Exam 3 -- Chapter 4

Question 1

Neurons

Answer 1

Cells of the nervous system that are specialized for the reception, conduction, and transmission of electrochemical signals.

Question 2

Parts of a neuron

Answer 2

• Cell Body (soma)
• Dendrites
• Axon (Axon hillock, Myelin, Buttons, Synapse, Synaptic vesicles)
• Neuron Cell Membrane

Question 3

Cell Body (soma)

Answer 3

• Nucleus (contains chromosomes (DNA)
• Cytoplasm
• Functions: Metabolism and Synthesis of proteins from genes

Question 4

Cytoplasm

Answer 4

Clear fluid outside the nucleus

Question 5

Metabolism

Answer 5

Energy production

Question 6

Dendrites

Answer 6

• Processes emanating from the cell body, which communicate with other neurons
• Receives most synaptic contact from other neurons

Question 7

Axon

Answer 7

• Process projecting from the cell body
• Carries the neural signal
• Made of: Axon hillock, myelin, buttons, synapse, and synaptic vesicles

Question 8

Axon hillock

Answer 8

• Cone-shaped region at the junction between the axon and cell body
• (nearby) involved in decision to increase or decrease signaling

Question 9

Myelin

Answer 9

• fatty insulation around many axons
• Nodes of Ranvier
• Speed up neural signals
• Multiple Sclerosis (MS): degeneration of myelin

Question 10

Nodes of Ranvier

Answer 10

Gaps between sections of myelin

Question 11

Buttons

Answer 11

• Knobby ending of axon branches

- Releases neurotransmitter into synaptic clefts (gaps)

Question 12

Neurotransmitter

Answer 12

Molecules released from neurons that influence other cells

Question 13

Synapse

Answer 13

• Junction between two neurons or a neuron and a muscle or a glad
• Chemical signals are released across the synaptic cleft (gap)

Question 14

Synaptic vesicles

Answer 14

Membrane covered balls containing neurotransmitters

Question 15

Neuron Cell Membrane

Answer 15

• Composed of lipid bilayer (inside and outside of neurons differ in chemical concentration)
• Do need to get some chemicals across this barrier
• Done by Channel Proteins and Signal Proteins

Question 16

Lipid Molecule

Answer 16

• Polar head region: attracts water
• Neutral Tail: repels water
• This difference helps keep the lipids lined up (heads toward water, tails away from water)

Question 17

Channel Proteins

Answer 17

Allow certain molecules to pass through the membrane

Question 18

Signal Proteins

Answer 18

Transfer a signal to the inside of the cell when particular molecules bind to them on the outside

Question 19

Classes of Neurons (By Structure)

Answer 19

• Multipolar
• Multipolar Interneuron
• Unipolar
• Bipolar

Question 20

Multipolar

Answer 20

• Neuron with more than two processes emanating from the cell body
• Most human neurons are multipolar***

Question 21

Multipolar interneuron

Answer 21

• Neurons with short axons or no axons
• Integrate neural activity within a signal structure
• Do not carry signals from one structure to another

Question 22

Unipolar

Answer 22

Neuron with one process emanating from the cell body

Question 23

Bipolar

Answer 23

Neurons with two processes emanating from the cell body

Question 24

Classes of Neurons (By Function)

Answer 24

• Sensory Neurons
• Motor Neurons
• Interneurons

Question 25

Sensory Neurons

Answer 25

Carry information from sense receptors to the CNS

Question 26

Motor Neurons

Answer 26

Carry information from the CNS to the muscles and glands

Question 27

Interneurons

Answer 27

• Communicate with other neurons

- Make up most of the human brain***

Question 28

Support Cells in the Nervous System

Answer 28

• Out number neurons (10 to 1)***