Priscilla Anzaldo P2 Nervous
Major Functions of Nervous System
Major Divisions/Subdivisions of Nervous System
Tissues
Classification of neurons
Connective Tissue Coverings
Major Parts/Functions of Brain
Major Parts/Functions of Spinal Cord
Action Potential and Nerve Impulse
Cranial Nerves
Spinal Nerves
Neurotransmitters
Compare and Contrast Autonomic Nervous System
Reflex Arc
Disorders & Diseases & Injury
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
External Inferior
External Superior
Internal Sagittal
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
Central Sulcus
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.
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
Injury
cerebellum: process input from cortex, thinking, language, emotion, balance and coordination
midbrain
Left: speech/ language
Right: art, creative thinking, intuition
concussion: temporary alteation in function
disorders
diseases
contusion: permanent damage
Subdural Hemorrhage: pressure from blood
ischemia: tissue deprived of blood supply
cerebral edema: swelling of brain
Hemiplegia: paralysis on one side
translent ischemic Attacks: temporary episodes of reversal cerebral ischemia
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"
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
- Olfactory
- Optic
- Oculomotor
- Facial
- Vestibulocochlear
4.Trochlear
- Abducens
10.Vagus
- Glossopharyngeal
- Hypoglossal
- Trigeminal
- Accessory
sensory function; smell
motor function: none
PS fibers: none
sensory function: vision
Motor function: none
PS fibers: none
sensory function: none
motor function: yes
PS fibers: yes
Sensory function: none
Motor function: yes
PS fibers: no
sensory function: general sensation
motor function: yes
PS fibers: no
sensory function: none
motor function: yes
PS fibers: no
sensory function: taste
Motor Function: yes
PS fibers: yes
Sensory function: hearing
motor function: some
PS fibers: no
sensory function: taste
motor function: yes
PS fibers: yes
Sensory Function: taste
motor function: yes
PS fibers: no
Sensory function: none
Motor function: yes
PS fibers: no
sensory functon: none
motor function: yes
PS fibers: none
central nervous system
peripheral nervous system
brain
spinal cord
somatic nervous system
motor efferent division
somatic nervous system
autonomic nervous system
sympathetic division
parasympathetic division
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
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
efferent pathways and ganglia
target organ responses to neurotransmitters
effectors
overlap of somatic and autonomic function
somatic: innervated skeletal muscle
Autonomic: innervates cardiac/ smooth muscle & glands
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
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
most spinal/ cranial nerves contain both somatic and automimic fibers
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
function classified in 2 groups
- Effects: excitatory vs. inhibitory
- Actions: direct vs. indirect
excitatory: depolarizing
inhibitory: hyperpolarizing
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
- 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
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
- neuroglia: small cells that surround neurons
- Neurons: excitable cells, transmit electrical signals
PNS
CNS
- satellite cells
- Astrocytes
- Microglial cells
- Epidymal cells
- oligodendrocytes
- Schwann cells
neuron cell body (soma)
neuron processes
cling to neurons, synaptic endings, capillaries
function: support neurons, guide migration of young neurons, respond to nerve impulses/neurotransmitters
small ovoid cells with thorny processes
migrate toward injured neurons
may be ciliated
lines central cavities of brain/ spinal column
forms preamble barrier between CSF in cavities/ tissues fluid bathing in CNS cells
branched cells
process wrap CNS nerve fibers forming myelin sheaths in thicker nerve fibers
surrounds neuron cell bodies in PNS
function similar to astrocytes in CNS
surround all peripheral nerve fibers and from myelin sheaths in thicker nerve fibers
vital for regeneration of damaged peripheral nerve fibers
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
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
- axon
receptive (input) region of neuron
convey incoming messsages toward cell body as graded potentials
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
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