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Nervous System Belinda Santiago Period 2 - Coggle Diagram
Nervous System Belinda Santiago Period 2
Major functions of the Nervy System
3 ovrlappng fnctns:
Integratn: Processng & interpretatn of sensory input
Motor output: activtn of effectr orgns (mscls & glands) produces a response
Sensory input: info gathrd by sensory receptrs abt internl & xtrnal changes
Major Divisions & subdivisions of the nervy system
Centrl Nervy Systm (CNS): integratv & cntrl cntrs
Peripheral Nervy Systm (PNS): communctn lines btween CNS & rest of bdy
Sensory Affernt Divisn: conducts impulses frm receptrs 2 CNS
Motor Effernt Divisn: Conducts impulses frm CNS 2 effectrs (mscls & joints)
Somatc nervy systm: condcts impulses frm CNS 2 skelly mscls
Autonomc nervy systm (ANS): condcts impulses frm CNS 2 cardc mscls, smooth mscl, & glands
Sympathetic Divisn: mobilizes bdy systms during activity
Parasympathetic Divisn: conserves enrgy, promotes housekeepng fnctns during rest
Tissues
Neuron: nerve cells
excitable cells tht trnsmit electrcl signls
3 main parts: dendrites (tree branch)-neuron receives input frm othr cells
axon (tree roots): long, thin structure; it sends an electrical message called an action potential throughout the entire axon
cell bdy/soma (tree trunk- nucleus lies here, neuron’s DNA is housed, proteins are made to b transported thru axon and dendrites.
Neuroglia: glial cells
smol cells tht surrnd & wrap delicate neurons
fnctn: provide metabolic and structural support for neurons, maintain conditions tht allow adequate functioning of neurons
4 types of cells
Ependymal cells- form permeable barrier btween CSF in cavities & tsu fluid bathing CNS cells
Oligodendrocytes- branchd cells; forms insulating myeln sheaths in thkr nerve fibrs
Microglial cells: smol ovoid; monitr neurons & migrate towrd injured neurons
Astrocytes- supprt, brace neurns, info procssng, respnd 2 nerve impulses & neurotrnsmttrs
Classification of neurons
Structural Classifictn
Multipolar: 3 or more processes (1 axon, othr dendrites; most cmmn & majr type in CNS)
Bipolar: 2 processes (1 axon, 1 dendrite; rare ex. retine & olfactory mucosa)
Unipolar: one T-like process (2 axons AKA pseudounipolar)
Functnl Classifictn
Motor: multipolr; mst cell bdies in CNS (xcept autonmc neurns); carry impulses frm CNS 2 effctrs
Intrneurons (AKA associatn neurns): btween motor & snsry neruons; most entirely within CNS; 99% of bdy's neurons, shuttle signls thru CNS pathways
Sensory: almost all unipolar; cell bdies locatd in ganglia (PNS); trnsmits impulses away frm snsry receptrs toward CNS
Cnnctv tsu covrings
Endoneurium- loose cnnctv tsu tht encloses axons & their myelin sheaths (Schwann cells)
Perineurium- coarse cnnctv tsu tht bndles fibers in2 fascicles
Epineurium- tuff fibrous sheath around all fascicls 2 form nerve; most affernt & effrnt fibers, somatc & autonmc fibrs
Major parts and fnctn of brain
Cerebellum: mscl coordination; balance, posture & mscl tone; bdy coordination and learnng 2 perform timed motor responses
Brain Stem-midbrain, pons,& medulla oblongata; pathway btween spinal cord & brain; regulates respiration, blood pressure, & heart rate.
Cerebrum: movmnt & snsry input
Midbrain- eye movemnt & auditry reflxes
Pons- relay signals from the forebrain 2 cerebellum, sleep-wake cycle, respiration, swallowing, bladder control, hearing, taste, eye movement, facial etc.
Medulla oblongta: controls many vital functions such as respiration and heart rate.
Thalamus-relays sensory stimuli; gathering and processing information from your senses
Hypothalamus- controls involuntary body functions such as; water balance & bdy temp.; controls emotional responses: motivation 4 eating, drinking & sexual desires
Action potential and nerve impulse
Actn Potential: main way neurons send signals; only in mscl cells & axon of neurons; signals the neuron as 'active'; travels the length of the axon; causes release of neurotransmitter into the synapse; allow the neuron to communicate with other neurons.
Nerve impulse: an action potential which propagates along the axon, from the cell body to the synapses.
