Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A&P 1 > A&P CH12 > Flashcards

A&P CH12 Flashcards

1
Q

What is the difference in signals that are carried by the afferent vs efferent divisions of the Peripheral Nervous system (PNS)

A

Afferent- brings sensory info. to the CNS from receptors in peripheral tissues and organs
Efferent- carries motor commands from the CNS to muscles, glands and adipose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name three groups of receptors and describe what they monitor

A
  1. special sensory receptors- monitor smell, taste, vision, balance and hearing
  2. Visceral sensory receptors- monitor internal organs
  3. somatic sensory receptors- monitor skeletal muscle, muscles, joints and skin surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the effectors of the Somatic Nervous system (SNS) and of the Autonomic Nervous system (ANS)

A

SNS- skeletal muscle
ANS- smooth muscle, cardiac muscle, glands and adipose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

There are three main anatomical divisions of the nervous system, but we will focus on the CNS and PNS. What nervous system organs are associated with each? (ie: What structures are part of the CNS? What structures are part of the PNS?)

A

CNS- brain and spinal cord
PNS- all nervous tissue outside of the CNS and ENS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the following neuron structures, and state their functions: soma (cell body), perikaryon, Nissl bodies, dendrites, axon, axolemma, axoplasm, telodendria, and axon terminals

A

soma (cell body)- large and round nucleus with a prominent nucleolus
perikaryon- cytoplasm surrounding the nucleus: contains organelles that provide energy and synthesize organic material
Nissl bodies- clusters of free ribosomes and RER in the perikaryon: give a gray color to areas containing neuron cell bodies
dendrites- extensions that extend and branch out from the cell body: (intercellular communication)receive electrical signals from other neurons and transmit them toward the some
axon- long cytoplasmic process capable of propagating an action potential
axolemma- plasma membrane of the axon surrounding the axoplasm
axoplasm- cytoplasm of the axon: contains neurofibrils, neurotubules, small vesicles, lysosomes, mitochondria and enzymes
telodendria- (terminal branches) terminal axonal branches that end in axon terminals
axon terminals- synaptic terminal: key role in communicating with another cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the significance of neurons not having centrioles

A

centrioles help to organize the cytoskeleton and microtubules that move chromosomes during mitosis- without them CNS neurons cannot divide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference between anterograde and retrograde axoplasmic transport

A

anterograde- the flow of materials from the cell body to the axon terminal: via kinesin
retrograde- the flow of materials from the axon terminal to the cell body: via dynein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of axoplasmic transport is associated with the virus that causes rabies. What is the outcome of rabies?

A

retrograde flow, virus enters axon terminals and is carried to the soma with fatal results

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name four structural classifications of neurons; describe what they look like, where are they located, and state their function?

A

1, Anaxonic - small with numerous dendrites and no visible axons, located in the brain and special sense organs, don’t know functions
2. Bipolar- 2 distinct processes; one dendrite and one axon, special sense organs, relay info from receptor cells to other neurons
3. Unipolar- (psuedounipolar) dendrites and axon are continuous and the cell body lies off to one side, sensory neurons of the PNS, carries sensations
4. Multipolar- two or more dendrites and a single axon, most common neuron in CNS, motor neurons that control skeletal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Name three functional classifications of neurons and state what they monitor

A
  1. Sensory neurons (afferent)- unipolar neurons that deliver info to the spinal cord or brain. collect info. about the external or internal environment
    somatic- monitor the outside world and our position in it
    visceral- monitor internal conditions and statuses of organs
  2. Motor neurons (efferent)- carry commands from CNS to effectors
    somatic-innervate skeletal muscle
    visceral- innervate all peripheral effectors other than skeletal muscles (smooth/cardiac muscle, glands and adipose)
    3, Interneurons - outnumber all other types of neurons combined, distribute sensory info, and coordinate motor activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of interneurons and where are they mainly found

A

Located between sensory and motor neurons-located within the brain and spinal cord with some in autonomic ganglia
main unction- integration: distribute sensory info, and coordinate motor activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

