounding out new words
Wernickes area
If stroke occurs here
Cannot follow a simple command like “be quiet”
But could understand “be” and “quiet” separately
Outgoing speech
Speech production
Coordination muscles of the tongue/ lips/ throat
Broca’s
Stoke damaged Broca’s area
Can make sounds
Cannot form words
CSF filled sac
Cyst
Symptoms- seizures
Epilepsy
Brief stroke
Petit mal
23 min. Convulsions, unconscious
Grand mal
Uncontrolled neuron, activity, no other signals can get through
Pathology of a stoke
Memory loss, disorientation, anger, hallucinations
Alzheimer’s disease
