The Nervous Tissue Part 1

Question 1

Nervous Tissue

Answer 1

• consists of nervous tissue whose function is essentially to control our functioning as a result of two fundamental properties: 1) irritability: ability to detect and react to stimuli-physical and chemical; 2) conductivity: ability to transmit the reaction to other parts of the body

Question 2

What are the two types of cells in nervous tissue?

Answer 2

• Neurons or nerve cells: specialized to receive stimuli from other cells and to conduct impulses to other parts of the system via their processes.
• Supporting cells: are non-conducting cells that are closely apposed to neurons. In the CNS they are called neuroglia and in PNS they are called Schwann cells and satellite cells

Question 3

Neuron

Answer 3

• structural and functional unit of the nervous system
• junction between two neurons is called the synaptic gap
• formed from a neuroblast which differentiates to form only one adult nerve cell

Question 4

Basic Structure of the Neuron

Answer 4

1) Cell body (soma): containing the nucleus and cytoplasm

2) Processes: one or many dendrite these are relatively short and branching and never extend very far from the cell

Question 5

Classification of Neurons

Answer 5

• There is considerable variation both in size and shape
• Using a special silver stain invented by Golgi, neurons can be placed into one of two types: 1. Golgi Type 1- have large cell bodies
  Golgi Type 2: these have small cell bodies

Question 6

Classification of Neurons:

Answer 6

• Based upon the number of processes extending from the cell body
  1) Pseudounipolar: typically seen in the sensory ganglia of spinal and cranial nerves
  2) they have one axon and one dendrite
  3) Multipolar: they have one axon and two or more dendrites