Chapt. 2

Question 1

What are the two cells that make up the human nervous system?

Answer 1

• Neurons

* Glia

Question 2

What are the major components of neurons?

Answer 2

• dendrites
• soma (cell body)
• axon
• presynaptic terminals

Question 3

Tell me about the cell body (soma).

Answer 3

• contains the nucleus, mitochondria, ribosomes, and other structures
• responsible for the metabolic work of the neuron

Question 4

Tell me about the membrane.

Answer 4

• it’s a structure that separates the inside of the cell from the outside environment
• protects, or shields, the cell

Question 5

Tell me about the nucleus.

Answer 5

• it’s a structure that contains the chromosomes

Question 6

Tell me about dem motherfucking mitochondria.

Answer 6

• it’s a structure that performs metabolic activates and provides energy that the cell requires

Question 7

Tell me about ribosomes.

Answer 7

• where the cell synthesizes new protein molecules

Question 8

Tell me about the endoplasmic reticulum.

Answer 8

• it’s a network of thin tubes that transport newly synthesized proteins to their location

Question 9

Tell me about dendrites.

Answer 9

• they are the branching fibers at the end of a neuron that are lined with synaptic receptors responsible for bringing info into the neuron

Question 10

Tell me about the axon.

Answer 10

• it’s a thin fiber of a neuron responsible for transmitting nerve impulses toward other neurons, organs, or muscles

Question 11

Tell me about the presynaptic terminals.

Answer 11

• the end points of an axon where the release of chemicals to communicate with other neurons occurs

Question 12

Different types of neurons?

Answer 12

• motor
• sensory
• inter

Question 13

Afferent axon…

Answer 13

bring info INTO a structure

Question 14

Efferent axon…

Answer 14

carrying info AWAY from a structure

Question 15

Name the different types of Glia in the brain

Answer 15

• astrocytes
• microglia
• oligodendrocytes
• Shwann cells
• Radial glia

Question 16

Astrocytes are..

Answer 16

a type of glia that help to synchronize the activity of the axon by wrapping around the presynaptic terminal and taking up chemicals released by the axon

Question 17

Microglia are…

Answer 17

a type of glia that remove waste material and other microorganisms that could prove harmful to the neuron

Question 18

Oligodendrocytes are..

Answer 18

these are located in the brain and spinal cord and they build the myelin sheath that surrounds and insulates certain vertebrate axons

Question 19

Shwann cells are

Answer 19

these are located in the periphery of the body and they also build the myelin sheath that surrounds and insulates certain vertebrate axons

Question 20

Radial glia are..

Answer 20

a type of glia that guide the migration of neurons and the growth of their axons and dendrites during embryonic development

Question 21

What is the Blood-Brain Barrier?

Answer 21

a mechanism that surrounds the brain and blocks most chemicals from entering

Question 22

What is active transport?

Answer 22

the protein-mediated process that expends energy to pump chemicals from the blood into the brain

Question 23

What are are some things active transport brings into the brain?

Answer 23

glucose, certain hormones, amino acids, a few types of vitamins

Question 24

What is glucose?

Answer 24

a sugar that is one of the few nutrients that CAN pass through the blood brain barrier

Question 25

What do vertebrate neurons depend almost entirely on for nourishment?

Answer 25

GLUCOSE!

Question 26

What is a nerve impulse?

Answer 26

an electrical message that is transmitted down the axon of a neuron

Question 27

What is resting potential?

Answer 27

the state of the neuron prior to the sending of an impulse

Question 28

What is polarization?

Answer 28

a difference in the electrical charge of two locations ( a difference in the electrical charge inside/outside of a cell)

Question 29

The membrane is selectively permeable. What does this mean?

Answer 29

it means it allows some chemicals to pass more freely than others (hence SELECTIVE)

Question 30

What is depolarization?

Answer 30

a decreasing of polarization towards 0

Question 31

What is happening to sodium and potassium when the membrane is at rest?

Answer 31

- sodium channels are closed | - potassium channels are slightly closed, allowing for a slow passage of potassium

Question 32

What is action potential?

Answer 32

a rapid depolarization of the neuron (this occurs when their is a stimulation of the neuron past the action potential's threshold of excitation)

Question 33

What is hyperpolarization?

Answer 33

increasing the polarization or the difference between the electrical charge of two places

Question 34

What do Voltage-Activated Channels do?

Answer 34

these are membrane channels whose permeability depend upon the voltage difference across the membrane

Question 35

The All-or-None Law states that..

Answer 35

the amplitude and velocity of an action potential are independent of the intensity of the stimulus that initiated it

Question 36

Action potentials vary from one neuron to another in terms of...

Answer 36

- amplitude - velocity - shape

Question 37

What happens during a refractory period?

Answer 37

at this time the neuron resists the production of another action potential (this happens after an action potential)

Question 38

What are the two types of refractory periods?

Answer 38

Absolute (happens first and cannot produce an action potential) and Relative (happens second and it takes a stronger than usual stimulus to trigger action potential)

Question 39

What is the axon hillock?

Answer 39

swelling where the axon exits the soma (cell body)

Question 40

What are the short, unmyelinated interrupted sections in the myelin sheath of axons?

Answer 40

Nodes of Ranvier

Question 41

What is Saltatory Conduction?

Answer 41

a term used to describe the "jumping" of the action potential from node to node (provides fast conduction of impulses and conserves energy for the cell)

Question 42

Local neurons have..

Answer 42

short axons that exchange info with only close neighbors and do NOT produce action potentials

Question 43

When local neurons are stimulated they produce..

Answer 43

graded potentials which are membrane potentials that vary in magnitude and do NOT follow the all-or-none law