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Nervous System - Coggle Diagram
Nervous System
Drugs
MDMA
aka ecstasy, methylenlony
swallow and snort
increases energy, euphoric feeling, and distortion in perceptions
jaw clench, muscle cramps, chills and sweats. panic seuizures, kidney and heart failure, and impacts body temp.
Nicotine
aka cigarettes, cigar, e-cig, pipe, chewing tobacco, nictoine gum, and sniff
smoke, inahle, vape, chew, and dip
heart rate and nerves increase
addicting and stopping will end up with wihdrawals: intense craving and concentration problems
leads: cancer, heart disease, stroke, etc.
inhalents
aka solvents, gases, and aersoal sprays
inhale
it impairs coordination and speech and judgments
impacts brain, speech provsions and hallucinations
psychedelics
aka LSD, shrooms,psilocybin, peyote cactus
swallow, snort, inject, or smoke
hallucinate and distortion in perception and intenses emotions and sensations
increase in body temp and heart pressure, blood pressure, loss of apetitie, nausea, paranoia, dilated pupils, panic, and loss of sleep
Opiods
aka morphine, codeine, hydrocodone, oxycodone, hydro morphone, fentanyl,
it is taken by snorting, mouth, injection, patch and smoking
It causes pinpoint pupils and rush of warmth an pleasure. You can be drowsy, itchy, nauseous, vomit and lose consciousness
dissosciative drug
aka lectamine, PCP,
swallow, snort, smoke
lose touch with reality, act unpredictly and violent
death feeling, seizures, fever, and coma
heroin
dopamine
releases inhibitory transmitters shut down, where dopamine is released. Heroine opiates and binds receptors to opiate
cocaine
blocks transporters which leads to dopamine being trapped @ synaptic cleft and overstimulates
active in the brain controlling voluntary movement making users fidgety
ecstacy
interferes with seontonin neurotrans. which releases dopamine which alters the transporter and allows it to do its job in reverse, which it leaves serontin stuck at synpatic cleft
takes affect on mood, sleep, perception, and apetite, which makes it slightly addictive
Metaphamine
mimics dopamine, where it enters the vesicles pushing the molecules out which leads to dopamine working and pumping in reverse
theexcess dopamine is trapped in the synaptic cleft forcing it to bind and bind overstimulating the cell
highly addictive having one feeling intense pleasure
alcohol
involved w GABA receptors and glutamate
once alcohol is consumed it punches receptors
affects memory formation, making choices, and impulse
marijuana
inhibitory neurotans. are active in synpase
cannaboid receptors turn off release of inhibitory neurotans, where THC mimics anadamide and binds to cannboid receptors where dopamine squirts into synapses
short term memory, allowes calming and relaxation
Disorders within N.S.
Alzehimer: brain disease that leads to dementia; results in memory loss, short attention span, disorientation, language loss, moodiness, confusion, hallicunation. The brain cells die so the brain shrinks
Concussion: temprorary alteration in function
hemiplegia: paralysis on one side
ischemia: tissue deprived of blood supply that leads to the death of brain tissue
TIA: reversible cerebral ischemia
contusion: permanent damage
cerebral edema: brain swells due to head injury
subdural: pressure from blood can force brain stem which leads to death
Spinal nerves and Cord
part of the peripheral nervous system
attach to spinal cord by 31 roots
designated by paired spinal nerves that arise from it
2 cords that run length of cord which divide into halves
dorsal:median sulcus
ventral: median fissure
central canal runs length of cord
Gray Matter and Spinal roots
found on each side of center that mirror images
ventral horns: some interneurons; somatic motor neurons
lateral horns:sympathetic
neurons
dorsal horns: t get somatic and visceral sensory input
ventral roots: motor neurons that exit
dorsal root: sensory input to cord
dorsal root ganglia: cell bodies of sensory neuron
White matter: myelinated/non-myelinated fibers that communicate between spinal cord and brain
runs in 3 directions: ascending, descending, and transverse
Parts of functions of the spinal cord
an enclosed vertebral column
a communication process to and from brain and body
Major reflex center: allows reflexes to be initiated
the bones, meninges, and CSF protect the spinal cord
