A&p Course Objectives - Exam 2

Front 1

Distinguish between sensory input, integration and motor output.

Back 1

The nervous system is the fundamental control system of the body. It takes in information, processes the information and elicites commands of action that are carried out by muscles or glands.

- sensory input - to monitor what goes on in the external environment as well as within the body, the nervous system gathers sensory information called sensory input. This input begins in sensory recepts which are specialized cells located outside the central nervous system in the periphery that transduce some form of energy (e.g. mechanical, electromagnetic or chemical) that originates inside or outside the body. Sensory neurons carry this information into the central nervous system

- integration - to intepret the sensory information and select an appropriate response to the stimulus, the information must be processed. The processing of sensory information and the selection of a response is called integration and occurs entirely in the central nervous system

- motor output - once the information is processed, the nervous system elicits a response by activating an effector organ, which may be either muscles or glands. This response is called motor output. Motor output originates in the central nervous system, but the response is elicited by actions of the periphery

All three basic functions (sensory input, integration and motor output) result from electrictal signals in cells called neurons which are sometimes referred to as nerve cells. Integration results when electrical signals are transferred among neurons at sites called synapses

Front 2

Relate the terms "sensory input", "integration" and "motor output" to sensory neurons, association neurons, interneurons and motor neurons.

Back 2

- sensory neurons - bring information to the central nervous system about the skin, skeletal muscles and joints. Because this information is coming from the body, the nerve cells carrying the information are called somatic afferents

- interneurons - important for processing sensory (afferent) information coming from the periphery and going into the central nervous system

- motor neurons - the motor division is also called the efferent (from the latin meaning to bring out) division

Front 3

Distinquish between the central nervous system and the peripheral nervous system.

Back 3

- central nervous system - consisting of the brain and spinal cord

- peripheral nervous system - consisting of the portion of the nervous system located outside of the central nervous system Much of the peripheral nervous system consists of nerves that carry both sensory and motor information

Front 4

Describe where the neurons in the central and peripheral nervous systems are located and relate their positions to the concept of the central and peripheral nervous systems.

Back 4

a

Front 5

Define afferent and efferent and relate these terms to the concept of the central and peripheral nervous systems.

Back 5

Both may be found in the CNS and the PNS:

- afferent - (latin: to carry forward) sensory - sending to

- efferent - motor - to carry away

Front 6

Define visceral and somatic.

Back 6

- visceral - pertaining to the soft internal organs of the body, especially those contained within the abdominal and thoracic cavities

- somatic - of or relating to the portion of the vertebrate nervous system that regulates voluntary movement

Front 7

Define caudal with respect to the central nervous system.

Back 7

relatively distant from the forehead, especially in reference to the brain and spinal cord

Front 8

What branches of the nervous system effect function in the visceral and somatic regions?

Back 8

a

Front 9

Define dorsal with respect to the central nervous system.

Back 9

toward the back (spinal side) of the body

Front 10

Within the visceral branch, distinguish between sympathetic and parasympathetic nervous systems.

Back 10

the autonomic nervous system is subdivided into two systems:

- sympathetic - tends to increase the activity of an organ

- parasympathetic - tends to decrease activity

Front 11

Define ventral with respect to the central nervous system.

Back 11

pertaining to the front of the body, the regions of the chest and abdomen

Front 12

Define rostral with respect to the central nervous system.

Back 12

relatively close to the forehead, especially in reference to structures of the brain and spinal cord

Front 13

Name the four major divisions of the brain and briefly describe their function.

Back 13

a

Front 14

Draw an outline of the spinal cord and label the gray and white matter. Draw the dorsal and ventral horns. Show which regions are sensory and which are motor.

Back 14

a

Front 15

What is gray matter? What is white matter? What is the function of each?

Back 15

- gray matter - is a collection of cell bodies and unmyelinated processes

- white matter - comprised of myelinated axons - is white because myelin contains large amounts of lipid that acts as an electrical insuling layer of the axon

Front 16

Trace the pathway of sensory information from the periphery to association neurons in the central nervous system to motor output.

