Nervous Tissue, Dr. Ayad

Front 1

Phsyiological properties

Back 1

-

Front 2

what is excitability?

Back 2

ability to produce action potential in response to a stimulus

Front 3

What is conductivity?

Back 3

ability to propagate action potential along the neural membrane

Front 4

NERVOUS TISSUE CELLS

Back 4

NERVOUS TISSUE CELLS

Front 5

Neurons are?

Back 5

cells with multiple processes,
one AXON conducting action potentials away from cell body

one or more DENDRITES conducting graded potentitlas toward the cell body

Front 6

Neuroglia cells are?

Back 6

cells of support to the nerve cells and their processes. (two main types, each has various subtypes)

Front 7

TYPES OF NEURONS

Back 7

Unipolar
pseudounipolar
Bipolar
Multipolar

Front 8

Unipolar or pseudopolar

Back 8

one process
e.g., in spinal ganglia

Front 9

Bipolar neurons

Back 9

with two processes
e.g., in retina

Front 10

Multipolar neurons

Back 10

are with two or more subtypes

Front 11

What are the Multipolar subtypes?

Back 11

1. Stellate-star shaped
e.g., in autonomic ganglia
2. pyramidal- e.g., in cerebral cortex
3. Piriform- pear shaped, e.g., in cerebellum
4. Granule cells- small with nucleus filling most of the cell
e.g., in cerebellum

Front 12

Golgi type I cells have long ____?

Back 12

axons

(nerve cells may be based on the length of axon)

Front 13

Golgi type II cells have short____?

Back 13

axons

Front 14

Nerve cell processes only have two types

Back 14

dendrites and axon

Front 15

Dendrites

Back 15

MAY BE ONE OR MORE
usually short thick wall, many branches.

Front 16

Axon

Back 16

ONLY ONE PER CELL
usually thin and long with terminal branches(telodendria)

Front 17

What are synapses?

Back 17

sites of contact between nerve cells or nerve cells and end organs

Front 18

What are the three type of synaptic contacts?

Back 18

Axosomatic
Axodendritic
Axoaxonic

Front 19

Name the nerve fiber coverings.

Back 19

Myelin sheath
neurolemma or schwann's sheath

Front 20

Describe Myelin sheath nerve fiber coverings.

Back 20

mainly formed of lipid
divided into segments, the internodal segments by constrictions known as NODES OF RANVIER.
Function: SPEED UP CONDUCTION

Front 21

Describe Neurolemma/Schwann's sheath.

Back 21

lie outside myelin sheath, series of flat cells with flat nuclei, known as SCHWANN CELLS.
Function: as protective covering, plays role in regenerating nerves, forms myelin sheath

Front 22

What are the Types of Nerve Fibers?

Back 22

1. NACKED FIBERS- No coverings-e.g., grey matter of CNS
2. MYELINATED BUT NO NEUROLEMMA- e.g., white matter of CNS
3. NEUROLEMMA BUT NO MYELIN- eg, autonomic nerves
4. NEUROLEMMA AND MYELIN- e.g., spinal nerves

Front 23

Neuroglia cells. what is their function and name the two main types.

Back 23

1. cells of support to nerve cells and their processes
Main types are Neuroglia Proper- Modified neuroglia

Front 24

Neuroglia proper are located?

Back 24

only in the CNS

Front 25

Modified Neuroglia are found?

Back 25

in CNS and PNS

Front 26

There are 3 subtypes of Neuroglia Proper. name them.

Back 26

Astrocytes
Oligodendroglia
Microglia

Front 27

Astrocytes

Back 27

star shaped, mutiple processes ending by perivasculatr feet over bl vessels. They FORM BLOOD BRAIN BARRIER

Front 28

What are the two subtypes of Astrocytes

Back 28

Protoplasmic astrocytes- FOUND IN GRAY MATTER OF CNS
Fibrous Astrocytes- FOUND IN WHITE MATTER OF cns

Astrocytes develop from ectoderm

Front 29

Oligodendroglia

Back 29

They FORM THE MYELIN SHEATH around nerves and develop from ectoderm

Front 30

Microglia

Back 30

they are PHAGOCYTIC CELLS arising from mesoderm, found in gray and white matter of CNS

Front 31

Modified Neuroglia are found in _____ and _____ and include the following

Back 31

1. CNS and PNS
2.Neurolemma Cells (schwann cells)- present only in PNS
Satellite Cells- are schwann cells SURROUNDING CELL BODIES OF NEURONS INSIDE GANGLIA
Ependymal cells- LINING VENTRICLES of the brain and central canal of sp cord, are columnar cells with some cilia

Front 32

Neuroglia in general carry these functions....

Back 32

1. support nerve cells and processes
2. control flow of material to N. tissue, perivascular feet form layer around bl vessels, thus BBB
3. defense of cns via phagocytic microglia
4. formation of myelin by oligodendroglia