Chap 11 Flashcards
1
Q
group of nerve cell bodies located outside of the central nervous system are called:
A
ganglia/ganglion
2
Q
category of cells of the nervous system that support and protect neurons are called;
A
neuroglia
3
Q
functions of the nervous system
A
- control muscles and glands
- integrate information
- receive sensory input
4
Q
a gap junction that allows an ionic current to flow between cells =
A
electrical synapse
5
Q
a synapse where one cell releases a neurotransmitter to communicate with another cell =
A
chemical synapse
6
Q
nerve is defined as a bundle of =
A
axons within the peripheral nervous system
7
Q
peripheral nervous system components;
A
- sensory receptors
- nerves
- ganglia
8
Q
propagation means =
A
travel ( across the plasma membrane)
9
Q
propagation of action potential in unmyelinated axon;
A
- initial action potential produced at a trigger zone
- action potential generates local currents
- depolarization of close areas of the membrane
- threshold reached in close areas of the membrane
- new action potential produced
10
Q
a cluster(group) of cell bodies and their dendrites in CNS
A
nucleus
11
Q
a cluster(group) of cell bodies and their dendrites in PNS
A
ganglion
12
Q
bundles of axons and their myelin sheaths in CNS
A
tract
13
Q
bundles of axons and their myelin sheaths in PNS
A
Nerve
14
Q
convergent pathways;
A
Many presynaptic neurons synapse/converge with smaller number of post synaptic neurons
15
Q
divergent pathways;
A
Small number of presynaptic neurons synapse with large number of postsynaptic neurons
16
Q
neurons arranged in a circular fashion that are repeatedly stimulated to produce action potentials;
A
oscillating circuit
17
Q
3 major structures of neurons are;
A
- multipolar = many dendrites and 1 axon
- bipolar = 1 dendrites and 1 axon
- pseudo-unipolar = no dendrites and 1 axon
18
Q
within a chemical synapse, the receptors bind to very specific ____.
A
ligands
19
Q
neuron consists of;
A
- cell body
- dendrites
- axon
20
Q
neurons conduct action potentials toward CNS;
A
sensory neurons
21
Q
neurons condyct action potentials away from the CNS toward muscles or glands;
A
motor neurons
22
Q
neurons conduct action potentials from one neuron to another within the CNS;
A
interneurons
23
Q
Action Potential (order);
A
- Stimulus open voltage-gated sodium gates open, Na+ rush into cells.
- threshold is reached
- depolarization spike until +35 millivolts
- repolarization=positively charged potassium ions exit the cell, inside cell become negative again
- afterpotential
- resting membrane potential (=electrical charge difference) re-established; inside of the plasma membrane is negative than the outside.
24
Q
activities of CNS associated with action potentials;
A
- perception (understand/notice) of pain
- control a muscle or gland
- remember names
25
2 type of cells make up the nervous system are;
- neurons
| - neuroglia (supportive)
26
central nervous system consists of;
brain, and spinal cord
27
peripheral nervous system consists of:
sensory receptors
nerves
ganglia
plexuses
28
autonomic motor nerves;
- sympathetic and parasympathetic divisions
| - signals to smooth muscle, cardiac muscle, glands
29
somatic nervous system;
efferent (motor); signals to skeletal muscles, voluntary control
30
afferent division;
sensory nerves of PNS
| carry sensory information into brain and spinal cord
31
efferent division;
motor nerves of PNS
| carry motor information from CNS to effectors
32
enteric nervous system;
| of Autonomic nervous system in PNS
controls digestive tract
33
intracellular fluid has the same number of positive and negative charges, therefore electrically;
neutral
34
dendrite =
cytoplasmic extensions that are short, highly breached (often).
35
multi-polar neuron =
neuron with many dendrites and 1 axon.
36
bipolar neuron =
neuron with 1 dendrite and 1 axon
37
electrical signals that are propagated along axons, regulating and coordinating body activities are;
action potentials
38
negatively charged proteins are synthesized inside the cell, too large to diffuse across the plasma membrane. They remain;
inside the cell.
39
response to stimuli, memories, emotions, perception are all due to
action potentials (electrical signals)
40
enlarged portion of a neuron contains nucleus and other organelles;
cell body / soma
41
transmits action potentials away from the cell body;
axon
42
receives stimuli and generates local potentials;
dendrite
43
rough endoplasmic reticulum of a neuron responsible for protein synthesis;
nissl body
44
branches of axon
collaterals
45
in the CNS, gray mater on the surface of the brain is called _____, clusters of gray mater located deeper within the brain are called _____.
cortex, nuclei
46
in the PNS, a cluster of neuron cell bodies is called a _____ .
