Neuro Tissue and Organization Flashcards
(115 cards)
1
Q
Towards the CNS (sensory)
A
Afferent
2
Q
Exiting the CNS/PNS (motor)
A
Efferent
3
Q
Cell body of a neuron
A
Soma
4
Q
Something that causes a response
A
Stimuli
5
Q
Electric polarization of a nerve cell (electrical current)
A
Action potential
6
Q
Projection or outgrowth of tissue from a larger body
A
Process
7
Q
Two divisions of the nervous system
A
Central Nervous System (CNS)-brain and spinal cord
Peripheral Nervous System (PNS) is nerves and ganglia
8
Q
The signal must be detected and converted somehow into neuronal activity
A
Transduction
9
Q
Anatomical division of the spinal cord
A
Central-brain and spinal cord
Peripheral-cranial nerves, spinal `nerves, ganglia
10
Q
Nervous system functions include:
A
Sensory perception, integration and motor planning
11
Q
Vision requires light from a visual scene to be ____ into a neural activity
A
Transduced
12
Q
The information in a signal must be processed and represented somehow by the transduced neuronal activity
A
Coding
13
Q
Divisions of the anatomical nervous system
A
Central: Brain and spinal cord
Peripheral: cranial nerves, spinal nerves ganglia
14
Q
Muscle contraction is almost always initiated by the activity of the ____.
A
Nervous system
15
Q
Synapses of motor neurons onto muscle cells=
A
the neuromuscular junction
16
Q
General somatic senses
A
General or “widespread” receptors spread throughout the body. Receptors include: touch, pain, vibration, pressure, temperature
17
Q
Type of somatic sense that detects stretch in tendons and muscle. Responsible for body sense-position and movement of body in space
A
Proprioceptive senses
18
Q
Hearing, balance, vision and smell are types of ____ senses
A
Special somatic senses
19
Q
Somatic (sensory and motor) and visceral (sensory and motor) are part of the _____
A
Peripheral nervous system
20
Q
General visceral senses include
A
Stretch, pain, temperature, nausea and hunger
21
Q
General visceral senses are widely felt where:
A
Digestive and urinary tracts, and reproductive organs
22
Q
Special visceral senses include
A
Taste and smell
23
Q
What division of the nervous system signals contraction of the skeletal muscles?
A
Somatic motor
24
Q
Somatic motor is also the -
A
voluntary nervous system
25
What regulates the contraction of smooth and cardiac muscle and controls function of visceral organs
Visceral motor
26
Visceral motor is also known as a) and b)
Involuntary nervous system
| Autonomic nervous system
27
What nervous system cells conduct nerve impulses from one part of the body to another?
Neurons
28
Nervous system cells that have a ___metabolic rate-need lots of ____ and ____
How long do they last?
They are mitotic or non-mitotic?
High, glucose and oxygen
Have extreme longevity
non-mitotic
29
Glial cells are
Large or small?
mitotic or non-mitotic
Raison d-etre?
Smaller than neuron cells
Mitotic
No nerve impulses but protect and nourish neurons
30
Fundamental physiological properties of neurons?
Excitability (irritability)-can respond to stimuli
Conductivity-can send signals to distant locations quickly
Secretion-can release chemical messengers (neurotransmitters)
31
Functional classes of neurons
Sensory (afferent) neurons
Interneurons
Motor (efferent) neurons
32
What type of neurons detect stimuli
Sensory (afferent) neurons
33
What type of neurons integrate and process information from other neurons and make decisions about response
Interneurons
34
What type of neurons send signals to muscles/glands to provide response?
Motor (efferent) neurons
35
Interneurons are confined to the _____
CNS
36
What is the control center of a neuron?
Soma or cell body
37
Unique to neurons, granular bodies found in the soma. Also, the site of protein synthesis
Nissl bodies
38
Short processes off the cell body that receive signals
Dendrites
39
long process off the cell body through which a neuron sends action potentials
Axon
40
Complex branches at axon's distal end
Terminal arborization (terminal branching)
41
Ending of an axon branch that communicates with another cells
Axon terminal or axon bouton
42
Triangular narrow portion of a cell body where axon begins. Action potentials generated here
Axon hillock
43
At the end of each terminal branch is an ____
axon terminal
44
The variation in a neuron structured is named by ____
The number of processes leaving the soma
45
Variations in a neuron structure
Multipolar: many dendrites, one axon (many processes)
Bipolar-one dendrite, one axon (2 processes)
Unipolar-no dendrites, one axon (one process)
46
Neurohistology-what do neurons look like?
Large, diffuse nucleus with dark, central nucleolus
Nissl bodie (RER)s may be visible as dark granules
Processes off the body-axons and dendrites
47
Meeting point of a neuron and other cells
Synapse
48
The presynaptic neuron can secret neurotransmitters that can either ___ or ___ the postsynaptic neuron
Excite, inhibit
49
Axon to dendrite synapse
Axodendritic synapses
50
Axon to soma synapse
Axosomatic synapses
51
Axon to axon synapse
Axoaxonic synapses
52
A junction between neurons may contain many synapses due to _____ and the presence of multiple ______
Terminal arborization, dendrites
53
Most neurons have a huge amount of presynaptic partners
10^3-10^4
54
Two varieties of synapses
Electrical synapses and chemical synapses
55
Type of synapse where there is a physical connection between the cytoplasm of the two neurons-relatively rare
Electrical synapses
56
Small gaps between neurons across which chemical messengers (neurotransmitters) diffuse
Chemical synapses
57
In an electrical synapses adjacent cells are joined by____
___ diffuse from cell to cell
Quick transmission
____transmission of electrical signal
Gap junctions
Ions
Simple, Sacrifice specificity for speed
58
presynaptic neuron releases neurotransmitter to a postsynaptic cell. The release is triggered by ____ arriving at axon terminal.
