Chapter 1: Nerve Cells & Nerve Impulses

Question 1

how does our neurology inform our mental experiences?

Answer 1

mental experiences are because of activity of separate but interconnected cells

Question 2

Neuro doctrine

Answer 2

(Santiago Ramón y Cajal)
1. individual cells in the nervous system remain separate
2. cells don’t merge (as previously thought, used staining techniques)
3. combine medicine and art

Question 3

2 major nervous system cells

Answer 3

1. neurons (receive and transmit information with electrical pulses)
2. glia (various functions)

Question 4

parts of a neuron cell

Answer 4

1. dendrites (branching fibers on the surface with synaptic receptors, share information between neurons)
   - more branches = more surface area = more information
2. soma/ cell body (nucleus, mitochondria, ribosomes)
   - metabolic work of cell, covered with synapses
3. axon (transmits nerve impulses to other neurons, organs, muscles)
   - has myelin sheath (insulating material and interruptions – nodes of Ranvier)
4. presynaptic terminals (release chemicals to communicate with other neurons)
   - at the end of axons

Question 5

interneurons (intrinsic neurons)

Answer 5

dendrites and axons within the same structure

Question 6

efferent axon

Answer 6

carries information away from structure

Question 7

affarent axon

Answer 7

brings information into structure

Question 8

microglia

Answer 8

(glial cell)
- removes waste, viruses, etc. from brain and removes dead neurons

Question 9

astrocytes

Answer 9

(glial cell)
- synchronizes axon activity (wrapping around presynaptic terminal and takes up chemicals released by axon)
- dilates blood vessels to increase nutrients into parts of brain with more activity

Question 10

myelin sheath

Answer 10

(glial cell)
- oligodendrocytes (brain and spinal cord), schwann cells (periphery of body) insulates axons

Question 11

radial glia

Answer 11

(glial cell)
- guide migration of neurons and growth during embryonic development
- eventually differentiates into neurons, astrocytes, oligodendrocytes

Question 12

blood-brain barrier

Answer 12

surrounds brain and blocks most chemicals and pathogens
- necessary to block harmful material from entering because neurons don’t regenerate
- most large/ charged molecules can’t cross
- small, uncharged (CO2, O2) and fat-soluble molecules (ex. melatonin) can pass
- active transport pump glucose and amino acid

Question 13

resting potential

Answer 13

• (-70 mV) inside membrane
• Na+/ K+ pump (protein complex) pumps 3 Na+ out while pumping 2K+ inside the cell

Question 14

the action potential

Answer 14

1. depolarization: lowers polarization towards 0
   - stimulation past excitation threshold leads to an ap
2. repolarization: returning to resting potential
3. hyperpolarization: increases polarization passed rest

Question 15

all-or-none law

Answer 15

action potentials = in speed/ intensity in any neurons despite intensity of stimulus
- amplitude, velocity, shape of action potential varies between neurons (variations between protein potentials)

Question 16

molecular basis on action potentials

Answer 16

1.