Cells & Synapses

Question 1

Neurons

Answer 1

“MVP, teachers pet, valedictorian”

Early anatomists viewed neurons as continuous series of tubes

Question 2

Neuron doctrine

Answer 2

Ramon y Cajal (1852-1934)

Cells of the brain (neurons and otherwise) are separate and independent in structure and function.

Informations is transmitted across tiny gaps (synapses)

Question 3

Axons _______, dendrites _______.

Answer 3

Speak, listen

Question 4

4 zones of neuron anatomy

Answer 4

Input (dendrites)

Integration (cell body)

Conduction (axon)

Output (axon terminals)

Question 5

Types of neurons and their functions

Answer 5

Sensory neurons- perceive senses, diverse shapes depending on associated sense, etc. LONG.

Interneurons- send electrical signals from one neuron to the next. SHORT.

Motoneurons- motor neurons, cause muscular contractions. LONG.

Question 6

Glial Cells/”Glia”

Types

Answer 6

“Runner-up, unsung hero, best sportsmanship”

Astrocytes

Oligodendrocytes

Microglia

(some glia respond to brain injury by swelling. This edema damages neurons and is responsible for many symptoms of brain injuries)

Question 7

Astrocytes

Answer 7

coordinate neuronal function

provide structure (scaffolding for neuron growth)

provide nutrients from blood

protection (blood brain barrier, preserve basic health of neurons)

diverse function

Question 8

Oligodendrocytes

Answer 8

(Called Schwann cells when in PNS)

Form myelin (the fatty sheath on axons that insulates axons and increases speed and efficiency)

More specialized function

Question 9

Microglia

Answer 9

Digest dead or damaged cells

Remove debris “clean up crew”

More diverse function

Question 10

Synapse

Answer 10

Tiny gap that information is transmitted across

Estimated 10^15 synapses in the brain

Question 11

Axon Hillock

Answer 11

On the cell body, converts input into electrical signals

Question 12

Axon

Answer 12

Conducts electrical signals to innervate target

Acts as connection of cell body and dendrites

Question 13

Types of axonal transport

Answer 13

Anterograde- forward, away from cell body, moves proteins to axon terminals

Retrograde- backward, toward cell body from axon terminal, move debris for recycling

Axodendritic (axon to dendrite)
Axoaxonic (axon to axon)
Axosomatic (axon to cell body/soma)

Question 14

Action Potential

Answer 14

Electrical nerve impulse

Short lived change in the cells membrane voltage

Cell to cell communication

“Spikes” or a neuron fires (frequency of neuron firing)

Question 15

Neuroplasticity

Answer 15

Capacity for continual remodeling of connections between neurons

Question 16

Electrical signaling

Answer 16

“Mass text,” immediate (transmitted directly between neurons)

Question 17

Chemical signaling

Answer 17

More common, take more time to be received and “read”, easier to control, more precise and selective

Use neurotransmitters which diffuse across the synaptic gap to send message

Can effectively convert signal in steps (electrical to chemical and vice versa)