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