Chapter 2 Nerve Cells and Nerve Impulses

Question 1

• A cell found in the nervous system, receive information and transmit it

Answer 1

Neurons

Question 2

Discovered the neuron, father of neuroscience, cells are not all connected but there is spcacs between them, Golgi-stains, teamed up and used stain to see neurons.

Answer 2

Ramon Y Cajal

Question 3

the surface of the cell, a structure that separates the inside of the cell from the outside environment. It is composed of two layers of fat molecules that are free to flow around one another. Most chemicals can NOT cross the membrane but specific protein channels allow a controlled flow of water, oxygen, sodium, potassium, calcium, chloride, and other important chemicals.

Answer 3

Membrane (Plasma Membrane)

Question 4

the structure that contains the chromosomes.

Answer 4

Nucleus

Question 5

the structure that performs metabolic activates, providing the energy that the cell requires for all other activities. _______require fuel and oxygen to function.

Answer 5

Mitochondrion

Question 6

the sites at which the cell synthesizes new protein molecules. Proteins provide building material for the cell and facilitate various chemical reactions.

Answer 6

Ribosome

Question 7

some ribosomes may attach to this; it is a network of thin tubes that transport newly synthesized proteins to other locations.

Answer 7

Endoplasmic Reticulum

Question 8

has its SOMA in the Spinal Cord. It receives excitation from other neurons through its dendrites and conducts impulses along its axon into the muscle. Every _________is an Efferent from the nervous system.

Answer 8

Motor Neuron

Question 9

specialized at one end to be highly sensitive to light, sound, or touch. Every _______is an Afferent to the rest of the nervous system.

Answer 9

Sensory Neuron

Question 10

branching fibers that get narrower near their ends. The ______ surface is lined with specialized synaptic receptors, which allows the ______to receive information from other neurons.

Answer 10

Dendrites

Question 11

the short out growths that increase the surface area available for synapses. Greater the surface area the more information it can receive.

Answer 11

Dendritic Spines

Question 12

contains the nucleus, ribosome, and mitochondria. Most of the metabolic work of the neuron occurs here.

Answer 12

Cell Body (SOMA)

Question 13

a thin fiber of constant diameter (longer than dendrites) considered the neurons information sender, conveying an impulse toward other neurons or an organ or muscle.

Answer 13

Axon

Question 14

insulating material that covers vertebrate axon speeds up the action potential around the axon “fatty” covering enables “jumping” (nodes of ranvier).

Answer 14

Myelin Sheath

Question 15

gaps between myelin sheath, where the sodium pumps are during an action potential, it jumps from node to node speeds up action potential.

Answer 15

Nodes of Ranvier

Question 16

the point from which the axon releases chemicals that cross through the junction between one neuron and the next.

Answer 16

Presynaptic Terminal

Question 17

brings information INTO a structure.

Answer 17

Afferent Axon

Question 18

carries information AWAY from a structure

Answer 18

Efferent Axon

Question 19

if a cells dendrites and axon are entirely contained within a single structure. A neuron that transmits impulses between other neurons, especially as part of a reflex arc.

Answer 19

Interneuron or Intrinsic Neuron

Question 20

space between the axon terminal and the next neuron.

Answer 20

Synapse

Question 21

end of the axon, message is going to be sent to the next neuron, neurotransmitter sent out.

Answer 21

Axon Terminal

Question 22

• The other major component of the nervous system, it is like the “GLUE” that holds the neurons together.

Answer 22

Glia

Question 23

star shaped, wraps around the presynaptic terminals of a group of functionally related axons. Helps synchronize the activity of the axons enabling them to send messages in waves. They also help remove waste material created when neurons die and control the amount of blood flow to each brain area.

Answer 23

Astrocytes

Question 24

very small cells also help remove waste as well as viruses, fungi, and other microorganisms. They function like the immune system.

Answer 24

Microglia

Question 25

Central Nervous System builds Myelin Sheath

Answer 25

Oligodendryocytes

Question 26

Peripheral Nervous System builds Myelin Sheath

Answer 26

Schwann Cells

Question 27

guide the migration of neurons and their axons and dendrites during embryonic development

Answer 27

Radial Glia

Question 28

a protein mediated process that expends energy to pump chemicals from the blood into the brain. Glucose, amino acids, purines, choline, certain vitamins, iron, ad a few hormones cross through ________

Answer 28

Active Transport

Question 29

a difference in electrical charge between the inside and outside of the cell. The neuron inside the membrane has a slightly negative electrical potential with respect to the outside.

Answer 29

Polarization (Electrical Gradient)

Question 30

the difference in voltage in a resting neuron. Measure using a microelectrode.-70 millivolts, neuron is at rest no action potential, measure of the difference in voltage across the membrane.

Answer 30

Resting Potential

Question 31

More Concentrated OUTSIDE the cell, tends to flow IN due to concentration gradients, and tends to flow in due to electrical gradient

Answer 31

Sodium (Na+)

Question 32

• More concentrated INSIDE the cell, tend to flow OUT due to concentration gradient, tend to flow IN due to electrical gradient

Answer 32

Potassium (K+)

Question 33

things go from high concentration to low concentration

Answer 33

Concentration Gradient

Question 34

opposites attract, positive sodium ions are going to be pulled inside the cell to negative charge, Potassium is going to flow in as well they are getting mixed signals to flow out but electrical gradient is tell them to stay in the negative charge, not as many potassium’s will leave.

Answer 34

Electrical Gradient

Question 35

the membrane is _______meaning some chemicals pass through more freely than others.

Answer 35

Selectively Permeable

Question 36

a protein complex, repeatedly transports three sodium ions out of the cell while drawing two potassium ions into it. Maintains Resting Potential

Answer 36

Sodium-Potassium pump

Question 37

channels in the membrane -55mV they suddenly open up the channels.

Answer 37

threshold

Question 38

more is going to rush out than normal (relative refractory period) pumps potassium out at a faster rate.

Answer 38

Undershoot

Question 39

change in a cells membrane potential makes it more NEGATIVE inhibits action potential. Potassium (k+) is exiting the cell.

Answer 39

Hyperpolarization

Question 40

reduce polarization to 0. Influx sodium cell undergoes dramatic electrical change.

Answer 40

Depolarize

Question 41

produces a massive depolarization od the membrane. When the potential reaches the threshold the membrane opens the SODIUM channels and permits sodium ions to flow into the cell.

Answer 41

Threshold of Excitation

Question 42

the amplitude and velocity of the action potential are independent of the intensity of the stimulus that initiated it, provided that the stimulus reaches the threshold.
either you fire or you don’t

Answer 42

All or None Law

Question 43

occurs immediately after an action potential, a period during which it resists the production of further action potentials.

Answer 43

Refractory Period

Question 44

the first part of the period, the membrane cannot produce an action potential regardless of the stimulation.

Answer 44

Absolute Refractory Period

Question 45

the second part, a stronger than usual stimulus is necessary to initiate an action potential. The sodium channels are closed ad potassium is flowing out of the cell at a faster than usual rate.

Answer 45

Relative Refractory Period

Question 46

o The neuron is fundamental structural and functional unit of the nervous system
o Neurons are discreet cells which are not continuous with other cells
o The neuron is composed of 3 parts
o Information flows along the neuron in one direction (from the dendrites to the axon via the cell body)

Answer 46

The Neuron Doctrine

3 Parts: Cell Body, Dendrites, & Axon

Question 47

means to leap, Action potentials travel down the axon and “jump” form node to node

Answer 47

Saltatory Conduction

Question 48

The Neuron is composed of 3 things

Answer 48

the dendrites, axon, and Cell Body