Back 16

1. sensory recepts initiate a response in the sensory neuron that conducts toward the central nervous system in the spinal cord

2. the sensory information enters the central nervous system through the dorsal root and the central process of the dorsal root ganglion neuron extends into the dorsal horn of the spinal cord

3. for one form of sensory information (light touch or joint position) the snesory neuron travels rostrally in the spinal cord and forms a synpase in the brain stem where it communicates with an interneuron that sends a process to the thalamus. in the thalamus, this neuron synapses onto nerve cells that extend process to the cerebral cortex. specifically, these thalamic neurons send processes to the primary samatosensory cortex which is located in the rostral portion of the parietal lob, just caudal to the central sulcus

4. association neurons (also known as interneurons) send processes from the sensory cortex to the association areas in the cerebral cortex of the frontal lobe. the association areas interpret the sensory information and send information to the motor and premotor areas

5. upper motor neurons are located in the primary motor cortex and receive information from the association regions. upper motor neurons extend descending procersses carrying efferent information down the corticospinal tracts to synapse on the lower motor neurons

6. activation of the lower motor neurons leads to the contraction of muscles and the initiation of movement

remember that afferent information entering the right hand side of the cord will make its way to the left cerebral hemisphere, and that efferent information from the motor cortex in the left cerebral hemisphere will make its way back to the right side of the spinal cord

Front 17

What are the parts of the neuron in the Bodian classification of the neuron?

Back 17

According to the Bodian classification of neuron structure, neurons have three functionally similar regions in common:

1. an input region
2. a conducting region
3. a secretory region

Front 18

Wha is the function of each of the regions of the Bodiean classification of the neuron?

Back 18

According to the Bodian classification of neuron structure, neurons have three functionally similar regions in common:

1. an input region sometimes referred to as a receptive or dendritric region

2. a conducting region that carries action potentials. this is the long distance communication part of the cell

3. a secretory region sometimes called the output region where neurotransmitter is released

Front 19

Where does protein synthesis occur in neurons?

Back 19

The cell body is the protein factory of the neuron. The cell body contains the nucleus and most of the protein synthesis in the neuron occurs in the cell body. There is some protein synthesis in the dendrites, but very little in the axons. The Nissl substance is characteristic of neurons and is an elaborated form of the rough ER

Front 20

How do proteins synthesized in the cell body find their way to the axon terminal?

Back 20

a

Front 21

Describe the structure of the axon. Compare the organization of a myelinated and unmyelinated axon.

Back 21

a

Front 22

Describe the structure of the axon terminal. What are synaptic vesicles? What are contained in synaptic vesicles?

Back 22

a

Front 23

How do the synaptic vesicles release their contents?

Back 23

a

Front 24

Describe the function and location of motor neurons, sensory neurons and interneurons. Where are the cell bodies for these neurons located?

Back 24

a

Front 25

Define afferent and efferent in terms of motor neurons and sensory neurons.

Back 25

a

Front 26

What are oligodendrocytes, where are they found, and what is their function?

Back 26

- in the central nervous system are responsible for forming the myelin sheaths around axons

- myelin forms the insulating layers around neurons so that the action potentials can conduct more rapidly

- are responsible for forming the white matter in the central nervous system

- they can envelope several axons and wrap them with myelin

- myelination proceeds when processes of oligodendrocytes wrap around the axon foring layer upon concentric layer of myelin

Front 27

What are astrocytes, where are they found, and what is their function?

Back 27

Astrocytes are important in regulating the concentration of ions, particularly K+.

Because the volume of extracellular space is small in the central nervous system, electrical activity in cells can change the local concentration of extracellular ions; one of the roles of astrocytes is to regulate the ion concentrations by pumping ions.

Astrocytes are also thought to be important in regulating the concentration of neurotransmitters in the extracellular space since neuronal activity can also lead to increases in the extracellular concentration of neurotransmitters.

