Lecture 8

Question 1

Describe the organization of the neural system

Answer 1

CNS/PNS Afferent/Efferent Autonomic/Somatic Parasympathetic/Sympathetic/Enteric

Question 2

What are the different structural and functional categories of neurons?

Answer 2

Structural: pseudounipolar, bipolar, anaxonal, multipolar CNS multipolar efferent
Functional: Afferent, interneuron, efferent

Question 3

What are the glial cells in the CNS?

Answer 3

astrocytes (general purpose), oligodendrocytes (myelin sheath on multiple axons), microglia, ependymal cells (barriers)

Question 4

What are the glial cells in the PNS

Answer 4

schwann cells (form myelin sheaths), satellite cells

Question 5

Describe the myelin sheath

Answer 5

made by schwann cell, made of multiple layers of cell membrane, has nucleus pushed to the outside

Question 6

Name 2 types of myelin degradation diseases

Answer 6

MS, Guillain-Barre

Question 7

Compare/contrast the two different types of electrical signals

Answer 7

graded potential: hyperpolarize/depolarize, can be summed, originates at the dendrites, uses all gated Na/Ca/Cl channels
action potential: depolarize only, all or none phenomenon, originates at the axon hillock, uses voltage gated Na/K channels,

Question 8

What determines the amplitude of a graded potential

Answer 8

strength of stimulus, density of receptors

Question 9

What is the length constant?

Answer 9

how far a signal will travel sqrt of Rm/Ri

Question 10

How can signals be summed?

Answer 10

temporally or spatially