Gray matter and Spinal nerves
3 areas of gray matter
lateral
sympathetic neurons
ventral
some interneurons; somatic motor neurons
dorsal
interneurons that recieve somatic and vsiceral input
dorsal roots:
sensory input to cord
ventral roots:
bundle of motor neuron axons that exit spinal cord
dorsal root ganglia
sensory neuron cell bodies
White matter
lateral
ventral
dorsal
Divisions and sub-divisions
Peripheral Nervous system
Motor
somatic
visceral
parasympathetic
Sensory
visceral
somatic
Central Nervous System
spinal cord
brain :
Brain regions
Cerebral hemispheres
superior part of brain
surface markings
sulci: shallow grooves
divide into 5 lobes
temporal
occipital
parietal
insula
frontal
fissures: deep grooves
transverse: seperates cerebellum and cerebrum
longitudal: seperates two hemispheres
gyri: ridges
diencephalon
thalamus: relay station for info coming into cortex
mediates sensation, motor activities, cortical arousal, learning, and memory
hypothalamus: forms cap over brain stem and forms inferlateral walls of third ventricle
located below thalamus
contains mamillary body
main visceral control & regulating center thats vital to
homeostasis
regulates body temperature
regulates hunger to respond to to nutrient blood levels/hormones
regulates hydration
regulates sleep-wake cycles
controls of endocrine system functions
epithalamus
dorsal portion of diencephalon
forms root of 3rd ventricle
brainstem
medulla: blends into spinal cord @ foramen magnum
aka medulla
contains 4th ventricle
functions:
respiratory: create respiratory rhythm to control rate and depth of breathing
Other: vomit, hiccup, swallow, cough, sneeze
cardiovascular: adjusts force and rate of heart contraction
midbrain: between diencephalon and pons
cerebral peduncles: 2 ventral bulges to have pyrimdal motor tracts
cerebral aqueduct: channel to connect third and fourth ventricle
pons: between medulla and midbrain
4th ventricle seperates pons from cerebellum
cerebral cortex
executive suite of brain
allows awareness, sensory perception, voluntary motor initation, communication, memory storage, and understanding
4 considerations
Lateralization of cortical function can happen @ only one hemisphere
hemisphere is concerned with contralateral side of body
Conscious behavior involves entire cortex in one way or another
functional areas
association: intergrate diverse information
sensory: awareness of sensation
happens @ parietal, insular, temporal, and occipital lobes
main areas:
primary somatosensory cortex, somatosensory
association cortex, visual areas, auditory areas, vestibular cortex, olfactory cortex, and gustatory cortex, and visceral sensory area
somatosensory: found at postcentral gyri of parietal lobe that gets general sensory information from skin and proprioceptors
Somatosensory association cortex: posterior to primary and determines sensory input from primary somatosensory cortex to understand and object
motor: control voluntary movement
@ frontal lobe
primary moter @ precentral gyrus
Somatotopy: muscles mapped on primary motor cortex
premotor cortex anterior to precentral
plans movements
controls learned, repetiuous/ patterned motor skills
Coordinates simultaneous actions
brocas area anterior-inferior pre motor area
usually @ left hemisphere
directs muscle of speech production
active in planning speech
Cerebellum
11% of brain mass
located @ dorsal pons and medulla
Contains thin gray matter with arbor vitae
function: processes input from cortex, brain stem, and sensory receptors to have precise movements @ skeletal. helps with thinking, emotions, and language. Also, balance and coordination
basal nuclei (ganglia)
includes a caudate nucleus, putamen, and glovus pladius
functions: muscle movements, role in cognintion and emotions, regulate intensity of slow/stereotypes movements. filter incorrect responses, and inhibit unnescessary movements
Major functions of N.S
N.S. controls and communicates the system of the body
3 overlapping functins
integration
process and interpretation of sensory input
motor output
activates effector organs
sensory input
gathered by sensory receptors about internal and external changes
2 prinicpal pats
peripheral: n.s. outside of CNS
2 divisions
sensory: 2 fibers
visceral: get impulses from visceral organs to CNS
somatic: get impulses from skin, skeletal muscles, and joints
