Question

part a assessments
match the terms in column a with the descriptions in column b. place the letter of your choice in the space provided. 1 2
column a
column b
a. astrocyte

1. sheath of schwann cell containing cytoplasm and nucleus

that encloses myelin
b. axon
c. chromatophilic substance

1. corresponds to rough endoplasmic reticulum in other cells

(nissl bodies)
d. collateral

1. network of fine threads extending into nerve fiber

e. dendrite
f. myelin sheath

1. substance of schwann cell composed of lipoprotein that

insulates axons and increases impulse speed
g. neurilemma
h. neurofibrils

1. neuron process with many branches that conducts an

impulse toward the cell body

1. branch of an axon
2. star - shaped neuroglia between neurons and blood vessels
3. nerve fiber arising from a slight elevation of the cell body

that conducts an impulse away from the cell body

Explanation:

• Astrocyte: Star - shaped neuroglia (support cells in the nervous system) that are located between neurons and blood vessels. They have multiple functions like providing nutrients, maintaining the blood - brain barrier, etc. So, it matches description 7.
• Axon: A nerve fiber that arises from a slight elevation of the cell body (axon hillock) and conducts an impulse away from the cell body. This corresponds to description 8.
• Chromatophilic substance (Nissl bodies): These are composed of rough endoplasmic reticulum and ribosomes. In neurons, they correspond to the rough endoplasmic reticulum found in other cells. So, it matches description 2.
• Collateral: As the name suggests, it is a branch of an axon. So, it matches description 6.
• Dendrite: A neuron process with many branches that receives signals (conducts an impulse toward the cell body). So, it matches description 5.
• Myelin sheath: Composed of lipoprotein (from Schwann cells in the PNS or oligodendrocytes in the CNS) that insulates axons and increases the speed of impulse conduction. So, it matches description 4.
• Neurilemma: The sheath of Schwann cell (in the PNS) that contains cytoplasm and nucleus and encloses the myelin. So, it matches description 1.
• Neurofibrils: A network of fine threads (intermediate filaments) that extend into the nerve fiber (axon or dendrite) and provide structural support. So, it matches description 3.

Answer:

a. 7, b. 8, c. 2, d. 6, e. 5, f. 4, g. 1, h. 3