Sofferman Chapter 11 Functional Organization Of Nervous Tissue

Front 1

What is a ganglion?

Back 1

A collection of neuron cell bodies

Front 2

Where are ganglions located?

Back 2

Outside of the CNS

Front 3

An extensive network of axons and, in some

cases, neuron cell bodies are called a....

Back 3

Plexus

Front 4

Where is the plexus located?

Back 4

Outside the CNS

Front 5

Large numbers of intermediate filaments

(neurofilaments) and microtubules form what?

Back 5

Bundles that organize the cytoplasm into

different regions.

Front 6

What separates abundant rough ER (also called Nissl Bodies)?

Back 6

Neurofilaments

Front 7

Where are nissl bodies primarily located?

Back 7

In the cell body and dendrites

Front 8

Nissl bodies are the primary site of?

Back 8

Protein synthesis in neurons

Front 9

Helps regulate the extracellular composition of the brain.

Back 9

Astrocytes

Front 10

How does astrocytes regulate the extracellular

composition of the brain?

Back 10

By releasing chemicals that promote the

formation of tight junctions between the

endothelial cells of capillaries.

Front 11

The endothelial cells with their tight junctions form what?

Back 11

blood-brain barriers

Front 12

What does blood-brain barriers determine?

Back 12

What substances can pass from the blood into the nervous tissue of the brain and spinal cord.

Front 13

Whats does the blood-brain barriers protect?

Back 13

Neurons from toxic substances in the blood

Front 14

What does blood-brain barriers allows the

exchange of?

Back 14

Nutrients and waste products between neurons and the blood

Front 15

What does blood-brain barriers prevent?

Back 15

Fluctuations in the blood composition from

affecting brain functions

Front 16

What are microglia?

Back 16

Neuroglia in the CNS that become mobile and phagocytic.

Front 17

Why does microglia become mobile and

phagocytic?

Back 17

In response to inflammation

Front 18

True or False? Microglia phagocytize necrotic

tissue, microorganisms, and other foreign

substances that invade the CNS.

Back 18

True

Front 19

Numerous microglia migrate to areas damaged by what?

Back 19

infection, trauma, or stroke

Front 20

True or False? Microglia perform phagocytosis.

Back 20

True

Front 21

How can pathologist identify damaged areas in the CNS during autopsy?

Back 21

Large numbers of microglia are found in them

Front 22

The ______________ pump uses ATP to pump _____

against its concentration gradient and keep it in high concentration _____ the cell and to pump

_____ against its concentration gradient and keep it in high concentration ______ the cell.

Back 22

sodium-potassium

K+

inside

Na+

outside

Front 23

Dealing with the sodium-potassium pump, how many Na+ are transported out of the cell for each ATP molecule used?

Back 23

Three

Front 24

Dealing with the sodium-potassium pump, how many K+ are transported into the cell for each ATP molecule used?

Back 24

Two

Front 25

What is the resting potential of neurons in mV?

Back 25

approx. -70 mV

Front 26

What is the resting membrane potential of skeletal muscle fibers?

Back 26

approx. -90mV

Front 27

Why is it that by convention, the potential

difference is reported as a negative number?

Back 27

The inside of the plasma membrane is negative compared with the outside.

Front 28

True or False? The greater the charge difference across the plasma membrane, the LESSER the potential difference.

Back 28

False....it is the greater the charge difference across the plasma membrane, the GREATER the potential difference.

Front 29

A cell with a resting membrane potential of -90 mV has a ________ charge difference between the inside of the cell membrane and the outside of the cell membrane than a cell with a resting membrane potential of ______.

Back 29

greater

-70 mV

Front 30

When the membrane potential becomes more POSITIVE and is the movement of the membrane potential CLOSER to zero it is.....

Back 30

Depolarization

Front 31

When the membrane potential becomes more NEGATIVE and is the movement of the

membrane potential FURTHER AWAY from zero it is.....

