Neurons Lecture Notes

Question 0

Parts of a neuron

Answer 0

Dendrites, soma (cell body), nucleus, Axon, myelin sheath, axon terminals.

Question 1

Neuron

Answer 1

The building block of the nervous system

Question 2

Dendrites

Answer 2

Receives messages from other neurons and carries them to the cell body

Question 3

Soma (cell body)

Answer 3

The neurons life support center. Contains the neurons nucleus. It’s the neurons decision-making center. It decides whether or not to fire and send a message (action potential) to the other neurons

Question 4

Nucleus

Answer 4

Inside the soma. Contains the neurons DNA

Question 5

DNA

Answer 5

Deoxyribonucleic Acid. An organism’s genetic code. Strands are held together by nucleotides (adenine, guanine, thymine and cytosine).

Question 6

Axon

Answer 6

The cell body since electrical impulses in the form of an action potential through the axon. It is like a wire or cable that carries the impulse to the axon terminals

Question 7

Myelin

Answer 7

A substance around the axon of a neuron that serves as insulation enables the action potential to travel rapidly

Question 8

Nodes of Ranvier

Answer 8

The periodic gaps in the Myelin sheath that helps the action potential travel rapidly

Question 9

Axon terminals

Answer 9

Located at the very end of the axon. They form connections with other neurons to relay messages (presynaptic)

Question 10

Dendritic spines

Answer 10

Protrusions on the dendrites of a neuron that form synapses with the terminal buttons from sending neuron’s (post synaptic)

Question 11

Synapse (synaptic gap or synaptic cleft)

Answer 11

A gap in the junction between the axon terminal are they sending neuron and the dendrite spine of the receiving neuron

Question 12

Neurotransmitters

Answer 12

Chemicals used to transmit messages between neurons

Question 13

Glutamate

Answer 13

The most excitable neurotransmitter

Question 14

Gamma amino butyric acid (GABA)

Answer 14

Neurotransmitter which generally inhibits activity in neurons

Question 15

Dopamine

Answer 15

Important in reward motivated behavior.

Question 16

Serotonin

Answer 16

Regulates mood, appetite, and sleep

Question 17

Synaptic vesicles

Answer 17

Groups of neurotransmitters package together and located with in the terminal button (presynaptic)

Question 18

Ionotropic receptors

Answer 18

Neurotransmitters released from synaptic vesicles bind, in a lock and key fashion, to ionotropic receptors located on dendritic spines (post synaptic)

Question 19

Threshold of excitation

Answer 19

A specific potential (voltage) that the neuron (cell membrane) must reach in order to trigger an action potential

Question 20

Excitatory post synaptic potentials

Answer 20

Bring the nerve potential closer to the threshold of excitation (more negative)

Question 21

Inhibitory postsynaptic potentials

Answer 21

Take the neuron potential farther away from the threshold of excitation (more positive)

Question 22

Three types of neurons

Answer 22

Sensory neurons (afferent), motor neurons (efferent) and interneurons (also called relay neurons)

Question 23

Sensory neurons

Answer 23

Brings messages in from the sensory organs to the brain

Question 24

Motor neurons

Answer 24

Sends messages out from the brain to muscles, organs, glands, etc.

Question 25

Interneurons (also called relay neurons)

Answer 25

Found in the brain. These neurons form connections between other neurons