Chapter 12 Neural Tissue Flashcards
1
Q
Nervous system has two subdivisions
A
Central nervous system
Peripheral nervous system
2
Q
Consists of the brain and spinal cord
A
Central nervous system CNS
3
Q
12 pairs of cranial nerves
31 pairs of spinal nerves
All nerve branches
A
PNS peripheral nervous system
4
Q
PNS has two subdivisions
A
Afferent nervous system
Efferent nervous system
5
Q
Carry sensory info to the CNS
A
Afferent NS
6
Q
Any detectable change in the environment
A
Stimulus
7
Q
Detect stimuli and send info to the CNS
A
Receptor cells
8
Q
2 types of receptor cells
A
Interorecptor
Exterorecptor
9
Q
Monitor internal environment
A
Interorecptors
10
Q
Monitor external environment
A
Exterorecptor
11
Q
Carry motor commands to effectors (muscles)
A
Efferent NS
12
Q
Efferent nervous system has two subdivisions
A
Somatic NS
Autonomic NS
13
Q
Controls skeletal muscle
A
Somatic NS
14
Q
Controls smooth and cardiac muscle
A
Autonomic NS
15
Q
Autonomic nervous system has two subdivisions
A
Sympathetic NS
Parasympathetic NS
16
Q
Both control smooth cardiac muscle
A
Sympathetic and parasympathetic NS
17
Q
Fight or flight
Active during stress
Increase levels of skeletal muscle and brain activity
Increase heart rate
Increase BP
Increase breathing rate
Increase blood flow to brain skeletal muscles heart and lungs
Decrease wastes and reproductive functions
A
Sympathetic NS
18
Q
Rest and digest
Active during low stress
Decrease levels of brain and skeletal activity
Decrease heart rate, BP, Breathing rate, blood flow to brain, skeletal muscles, heart and lungs
Increase digestive wastes & reproductive functions
Increase blood flow to these systems
A
Parasympathetic NS
19
Q
Are integral membrane proteins that allow specific ions to flow across the cell membrane
A
Ion channels
20
Q
Are always open and allow specific ions to flow across
A
Leak channels
21
Q
Don’t have an axon
A
Anaxonic neurons
22
Q
Soma
Long continuous axon with synaptic knobs and dendrites
A
Unipolar neurons
23
Q
Single dendrite, single axon, each coming off the soma
A
Bi polar neurons
24
Q
Have multiple branches/dendrites
Single axon
A
Multipolar neurons
25
The dendrites and axon are attached to the ?
Soma
26
Neuron cell body
Soma
27
Attached to the soma
Axon hillock
28
Dark staining area in a neuron around the nucleus
Perikaryon
29
Is the maintenance of this separation of electrical charge across the membrane while the cell is at rest.
Resting membrane potential
30
While passive channels are allowing ions to diffuse across the membrane, the ________ is pumping them back across where they came from at an equal pace to keep up with the membrane potential at rest.
Sodium potassium pump
31
Open and close in response to the presence of specific chemicals like neurotransmitters and drugs.
Chemically gated channels
32
Open at specific voltages and close at specific voltages
Voltage gated channels
33
Open in response to mechanical or physical distortions of the cell membrane
Mechanically gated channels
34
Ions have a higher concentration outside the cell
Sodium ions
35
Ion concentration much higher inside the cell than outside
Potassium ions
36
the neurons not conducting action potentials while the neurons at rest
-70 mv
37
Since the cell is polarized to minus 70, if I start moving closer to zero, any movement in a positive direction is
Depolarize
38
Gated channels are only found in
Excitable cells
39
Always open and help establish RMP
Leak channel
40
Stimulus to open and close is Excitatory chems and depolarize neurons/depolarize to threshold
Chemically gated NA+ sodium
41
Stimulus to open and close is Inhibitory chems hyper polarized neurons
Chemically gated K+ postassium
42
Stimulus to Open -60 mv close at +30 mv do rapid depolarization
Voltages gated na + channel sodium
43
Open +30 mv close -90 mv Repolarization hyperpolarization
Voltage gated K+ channel
44
@ synaptic knobs
Voltaged gated ca++ calcium channels
45
Most cell to cell communication within the nervous system is by
Chemical synapses
46
A __________ is a small localized change in the RMP.
