Nervous System Flashcards
What does the CNS control?
spinal cord + brain
Integration; command center
• Interpret incoming sensory information
• Issues outgoing instructions
What does the PNS control?
everything else
Serve as communication lines among: - sensory organs, - brain and spinal cord, - glands - muscles 
What is functional output?
sensory input vs motor output
subdivisions of nervous system?
anatomically + physiologically
What is part of the anatomical nervous system?
CNS, PNS
what is part of the physiological system?
sensory (afferent) vs motor (afferent)
What causes MS?
voluntary/somatic disorders
Parts of the glia cell?
astrocyte
ependymal cell
microglia
oligodendrocytes (CNS)/schwann cells (PNS)
What do astrocytes do?
from blood brain barrier (BBB) + filter out toxins from blood
what do ependymal cells do?
form CSF (cerebral spinal fluid)
what do microglia do?
phagocytosis for bacteria
what do oligodendrocytes/schwann cells do?
from myelin sheath (white matter) that surrounds and insulates neurone and allow them to conduct impulses at a faster rate
What does nervous tissue contain?
neurons
neuroglia
what do neurons do?
conduct electrical impulses (do not divide in adult life)
What do neuroglia do?
support, protect and insulate nerve cells (continue to divide throughout adult life)
What does the axon do?
moves impulses away from the cell
What do dendrites do?
move impulses to nerve cell (receptive)
How is a nerve impulse delivered?
- dendrite receives message
- nerve impulse moves down
- axon terminal receives impulse and sends message to next nerve cell in line
path of nerve impulse?
dendrite -> cell body -> axon -> terminal
what is the gap between two nerve cells called?
synapse
What is the sympathetic nervous system?
subdivision of the ANS is fight-flight (releases epinephrine, adrenaline)
what is the parasympathetic nervous system?
rest and digest (releases acetylcholine ACH)
functional organization?
only PNS
structural organization?
CNS + PNS
forebrain (L/R cerebral hemispheres)
include frontal,parietal,occipital,temporal lobes
includes cerebral cortex and is responsible for:
motor skills perception thinking memory speech
diencephalon includes?
thalamus + hypothalamus and epithalamus
thamalus: relay station for sensory input
hypothalamus: regulates autonomic functions (body temp, water balance, metabolism, appetite, sex drive/libido)
brain stem includes?
midbrain, pons, medulla oblongata
thamalus
relay station for sensory input
hypothalamus
regulates autonomic functions (body temp, water balance, metabolism, appetite, sex drive/libido)
midbrain
reflex center for vision/hearing
pons
controls breathing
medulla
regulates vital visceral activity (HR, BP, breathing, swallowing, sneezing)
cerebellum
control of motor skills + balance
What surrounds the CNS?
CSF
Characteristics of CSF
similar to plasma, less protein, rich in ascorbic acid, different Na and K ions.
if RBC present in CSF what does that mean?
can indicate meningitis, tumours, ms
What is the BBB
blood brain barrier
maintains constant environment in the brain
only allows water, amino acids and sugar to pass through
cranial nerves
12 pairs for head + neck
described by name, number, course and function
include sensory + motor function
ex: optic nerve
spinal nerves
31 pairs, each nerve divides into dorsal + ventral ramifications
what controls the sleep/wake cycle
reticular formation
what does the sympathetic nervous system thoracic-lumbar subdivision release?
epinephrine (speeds up system)
what does the parasympathetic nervous system cranial-sacral subdivision release?
ACH on effectors (slows down system)
characteristics of sympathetic nervous system?
increase HR, BP, glucose in blood, dilates arrays, reduces blood to digestive, decrease salivation, dilates pupils, sweating, increases metabolic rate and fat breakdown, increases blood to muscles, far vision
characteristics of parasympathetic nervous system?
increases activity in digestive tract, constricts airways, salivation, near vision, decreases HR, BP
three main functions of nervous system?
sensory, integrative, motor
sensory functions?
detect different types of
stimuli, both within body and outside body. Sensory (or afferent) neurons carry sensory information (from receptor) to brain and spinal cord.
The nervous system is responsible for all our?
– behaviors,
– memories,
– movements
Integrative function?
Nervous system integrates (processes)
sensory info and makes decisions for appropriate responses. Many interneurons are involved in this function.
Motor functions?
Involves responding to integrative decisions. Motor
neurons (or efferent) carry info from brain and spinal cord to other nerves or effector organs.