Back 31

Hyperpolarization

Front 32

What takes place because negatively charged molecules CANNOT follow the positively charged K+?

Back 32

A small negative charge develops inside the

plasma membrane.

Front 33

The negative charge inside of the cell attracts...

Back 33

positively charged K+

Front 34

When is an equilibrium established?

Back 34

When the negative charge inside the cell is great enough to prevent additional K+ form diffusing out of the cell through the plasma membrane.

Front 35

After the repolarization phase, the plasma membrane may be slightly hyperpolarized for a short period called......

Back 35

Afterpotential

Front 36

The second part of the refractory period and it follows the absolute refectory period....

Back 36

relative refractory period

Front 37

Act as a layer of insulation, forcing the local

currents to flow from one node of Ranvier to the next

Back 37

the lipids within the membrane of the myelin sheath

Front 38

Voltage-gated Na+ channels are highly

concentrated at the _______ of ______.

Back 38

Nodes

Ranvier

Front 39

The local current quickly flows to a node and ________ the voltage-gated Na+ channels to _____, resulting in the production of an ______ _______.

Back 39

stimulates

open

action potential

Front 40

Medium-diameter, lightly myelinated axons that conduct action potentials at 3-15 m/s

Back 40

Type B fibers

Front 41

Small-diameter, unmyelinated axons that

conduct action potentials at 2 m/s or less

Back 41

Type C fibers

Front 42

Which fiber types are primarily part of the ANS?

Back 42

Type B and C

Front 43

Which internal organs are stimulated by Type B and C fibers?

Back 43

the stomach, intestines, and heart

Front 44

The responses necessary to maintain internal homeostasis....

Back 44

digestion

Front 45

True or False? The responses necessary to

maintain internal homeostasis , need not be as rapid as responses to the external environment.

Back 45

True

Front 46

Limits the length of time the neurotransmitter molecules remain bound to their receptors.

Back 46

Diffusion of neurotransmitter molecules away from the synapse and into the extracellular fluid

Front 47

It is taken up primarily by liver and kidney cells

Back 47

Norepinephrine in the circulation

Front 48

Which two enzymes convert norepinephrine into inactive metabolites?

Back 48

Monoamine oxidase and

catechol-o-methyltransferase

Front 49

Which drug increases the release and block the reuptake of norepinephrine?

Back 49

Cocaine and amphetamines

Front 50

what results if the release is increased and the reuptake of norepinephrine is blocked?

Back 50

It results in overstimulation of postsynaptic neurons & deleterious effects on the body.

Front 51

Particularly effective at treating depression and behavioral disorders.

Back 51

Drugs that block serotonin reuptake

Front 52

Results when two or more action potentials

arrive in very close succession at a single

presynaptic terminal.

Back 52

Temporal summation

Front 53

In a chemical synapse......

Back 53

Action potentials in the presynaptic terminal cause voltage-gated Ca2+

Neurotransmitters can cause ligand-gated Na+ channels to open

Front 54

In a chemical synapse

Back 54

-action potentials in the presynaptic terminal cause voltage gated Ca2+ channels to open

-neurotransmitters can cause ligand-gated Na+ channels to open

-neurotransmitters can be broken down by enzymes

-neurotransmitters can be taken up by the presynaptic terminal

Front 55

An inhibitory presynaptic neuron can affect a postsynaptic neuron by...

Back 55

-Producing an IPSP in the postsynaptic neuron

-Hyperpolarizing the plasma membrane of the -postsynaptic neuron

-Causing K+ to diffuse out of the postsynaptic neuron

-Causing C1- to diffuse into the postsynaptic neuron.

Front 56

Causing Cl- to diffuse into the postsynaptic

neuron is an inhibitory presynaptic neuron that can affect a postsynaptic neuron

True or False?

Back 56

True

Front 57

what are sensory receptors? (Pg 362)

Back 57

the endings of neurons, or separate, specialized cells.