The position of astrocytic processes wrapped around capillaries indicates that these cells are important in regulating the movement of substances between the central nervous system and the blood

Front 28

What are microglia, what is their origin, and what is their function?

Back 28

Cells that are thought to be modified macrophages that are derived from a white blood cell called a monocyte.

They do not originate from neuroectodermal cells as do all neuronal and glial cells.

Front 29

What are Schwann cells, what is their function, where are they found, and how are they different from oligodendrocytes?

Back 29

Schwann cells are the myelin producing cells in the peripheral nervous system.

When Schwann cells myelinate an axon, they envelope a single axon. They extend multiple wraps around the axon to form numerous layers of myelin.

They clean up debris after peripheral nerve damage and support regeneratio of peripheral nerves. This is in contrast to eoligodendrocytes which inhibit regeneration of the central nervous system

Front 30

Distinguish between cations and anions. What is the charge of each type, and give examples of each.

Back 30

a

Front 31

Distinguish between permeant ions and impermeant ions in a neuron.

Back 31

a

Front 32

In a neuron at rest, how are the ions in a neuron distributed? Where is the concentration of Na+ highest? Where is the concentration of K+ highest? Where is the concentration of impermeant anions highest?

Back 32

a

Front 33

What is the relationship between the impermeant anions and K+?

Back 33

See membrane potential generation

Front 34

What is meant by a Na+ selective ion channel? What is meant by a K+ selective ion channel?

Back 34

a

Front 35

Define a leak channel. Define a voltage-gated channel.

Back 35

- leak channel - a K+ channel that is always open

- voltage-gated channel - charge-sensitive channels - local increase in + charge causes channel to open; this is usually a cascading effect

Front 36

How do the K+ leak channels and the impermeant anions serve to separate charge?

Back 36

a

Front 37

What is the relationship between the separation of charge and the formation of a potential?

Back 37

a

Front 38

What is the unit of measure for the separation of charge?

Back 38

a

Front 39

Define a voltage-gated channel and contrast it with a leak channel.

Back 39

See action potential gradient diagram

Front 40

How does the voltage-gated Na+ channel open?

Back 40

a

Front 41

What moves through the voltage-gated Na+ channel?

Back 41

a

Front 42

Define electrical current in terms of the open channel and the voltage.

Back 42

a

Front 43

What is the effect on the membrane potential when the channel opens and Na+ ions flow through it?

Back 43

a

Front 44

Why does the Na+ current stop flowing?

Back 44

a

Front 45

How is the potential across the membrane restored to rest? Describe the role of the voltage-gated K+ channel and the K+ current.

Back 45

a

Front 46

Graph the change in voltage versus time during an action potential. Relate the opening of voltage-gated Na+ and K+ channels to the following terms:

- threshold
- rising phase
- Na+ current
- Na+ channel closing
- K+ channel opening
- falling phase
- K+ current
- undershoot

Back 46

- threshold - balance between Na+ influx and K+ efflux

Front 47

What makes up the CNS?

Back 47

1. spinal cord
- contained within the vertebrae

2. brain stem
- extension of the brain
- controls movement in the head and neck
- receives sensory input from the head and neck
- plays a role in governing efferents
- plays a role in monitoring visceral afferents

3. diencephelon
a. thalamus
- serves as sensory relay site
b. hypothalamus
- plays a role in regulation of body function (hungry, thirsty, hot, cold, etc.)
- regulation of hormonal release from adenohypophesis

4. cerebrum
- cerebral cortex (outer shell)
- composed of six layers of neurons

Front 48

Diagram the nervous system as a machine.

Back 48

input -> analysis -> output
(sensory) (association (motor)
functions)

Front 49

Define sensory transduction

Back 49

conversion of one form of energy to another. for example, conversion of magnetic energy to cellular energy (movement of ions across biological membranes)

Front 50

What are the three forms of energy?

