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Angela Santander Period 1 Nervous system - Coggle Diagram
Angela Santander
Period 1
Nervous system
Major functions of the nervous system
The nervous system helps our body to communicate with each other
Spinal nerves
Part of PNS
Attached to spinal cord by 31 paired roots
Each spinal cord segment designed by pair spinal nerves that arise from it
Cervical and lumosadral enlargement
Nerves serving upper and lower limbs enlarge here
Claude equina : Collection of nerve roots at interior end of vertebral canal
Spinal cord cross-sectional anatomy
Gray Matter is located in core, white matter outside
Central canal run length of cord
Filled with CSF
2 lengthwise grooves run length of cord partially divided in into right and left halves
Dorsal (posterior) median sulcus
Ventral ( anterior) median fissure
Gray matter and spinal cord
Cross section of cord resemble butterfly of letter H
3 areas of gray matter found each side of center are are mirror images
Dorsal horns: Inter neurons receive stomatic and visceral sensory input
Ventral brown: some Inter neurons; stomatic motor neurons
Lateral horns: only in thoracic
Gray com us sure: bridges of gray matter that connect masss of gray matter on both sides
Encloses central canal
Ventral roots: bundle of motor neuron axons that exit the spinal cord
Dorsal roots: sensory input to cord
Dorsal roots (spinal ganglia) cell bodies of sensory neurons
Spinal nerves: formed by fashion pf dorsal and ventral roots
Gray matter divides into 4 groups based somatic or visceral inner vation
Somatic sensory (SS), visceral sensory, visceral motor, and somatic motor
White Matter
Myelinated and non nerve fiber allow communication between parts of spinal cord and brain
Divided onto 3 white columns (funiculi)
Lateral
Ventral (anterior)
dorsal (posterior)
Spinal and cord trauma and disorder
Localized injury spinal cord or roots leads to functional loses
Parenthesias: damage dorsal root or sensory tract
Sensory function loss
Paralysis: caused by damage to ventral roots/horn cells
2 types : Flaccid/spastic
Leads to motor function loss
parapielgia: transaction between T1 and L 1
Quadriplegia: transaction cervical region
Spinal shock: transient period functional loss caudal to lesion
Amyotrophic lateral sclerosis ( ALs)
Destruction ventral horn motor neurons and fiber of pyramidal tract
Symptoms: no ability speak, c]swallow and breathe
Compare & contrast the autonomic nervous system
consist of motor neurons
make adjustment ro wnsure optimal support for body activities
operate via subcpnscious control
Innervate smooth muscle, cardiac miscle,and glands
involuntary nervous system
comparison of motor neurons in somatic and autonomic nerbous sytem
autonomic nervous system
parasympathetic
lightly myelinated axons
ach to ganglion
nonmyelinated postganglionic axon
ACh ro smooth muscle, glands, cardiac muscle
Sympathetic
Ligt myelinated
ach to ganglion
Nonemyelinated axons
Ne
smooth muscle glands cardiac muscle
1 more item...
Ach to adrenal medulla
Somatic nervous system
heavu myelinated axons
single neuron from CNS to effector organds
Neurotrasmitter at effector
effector organs
Effect: stimulatory
Reflex arc (major parts & functions)
Recepors: site of stimulus action
Sensory NeuronL transmits afferent
Integration center: either monsynaptic or polysnaptic region within CNS
Motor neuron: condcuts efferent impulses from integration center to effector organ
Effector; muscle fiber or gland cell that responds to efferent impulses by contracting or secreting
autonomic reflexes: activate visceral effectors
Somatic reflexes: activate skeletal muscle
Drugs (Drugs of Abuse & Mouse Party)
Mouse Party
Methamphetamine
Dopamine neurotransmitter
Meth mics dopamine. Once the meth is inside the cell, it enter the dopamine vesicles forcing the dopamine molecules out. Excess dopamine causes transporter to work reverse. Pumping dopamine out the cells and into synapses.
Meth is addictive because it works directly on the reward pathways, user feeling intense pleasure and exhilaration
Alcohol
GABA inhibitory neurotransmitter and glutamate neurotransmitter
Delivers a double sedative punch interacts with gaba receptors to make them ore inhibitory. Binds to glutamate receptors, preventing glutamate from exciting cells
Affects area of the brain involving in memory formation, impulse control, and decision making
Cocaine
Dopamine neurotransmitter
Cocaine blocks dopamine transporters in synoptic cleft. Dopamine binds again to receptor overstimulation the cell
Brain controlling voluntary movement. Cocaine abuser are fidgety and unable to be still
LSD
Serotonin neurotransmitter
LSD may inhibit them and sometimes may excitable them.
