Control center and communication network:
Directs body functions, interprets external environment, determines reaction to pain
Nervous system>CNS
Brain and Spinal cord
Nervous system>PNS>___&___>______&______
somatic division and autonomic division
sensory neurons and motor neurons
Which division of the peripheral nervous system is involuntary?
Autonomic
Nerve cells
Neurons
Bundles of nerve cells or fibers
Nerves
Cells that support and protect, "nerve glue
Neuroglia
60% of our brain is made of what?
Neuroglia
What most often causes brain tumors?
Neuroglia
Astrocytes
Star shaped cells, support and connection
Oligodendroglia
Support, myelin sheath formation (only in CNS)
Microglial
Phagocytes that eat bacteria and cellular debris, protects CNS
Ependymal
line the ventricles of the brain and spinal cord
Schwann
form myelin sheaths in PNS
Which neuroglia cells form myelin sheath in CNS?
Oliodendroglia
Which neuroglia cells form myelin sheath in PNS?
Schwann
Cell body
Soma
Dendrite
Receptive areas- branchlike
Axon
extension of cell body, Schwann cells
Nodes of Ranvier
gaps in myelin
Myelin
whitish fatty material that looks waxy, protects axon and speeds up transmission
Axons outside of the CNS are myelinated by__
Schwann cells who wrap themselves tight around axon
Myelin function
provides protection and conduction
Detect environmental stimuli
Receptorsdet
Receive impulse
Sensory neuron
Sensory neuron AKA
Afferent
Transmit impulse for interpretation
Internuncial
Internuncial AKA
Interneurons
Reaction to stimulus, usually muscular response
Motor neurons
Motor neurons AKA
Efferent
Irritability
The ability to react to a stimulus and convert it to a nerve impulse
Conductivity
The ability to transmit the impulse to other neurons, muscles, or glands
Plasma menbrane of a resting neuron is __
polarized
Nerve cell resting potential
-70 mV
-Na+ higher on outside
-K+ higher on inside
- Some negatively charged Cl- ions
-Negative charge on inside
-Positive charge on outside
-As long as the inside remains more negative ,it will be inactive
Depolarization
-Change in the polarity of the neuron's membrane, approaches o mV
-Na+ rush inside cell, changes from neg to pos
-Inside is now more pos, outside is less pos
Action potential: Nerve impulse around
30 mV
Nerve impulse is an ____
All or none response
Repolarization
Outflow of positive ions from the cell restores the electrical condition to the resting state
Unmyleninated fibers
Conduct impulse over its entire length, but the conduction is slower than myelinated
Myelinated fibers:
travels by salutatory conduction
Nodes of Ranvier-
Breaks in the myelin sheath
Saltatory Conduction
-Action potential traveling down the axon jump from node to node
-"to leap"
- faster way to conduct because you're bypassing space
All or none law
If a nerve fiber carries any impulse, it will always be full strength
Imbalances
Factors that block the transmission of nerve impulses (alcohol, anesthesia)
Synapse
space between the axon of one cell and the dendrites of another
Synaptic transmission
-Axon terminal branches close to next dendrites
- Impulse reaches axon terminals
-Triggers neurotransmitter release into synaptic cleft
Neurotransmitter
a chemical messenger
Reflex
Simplest type of neural response, involuntary
Only a sensory and motor neuron involved in
Relfexes
Examples of reflexes
Knee jerk, blinking, coughing, sneezing, vomiting
Response
Reaction to a stimulus
Reflexes ONLY
go to spinal cord, not the brain, which is why is happens so fast
Nerves that carry out the plans made by the CNS
Motor nerves
Part of the nervous system that contains the brain and spinal cord
Central nervous system
Also described as afferent neurons
Sensory nerves
Nerves that gather information from the environment and carry it to the CNS
Sensory nerves
Part of the nervous system consisting of nerves that connect the brain and the spinal cord with the rest of the body
Peripheral nervous system
Also described as efferent nerves
Motor nerves
Common type of glial cell that supports and protects the neurons, the cells helps form the blood-brain barrier
Astrocyte
Nerve tissue that is called nerve glue
Neuroglia
Nerve cells that transmit information as electrical signals
Neurons
Type of glial cell that lines the inside cavities of the brain and helps form the cerebrospinal fluid
Ependymal cell
Glial cells that engage in phagocytosis of pathogens and damaged tissue
Microglia
Glial cells that form the myelin sheath in the PNS
Schwann cells
Clusters of cell bodies located in the CNS
Nuclei
Clusters of cell bodies located in the PNS
Ganglia
Part of the neuron that transmits information away from the cell body
Axon
Part of the neuron that contains the nucleus; dendrites bring information to this structure, and the axon carries information away from this structure
Cell body
White, fatty material that surrounds the axon; it increases the rate at which the electrical signal travels along the axon
Myelin sheath
Part of the axon where the neurotransmitters are stored
Axon terminal
Treelike part of the neuron that receives information from another neuron and transmits that information toward the cell body
Dendrites
A layer of cells that covers the axons and peripheral neurons; concerned with nerve regeneration
Neurliemma
Makes white matter white
Myelin sheath
Allows for saltatory conduction of the nerve impulse
nodes of Ranvier
A common neurotransmitter
Acetylcholine
Nerve cells that transmit information as electrical signals
Neurons
Internuncial AKA
Interneurons
Reaction to stimulus, usually muscular response
Motor neurons
Motor neurons AKA
Efferent
Irritability
The ability to react to a stimulus and convert i
Internuncial AKA
Interneurons
Reaction to stimulus, usually muscular response
Motor neurons
Motor neurons AKA
Efferent
Irritability
...
Internuncial AKA
Interneurons
Reaction to stimulus, usually muscular response
Motor neurons
Motor neurons AKA
Efferent
Internuncial AKA
Interneurons
Reaction to stimulus, usually muscular response
Motor neurons
Motor neurons AKA
Efferent
Internuncial AKA
Interneurons
Reaction to stimulus, usually muscular response
Motor neurons
Motor neurons AKA
Efferent
Internuncial AKA
Interneurons
Internuncial AKA
...
Receptors
det