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Priscilla Anzaldo P2 Nervous - Coggle Diagram
Priscilla Anzaldo P2 Nervous
Major Functions of Nervous System
sensory input: info gathered by sensory receptors for internal/ external changes
integration: processing and interpretation of sensory input
Motor output: activation of effector organs (muscles and glands) produces a response
Major Divisions/Subdivisions of Nervous System
central nervous system
brain
spinal cord
peripheral nervous system
somatic nervous system
motor efferent division
somatic nervous system
autonomic nervous system
sympathetic division
parasympathetic division
Tissues
neuroglia: small cells that surround neurons
PNS
satellite cells
surrounds neuron cell bodies in PNS
function similar to astrocytes in CNS
Schwann cells
surround all peripheral nerve fibers and from myelin sheaths in thicker nerve fibers
vital for regeneration of damaged peripheral nerve fibers
CNS
Astrocytes
cling to neurons, synaptic endings, capillaries
function: support neurons, guide migration of young neurons, respond to nerve impulses/neurotransmitters
Microglial cells
small ovoid cells with thorny processes
migrate toward injured neurons
Epidymal cells
may be ciliated
lines central cavities of brain/ spinal column
forms preamble barrier between CSF in cavities/ tissues fluid bathing in CNS cells
oligodendrocytes
branched cells
process wrap CNS nerve fibers forming myelin sheaths in thicker nerve fibers
Neurons: excitable cells, transmit electrical signals
neuron cell body (soma)
contains nucleus with neucleolus
part of receptive region
most located in CNS
nuclei: clusters of neuron bodies in CNS
Ganglia: clusters of neuron bodies in PNS
neuron processes
armlike processes, extend from cell body
CNS contains both
PNS contains only processes
Tracts: bundles of neuron processes in CNS
Nerves: bundles of neuron processes in PNS
2 types of processes
dendtrites
receptive (input) region of neuron
convey incoming messsages toward cell body as graded potentials
axon
each neuron contains 1 axon that starts cone shaped area called axon hillock
long axon: nerve fibers
distal endings called axon terminals/ terminal boutons
functional characteristics
conducting region of neuron
generates nerve impulses, transmits them along axon axolemma to axon terminal
terminal: region that secrets neurotransmitters, released into extracellular space
Classification of neurons
3 types based on direction in which nerve impulse travels relative to CNS
Sensory: transmit impulses from sensory receptors toward CNS (unipolar)
Motor: carry impulses from CNS to effectors (multipolar)
Interneurons (association neurons): lie between motor/ sensory neurons, shuttle signals through CNS pathways
Connective Tissue Coverings
Endoneurium: loose CT that encloses axons and their myelin sheaths/ schwann cells
perineurium: coarse CT that bundles fibers into fascicles
Epineurium: tough fibrous sheath around all fascicles to create the nerve
Major Parts/Functions of Brain
External Inferior
olfactory bulbs: determine smells
optic nerves: transfer visual info to eyes
optic chiasma: relay electrical signals
optic tract
infundibulum
mamillary body: memory
cerebral peduncle: developing new motor skills
pons: relays info from cerebrum to cerebellum
medulla oblongata: adjust heart rate, respiratory rhythm, regulated vomiting, hiccupping, swallowing, coughing, sneezing
spinal cord: breathing, heart rate, temp.
midbrain
External Superior
Frontal lobe: thinking, memory, behavior
Parietal lobe: language, touch
Occipital lobe: sight
Longitudinal fissure
Sulcus
Gyrus
Transverse fissure
Temporal lobe: hearing, learning, feelings
Dura Mater
Pia mater
Arachnoid mater
cerebrum
cerebellum: balance, coordination
cerebral hemisphere L&R
Left: speech/ language
Right: art, creative thinking, intuition
Central Sulcus
cerebellum: process input from cortex, thinking, language, emotion, balance and coordination
Internal Sagittal
Corpus callosum
Septum Pellucidum
Lateral ventricle
Fornix: emotional reaction, consciousness
Third ventricle
Thalamus: sorts, edits, relays ascending input (learning and memory)
Hypothalamus: regulates body temp, food intake, water balance, rhythm and drive
Corpa quadrigemina: vision and hearing
Pineal body/gland: produces melanin
Cerebral aquedut
4th ventricle
Abor vitae
Internal Coronal
Cerebral cortex: receives input from multiple sensory areas and sends output
White mater: protects fibers
Major Parts/Functions of Spinal Cord
midbrain: motor movement
pons: relays info from cerebrum to cerebellum, controls respiratory rate and depth
medulla oblongata: relays ascending sensory pathway impulses from skin
reticular formation: maintains cerebral cortex alertness, filter out repetitive alertness, regulates skeletal/ visceral muscle activity
Action Potential and Nerve Impulse
generation of action potential
resting state: all gated Na+ and K+ channels closed
Depolarization: Na+ channels open
Repolarization: Na+ channels are inactivating, K+ channels are open
Hyperpolarization: some K+ channels remain open, not all channels reset
propagation of action potential
propagation allows action potential to be transmitted from organ to axon length toward terminal
AP only occurs in forward direction
Once initiated AP is self- propagating
Cranial Nerves
Olfactory
sensory function; smell
motor function: none
PS fibers: none
Optic
sensory function: vision
Motor function: none
PS fibers: none
Oculomotor
sensory function: none
motor function: yes
PS fibers: yes
Facial
sensory function: taste
Motor Function: yes
PS fibers: yes
Vestibulocochlear
Sensory function: hearing
motor function: some