Excites region in brain known as locus coercieres feeling of wakefulness and evoking strake respond to unexpected stimulus
Heroine
Has Inhibitory neurotransmitter/dopamine inhibit action
Dopamine inhibit action turns off because heroin mimics natural opiates and binds to opiate receptors turning off dopamine inhibitiation
With dopamine allowed to flood the synopse, it produces immediate feelings of sedation and well-being
Marijuana
Has inhibitory neurotransmitter
THC mimics anandamide and binds to cannabinol receptors. Anandmide turns off the release of inhibitory neurotransmitters
Anadamine= removing short term memory. It has th feeling of relaxation, calm, and slow in movement
Ecstasy
Has Serotonin neurotransmitter
The transporter starts transporting Serrato in out of the cell. The excess section becomes trapped in synaptic cleft. It binds again to the receptor, overstimulation the cell.
Affects the mood, sleep, perception, and appetite. Also indirectly interacts with the reward pathways. Gives it addictive properties.
Drugs of abuse
Inhalents
Solvents, aerol spray , and gases
Inhaling
Common house jhold product
A chemical that can only be taken when inhaling. They can impart corrdination and speech and judgement. Affects brain with great force and spread can cause haventation confusion, seizure, brain damage, and death
MDMA
Synthetic drug
Swallowing or snorting
It can cause an increase of energy and it causes a feeling of euphoria and emotional connection other affects are involuntary, muscle cramping, chills and sweating. At high level can have panic attacks and seizure.
Ecstasy
Opioids
Morphine
Pills, patch, injecting, snorting, or smoking
Prescription drug
Opioids is a drug that makes you feel like you pupil is pinpoint, and a rush of warmth pleasure. Opioids cause itchy, neasusea, and vomiting. With heavy dose, you can lose conscious and stop breathing
Nicotine
Cigarettes
Smoking, inhaling, roping, vaping, chewing, dipping
Stimulant drug
Has stimulate effect. Increases nervous activity and heart rate fir regular users
Psychedelics
Swallowing, snorting, injecting, smoking
Made in lab found nature
LSD
Cause hulllucination and other distortions
Intensifies sensation and emotion
see, feel, and hear things that aren’t htere’rapid emotion
increase body temp, heart rate,, and pupil
GHB and Rohypnol
Funltrazepan
Swallowing
Depression
Relaxing effect
hallucination neasuos
Dissociative drugs
Swallowing, snorting, injection, smoking
Stimulant
PCP
Hullicanation
Detachment from the body and surrounding
Lose touch to reality
Causes fever, seguirles, death- high dosage
Cranial nerves
most are mixed nerves, but two pairs purely sensory
each numbered and named from rostral to caudal
12 pairs of cranial nerves are associated with brain
Two aattach to forebrain, rest with brain stem
Olfactory nerves
sensory nerves of smell
fibers synapse in olfactory bulbs
pathways terminates in primary olfacotry cortex
purely sensory function
Optic nerves
purely sensory function
optic radiation fibers run to occipital cortex
optic tract continue to thalamus, where they synapse
pass through ptic canals, converge and partially cross over at optic chiasma
Arise from retinas; really a brain tract
Oculomotor nerves
Function in raising eyelid, directing eyeball, constricting iris,and controlling lens shape
Fibers extend from ventral midbrain through superior orbital fissure to four of six extrinsic eye muscle
Trochlear nerves
primarly motor nerve that direct eyeball
Fibers from dorsal midbrain enter orbits via superior orbital fissures to innervate superior oblique muscle
trigeminal nerves
convey sensory impulses from various areas of face
supply motor fibers for mastication
largest cranial nerves; fiber extend from pons to face
Abducens nerves
primarly a motor, nnervating lateral rectus muscle
Fibers from inferior pons enter orbits via orbital fissures
Facial nerve
motor functions include facial expression, parasymapthetic impulses to lacrimal and salivary glands
sensory function from anterior two thirds of tongue
cheif motor nerves of face with five major branches
Fibers from pons travel through internal acoustic meatuses and emerge through stylomastoid foramina to lateral aspect of face
Vestibulocochlear nerves
formerly audiorty nerve
mostly sensory functions; small motor component for adjustment of sensititivity of receptors