Graded potential
47
Graded potentials individually are not strong enough to reach threshold and are often referred to as
Subthreshold potentials
48
The voltage necessary to begin opening voltage gated channels
Threshold
49
If the NT opens a sodium channel, sodium ions will ENTER the cell, the neuron will become more POSITIVE inside and is said to DEPOLARIZE or become EXCITED or have an
EPSP excitatory post synaptic potentials
50
If the NT opens potassium channels, potassium ions will exit the cell; the neuron will become negative and is said to hyperpolarize or have an
IPSP inhibitory post synaptic potentials
51
Graded potentials individually can result in _____ of stimulation
0.5 mv
52
Graded potentials can be increased in strength by adding several events together, called
Summation
53
_______ Are summated to bring the cell closer and closer to threshold, while ______ can be summated to bring cell further and further away from threshold and prevent action potentials
EPSP
IPSP
54
Results from continuous stimulation of a single synapse to add either EPSPs or IPSPs together.
Temporal summation
55
Results from simultaneous stimulation of numerous synapses to add either EPSPs or IPSPs together
Spatial summation
56
Occurs when a chemical raises the RMP closer to threshold for a period of time
Facilitation
57
Nicotine, caffeine, and cocoa can result in
Facilitation
58
Any detectable change in the environment/ anything that alters the RMP
Stimulus
59
If a graded potential depolarizes the membrane to a millivoltage that opens voltage gated channels, the cell will start an
Action potential
60
An ____ is a self propagating wave of voltage that will pass down the entire length of a neuron
Action potential
61
Is the level of depolarization necessary to cause an action potential
Threshold potential
62
Once threshold is reached an action potential will pass down the entire length of the axon, there is no turning back. This is referred to as the
All or none principal
63
Any ______ that brings the neuron to threshold will cause an action potential
Stimulus
64
A chemical stimulus opens chemically gated sodium channels to open, causing a depolarizing graded potential. If the graded potential reaches threshold 60mv, voltage gated sodium channels begin to open.
Depolarize to threshold
65
Sodium ions enter the cell making it more positively charged inside. The depolarizing continues to +30mv, the voltage at which all voltage gated sodium channels are closed
Rapid depolarization
66
At +30mv potassium channels are opening and potassium ions are flowing out of the cell making it less positively charged inside. This continues until cell reaches 70mv
Repolarization
67
At -70mv potassium channels begin to close, but do so very slowly, allowing excess potassium ions to leak out of cell causing it to hyperpolarize to -90mv.
Hyperpolarization
68
The sodium potassium pump restores resting membrane potential
Return to RMP
69
Period of time during an action potential where no stimuli can cause a second action potential
Absolute refractory period
70
Period of time during an action potential where new stimuli can cause a second potential, but it is relative to the strength of the stimulus.
Relative refractory period
71
The voltage carried into the cell by the ions will diffuse from an area of high concentration or they entered the cell out to other areas of the cell. If enough voltage spreads it can cause the next patch to reach threshold potential and fire an action potential identical to the last one. This will then cause the next patch and the next and the next to spread this action potential across the entire cell, this is called
Continuous conduction
72
The spreading of an action potential across the cell is called
Propagation
73
There are two ways to increase conduction velocity within an axon
Axon diameter
Myelination
74
Small diameter axons conduct action potentials at about
2mph
75
Large diameter axons like pain fibers can carry action potentials at about
300 mphs
76
perform continuous conduction where they must depolarize each consecutive patch of membrane for the action potential to reach the synaptic knob
Unmyelinated axons
Myelination
77
Myelinated axons Are surrounded by specialized ______ that are filled with a fatty substance called myelin
Schwann cells
78
Between the Schwann cells is a small gap called a _______ where the ions do have access to the ion channels
Node of ranvier
79
The voltage generated at one node is strong enough to jump to the next node and cause an action potential, which will then jump to the next successive node of ranvier, and so on. This jumping of the action potential is called
Saltatory conduction
80
Mechanism of action
Excitatory in skeletal muscle (opens Na+ channels)
Inhibitory in cardiac muscle (opens K+ channels)
Distribution
CNS PNS
Acetylcholine (cholergenic)
81
Mechanism of action
Usually excitatory (opens na channels )
Distribution
CNS and PNS sympathetic
Norepinephrine (adrenergic)
82
Mechanism of action
Inhibitory to motor neurons (low Parkinson’s)
Excitatory in emotional & pleasure centers (feel good NT)
Distribution
CNS
Dopamine
83
Mechanisms of action
Inhibitory for pain fibers runners high
Released during shock don’t feel injury
Distribution
CNS
Endorphins
84
Mechanisms of action
Released when fell bad like having the flu
Distribution
CNS
Enkephalins
85
Types of Neurotransmitters
Acetylcholine
Norepinephrine
Dopamine
Endorphins
Enkephalins
86
A _______ can communicate to a skeletal muscle cell at a neuromuscular junction across a synaptic cleft
Neuron
87
At a synapse a ________ is released by a presynaptic cell, it travels across the synaptic cleft, and then binds to receptor on the post synaptic cell.
