Nervous System Victoria Sanchez P.2
Major Functions of the Nervous System
3 Main Functions
Integration
Motor Output
Sensory Input
Information from internal/external changes
Processes & Interprets input
Produces a response
Major divisions and subdivisions of the nervous system
PNS
CNS
2 Divisions
Sensory ( afferent )
Motor ( efferent )
Visceral Sensory Fibers
Somatic Sensory Fibers
impulses from skin, muscles, and joints
impulses from visceral organs
Autonomic Nervous System
Somatic Sensory Fibers
Voluntary
Involuntary
Impulses from CNS ro skeletal muscles
Parasympathetic
Sympathetic
Brain
Spinal Cord
Think, Learn, Move, & Feel
Carries messages to and from
Tissues
PNS
CNS
Schwann cells
Satellite Cells
Surround cell bodies in CNS
Sorround all peripheral never fibers
Astrocytes
Microglial cells
Ependymal
Oligodendrocytes
Branced cells
Forms insulating myelin sheaths
Lines the central cavities of both brain and spinal cord
Squamous to columnar shape
Respond to nerve impulses
Most abundant
Small and ovoid cells
Transform into phagocytize microorganisms
Classification of Neurons
3 groups based on # of processes
Bipolar
Unipolar
Multipolar
3+ processes, 1 axon
2 processes, 1 axon 1 dendrite
1 T-like process , 2 axons
Most common
Rare
Psuedounipolar
3 groups based on direction of impulse
Motor
Interneurons
Sensory
99% neurons are interneurons
Shuttle signals through CNS
Multipolar
Impulses from CNS to effectors
Unipolar
Impulses from sensory to CNS
Connective Tissue Coverings
Nervous Disease/Disorder
Alzhiemers
Spinal Cord Injury
Autism
Meningtis
Cerebrovascular Accident
Multiple Sclerosis
Hereditary & Environmental Factors
Vision & Hearing loss
Autoimmune disease that damages myelin sheaths
NKC
Antibiotics or Hospitalization
Nausea & irritation
Drug allergies & Tumors
Infection in the meningitis
Paralysis
Surgery or P.T
Weak vertebral column
Damage to spinal cord
Memory loss/ mood changes
Uncurable
Hereditary or post head trauma
Form of dementia associated w/ age
Medication/ therapy
Anxiety/ depression
Family history
Brain disorder; makes communication difficult
Blood vessels burst
Blood flow to brain is halted
Loss of coordination/balance
Blood thinners/hospitalization
Drugs of Abuse
Perimysium
Epimysium
Endomysium
Surrounds single myocyte
Surrounds fasicle
Surrounds entire skeletal muscle
Heroine
Ecstasy
Marijuana
Methamphetamine
Heroine shuts off dopamine inhibitation
Dopamine
Dopamine floods synapse
Ecstacy absorbed by serotonin
Affects the serotonin pathways (affects sleep/mood)
Seratonin
Inhibitation shuts down and dopamine floods synapse
Short term memory loss
Dopamine & Anandamide
Forces dopamine molecules out
Transporters work in reverse
Dopamine
Alcohol
Cocaine
LSD
Alcohol makes it more inhibitory while glutamate prevents cell excition
Impulse control
Gaba and Glutamate
Dopamine left in synaptic cleft ; overstimulation
Involuntary movement
Dopamine
One inhibits, other excites
Responsible for wakefulness; unexpected stimuli
Seratonin
Major parts and functions of the brain
Cerebellum
Brain stem
Cerebrum
Interprets sights, sounds and touches
Maintains your balance, posture, coordination and fine motor skills
Regulates many automatic body function.
Composed of left/right hemisphers
Acts as a relay center connecting the cerebrum and cerebellum to the spinal cord
Major parts and functions of the spinal cord
Thoracic nerves
Lumbar nerves
Cervical nerves
Sacral nerves
Coccygeal nerves
C1-C8
T1-T12
L1-L5
C0
S1-S15
Action potential & the Nerve Impulse
4 main steps
Resting State
Depolarization
Repolarization
Hyperpolarization
Some K+ channels remain open
Na+ channels are reset
K+ exits through electrochemical gradient
Na+ channels close
A.P spike stops rising
-55mv to -50 mV
Na+ and K+ open and currents rush
Membrane polarity jumps to 30Mv
ONLY Na+ and k+ are open
Maintains resting membrane potental
Cranial Nerves
VI- Abducens
VII- facial
V- Trigeminal
VIII- Vestibulocochlear
IV- trochlear
IX- Glossopharyngeal
III- Oculomotor
X- Vagus
II- Optic
XI- Spinal Accessory
I- Olfactory
XII- Hypoglossal
Smell
Vision
Eye movement
Pupil reflex
Eye movement
Face sensation
Chewing
Eye movement
Face movement
taste
Hearing
Balance
Taste
Swallowing
Throat sensation
Movement
Sensation
Abdominal organs
Neck movement
SAME AS VAGUS
Spinal Nerves
Same as below 👇
Send electrical signals to the rest of body
Neurotransmitters
glutamate
histamine
GABA
norepinephrine
dopamine
serotonin
acetylcholine
stimulates saliva and sweat production
controls the heartbeat
triggers muscle contractions
behavior
regulating blood flow
memory
Can treat anxiety
post-traumatic stress disorder
depression
Excites or stimulates nerve cell
Wake-promoting
Rapid eye-movement
cognitive function
regulation of arousal