ganglion
47
white mater (bundles of axons and their myelin sheaths) of CNS forms;
nerve tracts
48
in the PNS, bundles of axons and their connective tissue sheaths are called;
nerves
49
synaptic vesiclescles contain chemicals called;
neurotransmitters
50
chemical synapse event;
| P.385
1. an action potential reaches the presynaptic terminal
2. voltage gated Ca++ channels open
3. Ca++ diffuses into the presynaptic terminal
4. neurotransmitters are released into the synaptic cleft
5. neurotransmitters bind to receptors on the postsynaptic membrane, opens a ligand-gated Na+ channel
6. depolarization (Na+ diffuses into cell) or hyprpolarization (K+ or Cl- diffuses out of the cell) of the postsynaptic membrane occurs
51
molecule that binds to a receptor (such as a neurotransmitter or a hormone) =
ligand
52
action potential characteristics;
- all-or-none
- propagate in a non-decremental (not decreased) fashion
- strength of the stimulus determine the frequency of the action potentials (not the number of stimuli)
53
hyperpolarization;
charge inside the plasma membrane becomes more negative.
54
electrical signals produced by cells, called ________ transfer information from one part of the body to another.
action potentials
55
plexus =
extensive network of axons / neuron cell bodies located outside the CNS
56
junction between a neuron and another cell is;
synapse
57
graded potentials characteristics
- size due to the strength of the stimulus.
- summation occurs when effects of one graded potential is added to another
- depolarization can cause an action potential
58
astrocytes =
- star shaped neuroglia in CNS
- regulate extracellular brain fluid composition
- blood-brain barrier=tight junction to protect brain blood vessels
59
functions of astrocytes;
- extracellular brain fluid composition
- cover surfaces of blood vessels and neurons / b.b.barrier
- wall off injured CNS tissue to limit spread of inflammation
60
ion channel that opens when a specific electrical current is present on the cell membrane is;
voltage-gated
61
ciliated, lining the ventricles of the brain and the central canal of the spinal cord help move cerebrospinal fluid, and production of cerebrospinal fluid;
ependymal cells
62
Neuroglia of CNS that form myelin sheaths surround axons;
oligodendrocytes
63
effect of one graded potential is added to the effect of another;
summation
64
ions that have higher concentration in the extracellular fluid;
- Ca++
- Cl-
- Na+
Calcium, chlorine, sodium
65
a gap junction allows local ionic current to flow between adjacent cells;
electrical synapse
66
neurotransmitters released by action potential in presynaptic terminal;
chemical synapse
67
electrical synapse event;
1. an action potential occurs within the membrane of an initial cell
2. a local current is generated
3. local current flows through a gap junction
4. this stimulates the production of action potential in an adjacent cell
68
Wrap around potion of only 1 axon to form myelin sheath (within PNS);
schwann cells
69
Surround neuron cell bodies in ganglia, provide support and nutrients;
satellite cells
70
myelinated axons;
- myelin protects and insulates axons
| - action potentials jump from a node of Ranvier to the next, conduction is much faster
71
unmyelinated axons;
- slow conduction
72
Sodium-Potassium Exchange Pump
1. three Na+ and ATP bind to the carrier molecule
2. ATP breaks down to ADP and phosphate, releases energy. carrier molecule changes shape, and Na+ are transported across the membrane.
3. Na+ diffuse away from the carrier molecule, two K+ bind to the carrier molecule, and the phosphate is released.
4. Carrier molecule resumes original shape, transporting K+ across the membrane, and K+ diffuse away from the carrier molecule. The carrier molecule can again bind to Na+ and ATP.
73
membrane permeability;
- nongated K+ channel = always open
- gated Na+ channel = closed
- nongated Cl- channel = always open
74
ligand-gated ion channels;
open or close in rsponse to ligand biding to receptor as ACh
75
voltage-gated ion channels;
open or close in response to small voltage _______
76
resting membrane potential characteristics;
- number of cherged molucules and ions inside / outside cell nearly equal.
- concentration of K+ higher inside than outside cell, Na+ higher outside than inside
- there is very little movement of K+ or other ions across plasma membrane
77
depolarization of RMP;
| resting membrane potential
- increase in extracellular K+ concentration
| - mvnt of RMP (resting membrane potential) toward zero = more positive
78
hyperpolarization of RMP;
| resting membrane potential
- decrease in extracellular K+ concentration
| - mvnt of RMP (resting membrane potential) further away from zero = more negative
79
Gray matter of the cerebrum (cortex and deeper nuclei) is made up primarily of;
neuron cell bodies
80
neuroglia of CNS that phagocytize dead tissue & foreign substances;
microglia
81
ion that is higher concentration in the intracellular fluid is;
potassium
82
similarity of EPSP (local depolarization) and IPSP (local hyperpolarization)
- both are graded potentials
- size of EPSP or IPSP is proportional to the strength of the stimulus
- they are conducted in a decremental fashion
83
Neuroglia of CNS (4) ;
- astrocytes
- ependymal cells
- microglia
- oligodendrocytes
84
Neuralgia of PNS;
Schwann cells , and satellite cells
85
Functional neuron classification;
- sensory/afferent = action potential toward CNS
- motor/efferent = action potentials away from CNS
- interneurons/association = within CNS from one neuron to another