List the neuroglia located in the CNS and state their function

A
  1. Astrocytes- maintain BBB, provide structural support, regulate ion, nutrient and dissolved gas concentrations, absorb and recycle neurotransmitters, form scar tissue after injury
  2. Ependymal cells- line ventricles (brain) and central canal (spine), assist in producing, circulating and monitoring CSF
  3. Oligodendrocytes- myelinate CNS axons, provide structural framework
  4. Mircoglia- remove cell debris, waste and pathogens by phagocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

List the neuroglia located in the PNS and state their function

A
  1. Satellite cells- surround neuron cell bodies in ganglia, regulate O2 and CO2, nutrient and neurotransmitter levels around neurons in ganglia
  2. Schwann cells- surround all axons in the PNS; myelinate peripheral axons, participate in repair after injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the function of myelin? Knowing this, what would a demyelination disease do to the speed of action potential transmission?

A

serves as an electrical insulation and increases the speed at which an action potential travels along the axon; slow it down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are internodes, and nodes of Ranvier?

A

large areas of axon wrapped in myelin, small gaps that separate adjacent internodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What neuron structures are primarily located in white matter? Gray matter? Why is white matter whitish in color?

A
  • myelinated axons
  • neuron cell bodies, dendrites and unmyelinated axons
    -because of the lipids in myelin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Wallerian degeneration?

A

a process in which the axon distal to the injury site degenerates and macrophages migrate to clean up debris- Schwann cells proliferate and create a path for the axon to grow and the Schwann cell wraps around the axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why is repair of damaged PNS neurons more likely than repair of CNS neurons

A

In CNS;
1. many more axons are likely to be involved
2. astrocytes produce scar tissue that prevents axon growth
3. astrocytes release chemicals that block axon regrowth

19
Q

State the difference between sodium (Na+) and potassium (K+) in respect to intercellular vs extracellular concentrations in a resting cell

A

Extracellular fluid contains high conc. of sodium and chloride ions
intracellular fluid (cytosol) contains high conc. of potassium ions and negatively charged proteins

20
Q

What is a leak channel? Do they ever close? In respect to resting membrane potential and leak channels, what occurs with Na+ and K+ ions. Are leak channels active or passive?

A

membrane channels that are always open, no
intracellular conc. of potassium is high so they move out of the cell through leak channels; the extracellular conc. of sodium is high so they move into the cell through leak channels
-movement driven by electrochemical gradient
-passive
-electrical gradient of potassium opposes the movement of K out of the cell

21
Q

What is the function of the sodium/potassium pump? Is it active or passive? Review page 97—how many of each Na+ and K+ ions are exchanged

A

exchanges 3 intracellular Na ions for 2 extracellular K ions
balances the passive forces of diffusion and resting potential stays stable as ionic conc. gradients are maintained

22
Q

When a cell is at rest, what molecules cause the inner surface of the plasma membrane to be more negatively charged?
-Review Figure 12-9 Electrochemical Gradients for Potassium and Sodium Ions.
Note that K+ or Na+ chemical gradients move ions from high concentration to low concentration through leak channels
Note that K+ or Na+ electrical gradients move ions that attract one another—in other words cations will move toward anions (opposites attract)
Note Remember under normal conditions, a cell’s plasma membrane is selectively permeable- meaning that it allows certain ions/molecules in while excluding others

A

negatively charged proteins and the leak of potassium

23
Q

What is the resting membrane potential of a neuron in millivolts?

A

-70

24
Q

What are gated ion channels; are they active or passive?

A

active channels that open or close in response to specific stimuli
-active

25
Q

What are the 3 types of gated ion channels? What makes each open and close?

A
  1. chemically gated/ ligand-gated ion channels; open or close when they bind a specific chemical or ligand
  2. voltage gated ion channels; open or close in response to changes in the membrane potential
  3. mechanically gated ion channels; open or close in response to physical distortion of the membrane surface
26
Q

What is a graded potential?