Action potential
59
Messenger molecules. Can be both excitatory and inhibitory
Neurotransmitters
60
What is a structure at a synapse that contains synaptic vesicles -packets of neurotransmitters
Axon terminal of a presynaptic cell
61
Structures at synapse
Axon terminal of presynaptic cell
Synaptic cleft
Neurotransmitter receptors on postsynaptic cell
62
Most synapses are _____ synapses
Chemical
63
Neurotransmitter that is responsible for feelings of well-being. Decrease in this neurotransmitter is a cause for depression
Serotonin
64
Neurotransmitter that is responsible for feelings of enjoyment and reinforcement, also motor inhibition
Dopamine
65
Describe the simplest possible circuit
One sensory neuron that synapses on to one motor neuron
66
More complex behaviors require more complex circuits involving ____-neurons that locally process information and send final decision to effector neurons
Interneurons
67
99% of the nervous system is _____
Interneurons
68
Neural circuit where one fiber synapses with several postsynaptic cells
Diverging
69
Neural circuit where several presynaptic cells converge on a single nerve fiber (i.e. the brainstem receives signals from multiple organ systems)
Converging
70
Neural circuit that is non-linear. Often involve negative feedback loops
Reverberating
71
Neural circuit where output neuron receives signals overtime based on the number of interneurons
Parallel after discharge
72
Type of neuron processing where neurons pass a signal to a specific destination along a single pathway from one to another
Serial processing
73
Type of neuron processing where input is delivered along many pathways; a single sensory stimulus results in multiple perceptions
Parallel processing
74
Types of neural processing
Serial processing
| Parallel processing
75
Types of neural circuits
Diverging
Converging
Reverberating
Parallel after discharge
76
What type of neural processing is associated with higer order functioning?
Parallel processing
77
Neurons can be classified by their functions. What are the associated functions?
Sensory neurons-a
Motor neurons-b
Interneurons-c
A) Afferent neurons
B) Efferent neurons
C) Association neurons (connect neurons, sometimes sensory to motor)
78
Sensory neurons are mostly:
Multipolar or unipolar?
Cell bodies found in ganglia (inside or outside) spinal cord
Unipolar
| Outside
79
Motor neurons are mostly:
Multipolar or unipolar?
Cell bodies (inside or outside) spinal cord
Multipolar
| Inside
80
Interneurons are located where?
Entirely within the CNS
81
Glial cells outnumber neurons ____
10-1
82
Are glial cells in the CNS and PNS the same?
No
83
Glial cells do or do not transmit signals
Do not
84
Glial cells perform what type of functions?
Many metabolic/support functions for neurons
85
Types of central nervous system glial cells
Oligodendrocytes
Ependymal cells
Microglial cells
Astrocytes
86
Types of peripheral nervous system cells
Schwaan cells
| Satellite cells
87
Long processes from oligodendrocytes membranes wrap around neuronal axons to help _____
Make impulses travel faster
88
The oligodendrocytes wrapping around neuronal axons is called the _____
Myelin sheath
89
Cells that resemble cuboidal epithelial cells that line the fluid filled cavities in the brain and spinal cord
Ependymal cells
90
Do ependymal cells have a basement membrane?
No
91
Ependymal cells produce_____
Cerebrospinal fluid (CSF)
92
What part of the ependymal cells help circulate CSF?
Apical cilia
93
Cells that perform immune functions in the CNS by phagocytizing pathogens from dead tissue?
Microglial cells
94
What cells develop white blood cells involved in immune response?
Microglial cells
95
What cell is a star like shape?
Astrocytes
96
Astrocytes are most abudent where?
The CNS
97
Functions of astrocytes
Support nervous tissue
Forms the blood-brain barrier
Selective passage of molecules necessary for neuron function
98
How do astrocytes form the blood-brain barrier?
Astrocytes projections wrap around capillaries to limited unwanted substances from reaching the neuron
99
What does the blood brain barrier (BBB) do?
Prevents immune cells, proteins and charged molecules from entering the brain
Helps protect our brain from chemical compounds/inflammation/infection
100
What type of cells surround the soma in the ganglia and organize waste/nutrient exchange?
Satellite cells (PNS)
101
What type of cells surround axons with extensions of their plasma membranes to help nerve impulses travel faster?
Swhwann Cells (PNS)
102
Swhwann Cells (PNS) are analogous to ____ because they produce a myelin sheath
Oligodendrocytes
103
What is a fatty covering on axons that insulates the wires?
Myelin sheaths
104
Myelination increases ______ allowing action potentials to_____
Membrane resistance
| Propagate faster
105
Swhwann Cells make myelin in the ____
| Oligodendrocytes make myelin in the ____
PNS
| CNS
106
Swhwann Cells extend their _____ to wrap around axons
Plasma membranes
107
Myelin sheaths are mostly ____
Lipids
108
Myelin sheaths appear ____ on cadaver. Called ____ matter.
| Why does it appear this way?
White, white
| Coiling gives white color
109
Fiber segment covered by myelin
Internodes
110
Nerve segment lacking myelin
Nodes of Ranvier
111
Impulse travels along axon and is only exposed at ____
Nodes of Ranvier
112
Unmyelinated PNS axons are also surrounded by Schwann cells, but Schwann cells do not ____
coil densely around these axons
113
This is called ____ matter
Grey matter.
114
A nerve impulse rests on the axon membrane and as a ___ charge
negative
115
As a nerve impulse travels along the axon, the membrane goes from a ____ charge to a ____ charge. Then the membrane behind the impulse returns to a ____ charge
Negative
Positive
Negative
