chapter 2: cells and structures Flashcards
1
Q
Neurons
A
The basic unit of the nervous system, each composed of receptive extensions called dendrites, and integrating cell body, a conducting axon, and a transmitting axon terminal
Also called nerve cells
2
Q
Glial cells
A
Nonneuronal brain cells that provide structural, nutritional, and other types of support to the brain
Also called glia
3
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Synapse
A
The cellular location at which the information is transmitted from a neuron to another cell
4
Q
Input zone
A
The part of a neuron that receives information, from other neurons or from specialized sensory structures
5
Q
Dendrite
A
An extension of the cell body that receives information from other neurons
6
Q
Integration zone
A
The part of a neuron that initiates nerve electrical activity
7
Q
Cell body or soma
A
The region of a neuron that is defined by the presence of the cell nucleus
8
Q
Conduction zone
A
The part of a neuron over which the nerve’s electrical signal may be actively propagated
9
Q
Axon
A
A single extension from the nerve cell that carries action potentials from the cell body toward the axon terminals
Also called nerve fiber
10
Q
Output zone
A
The part of a neuron at which the cell sends information to another cell
11
Q
Axon terminal
A
The end of an axon or axon collateral, which forms a synapse on a neuron or other target cell
Also called synaptic bouton
12
Q
Motoneuron
A
A neuron that transmits neural messages to muscles or glands
Also called motor neuron
13
Q
Sensory neuron
A
A nerve cell that is directly affected by changes in the environment, such as light, odor, or touch
14
Q
Interneuron
A
A nerve cell that is neither a sensory neuron nor a motoneuron; interneurons receive input from and send output to other neurons
15
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Multipolar neuron
A
A nerve cell that has many dendrites and a single axon
16
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Bipolar neuron
A
A nerve cell that has a single dendrite at one end and a single axon at the other end
17
Q
Unipolar neuron
A
A nerve cell with a single branch that leaves the cell body and then extends in two directions; one end is the input zone, and the other end is the output zone
Also called monopolar neuron
18
Q
Presynaptic
A
Referring to the region of a synapse that releases neurotransmitter
19
Q
Postsynaptic
A
Referring to the region of a synapse that receives and responds to neurotransmitter
20
Q
Presynaptic membrane
A
The specialized membrane on the axon terminal of a nerve cell that transmits information by releasing neurotransmitter
21
Q
Postsynaptic membrane
A
The specialized membrane on the surface of a nerve cell that receives information by responding to neurotransmitter from a presynaptic membrane
22
Q
Synaptic cleft
A
The space between the presynaptic and postsynaptic neurons at a synapse
23
Q
Synaptic vesicle
A
A small, spherical structure that contains molecules of neurotransmitter
24
Q
Neurotransmitter
A
The chemical released from the presynaptic axon terminal that serves as the basis of communication between neurons
25
Golgi stains
Cell stain that fills the whole cell, useful for identifying type and shape of cells in a region
26
Nissl stains
Outline all cell bodies, useful for measuring cell body size and density of cells in particular regions
27
Autoradiography
Cells are manipulated into taking photographs of themselves by staining them with radioactive drugs and placing the brain section on a slide
28
Immunocytochemistry (ICC)
Brain sections exposed to antibodies that are selective for a protein of interest, then chemicals make the antibodies visible (reveals only the cells that make that protein visible)
29
In situ hybridization
Uses radioactively labeled lengths of nucleic acid to identify neurons in which a gene of interest has been turned on
30
Immediate early genes (IEGs)
Expressed when neurons become more active
Researchers use ICC to label the IEG product to identify brain regions that are active during particular behaviors being performed by the animal before death
31
Horseradish peroxidase (HRP)
Used to identify the cells of origin of a particular set of axons; HRP is taken up into the axon at the terminals and transported back to the cell body
32
Neurotransmitter receptors
A protein that captures and reacts to molecules of a neurotransmitter or hormone
Also called receptor
33
Neural plasticity
The ability of the nervous system to change in response to experience or the environment
Also called neuroplasticity
34
Axon hillock
The cone-shaped area on the cell body from which the axon originates
35
Innervate
To provide neural input to
36
Axon collateral
A branch of axon
37
Axonal transport
The transportation of materials from the neuronal cell body to distant regions in the dendrites and axons, and from the axon terminals back to the cell body
38
Oligodendrocyte
A type of glial cell that forms myelin in the central nervous system
39
Schwann cell
A type of glial cell that forms myelin in the peripheral nervous system
40
Myelin
