Topic 37 - Nervous tissue : The Neurone

Question 1

Morphology of the neurone?

Answer 1

• Cell body (soma) consists of cell organelles
• Branched processes (dendrites)
• One myelinated process (axon).

Question 2

Polarity types?

Answer 2

Unipolar
Pseudi-unipolar
Bipolar
Multipolar

Question 3

Unipolar?

Answer 3

single dendrite, with possible branching. Seen in invertebrates.

Question 4

Pseudo-unipolar and bipolar?

Answer 4

two dendrites. Found in sensory ganglia with peripheral end.

Question 5

Multipolar?

Answer 5

-more than two dendrites. Axon originates from axon hillock. Has achromatic nucleus, RER stacks, mitochondria and Golgi.

Question 6

Motor neurons?

Types and morphology

Answer 6

• Cortical pyramidal cells: apical branching dendrites towards cerebellum, with single basal axon, pyramidal cell.
• Cerebellar Purkinje cells: apical branching dendrite to dorsal cerebellum, with single basal axon, rounded cell.

Question 7

Function:

Excitatory cell

Answer 7

-spiny dendrites. Axon forms asymmetrical synapses with excitatory neurotransmitters.

Question 8

Function:

Inhibitory cell:

Answer 8

-non-spiny beaded dendrites. Axon forms symmetrical synapses with inhibitory neurotransmitters.

Question 9

Function:

Dendrites

Answer 9

highly branched processes. Proximal portion contains cytoplasm. Contain microtubules, neurofilaments, SER, ribosomes and mitochondria. Possess postsynaptic densities (site of synaptic transmission, dendrites receive the impulse).

Question 10

Function:
Axons:

Answer 10

cylindrical process with minimal branching but multiple terminal branches (telodendrion). Originates from axon hillock (unmyelinated region, able to receive synapses). Terminates with synaptic bouton (terminal bulb).