Microscopic Anatomy

Question 1

Nervous tissue consists of 2 types of cells

Answer 1

neurons

neuroglia

Question 2

Describe neurons

Answer 2

the functional component of the nervous system, responsible for sensing, thinking, remembering. controlling muscle activity and regulating glandular secretions

Question 3

Describe neuroglia

Answer 3

acts as the ‘glue’ between neurons, they support, nourish and protect the neurons and help maintain homeostasis

Question 4

Most neurons have 3 parts

Answer 4

cell body
dendrites
axon

Question 5

Describe the cell body of a neuron

Answer 5

contains a nucleus and other typical cellular organelles, also contains clusters of RER known as Nissl bodies

Question 6

Describe the role of Nissl bodies

Answer 6

they synthesise proteins to replace cellular components for growth and to regenerate damaged axons in the PNS

Question 7

Describe the role of the cytoskeleton

Answer 7

provides cell shape and support and aids in the transport of materials between the cell body and axon

Question 8

Describe the role and appearance of the dendrites

Answer 8

the receiving or input portions of a neutron, they are multiple, short and highly branched (tree-shaped) and extend from the cell body

Question 9

Describe the role and appearance of an axon of a neuron

Answer 9

single axon conducts nerve impulses toward another neuron, muscle fibre or gland cell, long, thin, cylindrical projection that often joins the body at a cone-shaped elevation called the axon hillock

Question 10

The part of the axon closest to the axon hillock is the …

Answer 10

initial segment

Question 11

In most neurons, nerve impulses arise in …

Answer 11

the junction of the axon hillock and the initial segment - and then travel along the axon to their destination

Question 12

The cytoplasm (axoplasm) is surrounded by a plasma membrane known as the …

Answer 12

axolemma

Question 13

The axon ends by dividing into many fine processes known as …

Answer 13

axon terminals

Question 14

Describe what a synapse is

Answer 14

the site of communication between 2 neurons or between a neuron and an effector (muscle fibre or gland)

Question 15

Describe a synaptic end bulb

Answer 15

where the tip of an axon terminal swells into a bulb-like structure

Question 16

Describe a synaptic vesicle

Answer 16

tiny membrane-enclosed sacs contained within the synaptic end bulb, stores chemical neurotransmitters

Question 17

Describe what occurs when neurotransmitter molecules are released from synaptic vesicles …

Answer 17

they excite or inhibit other neurons, muscle fibres or glands

Question 18

Describe the structural diversity in neurons

Answer 18

neurons have great diversity in size and shape, some have no axon, others have a small one, others from brain to toes, classified by their structure and function

Question 19

Describe how neurons are classified structurally and give the 3 categories

Answer 19

according to the number of processes extending from the cell body
Multipolar - several dendrites and one axon, located in the brain and spinal cord
Bipolar - one main dendrite and one axon, found in the retina, inner ear, and the olfactory area of the brain
Unipolar - have dendrites and one axon fused together to form a continuous process that emerges from the cell body, mostly found in the ganglia of spinal and cranial nerves

Question 20

Describe the function of dendrites

Answer 20

function as sensory receptors detecting stimuli such as touch, pressure, pain or temperature