PS fibers: no
4.Trochlear
Sensory function: none
Motor function: yes
PS fibers: no
Abducens
sensory function: none
motor function: yes
PS fibers: no
10.Vagus
Sensory Function: taste
motor function: yes
PS fibers: no
Glossopharyngeal
sensory function: taste
motor function: yes
PS fibers: yes
Hypoglossal
sensory functon: none
motor function: yes
PS fibers: none
Trigeminal
sensory function: general sensation
motor function: yes
PS fibers: no
Accessory
Sensory function: none
Motor function: yes
PS fibers: no
Spinal Nerves
8 pairs of cervical nerves
12 pairs of thoracic nerves
5 pairs of lumbar nerves
5 pairs of sacral nerves
1 pair of coccygeal nerves
each pair is connected to spinal cord via 2 types of roots
Ventral roots: contain motor efferent fibers from ventral horn neurons and innervate skeletal muscles
Dorsal roots: contain sensory afferent fibers from, sensory neurons in dorsal root ganglia. conduct impulses from peripheral receptors
Neurotransmitters
function classified in 2 groups
Effects: excitatory vs. inhibitory
excitatory: depolarizing
inhibitory: hyperpolarizing
Actions: direct vs. indirect
direct: neurotransmitter binds directly to and opens ion channels
indirect: neurotransmitter acts through intracellular second messengers
classified by chemical structure and function
ACh
released at neurotransmitter junctions
synthesized from acetic acid and choline
degraded by enzyme AChE
Biogenic amines
catecholamines: dopamine, norepinephrine, epinephrine made from tyrosine
indolamines
seratonin: made from tryptophan
histamine: made from histidine
Amino acids
Peptides (neuropeptides): strings of amino acids
endorphins: natural opiates, reduce pain perception
gases and lipids
endocannabinoids: act like THC
Compare and Contrast Autonomic Nervous System
efferent pathways and ganglia
somatic: cell body in CNS, single, thick, myelinated group od A axon extends in spinal/ cranial nerves directly too skeletal
Autonomic: pathway uses a 2-way neuron chain
2-way neuron chain
preganglionic neuron: cell body in CNA with thin, lightly myelinated preganglionic axon extending to ganglion
Postganglionic neuron: cell body synapses with preganglionic axon in autonomic ganglion with nonmyelinated postganglionic axon that extends to effector organ
target organ responses to neurotransmitters
somatic: all motor neurons release ACh effect is always stimulatory
autonomic: preganglionic fibers release ACh, postganglionic release norephrine or ACh at effectors, effect is stimulatory or inhibitory depending on receptors
effectors
somatic: innervated skeletal muscle
Autonomic: innervates cardiac/ smooth muscle & glands
overlap of somatic and autonomic function
most spinal/ cranial nerves contain both somatic and automimic fibers
Reflex Arc
components
receptor: site of stimulus action
sensory neuron: transmits afferent impulses to CNS
Integration center: monosynaptic or polysynaptic region in CNS
Motor Neuron: conducts different impulses from integration center to effector organ
Effector: muscle fiber or gland cell that responds to efferent impulses by contracting or secreting
Disorders & Diseases & Injury
Injury
concussion: temporary alteation in function
contusion: permanent damage
Subdural Hemorrhage: pressure from blood
ischemia: tissue deprived of blood supply
cerebral edema: swelling of brain
disorders
Hemiplegia: paralysis on one side
translent ischemic Attacks: temporary episodes of reversal cerebral ischemia
diseases
Alzheimers disease: progressive degenerative disease of brain, results in dementia
Parkinson's disease: degeneration of dopamine- releasing neurons
Huntington's disease: fatal hereditary disorder caused by accumulation of protein in brain cells causing "flapping movement"
Drug of Abuse On Mice
Heroine
Neurotransmitters affected
: Inhibitory and Dopamine neurotransmitters
How it affects neurotransmitter
: Heroine shuts down inhibitory neurotransmitter allowing dopamine to release into synapse
Symptoms
: Creates a sedation feeling, affects transmission of stress and emotional attachment
Ecstasy
Neurotransmitters affected
: Seratonin neurotransmitter
How it affects neurotransmitter
: Ecstasy is taken by seratonin transporters confusing the transporter and transports seratonin out of the cell into receptor
Symptoms
: effects mood, sleep, perception, appetite and contains addictive properties
Marijuana
Neurotransmitters affected
: Inhibitory and Dopamine neurotransmitters
How it affects neurotransmitter
: THC binds to natural cannabinoid receptor turning off release of inhibitory neurotransmitters releasing dopamine
Symptoms
: removes short term memory, slow movement, calm behavior
Methamphetamine
Neurotransmitter affected
: Dopamine Neurotransmitter
How it affects neurotransmitter
: meth enters dopamine vesicles forcing dopamine out, excess dopamine is released out the cell and into the synapse
Symptoms:
affects brains reward pathway, intense pleasure and exhilaration
Alcohol
Neurotransmitters affected
: GABA and Glutamine neurotransmitter
How it affects neurotransmitter
: makes GABA receptors inhibitory, alcohol binds to glutamine preventing it from leaving the cell
Symptoms
: affects memory formation, decision and impulse control
Cocaine
Neurotransmitters affected
: dopamine neurotransmitter
How it affects neurotransmitter
: blocks dopamine transporter inhibiting dopamine neurotransmitter
Symptoms
: effects voluntary movement, causes fidgeting
LSD
neurotransmitter affected
: serotonin neurotransmitter
how it affects neurotransmitter
: LSD inhibits and excites receptors by resembling serotonin
Symptoms
: wakefulness, startle response to unexpected stimuli, hallucinations