Depolarization, Repolarization and Recovery
Major parts & fnctn of spinal cord
Fnctns: provides 2 way communctn to & frm brain & bdy; major reflx centr: reflxs are initiatd & completed @ spinal cord
Structrs: 8 Cervicl (neck), 12 Thoracic (chest), 5 Lumbar (lowr back), 5 Sacral, & 1 Coccygeal segmnts
Cranial Nerves
I (Olfactory): Pure sensory nerves & Smell
II (Optic): Pure Sensory Nerves & VIsion
III (Oculomotor): adjst & coordinate eye positn/ mvment
IV (Trochlear): Eye movement up and down & pupil dialatn
V (Trigeminal): Provides sensation to face
VI (Abducens): cntrls outward movmnt of eye
VII (Facial): Supplies the mscles of facial expression
VIII (Vestibulocochlear): Hearing
IX (Glossopharyngeal): helps when swallowing; elevates pharynx and larynx
X (Vagus): Coughing, sneezing, swallowing, and vomiting
XIII (Accessory): Head, neck, and shoulder movements
XIII (Hypoglossal): cntrls tongue movmnts
Spinal Nerves (all mixed and named for point of tsu frm spinal cord)
31 pairs
5 pairs lumbar (L1-L5)
5 pairs sacral (S1-S5)
12 pairs thoracic (T1-T12)
1 pair tiny coccygeal (C0)
8 pairs cervicl nerves (C1-C8)
send electricl signls btween ur brain, spinal cord, & rest of bdy; cntrl motor & autonmc fnctns
Neurotransmittrs: language of nervy system; released @ 2 dif stimultn frequencies; most neurons make 2+
ACH: released @ neuromsculr jnctns
Biogenic amines: emotnal behaviors & biologel clock
Amino Acids: make up all proteins; diffcult 2 prove which r nrtrnsmttrs
Peptides: monomrs of nuclei acids
Gases & lipids
Endocannabinoids: acr as same receptrs as THC
fnctns groupd in 2 classifictns
Effects (determnd by receptr 2 which it binds) : excitatry (depolarzng) vs inhibitry (hyperpolrzng)
Actions: direct (neurotrnsmttr binds directly 2 & opens ion channels) vs. indirect (neurotrnsmttr acts thru intracellulr 2nd msngrs
compare and contrast
Autonomc Nervy System
Somatic Nervy System
nerves that go 2 skin & muscles & involved in conscious activities.
involuntry nervy systm
innrvates smooth mscls, cardiac mscls, & glands
stimulates skeletal mscls
voluntry nervy systm
nerves tht connect CNS 2 visceral organs such as the heart, stomach, and intestines. It mediates unconscious activities.
Both regulate higher brain centers, coordinate both systms,contain both somtc and autonmc fibrs & most r cranial and spinal nerves
Reflex arc
5 components
Receptor: Sense organ in skn, mscl, or othr organ
Sensory Neuron: Carries impulse towards CNS
CNS Integratn centr: Carries impulse within CNS
Motor Neuron: Carries impulse away from CNS
Effector: Structr by which animal responds (mscl, gland, etc)
Disorders/DIseases
Cerebrovascular Accident (Stroke): Occurs when blood flow to a portion of the brain is halted
Causes: Hereditary, blood vessel clogged by plaque or blood clot, blood vessel bursts, diabetes, high cholesterol
Symptoms: Severe headache, change in alertness, change in hearing, taste, touch, or vision
Treatment: Hospitalization, blood thinners, surgery
Autism: Brain disorder that makes it difficult to communicate
Causes: not understood, family history, hereditary, mostly males, environmental
Symptoms: Delay in learning to talk/non verbal, repeated behaviors, anxiety, unusual attachment to object or routine
Treatment: Medication, Coping skills, and specialized therapy
Alzheimer's Disease: A form of dementia associated with age
Causes: Hereditary, Family history, age over 60, high insulin levels
Symptoms: Memory loss, Confusion & Disorientation, Difficulty performing, and everyday functions
Treatment: Uncurable, Medication, Stem Cells, Herbal Therapies
Spinal Cord Injury: Damage to Spinal Cord
Causes: Direct Injury, Assault, fall, accident, weakened vertebral column, men ages 15-35, fluid build up around spinal cord
Symptoms: Weakness, Loss of feeling below damages site, spastic muscles, paralysis
Treatment: Surgery, if completely severed can't be cured, spinal traction
Meningitis: Infection in the meninges surrounding the brain
Causes: Bacteria or viral infection, drug allergies, fungi or parasites
Symptoms: Nausea & vomiting, sensitivity to light, fever & chills, stiff neck
Treatment: Bacterial-hospitalization, antibiotics, medication, prevent with vaccine
Multiple Sclerosis: Autoimmune disease that damages the myelin sheath
Causes: Hereditary, Family history, 20-40 year olds, nerve damage by inflammation
Symptoms: Muscle weakness, spasms, tremors, numbness, vision & hearing loss, constipation, and stool leakage
Treatment: no known cure, physical therapy, steroid treatments, and assistive devices
Drugs of abuse MP
Ecstasy
interferes w serotonin; altrs the transportr, gets confusd, does job in reverse & ovr stimulates cell; slightly addictive, negativly affect mood, sleep, perceptn, and appetite
Heroine
interferes w opiate and dopamine neurtrnsmittrs; mimics opiate & binds to opiate resultng in dopamine inhibitn turnd off; sedation and well being, affects pain signls, stress responses & emotnal attchmnt
Marijuana
intrferes w inhibitry & dopamine neurotrnsmttrs; mimics anandomide & binds to cannabinoid receptrs; dopamine squirt in2 synapse; removes unnecessry short term memories, slow down mvmnt, make person feel relaxed & calm
Methamphetamine
interferes w dopamine neurotrnsmttrs; once meth entrs dopamine vesicles, forces molecules out & trnsportrs work in reverse + ovrstimulates cell; highly addictiv, intense pleasure & exhilaratn
Alcohol
interferes w glutamate & GABA inhibitry trnsmttrs; delivers a sedatv punch & intracts w GABA receptrs making them more inhibitry + prevents glutamate frm excitng cell; affects memory formatn, decisn making, and impulse control negatively
Cocaine
interferes w dopamine trnsmttrs; blocks trnsportrs leaving dopamine trapped in synaptc cleft= overstimulates cell; controls involuntary mvmnt & makes person fidgety & unable to b still
LSD
interferes w serotonin; inhibt receptrs & excite them; affects wakefulness & evokes startle response 2 unexpectd stimuli