Sensory (afferent) division?
– Nerve fibers that carry information to the central
nervous system
• Motor (efferent) division?

– Nerve fibers that carry impulses away from the central nervous system
Two subdivisions
• Somatic nervous system = voluntary – Consciously controls skeletal muscles
• Autonomic nervous system = involuntary
– Automatically controls smooth and cardiac muscles and glands
– Further divided into the sympathetic (stress: fight or flight) and parasympathetic (rest & digest) nervous systems

neuroglia functions (CNS)?
- Support
– Insulate
– Protect neurons
Astrocytes functions (CNS)?
– Abundant,star-shapedcells
– Controlthechemicalenvironment
-Formbarrierbetweencapillaries and neurons of the brain
– Stabilize/brace neurons
most abundant and versatile neuroglia?
Astrocytes
Microglia functions (CNS)?
– Spiderlike phagocytes
– Dispose of debris
-defend CNS cells
Ependymal cells functions (CNS)?
– Line cavities of the brain and spinal cord
– Cilia assist with circulation of cerebrospinal fluid (formed by choroid plexus = spongy blood vessels in ventricles of brain)
Oligodendrocytes functions (CNS)?
– Wrap around nerve fibers in the central nervous system – Produce myelin sheaths (similar to Schwann cells in PNS)
Satellite cells functions (PNS)?
– Protect neuron cell bodies (similar to astrocytes of CNS)
Schwann cells functions (PNS)?
– Form myelin sheath in the peripheral nervous system
Neurons = nerve cells?
– Cells specialized to transmit messages
– Major regions of neurons
Cell body (aka Soma)?
—nucleus and metabolic center of the cell
• Processes (ex. dendrites)
—fibers that extend from the cell body
Cell body?
– Nissl bodies/substance • Specialized rough endoplasmic reticulum • Site of protein synthesis Neurofibrils • Intermediate cytoskeleton • Maintains cell shape – Nucleus with large nucleolus 
Dendrites?
—conduct impulses toward the cell body • Neurons may have hundreds of dendrites
Axons?
—conduct impulses away from the cell body
• Neurons have only one axon arising from the cell body at the axon hillock
– End in axon terminals (aka terminal buttons)
– Axon terminals contain vesicles with neurotransmitters
– Axon terminals are separated from the next neuron by a gap

Synaptic cleft?
—gap between adjacent neurons
Synapse?
—junction between nerves
– ex. one nerve synapses with the other, neurotransmitters are transmitted across the synaptic cleft
Myelin sheath?
—whitish, fatty material covering axons
Schwann cells?
— produce myelin sheaths in jelly roll- like fashion around axons (PNS)
Nodes of Ranvier?
—gaps in myelin sheath along the axon
– Oligodendrocytes
—produce myelin sheaths around axons of the CNS
Sensory(afferent)neurons?
– Carry impulses from the sensory receptors to the CNS
• Cutaneous(skin)senseorgans
• Proprioceptors—detect stretch or tension
Motor(efferent)neurons?
– Carry impulses from the central nervous system to viscera,
muscles, or glands
Interneurons (association neurons)?
– Found in neural pathways in the central nervous system – Connect sensory and motor neurons
All neurons exhibit?
(i) Irritability
– Ability to respond to stimuli
(ii) Conductivity
– Ability to transmit an impulse (aka action potential)