Back 50

1. electromagnetic (light)
2. mechanical (touch, hearing, etc.)
3. chemical (taste, smell)

Front 51

Define afferents

Back 51

to carry forward - sending information into the CNS

sensory:
- somatic afferents (from body - concious)
- visceral afferents (interal organs - unconcious)

Front 52

Define efferents

Back 52

to carry away from (effect - to carry a response)

motor:
- somatic efferents - body muscles - concious
- visceral efferents - unconcious muscle movement

Front 53

Describe the basic diagram of CNS vs. PNS

Back 53

sensory -> CNS -> motor
(afferents) (efferents)

CNS
- brain
- spinal cord

PNS
- sensory (afferents)
- motor (efferents)

Front 54

Define neuron doctrine

Back 54

the nervous system is a collection of separate cells connected and their chemical synapses

Front 55

Define the cells of the nervous system

Back 55

1. neurons
- electrically active cells

2. glia
- once thought to be just glue
- support cells

a. astrocytes
- responsible for regulating ion concentrations in the space around neurons
- responsible for regulating concentration of neurotransmitters around neurons

b. oligodendrocytes
- produce myelin - the insulating wrap around neurons

c. "microglia"
- actually macrophages and not glia
- cells of the immune system

d. Schwann cells
- glial cells in the pheripheral nervous system

Front 56

Describe axoplasmic transport

Back 56

the long-distance movement of proteins and memory

a. package protein in vesicles
b. transport vesicles on microtubules

Front 57

What are microtubles made of?

Back 57

polymers of a protein called tubulin

Front 58

Describe the anatomical organization of a generic neuron.

Back 58

Label the:

- dendrite
- cell body
- axon
- conductile region
- input region
- output region
- axon terminal
- secretory region
- synaptic vesicles

Front 59

Define passive membrane

Back 59

a membrane that lacks voltage-gated channels

Front 60

Define myelin

Back 60

the insulating layer around axons

Front 61

List some characteristics of astrocytes

Back 61

(glial cells) maintain a favorable environment for neurons

1. maintain a constant ion concentration in the extracellular space (act as K+ sponges)

2. take up excess neurotransmitter (act as neurotransmitter sponges)

Front 62

Define microglial

Back 62

(macrophages)
- dendrite cell (cell of the immune system)

- extension of the immune system in the central nervous system

Front 63

Where do glial cells occur?

Back 63

- glial cells are found in the central nervous system

- in the peripheral nervous system, glial cells are called Schwann cells

Front 64

Define voltage gate

Back 64

a voltage gate is a charge-sensitive channel

a local increase in positive charge causes the channel to open

Front 65

What are the neurotransmitters that open ligand-gated ionotropic channels

Back 65

1. acetylcholine
- neuromuscular junction
- autonomic nervous system
- approximately 8 receptors

2. glutamate - most abundant neurotransmitter in the CNS
- 12 receptors

3. serotonin

Front 66

What is an EPSP?

Back 66

excitatory postsynaptic potential

Front 67

What is an IPSP?

Back 67

inhibitory postsynaptic potential

Front 68

What is a trigger zone?

Back 68

a cluster of Na+ and K+ voltage-gated channels

Front 69

Define synaptic integration

Back 69

EPSPs and IPSPs work together to permit a decision by the neuron to fire an action potential

Front 70

Define spatial summation

Back 70

the summation of synaptic potentials from separated sites on the input region

Front 71

Define ganglion

Back 71

collection of neuronal cell bodies in the peripheral nervous system

Front 72

Describe what becomes of current (ions) injected into a cylinder of axoplasm surrounded by axon membrane at the site of current injection, and at 1, 3 and 5 millimeters away from the injection site. Assume that there are no voltage-gated channels in the membrane.

Back 72

a

Front 73

Describe what becomes of current (ions) injected into a cylinder of axoplasm surrounded by axon membrane at the site of current injection, and at 1, 3 and 5 millimeters away from the injection site. Assume that there are no voltage-gated channels in the membrane. Frame these answers in terms of voltage, current and resistance.