Afferent fibers from hearing receptors and equilibrium receptors pass from inner ear through internal acosutic meastuses and enter brain stem at pons-medulla border
Glossopharygenal nerves
Motor function: innervate part of tongue and parynx for swallowing and provide parasympathetic fibers to parotid salivary glands
sensory functions: fibers conduct taste and general sensory impulses from pharynx and posterior tonguen, and impulses from carotid chemoreceptors and baroreceoptors
fibers from medulla leave skull via jugular forearm and run to throat
Vagus nerves
Mosy motor fibers are parasympathetic fibers that help regulate activities of heart lungs and abdominal viscera
sensory fibers carry impulses fro thoracic and abdominal viscera, barereceptor, chemoreceptor, and taste buds of posterior tongue and pharynx
fibers from medulla exit skull via jugular forearm
Only cranial nerves that extend beyond head and neck region
Neurotransmitters
language of nervous sytem
most neurons make two or more neurotransmitters
Classified by chemical and function
Acetylcholine
released at neromuscular junction
synthesized from acetin acid and choline by enzyme choline acetyltranseferase
degraded by enzyme acetylcholinesterase
First identified and best understood
Biogenic amines
catecholamines
Dopamine, norepinephrine and epinephrine made from the amino acid tyrosine
indolamines
histamine; amino acid histidine
seotonin; made from amino acid tryptophan
amino acid
make up all protein , difficult to prove which nueurotransmitters
peptides
endorphins
effects ; excitatroy versus inhibitory
neurotransmitter effects can be excitatory
effect determined by receptors to which it binds
Actions: direct versus indirect
Indirect action: neurotransmitters act through intracellular second messengers
Direct action: neurotransmitters binds directly to and opens ions channels
Major parts and functions of the spinal cord
Spinal cord I’d endowed in vertebral colum
Begins at the forearm magnum
Ends at l1 tor L2 vertebrae
Function: provides 2 wat communication to and from brain and body
major reflex center: reflexes are initiated and completed at spinal cord
Major parts and functions of the brain
Network of neuron work together but span wide are of brain
Reticular formation
Extends through central core of brain stem
Agonal connection w/ hoop, thalamus, cerebral cortex, cerebellum, and spinal cord
Govern brain arousal
Motor function of reticular formation helps control coarse limb movement
Reticular autonomic center regulate visceral motor function
Límbic system
Fornix: fiber tract links limbic system regions
Structures on medial aspects of cerebral hemisphere and dicenphalon
Includes part of die. And some cerebral structure encircle brain stem
Large part of emotional affective brain
Limbic system puts emotional response orders
Ex: skunks smell bad
Output relayed via hypothalamus
Physchosomatic illnes
Limbic interacts with prefrontal lobe
Allows us react emotionally
Hypocampus: memory
Cerebral hemishphere
Function
Cortical gray matter
Localized and interprets sensory inputs
Controls voluntary and skilled skeletal muscle activity
Function in intellectual and emotional process
Basal nuclei (ganglia )
Subcortical motor center motor center
Helps control skeletal muscle movement
Thalamus:
Relays sensory impulses to cerebral cortex
Increases impulses between cerebral motor cortex and lower motor center, including cerebellum
Involved in memory
Hypothalamus:
Chief integration center of autonomic nervous system
Regulates body temp. Food intake, water imbalance, thirst, and biological rhythms and drives
Regulates hormonal output of anterior pituitary glands
Act as endocrine organ, producing pituitary hormones AHD and oxytocin
Midbrain:
Contains nuclei of cranial nerves III-IV
Contains visual and auditory reflex center
Contains subcortical motor center
contains projection fiber
Pons:
Relays information from cerebrum - cerebellum
Cooperates w medullary respiratory center to control respiratory rate and depth
Contains nuclei of cranial nerves V-VII
Contain projection fiber
Medulla oblongata
Relays ascending sensory pathways impulses from skin and proprioceptor through nuclei cuneatus and gracillis
Contains visceral nuclei controlling heart rate, blood vessel diameter, respiroty rate, committing
Relays sensory information to cerebellum through interior
Olivary nuclei
Contains nuclei of cranial nerves VII-X and XII
Projection fiber
site of decussation of pyramids
Reticular formation
