62 terms

"The nervous system"

1) Functions and structure, of the nervous system.
Sensory Intput
1) Gather Information
2) To monitor changes occuring inside and outside the body
3) Changes or stimuli
To process and interpret sensory input and decide if action is needed.
Motor Output
1) a response to integrated stimuli
2) The response activities muscles or glands
Central nervous System (CNS)
Brain and the spinal cord
Peripheral nervous system (PNS)
Nerves outside the brain and spinal cord. (spinal nerves and cranial nerves)
Motor (efferent) neurons
Nerves that carry impulses to the central nervous system to the viscera or glands.
Motor (efferent) division
Nerves that carry impulses away from the central nervous system
Subdivision of the Peripheral nervous system
1) Somatic voluntary nervous system
2) autonomic involuntary nervous system
Support cells
are made from connective tissue
Support cells functions
Are to support, insulate, and protect neurons.
1) Control the chemical of the brain
2) Form blood brain barrier (BBB) between capilaries and neurons.
3) Abundant star shaped cells and brace neurons.
Spiderlike phagocytes and disposed of debris.
Ependymal cells
line cavities od the brain, spinal cord and it also circulate cerebrospinal fluid.
Produce myelin sheath and are wraped aroundnerve fibers in the central nervous system
Satellite cells
Protect neuron cell bodies
Schwann cells
forms myelin sheath in PNS in jelly roll-like fashion
Myelin sheaths
Whitish, fatty mateial covering axons. They are also synthesize by CNS
Nerves in the kidneys
Component of the cell body
Nissl Substance, Neurofibrils, Nucleus, large nucleolus
Nissl substance
Specialized rough endoplasmic ER
Intermediated cytoskeleton, Maintain cell shape.
Nerves processes
1) Dendrites conduct impulses toward the cell body
2) Axons conduct impulses away from the cell body
3) Axons end in axonal terminants
4) Axonal terminals are separated from the next neuron by a gap
Synaptic cleft
gap between adjacent neurons
Junction between nerves( comunication point of two neurons)
Node of Ranvier
gaps in myelin sheath along the axon
Gray Matter
Cell bodies and un myelinated fibers.
basal Nuclei
Clusters of the cell bodies within the white matter of the central nervous.
Ganglia (PNS)
Collections of cells bodies outside the central nervous system
Sensory (Afferent) neurons
1) Carry impulses from the sensory receptors to the CNS
2) Cutaneous sense organs
3) Propriceptors (sense of postition) - detect stretch or tension
Found in neural pathways inthe central nervous system an it connect sensory motor neurons.
Multipolar neurons
many extension from the cell body
Bipolar neurons
One axon and on dentrite
unipolar neurons
have a short single process leaving the cell body
Functional propeerties of neurons
irritability, and conductivity
Ability to respond to a stimuli
Ability to transmit an impulse
Fewer positive ions are inside the cell than outside the cell
membrane allows sodium (Na+) to flow inside the member because of a stimulus
Potassium ion (K) goes out the neurons cell ATP energy pumped sodium ion (Na+) out of the cell
Ation potential
1) If the actrion potential starts, it is propagated over the entire axon.
2) impulses travel faster when fibers have a myelin sheath
Transmission of a signal at sypanases
1) Impulses are able to cross the sypnase to aothe nerve.
2) Neurotransmitter is released from a nerve's axon terminal
3) The dendrite of the next neuron has receptors that are stimulated by neurotransmitter
4) an action potential is started in the dendrite
Rapid, predictable and involuntary response to a stimulus.
reflex arc
the connection of the afferent neurons to the interneurons to the efferent neurons, resulting in a reflex action
somatic reflex
reflex which controls skeletal muscle contractions
autonomic reflexes
smooth muscle regulation, heart and blood pressure regulation, regulation of glands, digestive system regulation
regions of the brain
Cerebral hemispheres(cerebrum), Clencephalon, Brain Stem, Cerebellum
Layers of the cerebrum (Cerebral hemispheres)
Gray matter, white matter, corpus collosum, basal Nuclei
geay matter
the outer layer in the cerebral cortex composed of mostly neuron cell bodies
white matter
fiber tracts deep to the gray matter
corpus callosum
connects hemisphers
basal nuclei
island of gray matter within the white matter
Sits on top of the brain stem, it enclosed by the cerebral hemisphere and made of three parts. Thalmus, hypothalmus, epithalmus.
surround the third ventrical, relay station for sensory impulsesm transfer impulses to the correct cortex for localizin, and interpreting.
locate under thalmus. an autonomis nervous system. responsible for regulating body temp and metabolism, control water balance.
forms root of the third ventricle. house the pineal gland, include chorochoid plexus that forms cerebrospinal fluid.
brain stem
attaches to the spinal cord. different parts of brain stem are midbrain, pons, and medulla oblongata, reticular formation.
reflex center for hearing
bulging part of the brain stem, composed of fiber tracts, and control breathing.
medulla oblongata
lowest part of the brain stem. merges into spinal cord control center for vital signs except temperature.
reticular formation
diffuse mass of gray matter. involved in visceral organ control plays role in awake/sleep cycle and consciousness
provide involuntay coordination of body movements. two hemispheres with convoluted surfaces.
nervous system protection
Scalp, skin, skull, vertebral column, dura mater, arachnoid layer, spinalcerebral fluid, and pia mater.