A&P Chapter 11
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A&P Chapter 11
A&P Chapter 11
What are the two divisions of the nervous system?
CNS & PNS
What are the compnents of the CNS?
brain and spinal cord
What is the integrating and command center of the whole NS?
What NS responds to the outside (sensory)?
What does it mean to be touched/affected by a nerve?
Most cells are only ____ cells away from a neuron.
Is afferent or efferent flowing into the integrating center?
Is afferent sensory or motor?
Is afferent or efferent flowing out of the integrating center to the organs?
Is efferent sensory or motor?
What are some examples of effector organs?
smooth muscle around arteries, veins, and digestive system
Afferent is (motor/sensory) (output/input) and efferent is (motor/sensory) (output/input).
Which nervous system conducts impulses from the CNS to skeletal muscles?
Somatic Nervous System
Which nervous system is an involuntary system?
Does the Somatic/ANS begin at the Motor/Efferent division?
NO! Begins at CNS.
What are the 2 parts of the ANS?
Sympathetic & Parasympathetic division
What are the cells that regulate the chemical environment around neurons and exchange nutrients, waste, & O
between neurons and capillaries?
Astrocytes make up ___% of the cells in the brain. The other ____% are _____.
90% is neuroglia
Astrocytes belong to _NS.
Only a few ____ touch the capillaries directly.
What is the blood brain barrier? Which cells contribute to it?
The BBB helps prevent neurons from touching blood (which can be toxic to neurons). The astrocytes help contribute to it.
Which cells line the ventricles containing CSF?
Ependymal cells belong to _NS.
Which cells are responsible for immunity and monitor health and defend neurons?
Microglia cells belong to _NS.
These cells form the myelin sheaths of the CNS.
These cells form the myelin sheaths of the PNS.
These cells surround the neuron cells within the ganglia.
Satellite cells are part of the _NS.
Ganglia is a cluster of cell bodies in the _NS.
Nuclei is the cluster of cell bodies in the _NS.
A collection of axons in the PNS is a(n) ____.
A collection of axons in the CNS is the ____.
What are the main messaging system?
Which cell is a connector from one body of stuff to another?
True or false. All neurons cannot touch blood.
Which cells are important for memory? What is special about them?
Hippocamus. They can divide.
What are the main components of neurons?
node of ranvier
What are the main functions of a neuron?
-never really at rest
-high metabolic rate requiring oxygen and glucose
Action potentials and graded potentials are examples of _____ _____ and are in the ___ phase of mitosis.
electrical impulses; G
What are the main receptive regions of the neuron?
What is the biosynthetic center of the neuron?
What generates and conducts nerve impulses away from the cell body?
What are some characteristics of myelin sheath?
What is the trigger zone of the neuron?
What is the forward movement along the axon?
What is the movement of going back up the axon?
What is the difference between Schwann and oligodendrocytes?
Schwann = singular wrapped in sheath
oligodendrocytes = multiple wrapped in sheath
What is the difference between a myelinated and unmyelinated axon?
An unmyelinated axon is still wrapped but much looser, not as tight.
What does wrapping help with?
guiding the growth of the fibers
What are the 3 structural classes of neurons?
Which of the 3 structural classes of neurons is the most common?
Which of the 3 structural classes of neurons lack a dendritic region?
What are the 3 functional classes of neurons?
Which of the 3 functional classes of neurons is the most common?
What is capable of conduction an action potential?
Structure has to do with ______.
What are the 3 principles/characteristics of electricity?
What is the flow of electrical charge from point to point?
What is the amount of difference (the space) between one membrane and another?
What is the hindrance of flow?
The potential difference is a measure of _____.
At RMP, the cell is _____ inside and ____ outside with a average voltage of _____.
negative; positive; -70mV
A leaky membrane ion channel is always ___.
The membrane ion channel is 75% more leaky to ___ than ___.
A gated membrane ion channel is a proetin gate that changes ___ or ___ in response to a certain stimulus.
What are the 3 types of gating?
All cells are ____ to some degree.
The membrane is _____ _____ to solutes.
A voltage of -70 means the cell is negative ____ of the membrane.
A chemical/ligand channel is closed until when?
Until a chemical binds to it.
A voltage membrane is closed until when?
Until the voltage inside/outside of the membrane changes.
Changing from -70 is a means of ______.
The interior of the cell going from -70 to -60 is ______.
The interior of the cell going from -70 to -80 is _____.
Graded potentials are short-lived, ____ changes in membrane potentials.
Where do these differences in voltage take place?
right along the membrane
In the K/Na pump, ___ K go ___ and ___ Na go ___.
3 out; 2 in
More ___ can leak out than ___ can leak in.
What causes the Na to flow fast into the cell?
electrical & mechanical gradient
At RMP there is a(n) _____ amount of K going in and K going out.
K gets sucked out because ____.
There is all the positive Na going in.
Depolarization shows a (rise/drop) in the curve and is _PSP.
