Histology Lecture 5 - Nervous System

Name the two parts of the Nervous system

central nervous system and peripheral nervous system

What are the two types of cells in the nervous system?

Nerve cells (neurons) and glial cells

Name the parts of a neuron

cell body (part of which is called the axon hillock), nissl substance, axon, dendrites

What is the part of a neuron that receives impulses?

The dendrites

What is the part of a neuron that sends impulses?

The axon

What is the name of the pigment that shows lysosomes with undigested debris in nerve cells?

Lipofuscin

Axons branch terminally into what?

telodendria

What are the 3 parts of a neuron synapse?

Presynaptic axon terminal
Synaptic cleft
Postsynaptic structure

What is the space between the pre and post synaptic structures called?

Synaptic cleft

Are neurons or glial cells more abundant in the brain?

glial cells (10x more)

What is the function of glial cells?

They support and protect neurons by supplying nutrients

What are the 5 types of Glial cells?

Astrocytes
Ependymal cells
Microglia
Oligodendrocytes
Schwann cells

Where are astrocytes found?

CNS

What is the function of astrocytes?

Provides structural support, helps repair cells, participates in blood-brain barrier,
provides nutrition

What is the most numerous of all glial cells?

Astrocytes

What is the name of the intermediate filament found in astrocytes?

Glial fibrillary acid protein (GFAP)

Where are oligodendrocytes located?

CNS

What is the function of oligodendrocytes?

produces myelin in CNS and insulates axons

Where are Schwann cells located?

PNS

What is the function of Schwann cells?

forms the myelin sheath in PNS to insulate axons

Where are ependymal cells found?

CNS: Lining cavities of the brain and spinal cord.

Where are microglial cells found?

CNS

What is the function of microglial cells?

Eats up debris and dead cells

What is the name of the dense network of astrocyte processes, axons, and dendrites within gray matter?

Neuropil

What part of the brain contains neuron cell bodies, dendrites, unmyelinated axons, glial cells and synapses

Gray matter

What part of the brain contains myelinated axons and oligodendrocytes

White matter

Describe where white and gray matter are located in the brain?

Gray matter is outside (and very deep inside) white matter is inside

Describe where white and gray matter are located in the spinal cord?

Gray matter is inside and white matter is outside

How many layers does the cerebral cortex have?

6 layers

What is the most abundant type of neuron in the cerebral cortex?

pyramidal neurons

How many layers of gray matter are there in the cerebellum?

3 (molecular layer, purkinje cell layer, and granular layer)

Name the 3 layers of the meninges

dura mater, arachnoid, pia mater

What is the function of the blood brain barrier?

Prevent passage of some drugs and toxins from blood into CNS tissue

What are the nodes of Ranvier?

gaps in the myelin sheath within the PNS

What is a collection of neuron cells within the PNS called?

Ganglia

What are the 3 types of nerve bundles?

Epineurium
Perineurium
Endoneurium

What is the name of the cell located in the roof of ventricles in the brain that forms the choroid plexus?

Ependymal cells

Which cell is responsible for the production of Cerebrospinal fluid (CSF)?

Ependymal cells (specifically of the choroid plexus)