Ch 14
Have a starlike shape; most abundant glial cells in the CNS, control ionic environment, induce formation of blood brain barrier
Astrocytes
What is the function of synaptic knobs
Slightly expanded regions at the tips of telodendria Helps regulate synaptic transmission.
What is a node of ranvier
Small spaces between myelin sheaths, where excitation can happen
Central nervous system
Consists of the brain and spinal cord
Describe components of a nerve from small to big
Axon, endoneurium, fasicle, perinuerium, epineurium
Distinguish between CNS and PNS
CNS: Brain and spinal chord PNS: Cranial nerves, spinal nerves and ganglia
Where are cell bodies and axons in CNS
Cell bodies: CNS gray matter Axons: CNS white matter
Where are cell bodies and axons in PNS
Cell bodies: PNS ganglia Axons: PNS nerves
Multipolar neurons
Most common, Motor neurons, interneurons( go in between sensory and motor)
Cuboidal epithelial cells; line internal cavities of the brain secrete CSF
Ependymal cells
What are interneurons
Found only in CNS; facilitates communication between motor and sensory neurons
Peripheral nervous system
Includes cranial nerves, spinal nerves, and ganglia
What is the function of a synapse
It is a site at which neurons communicate with other neurons, muscles, or glands
Small cells; wander through the CNS in response to infection, macrophages of CNS
Microglial cells
Also called Schwann cells; myelinate PNS axons
Neurolemmocytes
What is the function of an axon
Neuron process that conducts nerve impulses away from the cell body ("output")
Large cells; wrap around CNS axons forming a myelin sheath
Oligodendocytes
Which of the following glial cells form a myelin sheath around axons?
Oligodendrocyte, neurolemocyte
What are the structures of a synapse
Presynaptic neuron- Synaptic vesicles contain neurotransmitters, Synaptic cleft Postsynaptic neuron (contains receptors
function of the nervous system
Processing and evaluating information Collecting information Responding to information
What is the function of a dendrite
Receive incoming signals from other cells and transmit the information to the cell body.
Flattened cells in the PNS; around neuronal cell bodies in ganglia, protect and regulate nutrients for cell bodies in ganglia
Satellite cells
Afferent neuron
Sensory
Unipolar neurons
Sensory neurons
The ___________ nervous system transmits information from receptors to the CNS, while the ___________ nervous system transmits information from the CNS to the rest of the body.
Sensory, motor
What is the function of a cell body (soma)
Serves as the neuron's control center and is responsible for receiving, integrating, and sending nerve impulses.
What is the structure and function of myelin sheaths
Structure: Made by oligodendrocytes in the CNS and schwann cells in the PNS, are a white fatty coating and have nodes of ranvier Function: Supports and protects and insulates axon, increases speed of conduction
Why do neurons differ from other body cells
They have a high metabolic rate (the need for constant glucose and oxygen They have a high longevity which means they can live for your whole lifetime if you don't kill them They cannot be reproduced like other cells
Motor (efferent) nervous system
Transmits info from CNS to effectors is comprised of somatic and autonomic motor systems
Sensory (afferent) nervous system
Transmits info from receptors to CNS is comprised of somatic and visceral sensory systems
Efferent neuron
motor
Bipolar neurons
special senses like sight and smell, uncommon found in eye and nose
What are myelin sheaths
the insulating covering around the axon consisting of concentric layers of myelin. Insulating covering
What is the function of an axon hillock
triangular region that the axons attaches to, decides to let impulse go through
