Neural Tissue Ch. 13

Synaptic terminals

a bulb at the end of an axon in which neurotransmitter are stored and released.

Dendrities

dendrites are responsible for picking up information from neighboring neurons and transmitting this information to the cell body

What is the function of the myelin sheath? What are the cells that form this sheath in the central and peripheral nervous system?

insulation - much like the coating on the outside of electrical wires. It improves speed at which nerve impulses is conducted along axon CNS- oligodendrocyte PNS- Schwann cells, The Schwann cells cytoplasm creates the second layer and is called the neurolemma.

Motor neurons

multipolar in structure, form the efferent division of the nervous system, cell bodies inside the CNS, impulses away from the CNS

Interneurons

multipolar in structure, most numerous type of neuron, inside the CNS, association neurons

What is the difference between myelinated and unmyelinated axons?

myelinated- multilayered membrane sheath composed primarily of phospholipids that wraps around (coats) axon. unmyelinated- axons that are incompletely covered by oligodendrocyte processes(cns)

Sensory neurons

pseudounipolar in structure, cell bodies outside the CNS, form the afferent division of the PNS, carry impulses to the CNS

axon hillock

the conical area of origin of the axon from the nerve cell body

Neurilemma

the outer surface of a glial cell that encircles an axon

Difference between nucleus and ganglion

-A CNS center with discrete anatomical boundaries -collection of sensory /motor neuron cell bodys

Difference between gray and white matter

-Neural tissue dominated by neuron cell bodies -Neural tissue dominated by myelinated axons

Difference between tract and nerve

-a bundle of axons within the CNS that share a common origin, destination, and function -a bundle of axons in the PNS

Difference between sensory and motor tracts

-carries sensory info from the pns to cns -carrie motor commands from cns toward pns

Compare and contrast the somatic and autonomic nervous systems.

1. SOMATIC BRANCH - output to skeletal muscle. VOLUNTARY 2. AUTONOMIC BRANCH - output to smooth muscles and glands. INVOLUNTARY

Axon

A long, slender cytoplasmic process of a neuron; axons are capable of conducting nerve impulses(( action potentials)

Astrocytes

CNS support cell -Blood-brain barrier -Structural support -Repair damaged neural tissue -Neuron development -Create 3-D framework for the CNS

Oligodendrocytes

CNS support cell -Provides myelin covering of CNS axons -Improves functional performance of neurons

Microglia

CNS support cell -Smallest of the glial cells -Phagocytic cells of the CNS -Engulf and remove cellular debris, waste products, and pathogens

What are the components of the central nervous system and the peripheral nervous system?

CNS- Brain and spinal cord PNS- The peripheral nervous (PNS) includes all of the neural tissue outside the CNS.

What are the characteristics of neural tissue?

NEURONS - responsible for transfer and processing of information SUPPORT CELLS (NEUROGLIA) - isolates the neurons, supporting framework for the neural tissue. Five times as many support cells as neurons

Satellite cells

PNS support cell -Surround neuron cell bodies in peripheral ganglia -Regulate exchange of nutrients and waste products -Isolates neurons from other cells in the ganglia

Ependymal cells

Support cell of the CNS -These cells line the ventricles of the brain -Monitor the composition of CSF

Schwann cells

Support cell of the PNS -Associated with all axons of the PNS -On some axons the Schwann cell wraps around the axon to from the myelin sheath -Typically a Schwann cell can cover or myelinate about 1mm of axon length -Space between the myelin sheath is the Node of Ranvier also called the neurofibril node -On other axons the Schwann cell is merely associated with the axon and does not wrap around - unmyelinated axons -Presence of the sheath is to "insulate" the axons and speed up rate of nerve conduction

What is the difference between the central and peripheral nervous system?

The CNS is responsible for integrating, processing, and coordinating sensory input and motor output. The PNS provides sensory information to the CNS and carries motor commands from the CNS to peripheral tissues and system.