Back 73

a

Front 74

Compare the electrical events in a cylinder of axoplasm and axon membrane which lacks voltage-gated ion channels to a leaky garden hose.

Back 74

a

Front 75

Describe the distribution of voltage-gated Na+ and K+ channels along the length of an unmyelinated axon.

Back 75

a

Front 76

Describe propagation of the action potential along the length of an unmyelinated axon.

Back 76

See propagation of unmyelinated neurons

Front 77

Describe the structure of a myelinated axon. What are nodes of Ranvier and internodal regions? What cell types are involved in myelination in the central and peripheral nervous systems?

Back 77

a

Front 78

Compare the distribution of voltage-gated Na+ and K+ channels along the length of a myelinated and unmyelinated axon.

Back 78

a

Front 79

Compare the propagation of action potentials in myelinated and unmyelinated axons.

Back 79

See propogation of myelinated neurons

Front 80

Why does myelinated increase the rate of action potential propagation along the axon?

Back 80

a

Front 81

What is the term that describes the rate of propogation?

Back 81

a

Front 82

Using a sensory neuron as an example, describe how a generator potential is initiated.

Back 82

a

Front 83

Describe how the generator potential leads to the production of an action potential. In your describe, include the concepts of stretch-activated channel, graded potential, trigger zone, voltage-gated Na+ channels and threshold.

Back 83

a

Front 84

What are the differences between passively propagated potentials (graded potentials) and action potentials?

Back 84

a

Front 85

Describe how graded potentials add together (summate) at the trigger zone to initiate an action potential.

Back 85

a

Front 86

What is the literal definition of synapse?

Back 86

a

Front 87

Define presynaptic cell

Back 87

a

Front 88

Define postsynaptic cell

Back 88

a

Front 89

Define synaptic vesicle

Back 89

a

Front 90

Define exocytosis

Back 90

a

Front 91

Define neurotransmitter

Back 91

a

Front 92

Define voltage-gated Ca2+ channel

Back 92

a

Front 93

Define neurotransmitter release

Back 93

a

Front 94

Define ligand-gated channel

Back 94

a

Front 95

Define postsynaptic potential

Back 95

a

Front 96

Make a drawing of a chemical synapse. Show the position of each of the following structures:

- presynaptic cell
- postsynaptic cell
- synaptic vesicle
- exocytosis
- neurotransmitter
- voltage-gated Ca2+ channel
- neurotransmitter release
- ligand-gated channel
- postsynaptic potential

Back 96

a

Front 97

List in chronological order the sequence of events from the arrival of an action potential in the teldendrion to the release of the neurotransmitter.

Back 97

a

Front 98

What is the role of intracellular Ca2+ in neurotransmitter release?

Back 98

a

Front 99

What is the source of this Ca2+ and how does it get into the terminal?

Back 99

a

Front 100

How is the synaptic vessicle membrane retrieved following exocytosis?

Back 100

a

Front 101

Define ligand

Back 101

a

Front 102

Define receptor

Back 102

a

Front 103

Define ligand-gated channel

Back 103

a

Front 104

Define ionotropic receptor

Back 104

a

Front 105

Define excitatory postsynaptic potential (EPSP)

Back 105

a

Front 106

What does the neurotransmitter bind to on the postsynaptic cell?

Back 106

a

Front 107

Describe the effect on the membrane potential in the postsynaptic cell when neurotransmitter binds to a receptor that opens a cation channel.

Back 107

a

Front 108

Describe the relationship between the amplitude of the EPSP and the number of ionotropic channels that are opened by neurotransmitter.

Back 108

a

Front 109

Why are these postsynaptic potentials said to be graded?

Back 109

a

Front 110

Related the initiation of EPSPs in the dendritic region of the neuron with the initiation of action potentials at the trigger zone in the axon.

Back 110

a

Front 111

What is an inhibitory postsynaptic potential?

Back 111

a

Front 112

How is an inhibitory postsynaptic potential generated?

Back 112

a

Front 113

What are the inhibitory neurotransmitters?