motor: two divisions
Autonomic n.s involuntary: regulation of smooth and cardiac muscle, and glands
sympathetic: mobilization of body during activity
parasympathetic: conserves energy
somatic n.s (voluntary): give impulses from CNS to skeletal
central NS: brain and spinal corrd that interprets sensory input and controls output
Connective tissue coverings
perimysium
surrounds fascicles
common @ muscles and allows specific movement
endomysium: muscle fiber that encases thin C.T of collagen and reticular fibers
surrounds extracellular matrix and transfers force by muscles to tendons
epimysium
sheath of dense irregular tissues
allows contraction and movement while mainting structural integrity. It divides muscle from other tissues
Action potential & Nerve impulse
resting membrane
it is generated by differences in ionic composition and differences in plasma membrane permeability
changes occur when ion concentrations change or membrane permeablity to ions shift
2 signals
action potential: long-distance signals of axons
graded potentials: signals operate over short distance
depolarization: decrease in membrane potential
hyperpolarization: increase in membrane potential
action potential: neurons sending signals; long distance neural communication
4 steps
resting state:gated Na+ and K+ channels are close
depolarization: Na+ channels open
Repolarization: Na+ channels are inactivating, and K+ channels open
Hyperpolarization: Some K+ channels= open and Na+ channels reset
Synapse: neurons are connected and mediate information transfer
presynpatic neuron: sends information/conduct transmitions
postsynpatic neuron:transmits electrical signal
Chemical Synpase
•Info transfer across chemical synapses
AP reaches axon terminal of presynaptic neuron
Voltage-gated Ca2+ channels open and Ca2+= enters axon terminal
Ca2+ entry causes synaptic vesicles that release neurotransmitter
Neurotransmitter diffuses across the synaptic cleft and binds to specific receptors on the postsynaptic membrane
Binding of neurotransmitter opens ion channels that create graded potentials
Neurotransmitter effects are terminated
Tissues
Neuroglia: tiny cells to wrap and surround neurons
n.s. connects to this principal cell
4 types for CNS
microglial: small and oval cells to touch and monitor neurons and move to injured neurons
ependymal: can be squamous/columnar that line the central cavities of brain and spinal column
oligodendocytes: branched fibers to wrap CNS nerve fibers and forming insulating myelin sheats
astrocytes: abundant and highly branched glial cells that hang onto neurons, synpatic endings and capillaries
2 in PNS
Schwann: surround peripheral fibers and form myelin sheaths similar to oligodendrocytes
Satelite cells: surround neuron cell bodies @ PNS and same function as astrocytes
Neurons: structures for N.S
last person´s lifetime
amitotic
high metabolic rate
Neuron Cell body
aka perikaryon/soma
synthesizes proteins, membranes, and chemicals
has nucleus w/ nucleous
most located @ CNS
ganglia: clusters @ CNS
nuclei: clusters @ CNS
Classification of neurons
3 types of direction
Motor: carry impulses from CNS to effectors and are multipolar that are mainly found in CNS
Interneurons (association neurons): found between motor and sensory neurons that send signals to CNS pathways
Sensory: mainly are all unipolar that send impulses from sensory receptors towards CNS
structual : 3 types
multipolar: 3 or more processes 1 axon and other dendrites
bipolar: 2 processes; 1 axon 1 dendrite
unipolar: 1 t-like process (2axons)
process
tract: bundles of neurons @ CNS
nerves: bundle of neurons @ PNS
2 types of process
axon
function: conducting region of neuron to make impulses and transmit them to axolemma to terminals. It can carry multiple conversations w/ different neurons and decays fast if cut/damaged
structure: each neuron has one where they can be short/absent or even as long as a cell where they profusely at their end. distal endings aka axon terminals
dendrites: receptive region to get messages toward cell body as graded potentials
myelin sheath: made of myelin to protect and insulate axon and higher speed of nerve impulse transmission
nonmyelinated: dont have sheath and conduct slow impulses
myelinated fibers: segmented sheaths to surround large/long axons
myelinated fiber @ PNS
schwann cells form this