Front 58

what do they detect?

Back 58

they detect temperature, pain, touch, pressure, light, sound, odor, and other stimuli.

Front 59

where are sensory receptors located?

Back 59

in the skin, muscles, joints, internal organs, & specialized sensory organs, such as the eyes and ears.

Front 60

a bundle of nerve fibers, called axons, and their sheaths.

Back 60

Nerve

Front 61

what does a nerve connect?

Back 61

It connects the CNS to sensory receptors, muscles, and glands.

Front 62

How many pairs of cranial nerves are there?

Back 62

12

Front 63

Where do the cranial nerves originate?

Back 63

from the brain

Front 64

how many pairs of spinal nerves are there?

Back 64

31

Front 65

where do the spinal nerves originate?

Back 65

the spinal cord

Front 66

what are the 2 functional subdivisions of the PNS?

Back 66

The sensory, or afferent ("toward") division

The motor, or efferent (away) division

Front 67

The sensory division

Back 67

transmits action potentials from the sensory receptors to the CNS

Front 68

where are the cell bodies of sensory neurons located? (2)

Back 68

in the dorsal root ganglia near the spinal cord or in ganglia near the origin of certain cranial nerves.

Front 69

The motor division

Back 69

transmit action potentials from the CNS to effector organs, such as muscles and glands.

Front 70

What are the 2 subdivisions of the motor division? (364)

Back 70

Somatic nervous system (voluntary)

Autonomic nervous system (ANS) (involuntary)

Front 71

The somatic nervous system

Back 71

allows us to consciously control movements of our skeletal muscles through action potentials that originate in the CNS & are transmitted by the somatic nervous system to the same skeletal muscles.

Front 72

The cell bodies of somatic motor neurons are located within the ______ & their axons extend through _____ to form connections w/________.

Back 72

CNS

Nerves

skeletal muscle cells.

Front 73

A synapse is

Back 73

the junction of a neuron with another cell

Front 74

neurons can also form synapses with

Back 74

other neurons, smooth muscle cells, cardiac muscle cells, and gland cells

Front 75

The ANS is subdivided into the (2)

Back 75

sympathetic and parasympathetic divisions

Front 76

the sympathetic division

Back 76

is most active during physical activity

Front 77

the parasympathetic division

Back 77

regulates resting functions, such as digesting food or emptying the urinary bladder.

Front 78

consists of plexuses within the wall of the digestive tract

Back 78

Enteric nervous system (ENS)

Front 79

what is a unique feature of the enteric neurons?

Back 79

They monitor & control the digestive tract independently from the CNS through local reflexes.

Front 80

How can the CNS override enteric functions?

Back 80

via the parasympathetic and sympathetic actions

Front 81

The ENS is an independent subdivision of the _____ that is integrated w/the ______.

Back 81

PNS, ANS

Front 82

What forms the choroid plexuses? (pg 367)

Back 82

Specialized ependymal cells & blood vessels

Front 83

Where are choroid plexuses located?

Back 83

within certain regions of the ventricles

Front 84

What do choroid plexuses secrete?

Back 84

Cerebral spinal fluid that flows through the ventricles of the brain.

Front 85

Neurons expend energy to maintain what?

(pg. 371)

Back 85

an uneven distribution of ions across the plasma membrane.

Front 86

After repolarization, the plasma membrane may be slightly hyperpolarized for a short period. This is called..... (pg. 376)

Back 86

afterpotential

Front 87

The 2nd part of the refractory period, called the _______, follows the absolute refractory period.

Back 87

Relative refractory period

Front 88

when can another action potential during the relative refractory period be initiated?

Back 88

when there is a stronger than threshold stimulus, but only before the relative refractory period is completed.

Front 89

temporal summation results when

Back 89

another action potential initiates another graded depolarization before the depolarization caused by the previous action potential returns to its resting value.