Nervous System

Question 1

Specialized cells capable of transmitting electrical impulses & then translating them into chemical signals are known as ?

Answer 1

Neurons

Question 2

The nucleus, ER, & ribosomes are located in which structure ?

Answer 2

Cell body (soma)

Question 3

Appendages that receive incoming signals from other cells are known as ?

Answer 3

Dendrites

*messages integrated in axon hillock

Question 4

Mammalian nerve fibers are coated in which signal loss prevention structure ?

Answer 4

Myelin

* produced by oligodendrocytes (CNS) & schwann cells (PNS)

Question 5

Chemicals that transmit info between neurons are known as ?

Answer 5

Neurotransmitters

Question 6

The space between 2 neurons where neurotransmitters are secreted is known as the what ?

Answer 6

Synaptic cleft

Question 7

Cells that support and myelinate neurons are known as ?

Answer 7

Neuroglia (glial cells)

Question 8

The net electrical potential difference that exists across the cell membrane due to movement of charged particles is known as ?

Answer 8

Resting potential

*-70 mV for neurons

Question 9

What does the cell membrane have to facilitate the movement of K+ out of the cell ?

Answer 9

K+ leak channels

Question 10

The potential difference that represent the K+ equilibrium is known as ?

Answer 10

Equilibrium potential of K+

*-90 mV

Question 11

The movement of Na+ into the cell is facilitated by which channels?

Answer 11

Na+ leak channels

-equilibrium potential of Na+ is +60 mV

Question 12

A form of active transport that moves Na+ & K+ against their conc. gradients is known as ?

Answer 12

Na/K ATPase

-3 Na+ out, 2 K+ in

Question 13

Excitatory input causes what type of rxn to the neuron ?

Answer 13

Depolarization (raise membrane potential)

*If high enough to reach threshold (-55 to -40 mV), then action potential will be triggered

Question 14

Inhibitory input leads to what type of rxn in a neuron ?

Answer 14

Hyperpolarization (lowers membrane potential)

Question 15

What does the electrochemical gradient promote in a cell?

Answer 15

Migration of Na+ into the cell

Question 16

What happens to Na+ channels when Vm approaches +35 mV ?

Answer 16

Channels inactivated

Question 17

What are the 3 different states that the Na+ channel can exist in ?

Answer 17

1. Closed: before cell reaches threshold but after inactivation has been reversed
2. Open: from threshold to approx +35 mV
3. Inactive: approx +35 mV to resting potential

Question 18

The efflux of K+ & the restoration of the negative membrane is known as ?

Answer 18

Repolarization

*Makes the neuron refractory to further action potentials

Question 19

What period constitutes that no amount of stimulation can cause another action potential to occur ?

Answer 19

Absolute refractory period

Question 20

The period in which there must be a greater than normal stimulation to cause an action potential due to the membrane starting from a potential lower than the resting potential is known as ?

Answer 20

Relative refractory period

Question 21

If a neuron signals to a gland or muscle instead of another neuron, then the postsynaptic cells is termed what ?

Answer 21

Effector

Question 22

How are neurotransmitters regulated ?

Answer 22

1. Enzymes
2. Reuptake carriers
3. Diffusion