Back 113

a

Front 114

When an inhibitory transmitter binds to the ligand-gated receptor, what is the charge on the ion that usually flows through these channels?

Back 114

a

Front 115

How do EPSPs and IPSPs interact at the trigger zone to affect action potential generation?

Back 115

a

Front 116

Give two examples of inhibitory neurotransmitters that open ionotropic anion channels.

Back 116

a

Front 117

Describe how EPSPs summate to elicit an action potential.

Back 117

a

Front 118

Describe what hapens to the amplitude of an EPSP between the time when it is initiated in the dendritic region of a neuron and when it arrives at the trigger zone.

Back 118

See membrane properties influnce action potential generation

Front 119

Describe spatial summation.

Back 119

a

Front 120

Describe the effects of inhibition on spatial summation.

Back 120

a

Front 121

Draw a spinal cord in cross section showing dorsal, ventral, medial and lateral orientations.

Back 121

See spinal cord organization

Front 122

Draw a spinal cord in cross section labeling the gray matter.

Back 122

a

Front 123

Draw a spinal cord in cross section labeling the white matter.

Back 123

a

Front 124

Describe why the gray matter is gray and the white matter is white.

Back 124

a

Front 125

Draw a spinal cord in cross section placing the dorsal root ganglion in the proper place.

Back 125

a

Front 126

What types of neurons have their cell bodies located in the dorsal root ganglion? Where is the input region of these neurons? Where is the output region of these cells? Describe action potential initiation and conduction in these neurons.

Back 126

a

Front 127

Draw a spinal cord in cross section labeling the dorsal and ventral horns.

Back 127

a

Front 128

What types of neurons have their cell bodies in the dorsal horn?

Back 128

a

Front 129

The cell bodies of what types of neurons are located in the ventral horn?

Back 129

a

Front 130

Draw a spinal cord in cross section labeling the dorsal and ventral roots. What type of information is carried in each of these structures?

Back 130

a

Front 131

What is the spinal nerve and what type of information is carried in spinal nerves?

Back 131

a

Front 132

Define proprioception.

Back 132

a

Front 133

Where is the input zone for the sensory neurons that are responsible for initiating the reflex arc?

Back 133

see reflex arc

Front 134

How is the action potential in the stretch receptor neuron initiated?

Back 134

see neuron structure

Front 135

What type of neuron does the sensory neuron synapse onto, and where in the spinal cord is this synapse located? What is the effect of bringing this neuron to threshold? Where does this neuron form synapses?

Back 135

a

Front 136

What type of interneuron does the sensory neuron innervate in the spinal cord? What neurons does this interneuron innervate?

Back 136

a

Front 137

Describe the reflex arc of the patellar tendon reflex from its initiation in the muscle spindle to the response in the extensor (quadriceps) and flexor (hamstring) muscles.

Back 137

a

Front 138

Why is the autonomic system called the involuntary nervous system?

Back 138

a

Front 139

What are the two divisions of the autonomic nervous system?

Back 139

see overview of autonomic nervous system

Front 140

What is meant by the statement that the sympathetic brance of the autonomic nervous system is responsible for the flight or fright response? What responses are typical of activing this system?

Back 140

a

Front 141

How do the sympathetic responses compare with the responses of the parasympathetic nervous system?

Back 141

a

Front 142

What is the function of the preganglionic neuron in the automnomic nervous system?

Back 142

a

Front 143

What is the function of he postganglionic neuron in the autonomic nervous system?

Back 143

a

Front 144

How are the preganglionic neurons in the sympathetic and parasympathetic brances of the autonomic nervous system similar? How are they different?

Back 144

see overview of autonomic nervous system

Front 145

Where are the cell bodies for the preganglionic sympathetic neurons located

Back 145

see gross anatomy of the sympathetic system

Front 146

Where are the cell bodies for the postganglionic sympathetic neurons located?

Back 146

a

Front 147

Where are the cell bodies for the preganglionic parasympathetic neurons located?

