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Alanna Garcia P.5 Nervous System - Coggle Diagram
Alanna Garcia P.5 Nervous System
Major Functions of the Nervous System:
3 functions overlapping:
integration: processing and interpretation of sensory input
motor output: activation of effector organs (muscles and glands) produces a response
sensory input: informations gathered by sensory receptors
Major parts and functions of the spinal cord:
Spinal cord is enclosed in vertebral column
Begins at the foramen magnum
Functions:
Major reflex center: reflexes are initiated and completed at spinal cord
provides two-way communication to and from brain and body
Action potential & the Nerve Impulse:
Generating an AP 4 main steps:
Depolarzation: Na+ channels open
Repolarization: Na+ channels are inactivating, and K+ channels open
resting state: all gated Na+ and K+ channels are closed
Hyperpolarization(slight dip below resting voltage): Some K+ channels remain open, and Na+ channels reset
Reflex arc(major parts and functions):
reflexes occur over pathways called reflex arcs(neural path) that have 5 components: system works in all-or-none manner to produce specific, anticipated response
CNS Integration center: either monosynaptic or polysynaptic region within CNS
Motor Neuron: conducts efferent impulses from integration center to effector organ
Sensory Neuron: transmits afferent impulses to CNS
Receptor: site of stimulus action
Effector: muscle fiber or gland cell that responds to efferent impulses by contracting or secreting
Disorders/Diseases:
Meningitis: infection in the meninges
cause- tumors, fungi or parasites /symptoms- irritation, stiff neck /treatment- antibiotics, prevention w/ vaccination
Multiple Sclerosis: autoimmune disease that damages the myelin sheath
cause- hereditary, possibly viral infection /symptoms- memory loss, vision & hearing loss/treatment- no known cure, physical therapy
Spinal cord injury: damage to the spinal cord
cause- fluid build-up, direct injury or disease /symptoms- weakness, paralysis /treatment- surgery, spinal traction
Alzheimers Disease: a form of dementia associated w/ age
cause- hereditary, high insulin levels /symptoms- memory loss, unfounded suspicions /treatment- uncurable, medication
Autism: brain disorder that makes it difficult to communicate
cause-family history, environmental /symptoms-depression, repeated behaviors /treatment- medication, coping skills
Cerebrovascular accident (Stroke):
cause-diabetes, high cholesterol /symptoms-severe headache /treatment- hospitilization, blood thinners
Drugs of Abuse (Mouse Party
Methamphetamine: interferes w/ dopamine neurotransmitters
makes user feel- intense pleasure, exhileration
Alcohol: interferes w/ GABA & glutamate
makes user feel- decision making, impulse control
Marijuana: interferes w/ dopamine & inhibitory neurotransmitters
makes user feel- relaxed, natural high, slow movements
Cocaine: interferes w/ dopamine neurotransmitters
makes user feel- fidgeting
Ecstasy: interferes w/ seratonin neurotransmitters
makes user feel- mood, sleep, appetite
LSD: interferes w/ seratonin neurotransmitters
makes user feel- wakefulness, unexpected stimulus
Heroine: interferes w/ dopamine & inhibitory neurotransmitters
makes user feel- sedation, well-being, pain killer
Major divisions and subdivisions of the nervous system (and PNS):
diencephalon
thalamus, hypothalamus, epithalamus (enclose 3rd ventricle)
thalamus: sorts, edits, relays ascending input
hypothalamus: below thalamus regulating center vital to homeostasis ex: bp, hr, digestive tract, pupil size
epithalamus: secretes melatonin
brain stem(medulla oblongata, pons, midbrain)
pons: reticular formation * rhythm of breathing
medulla oblongata: cardiovascular center, respiratory center, regulate: vomiting, hiccuping, swallowing, coughing, sneezing
midbrain: forms pillars that hold up cerebrum
cerebral hemispheres
lobes: frontal, parietal, temporal, occipital, insula
Cranial nerves:
optic nerves: vision
oculomotor nerves: motor to eye
olfactory nerves: smell
trochlear nerves: somatic motor fibers
trigeminal nerves: motor fiber for mastication
abducens nerves: innervating lateral rectus muscle
facial nerves: impulses to lacrimal & salivary glands
vestibulocochlear nerves: hearing
glossopharyngeal nerves: throat
vagus nerves: regulates heart, lung, & abdominal viscera activites
accessory nerves: innervate trapezius & sternocleidomastoid muscles
hypoglossal nerves: contribute to swallowing & speech
Spinal nerves:
31 pairs of spinal nerves:
5 pairs of sacral nerves
1 pair of coccygeal nerves
5 pairs of lumbar nerves
12 pairs of thoracic nerves
8 pairs of cervical nerves
connected to spinal cord via 2 roots:
dorsal roots: contain sensory (afferent) fibers from sensory neurons in dorsal root ganglia that conduct impulses from peripheral receptors
ventral roots: contain motor (efferent) fibersfrom bentral horn motor neurons that innervate skeletal muscles
Compare & Contrast the autonomic nervous system w/ the somatic nervous system:
Both ANS & SNS have motor fibers but differ in effectors.
SNS innervates skeletal muscles, ANS innervates cardiac muscle, smooth muscle, and gland
Efferent pathways & ganglia:
ANS: pathways uses a 2 neuron chain 1. preganglionic neuron 2. postganglionic neuron
SNS: cell body is in CNS, & a single, thick myelinated group A axon extends in spinal or cranial nerves directly to skeletal muscle
Target organ responses to neurotransmitters
SNS: effect is always stimulatory
ANS: effect is either stimulatory or inhibition, depending on type of receptors
Classifications of neurons:
sensory: transmist impulses from sensory receptors toward CNS
motor: carry impulses from CNS to effectors
interneurons: shuttle signals through CNS pathways 99% of body neurons
Tissues (structure & function of neurons & neuroglia):
Neurons(nerve cells) are stuctural units of nervous system
amitotic, w/ few exceptions
high metabolic rate
extreme longevity
Connective Tissue Coverings:
perimysium: covering each fasscicle
endomysium: innermost sheath surrounding individual muscle fibers
Major parts & functions of the brain:
sensory areas: conscious awareness of sensation
association areas: integrate diverse information
motor areas: control voluntary movement
All 3 are a part of the cerebral cotrex.
Neurotransmitters:
language of nervous system
50 or more neurotransmitters have been identified
most neurons make 2 or more neurotransmitters
usually released at different stimulation frequences
classified by
chemical structure
function