Hyperpolarization shows a (rise/drop) in the curve and is _PSP.
Will a weak graded potential still lead to an action potential?
What is graded potential?
Diffusion of an ion down inside of the membrane.
With graded potential, what is the "motion" of the ion?
It rushes in and spreads out along inside.
The membrane becomes positive inside once ___.
enough of the positive ions spread within
Graded potential happens mostly on ____.
If a graded potential happens on the axon, it leads to ____. When?
an action potential; immediately
_______ is the principle way neurons communicate.
In ____, there is a(n) _____ in Na permeability, a(n) _____ in Na permeability, and then a(n) _____ in K permeability.
generation; increase; decrease; increase
What is it when the depolarization of an area leads to the depolarization of the forward adjacent area?
_____ is the outside part of the Schwann cell. It is made of ___.
What are the 3 properties of a neuron?
What do neurons secrete?
There is a(n) ____ increase from rest to activity for muscle cells and a(n) ____ increase from rest to activity for neurons.
What restores the RMP after it has been depolarized?
If the membrane voltage does not reach ___, then no action potential occurs.
What is the critical minimum for depolarization?
Action potentials are a(n) _____ phenomenon.
The slight overshoot once the K channels are open and Nc channels close is called _____.
The stimulus intensity is encoded in the _____ of action potentials.
What is the name of the period of time required so that a neuron can generate another action potential?
What are the 4 phases of voltage gated?
1. all gates are closed
2. Na gates open
3. Na gates start to close, K gates start to open
4. Na gates are closed, K gates are open; slight hyperpolarization
In a voltage gated channel, what happens when the threshold (-55mV) is reached?
Na gates open and Na starts to enter
What happens when the Na channels are closing?
K channels are opening and K is leaving the cell
Will the gates respond at -25mV?
yes (depolarization) The gates will open
In the fourth stage of voltage gated channels, what is the slight overshoot?
The period of a lack of activity occurs for how long? What is the length traveled?
1-2 minutes; 1 mm of axon length
What is the absolute refractory period?
The period from the opening of Na channels until they begin to reset to original state.
Na is open and Na is entering.
Follows stimulation during which no additional action potential can be evoked.
Absolutely nothing can happen!
What is the relative refractory period?
Follows absolute refractory period.
Interval when a threshold for action potential stimulation is elevated.
Na has returned to resting state, some K is still open (and K is still leaving), repolarization is occurring.
What are the 2 refractory periods (in order)?
absolute & relative
What are the factors that affect conduction velocity? How so?
Size (the bigger the axon, the more conductive)
Myelination (the more myelinated, the more conductive)
What are the 2 methods of conduction?
continuous conduction & saltatory conduction
What is continuous conduction? Is it for myelinated or unmyelinated fibers?
Threshold voltage in trigger zone begins impulse.
Chain reaction (walking slowly and deliberately) of opening of Na channels...adjacent to adjacent to adjacent.
How fast does continuous (impulse) conduction occur?
What is saltatory conduction? Is it for myelinated or unmyelinated fibers?
Skipping parts to go faster (walking normally).
Skipping from node to node (excessive channels at nodes of ranvier).
How fast does saltatory conduction occur?
Is pain transmission happens down a myelinated or unmyelinated axon?
unmyelinated (takes a while for the pain to register)
Why do large fibers have a higher velocity of nerve signal?
More surface area for signals.
Small, unmyelinated fibers travel at what speed?
0.5 - 2 m/s
Small, myelinated fibers travel at what speed?
3 - 15 m/s
Large, myelinated fibers travel at what speed?
up to 120 m/s
You pull your hand away from a hot stove even before the pain sets in. This is an example of...
A junction that mediates information transfer between neurons or between a neuron and an effector cell.
What is toward (before) the synapse?
What is away from (after) the synapse?
What have neurons that are electrically
coupled via protein channels
and allow direct exchange of ions from cell to cell (e.g from one muscle cell to another)?
Specialized for release and reception of chemical neurotransmitters
What are the 3 ways in which neurotransmitter effects are terminated?
Prozac is an example of _____ (terminated neurotransmitter effect)
______ is the termination of neurotransmitters by enzymes; postsynaptic cell or within the synaptic cleft
______ is the termination of neurotransmitters by astrocytes or the presynaptic cell
______ is the termination of neurotransmitters away from the synapse
What are the 3 synaptic regions?
____ junctions are important for electrical synapses.
These 2 muscle types are involved in electrical synapse.
smooth & cardiac
What mediate, modulate, and alter graded potentials on the postsynaptic cell? They can be ______ or _____.
neurotransmitters; excitatory or inhibitory
What are the two types of summation be the postsynaptic neuron?
temporal and spatial
Which summation is the response to successive releases of NT?
Which summation is the postsynaptic cell stimulated at the same time by multiple terminals?
When a presynaptic cell is stimulated repeatedly or continuously, enhancing the release of NT.