Back 147

a

Front 148

Where are the cell bodies for the post ganglionic parasympathetic neurons located?

Back 148

a

Front 149

Where are the synapses between pre and post ganglionic neurons in the sympathetic system?

Back 149

a

Front 150

Where are the synapses between pre and post ganglionic neurons in the parasympathetic system?

Back 150

a

Front 151

What is the neurotransmitter at the synapse between the preganglionic and post ganglionic neurons in both brances of the autonomic nervous system?

Back 151

see autonomic transmitter and receptors

Front 152

What is the neurotransmitter in the postganglionic sympathetic neurons?

Back 152

a

Front 153

What is the receptor for the neurontransmitter in the post ganglionic sympathetic neurons?

Back 153

a

Front 154

What is the neurotransmitter in the postganglionic parasympathetic neurons?

Back 154

a

Front 155

What is the receptor for the neurotransmitter in the postganglionic parasympathetic neurons?

Back 155

a

Front 156

Describe the effects of the sympathetic and parasympathetic postganglionic neurotransmitters on their respective receptors.

Back 156

a

Front 157

How are the sympathetic and parasympathetic postganglionic neurotransmitters receptors different from the ionotropic recepts?

Back 157

a

Front 158

Define GTP.

Back 158

see autonomic metabotropic recepts

Front 159

Define GTP binding protein.

Back 159

see autonomic metabotropic recepts

Front 160

Define adenelyl cyclase.

Back 160

see autonomic metabotropic recepts

Front 161

Define cyclic AMP.

Back 161

see autonomic metabotropic recepts

Front 162

Define protein kinase A.

Back 162

see autonomic metabotropic recepts

Front 163

Define protein phosphorylation.

Back 163

see autonomic metabotropic recepts

Front 164

Define phosphatase.

Back 164

see autonomic metabotropic recepts

Front 165

Define protein dephosphorylation.

Back 165

see autonomic metabotropic recepts

Front 166

Using the terms below, describe the sequence of events between the binding of neurotransmitter to a metabotropic receptor and the opening of a channel:

- GTP
- GTP binding protein
- adenelyl cyclase
- cyclic AMP
- protein kinase a
- protein phosphorylation
- phosphatase
- protein dephosphorylation

Back 166

see autonomic metabotropic receptors

Front 167

How do ionotropic receptors respond when they bind to neurotransmitter?

Back 167

a

Front 168

Describe how sensory information from the baroreceptors in the carotid arteries affects the heart beat.

Back 168

a

Front 169

If there is an increase in stretch, what information is fed through the Nucleus of the Solitary Tract to reduce the heart rate and strength of contraction?

Back 169

a

Front 170

What branch of the autonomic nervous system is used to reduce the heart rate?

Back 170

a

Front 171

If the stretch on the baroreceptors is reduced, what brance of the autonomic nervous system is used to increase the strength of contraction?

Back 171

a

Front 172

Information from the sensory cortex along with centers deep in the brain including the basal nuclei initiate activity in the premotor regions of the brain.

Back 172

a

Front 173

The premotor regions in the frontal cortex appear to be important for planning the execution of movement.

Back 173

a

Front 174

Action potentials from neuron in the prefrontal cortex convey information to the motor cortex.

Back 174

a

Front 175

How is the homunculus arranged in the motor cortex?

Back 175

see somatotopy in the motor cortex

Front 176

What are the neurons in the motor cortex called that initiate the movement?

Back 176

a

Front 177

What is the name of the descending tract that contains the axons of neurons that synapse onto lower motor neurons?

Back 177

see motor cortex and the corticospinal tract

Front 178

Where do the axons of neurons that synapse onto the lower motor neurons decussate?

Back 178

a

Front 179

What are the pyramids and where are they located?

Back 179

a

Front 180

Related the homunculus of the motor cortex to the general position in the spinal cord of the targets for the upper motor neurons.

Back 180

a

Front 181

Discribe how activation of an upper motor neuron leads to the activation of a lower motor neuron.

Back 181

a