Apologia Advanced Biology Module 7 Lecture 1

Front 1

Nerves

Back 1

Bundles of axons and their sheaths which extend from the CNS

Front 2

Ganglia

Back 2

Collections of neuron cell bodies which are outside of the CNS

Front 3

central nervous system (CNS)

Back 3

brain and the spinal cord

Front 4

peripheral nervous system (PNS)

Back 4

nerves and ganglia

Front 5

Spinal nerves

Back 5

Nerves which originate from the spinal cord

Front 6

Cranial nerves

Back 6

Nerves which originate from the brain

Front 7

Afferent neurons

Back 7

Neurons which transmit action potentials from the sensory organs to the CNS

Front 8

Efferent neurons

Back 8

Neurons which transmit action potentials from the CNS to the effector organs

Front 9

action potential

Back 9

is an electrical signal that travels along a neuron

Front 10

Somatic motor nervous system

Back 10

The system that transmits action potentials from the CNS to the skeletal muscles

Front 11

Autonomic nervous system

Back 11

The system that transmits action potentials from the CNS to the smooth muscles, cardiac muscles, and glands

Front 12

Sympathetic division

Back 12

Division of the ANS that generally prepares the body for physical activity

Front 13

When you touch a hot stove, you immediately pull your hand away to avoid being seriously burned. Which system of the PNS (efferent or afferent) is utilized first in this situation?

Back 13

afferent

Front 14

When you flex your forearm, which division of the PNS (efferent or afferent) is being used?

Back 14

efferent

Front 15

What would be the most specific way to describe the part of the PNS that is being used when you flex your forearm?

Back 15

somatic motor nervous system (SMNS).

Front 16

soma

Back 16

cell body houses the cell nucleus.

Front 17

Dendrites

Back 17

are receptive to stimuli and bring stimuli from the environment (sensory epithelial cells or other neurons) to the cell body. There are usually several dendrites per neuron.

Front 18

Perikaryon

Back 18

(cell body) is also receptive to stimuli, but also serves as the trophic or synthesizing center for the whole nerve

Front 19

Axon hillock

Back 19

Where the action potential begins and the area that marks the end of the cell body and the beginning of the axon. Once an action potential begins here, it will be conducted all the way down to the far end of the axon.

Front 20

myelin sheath

Back 20

which is a fatty wrapping that actually speeds up the transmission of the action potential down the axon.

Front 21

neuroglia

Back 21

specialized cells that produce myelin sheaths.

Front 22

Schwann cells

Back 22

neuroglia in the PNS

Front 23

oligodendrocytes

Back 23

neuroglia in the CNS

Front 24

nodes of Ranvier

Back 24

gaps in the myelin sheath

Front 25

Collaterals with telodendria

Back 25

Axons can split into collateral axons, and they end by branching into presynaptic terminals, which are also called terminal boutons

Front 26

unipolar neuron

Back 26

it really has only one process, and the cell body “hangs” off of that process

Front 27

pseudo dendrite

Back 27

it does what a dendrite does (sends signals towards the cell body), it sends signals the way that an axon does.

Front 28

bipolar neuron

Back 28

have two processes: an axon and a single dendrite split into many branches

Front 29

multipolar neuron

Back 29

has many processes: several dendrites but only one axon

Front 30

Association neuron

Back 30

A neuron that conducts action potentials from one neuron to another neuron within the CNS

Front 31

A signal is traveling down the process of a neuron. It is traveling in the same direction as another signal in another process of that same neuron. Is this signal traveling towards or away from the cell body?

Back 31

to the cell body

Front 32

An axon has a myelin sheath produced by a Schwann cells. Is this neuron in the PNS or CNS?

Back 32

PNS

Front 33

what are the four types of neuroglia in the CNS?

Back 33

Ependymal cells
Related to cerebrospinal fluid
Astrocytes
Largest and most numerous
Oligodendrocytes
Myelination of CNS axons
Microglia
Phagocytic cells

Front 34

What are two types of neuroglia in the PNS?

Back 34

Satellite cells
Surround neuron cell bodies within ganglia
Schwann cells
Ensheath axons in the PNS

Front 35

Ependymal cells (function)

Back 35

1. Line venticles (brain)& central canal (spinal cord)
2. Assist in producing, circulating & monitoring of cerebrospinal fluid.

Front 36

Astrocytes (function)

Back 36

1. Maintain blood brain barrier.
2. Provide structural support.
3. Regulate ion, nutrient & dissolved gas caoncentration.
4. Absorb & re-cycle neurotransmitters.
5. Form scar tissue after injury.

Front 37

Oligodendrocytes (function)

Back 37

1. Mylenate CNS axons.
2. Provide structural framework.

Front 38

Microglia (function)

Back 38

1. Remove wastes, cell debris, and pathogens via phagocytosis.

Front 39

Satellite cells (function)

Back 39

1. Surround neuron cell bosies in ganglia.
2. Regulate O2, CO2, nutrient and neurotransmitter levels around neurons in ganglia.

Front 40

Schwann Cells (function)

Back 40

1. Surround axons in PNS.
2. Mylenate peripheral axons.
3. Participate in repair process after injury.

Front 41

Endoneurium

Back 41

a thin connective tissue layer surrounding each individual fiber

Front 42

Epineurium

Back 42

is a more extensive connective tissue layer between the bundles and extending to the most peripheral parts of the nerve.

Front 43

Perineurium

Back 43

Fibers are grouped in bundles, which are also surrounded by a connective tissue layer.

Front 44

Sensory nerves

Back 44

Nerves possessing only sensory fibers.

Front 45

Motor nerves

Back 45

nerves possessing only motor fibers.

Front 46

Mixed nerves

Back 46

Nerves that possess both sensory and motor fibers.

Front 47

A group of axons bundled together is severed and does not heal. There are two possible reasons. What are they?

Back 47

the axons are in the CNS or the two severed ends were not lined up well

Front 48

Carpal tunnel syndrome is a problem resulting from pressure in the flexor retinaculum which compresses the median nerve, a nerve that is about the thickness of a shoestring and is found in the wrist. When that nerve doesn't function properly, the grip gets weak and the hand goes numb. Is the median nerve a motor nerve, a sensory nerve, or a mixed nerve?

Back 48

mixed nerve

Front 49

Suppose the membrane suddenly became very permeable to sodium ions. What would happen to the potential difference between the inside and outside of the axon?

Back 49

The potential difference would become less negative

Front 50

Excitability

Back 50

The ability to create an action potential in response to a stimulus

Front 51

Potential difference

Back 51

A measure of the charge difference across the cell membrane

Front 52

These simple rules create the resting potential:

Back 52

1) Concentration gradient moves ions from high to low concentration
2) Electrical force moves ions with same charge away from each other and ions with opposite charge towards each other.
3) Na+/K+ pump moves Na+ to the extracellular space. It can't get back in because the membrane is impermeable to Na+.
4) The membrane is permeable to K+ (i.e., it flows either way)
5) Large negatively charged proteins (A-) are stuck inside the neuron Na+ and K+ are driven intracellularly to A- by the electrical force. The concentration gradient is going to push Na+ intracellularly and K+ extracellularly. The Na+/K+ pump is going to move Na+ extracellularly.