Neurotransmitter
88
At the post synaptic membrane this NT will open a specific type of chemically gated channel and alter resting membrane potential until the NT is removed by an
Enzyme
89
As soon as the NT breaks down the channel will close, diffusion of ions stops, and the sodium postassium pump returns the cell to
Resting membrane potential
90
-60 mv
Threshold potential
91
-70 mv
RMP
92
Chemically gated channels are located
Soma
93
Voltage gated channels are located on the
Axon
94
At the post synaptic membrane, if I open chemically gated sodium channels I’m going to get an
EPSP excitatory post synaptic potential
95
Action potentials must always reach
Threshold
96
-90 mv
Hyperpolarization
97
Above -60mv and back to -60mv
Absolute refractory period
98
Two ways to reach threshold
Temporal and spatial summation
99
Schwann cell is a
Glia cell
100
Insulates the axon from the surrounding fluid and blocks ion access to the ion channels
Myelin
101
The collection of Schwann cells
Myelin sheath
102
have slower action potentials
Unmyelinated axons
103
the action potential can travel more rapidly
Myelinated axons
104
Blood vessels that filter blood and CSF
Choroid plexus
105
Information processing and fine action potential
Neurons
106
No information processing (do not conduct action potentials) support neurons physically, nutritionally, biochemically
Neuroglia
107
Star shaped, provide framework for neurons of brain and spinal cord. Also help form the blood brain barrier.
Astrocytes
108
Line the walls of brain ventricles and central canal of spinal cord, they monitor and alter components of CSF
Ependymal cells
109
Myelinate axons in the CNS
Oligodendrocytes
110
White blood cells (immune cells) that phagocytose debris, damaged, tissue or infectious agents
Microglia
111
Myelinate some axons in PNS to increase action potentials
Schwann cells
112
In the CNS, a collection of somata that perform same function is called a
Nucleus or center
113
In the PNS, a collection of somata that perform the same function is called
Ganglion
114
A bundle of axons in the CNS is called a
Tract or fasicle
115
A bundle of axons in the PNS is called
A nerve
116
House centers for vital functions, breathing, heart beat, digestive system
Medulla pons
117
Visual reflexes
Superior colliculus
118
Auditory reflexes
Inferior colliculus
119
Motor coordination
Cerebellum
120
Is made of somata (cell bodies of neurons) and unmyelinated axons. It appears darker or gray in color due to lack of Myelination
Gray matter
121
Is made up of myelinated axons. The Myelination, provided by oligodendrocytes, gives it a whiter or lighter appearance than gray matter.
White matter
122
The brain stems consists of
Medulla
Pons
Midbrain
123
Connects directly to the spinal cord, is the lowest and most primitive part of the brain, and controls basic vital functions like breathing, heart rate, and digestive functions
Medulla
124
Sits on top of the medulla, is a bridge to the cerebellum, and carries fibers that relay information to and from the cerebellum regarding motor control. The ______ also houses to centers that are involved in regulating respiratory rhythms
Pons
125
Controls muscle patterns for posture, walking, and visual and auditory reflexes
Midbrain
126
Coordinates somatic motor patterns and muscle memory like dancing, juggling, shooting a basketball, playing a musical instrument
Cerebellum
127
Consists of the hypothalamus and thalamus
Diencephalon
128
Contains numerous center or nuclei that regulate the internal environment including body temperature, hunger, sex drives, emotions, and hormones.
Hypothalamus
129
Contains nuclei and centers involved in filtering and relaying sensory information to the cerebral cortex
Thalamus
130
Highest level of thinking, problem solving, sequential, complex thought
Cerebrum
131
The _____ is a clear fluid that is filtered out of specialized capillary beds called the choroid plexus
CSF
132
Delivers glucose, other nutrients, and ions necessary to keep neurons functioning properly, it also washes away wastes and debris to be reabsorbed back into the blood stream
CSF
133
The _____ is maintained by astrocytes
Blood brain barrier
134
Monitors electrolytes salts and water concentrations and is the brains link to the endocrine system via pituitary gland
Hypothalamus
135
Secretes a number of hormones into the blood controlling numerous other hormones and endocrine glands. Often called master control gland.
Pituitary gland
136
Secretes a hormone called melatonin into the blood which regulates our day/night rhythms, called circadian rhythm’s
Pineal gland
137
Largest region of the brain, processes sensory and motor information that we are consciously aware of, performs intellectual functions like thinking and problem solving
Cerebrum
138
Information passes from neuron to neuron across a small gap called a
Synaptic cleft
139
If a neuron makes and uses a particular NT, that cell only releases that _____ and no others
Neurotransmitter
