28 Nervous System (Neurons & Synapsis)

Question 1

What are the 2 types of nervous tissue?

Answer 1

Neurons (nerve cells)

Neuroglia (supporting cells)

Question 2

What are the 6 types of neuroglia?

Answer 2

4 in CNS:
astrocytes (support and exchange)
microglial (monitor neuron health)
ependymal (barrier between CSF and CNS cells)
oligodendrocytes (insulation)

2 in PNS:
satellite cells (support and exchange)
Schwann cells (insulation)

Question 3

What are the 3 types of neurons?

Answer 3

motor / efferent
sensory / afferent
interneuron

Question 4

What are the 4 characteristics of neurons?

Answer 4

excitability
longevity
amitotic
high metabolic rate

Question 5

What are the 5 features of a neuron?

Answer 5

cell body

dendrites (receptive tendrils)

axon hillock (portion of cell body where axon emerges)

axons (generate nerve impulses away from body)

axon terminal (end region of an axon, secretory region of a neuron)

Question 6

What type of cells insulate axons in the CNS and PNS?

Answer 6

CNS: oligodendrocytes

PNS: Schwann cells (layered around neuron with nodes of Ranvier in between)

Question 7

What are the 2 types of synapses?

Answer 7

chemical (most common)

electrical (very uncommon, mostly in brain)

Question 8

what is a synapse?

Answer 8

the junction where information is passed from one neuron to another neuron or to an effector cell

Question 9

What are the 3 components of a synapse?

Answer 9

pre-synaptic neuron
synaptic cleft
post-synaptic neuron

Question 10

what is the synaptic cleft?

Answer 10

a fluid filled space between the pre-synaptic and post-synaptic neuron, neurotransmitter diffuses across synaptic cleft

Question 11

What are the 7 types of chemical synapsis?

Answer 11

AP arrives at pre-synaptic axon terminal

AP opens voltage gated calcium channels on axon terminal membrane

calcium stimulates release of neurotransmitter from pre-synaptic vesicles into synaptic cleft

neurotransmitter diffuses across synaptic cleft

neurotransmitter binds to receptors on post-synaptic membrane

post-synaptic neuron / effector cell may be excited or inhibited by neurotransmitter

neurotransmitter cleared from synaptic cleft by reuptake, enzymatic breakdown or diffusion

Question 12

what is a neurotransmitter?

Answer 12

chemicals used for neuronal communication

can be inhibitory or excitatory

Question 13

what do EPSP and IPSP mean?

Answer 13

EPSP = excitatory post synaptic potential

IPSP = inhibitory post synaptic potential