myelin sheath gaps: gaps between adjacent schwan cells
nonmyelinated: thin and not wrapped in myelin and surrounded by schwan cells
myelin @ CNS
oliogendrocytes form this
can wrap up to 60 axons
white matter: regions of brain & spinal w dense myelinated
gray: mainly neuron cell body & nonmyelinated
Parts and functions of the brain
4 regions
cerebellum
brainstem
midbrain
medulla
pons
diencephalon
cerebral hemispheres
high mental functions
memory
storage and retrival of informatin
brain waves
consciousness
sleep and wake cycles
language
association cortex of left hemisphere
meninges
cover and protect
contain 3 parts
arachonoid mater
pia mater: connective tissue that clings to brain
dura mater: strongest menix
Neurotransmitters
language of N.S. that contain 50+ where majority of neurons make two or more neurotansmitters
classified by
chemical structure
Acetylcholine: first identitified and released at neuromuscular junctions, synthesized from acetic acid and choline
Biogenic amines
Indolamines
Histamine: histidine
Serotonin: tryptophan
Catecholamines
Dopamine, norepinephrine and epinephrine
Amino acids: produce all proteins and are proven neurotransmitters
Peptides: strings of amino acids
Purines
Gases and lipids
Endocannabinoids: similar to receptors of THC
Effects and actions
effects: excitatory vs inhibitory
actions: direct vs. indirect
Cranial Nerves
12 pairs
Abducens nerves
innervating lateral rectus muscle
Facial nerves
pons travel through internal acoustic meatuses and emerge through stylomastoid foramina to lateral aspect of face
functions: facial expression, parasympathetic impulses to lacrimal and salivary glands
sensory function: taste
Trigeminal nerves
largest cranial nerves
3 divisions
Ophthalmic: pass through superior orbital fissure
Maxillary: passes through foramen rotundum
Mandibular pass through foramen rotundum
Trochlear nerves
midbrain enter orbits superior orbital fissures to innervate
superior oblique muscle
directs eyeball
Oculomotor nerves:
extend from ventral midbrain to superior orbital fissures to 4/6
extrinsic eye muscles
raise eyelids, direct eyeball, parasympathetic, and control lens shape
Vestibulocochlear nerves
auditory nerve
hearing and equilibrium receptors
optic nerves
pass through optic canals and partially cross over at optic chiasma
synapse at thalamus
visual function
Glossopharyngeal nerves
fibers leave skull and go to throat
innervate part of tongue and pharynx which leads to swallowing and parasympathetic fibers to salivary glands
conduct taste
:Olfactory nerves
sensory nerve of smell
fibers synapse in olfactory bulbs
purely sensory function
Vagus nerves
cranial nerves extend beyond head
fibers from medulla exit skull
help regulate activities of heart,
lungs, and abdominal viscera
s carry impulses from thoracic and abdominal viscera, baroreceptors, chemoreceptors, and taste buds of posterior tongue and pharynx
Accessory nerves
formed from ventral rootlets
pass into cranium
formerly spinal accessory nerve
Hypoglossal nerves
exit canal
Innervate extrinsic and intrinsic muscles of tongue to help swallow and speak
mixed nerves and 2 pairs purely sensory
Reflex arc
components
stimulus
1 receptor
site of stimulus action
3 intergration center
monosynaptic or polysynaptic region @ CNS
2 sensory neuron
sends afferent impulses to CNS
4 motor neuron
has efferent impulses from integration center to effector
organ
5 component
muscle fiber/gland cell to respond to efferent impulses by
contracting or secretion
response
classified as
autonomic: activate visceral
somatic: activate skeletal
Compare and contrast
autonomic N.S.
activate smooth and cardiac muscles, and glands
adjustments to ensure optimal support for body activities
a.ka. involuntary N.S. / general visceral system
2-neuron chain:
postganglionic: cell body synapses with preganglionic @ autonomic ganglion w/ nonmyelinated postganglionic
preganglionic: thin and light myelinated that extends to ganglion
preganglionic fibers release ACh and post ganglionic release norepinphrine
2 arms
sympathetic: mobilize body during activity
parasympathetic: maintenance function and conseerves energy
difference
effectors: SNS activates skeletal muscles
efferent pathway: SNS cell body @ CNS with a single thick myelinated group. axon stretches to spinal/cranial directly to skeletal
ALL SNS release ACh