A

(local potentials) changes in the membrane potential that cannot spread far from the site of simulation

27
Q

Define depolarization. What initiates depolarization? What occurs ionically to cause depolarization

A

occurs when the plasma membrane of a resting cell is exposed to a chemical that opens chemically gated sodium ion channels
any shift in the membrane potential toward a less negative potential- towards 0mV
sodium ions enter the cell and are attracted to the negative charges along the inner surface of the plasma membrane

28
Q

Define repolarization. What initiates repolarization? What occurs ionically to cause repolarization?

A

the process of restoring the membrane potential after depolarization
occurs when the chemical stimulus is removed and normal permeability is restored

29
Q

Define hyperpolarization.
-Review Table 12-2 Graded Potentials

A

caused by the loss of positive ions, an increase in the negativity of the resting membrane potential

30
Q

What is the difference between a graded potential and an action potential?

A

action potentials are propagated- they spread along the surface of an axon and do not diminish as it moves away from the source while graded potentials do not spread

31
Q

Define threshold. What is the threshold in mV of an axon?
-Review Spotlight Figure 12-13 Generation of an Action Potential

A

the membrane potential at which an action potential begins

32
Q

Know what occurs in steps 1-4 of Spotlight Figure 12-13

A
  1. Depolarization to threshold- graded potential is large enough to depolarize the membrane of the initial segment to threshold
    2.Activation of sodium ion channels and rapid depolarization- sodium rushes in driven by its electrochemical gradient
  2. inactivation of sodium ion channels and activation of potassium ion channels start repolarization- K ions move out of the cytosol
  3. temporary hyperpolarization- potassium channels are slow to close so additional potassium leaves the cytosol
33
Q

What is the refractory period?

A

the time between the initiation of an action potential and the restoration of the normal resting membrane potential- membrane will not respond to stimuli

34
Q

The presence of what substance on an axon determines whether continuous or saltatory propagation of an action potential occurs? What occurs in saltatory propagation?

A

myelin- the presence of myelin increases the resistance to the flow of ions across the membrane
-continuous propagation cannot occur along a myelinated axon
-saltatory propagation: the relatively rapid propagation of an action potential between successive nodes of a myelinated axon

35
Q

What are two factors that affect action potential propagation speed?

A

myelination and axon diameter
axon diameter- ions must move through the cytosol in order to depolarize adjacent portions of the plasma membrane

36
Q

When discussing Type A, B, and C fibers, which one propagates actions potentials the fastest? Which one is unmyelinated?

A

Type A is the fastest (120 m/sec) bc they are myelinated
Type C is the slowest (1 m/sec) since they are unmyelinated

37
Q

What is released at a chemical synapse?

A

information passes from the presynaptic neuron to the postsynaptic neuron

38
Q

What is a neuromuscular junction? What is a neuroglandular junction

A
  • a synapse between a neuron and a skeletal muscle cell
    -a cell junction at which a neuron controls or regulates the activity of a secretory (gland) cell
39
Q

What neurotransmitter is released at cholinergic synapses?

A

ACh- acetylcholine

40
Q

What ion enters the axon terminal triggering the release of ACh?

A

calcium ions

41
Q

What enzyme breaks down ACh into choline and acetate?

A

AChE- acetylcholinesterase

42
Q

Name 4 classes of neurotransmitters. Which type acts as neuromodulators?

A
  1. biogenic amines
  2. amino acids
  3. neuropeptides- neuromodulators : alters the rate of neurotransmitter release by the presynaptic neuron or change the postsynaptic cells response to neurotransmitters
    4, dissolved gases
43
Q

What is an excitatory postsynaptic potential (EPSP)? What is an inhibitory postsynaptic potential (IPSP)?

A

EPSP- a graded depolarization caused by the arrival of a neurotransmitter at the postsynaptic membrane
IPSP- a graded hyperpolarization of the postsynaptic membrane

44
Q

What is the difference between temporal and spatial summation?

A

summation- the temporal or spatial addition of contractile force or neural stimuli
temporal- the addition of stimuli occurring in rapid succession at a single synapse that is active repeatedly
spatial- occurs when simultaneous stimuli applied at different locations have a cumulative effect on the membrane potential

A&P 1 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions