Chapter 4 The Nervous System

Question 1

Neuron

Answer 1

So capable of transmitting electrical impulses and translating electrical impulse into chemical signals

Question 2

Soma

Answer 2

• cell body
• Contains the endoplastic reticulum and ribosomes

Question 3

Dendrites

Answer 3

Appendages coming out of the cell body that receive incoming messages from other cells

Question 4

Axon hillock

Answer 4

Integrates information received from the dendrites that first travels to the cell body before reaching the axon hillock
* Plays an important role in the transmission of action potentials

Question 4

axon

Answer 4

Long appendage That ends close to the target sector which can be an a muscle a grande or another neuron

Question 5

Myelin sheath

Answer 5

Fatty membrane that insulates nerve fibers to prevent signal loss or crossing of signals

Question 6

Nodes of Ranvier

Answer 6

Breaks in the Milan sheath along the axon critical for rapid signal conduction

Question 7

Nerve terminal

Answer 7

Transmit signals to the next neuron this is where the new transmitters are released

Synaptic knob

Question 8

Synaptic cleft

Answer 8

The space between neurons

Question 9

Synapse

Answer 9

The nerve terminal, synaptic cleft, and postsynaptic membrane

Question 10

Nerve

Answer 10

• Bundle of neurons in the peripheral nervous system
• Maybe sensory, motor, or mixed

Question 11

tract

Answer 11

Accents are bundled and carry only one type of information unlike nerves

Question 12

Multiple sclerosis

Answer 12

Immune response that leads to do myelination slows down the information transfer along a neuron

Question 13

Glial cells

Answer 13

The other cells in the nervous system

Question 14

Astrocytes

Answer 14

Nurse neurons and from the blood brain barrier

Question 15

ependymal cells

Answer 15

Line the ventricles of the brain and Producer cerebrospinal fluid

Question 16

Microglia

Answer 16

Phagocytic cells in the central nervous system

Question 17

Cells that produce myelin around axons

Answer 17

Oligodendrocytes (CNS) and swans cells (PNS)

Question 18

Sensory neuron

Answer 18

A.k.a. affarent neuron
* Transmit sensory information from Cincy receptive towards the spinal cord and brain

Question 19

Motor neurons

Answer 19

A.k.a. affferent neurons
* Transmission and motor information from the brain and spinal cord to the muscles in grams

Question 20

Interneurons

Answer 20

• Found between other neurons,
• the most neumerous
• Link to reflexive behavior
• Located predominantly in stone cordon bleu

Question 21

Supraspinal circuits

Question 22

Gray matter

Answer 22

Cell bodies and dendrites

Question 23

White matter

Answer 23

axons

Question 24

Spinal cord

Answer 24

* Cervical, thoracic, lumbar, sacral regiona * Protected by the vertebral column * The white matter is on the outside of a cord and gray matter is in the center[](http://)

Question 25

Structure of the spinal cord

Answer 25

Sensory neurons bring information and enter through the back door so side of the spinal cord, modern neurons exit the spinal cord on the front ventral side. *The cell body of the motor neuron is inside the spinal cord where received information the cell body of the sensory neuron is in the dorsal root ganglia which is outside the spinal cord | look up picture

Question 26

neurons in the autonomic nervous system

Answer 26

* Preganglionic neuron has a soma in the Central nervousystem postganglionic neuron peripheral nervous system

Question 27

Reflex arc

Answer 27

No input from the brain is required reflexes only require processing at the level of the spinal cord | Neural circuit

Question 28

Monosynaptic reflex arc

Answer 28

There is one tonight between the sensory neuron in the motor neuron example knee-jerk reflex | Feedback loop

Question 29

Polysynaptic reflex arc

Answer 29

* There is at least one interneuron between the sensory and motor neurons * Example withdrawal reflex both quadricep muscles must be stimulated when stepping on a nail

Question 30

Action potential

Question 31

Resting membrane potential

Answer 31

-70 mV inside of the neuron is negative relative to the outside, potassium and sodium are used to maintain and generate the resting membrane potential

Question 32

Leak channels

Answer 32

* Potassium channels allowed league of sodium potassium in route or out of the cell * Potassium channels are more likely than sodium channels which means that the resting potential is closer to the equilibrium potential of potassium

Question 33

Equilibrium potential potassium

Answer 33

-90 mV Negative convention is because a positive ion is leaving the cell

Question 34

Because of the brain potential of sodium

Answer 34

60mV Positive because sodium is going into the cell

Question 35

Na⁺/K⁺-ATPase

Answer 35

Sets up the gradient

Question 36

Depolarization

Answer 36

Raising the membrane potential from interesting potential makes neurons more likely to fire and action potential

Question 37

Hyper polarization

Answer 37

Lowering the membrane potential from its resting potential making the neuron less likely to fire in action potential

Question 38

Threshold

Answer 38

-55mV - -40mV If they ask on Hubaq receives enough excitatory input to be depolarized to threshold an action potential will be triggered

Question 39

Summation

Answer 39

The additive effect of multiple signals which may be inhibitory or excitatory

Question 40

Temporal summation

Answer 40

Multiple signals integrated in a short period of time

Question 41

Spatial summation | review

Answer 41

Additive effects based on the number of signals and the location of the signals

Question 42

Sodium channels

Answer 42

*** Closed:** before thrshold is reached * **Open**: from thrshold to +35mV *** Inactive:** +35 to reesting potential

Question 43

Repolarization

Question 44

Refractory periods

Question 45

Absolute refractory period

Question 46

Did refractory period

Question 47

154-157