Maintain cerebral cortical alertness
Filters out repetitive stimuli
Helps regulate skeletal and visceral muscle activity cerebellum
Process into from cerebral motor cortex, propirocepto and visual and equilibrium pathways
Protection of Brain
Meninges
Function
Protect blood vessels and enclose venous sinuses
Contain cerebrospinal fluid
Cover and protectingcns
Form partition in skull
Consist of three layers
Pía mater
Delicate connective tissue clings tightly to brain
Contains many tiny blood vessel feed brain
Arachnoïdmater
Middle layer with like extension spiderweb
Separated from dura mater by subduer space
Subarachnoid space contains CSf and largest blood vessel of brain
Dura mater
Strongest mining
Major divisions and subdivisions of the nervous system (include all subdivisions of CNS
and PNS)
Central Nervous system (CNS)
sensory (afferent) division
Peripheral Nerous system
Motor (efferent0 division
Autonomic nervous system
Parasympathetic division
Sympathetic division
Somatic nervous system
Action potiental and nerve impulses
A way neuron send signal
It is a long distance signal of axons
Occurs in muscle cells and axons of neurons
Do not decay over distance
Voltage ~100mV
4 main steps
Repolarization: Na+ channels are inactivating and K= channel open
Voltage-gated K+ channels open
K+ exit cell down its electrochemical gardient
Na+ channel inactiviation gate close
AP spikes stop rising
membrane permeability to Na+ declines to resting state
repolarazation membrane returns to resting membrane potiential.
Resting state All gated Na+ and K+ channels are closed :
Leakage channels Na+ and K+ are open
Maintains resting membrane potential
Depolarization: Na= Channels open
Local current open valtag-gated Na+ channels, and Na+ rushes into cell
Na+ influx causes more de., which is opens more Na+ channels
At threshold (-55 to -50 mV) postive feedback causes opening of all Na+ channels
Membrane polarity jumps 30mV
result in large action potiental spike
Not all depolarization. Events produce AP
Hyperpolarized = some K+ channels remain open and Na+ channels reset
K+ channels remain open: allowing K+ efflux
Inside of membrane becomes more negative than in resting
Causes hyper polarized of membrane
Na+ channels begin to reset
Reset electrical condition, not ionic condition
After, Na+/K+ pumps restore ionic. Condition
All or nothing. An AP that either happens completely, or does not happen at all
Propagation : allows AP to be transmitted from origin down entire axon length towards terminal
Refractory period: time in which neuron canno trigger another AP t
Ap occurs in only axon, not other cells
Ap conduction velocities in axons vary widely
Disorders associated with Nervous System
Parkinson Disease
Treatment: includes L-dopa, deep brain stimulation, gene therapy
basal nuclei deprived of dopamine become overactive, resulting in tremors at rest
unknown, but theories include mitochondrial abnormal or protein degradation pathway
Degeneration of dopamine-releasing neurons of substantia nigra
Huntington disease:
later marked by mental deterioration
treated with drugs that block dopamine effect
Initial symptoms include wild, jerky " flapping " movement
stem cell implant research is promising
Fatal hereditary disorder cause by accumulation of protein huntingtin in brain cells
Alzheimer's disease
as brain cells die, brain shrinks
neurofibrillary tangles inside neurons interfere with transport mechanismseventualy killing neurons
Plaques of beta-amylod peptides form in brain
memory loss, short attention span, disorentation, eventual language loss, irritability, moodiness, confusion, hallucination
Progressive degenerative disease of brain that result in dementia
Amyotrophic lateral sclerosis
symptoms: loss of ability to speak, swallow, and breathe
caused by enviromental factors and genetic mutation involving RNA processing
death in 5 years
destruction of ventral horn motor neurons and fiber of pyramidal tract
drug riluzole interfere with glutamate signaling; only treatment
Also called lou gehrig disease
Multiple sclerosis
symptoms: visual disturbance, weakness, loss of muscular control, speech disturbance, incontinence
treatment: drugs that modify immune system activity
Myelin sheaths in CNS are destroyed when immune system attacks myelin
May not be able to prevent, but maintaining high blood levels of vitamin D may reduce risk of development
Is an autoimmune diseases that affect primarrily young adults