The fatty insulation around an axon, formed by glial cells. This sheath improves the speed at which nerve impulses are conducted
41
Node of Ranvier
A gap between successive segments of the myelin sheath where the axon membrane is exposed
42
Multiple sclerosis
A disorder characterized by the widespread degeneration of myelin
43
Astrocytes
A star-shaped glial cell with numerous processes (extensions) that run in all directions. Help to modulate neural activity (and blood flow), form synapses, and form the tough outer membranes that swaddle the brain
44
Microglial cells
Extremely small glial cells that remove cellular debris from injured or dead cells
Also called microglia
45
Edema
The swelling of tissue, especially in the brain, in response to injury
46
Gross neuroanatomy
Anatomical features of the nervous system that are apparent to the naked eye
47
Central nervous system (CNS)
The portion of the nervous system that includes the brain and the spinal cord
48
Peripheral nervous system
The portion of the nervous system that includes all the nerves and neurons outside the brain and spinal cord
49
Nerve
A collection of axons bundled together outside of the central nervous system
50
Motor nerve
A mere that transmits information from the central nervous system to the muscles and glands
51
Sensory nerve
A nerve that coneys information from the body to the central nervous system
52
Cranial nerve
A nerve that is connected directly to the brain; there are 12 pairs (one left-sided and one right-sided in each pair)
53
Spinal nerve
A nerve that emerges from the spinal cord; there are 31 pairs of nerves (one left, one right)
Also called somatic nerve
54
Autonomic nervous system
The part of the peripheral nervous system that supplies neural connections to glands and to smooth muscles of internal organs
55
Cervical
Referring to the topmost 8 segments of the spinal cord, in the neck region
56
Thoracic
Referring to the 12 spinal segments below the cervical (neck) portion of the spinal cord, corresponding to the chest
57
Lumbar
Referring to the 5 spinal segments that make up the upper part of the lower back
58
Sacral
Referring to the 5 spinal segments that make up the lower part of the lower back
59
Coccygeal
Referring to the lowest spinal vertebra (the coccyx, also known as the tailbone)
60
Sympathetic nervous system
The division of the autonomic nervous system that arises fro the thoracic and lumbar spinal cord. This division prepares the body for immediate action (fight or flight responses)
61
Parasympathetic nervous system
The division of the autonomic nervous system that arises from both the cranial nerves and the sacral spinal cord. This division helps the body to relax, recuperate, and prepare for future action.
62
Cerebral hemisphere
One of the two halves–right or left–of the forebrain
63
Cerebral cortex
The outer covering of the cerebral hemispheres, which consists largely of nerve cell bodies and their branches
Also called cortex
64
Gyrus
A ridged or raised portion of a convoluted brain surface
65
Sulcus
A crevice or valley of a convoluted brain surface
66
Frontal lobe
The mot anterior portion of the cerebral cortex
67
Parietal lobe
The large region of cortex lying between the frontal and occipital lobes in each cerebral hemisphere
68
Temporal lobe
The large lateral region of cortex in each cerebral hemisphere. It is continuous with the parietal lobe posteriorly and separated from the frontal lobe by the Sylvian fissure
69
Occipital lobe
A large region of cortex that covers much of the posterior part of each cerebral hemisphere
70
Sylvian fissure
A deep fissure that demarcates the temporal lobe
Also called lateral sulcus
71
Central sulcus
A fissure that divides the frontal lobe from the parietal lobe
72
Corpus callosum
The main band of axons that connects the two cerebral hemispheres
73
Sagittal plane
Bisects the body into right and left halves
74
Coronal plane
Divides the body into a front (anterior) and back (posterior) part
Also called frontal plane or transverse plane
75
Horizontal plane
Divides the brain into upper and lower parts
76
Medial
Toward the middle
77
Lateral
Toward the side
78
Ipsilateral
Same side of body
79
Contralateral
Opposite side of body
80
Superior
Above
81
Inferior
Below
82
Anterior, rostral
Head end
83
Posterior, caudal
Tail end
84
Proximal
Near the center
85
Distal
Toward the periphery or end of a limb
86
Afferent
An axon, tract, or nerve that carries information into a region
Afferents arrive
87
Efferent
An axon, tract, or nerve that carries information away from a region
Efferents exit
88
Dorsal
Toward or at the back
89
Ventral
Toward or at the belly
90
Postcentral gyrus
The strip of parietal cortex, just behind the central sulcus, that receives somatosensory information from the entire body
91
Precentral gyrus
The strip of frontal cortex, just in front of the central sulcus, that is crucial for motor control
92
Gray matter
Areas of the brain that are dominated by cell bodies and devoid of myelin. Gray matter mostly receives and processes information
93
White matter
A lighter-colored layer of tissue, consisting mostly of myelin-sheathed axons, that lies underneath the gray matter of the cortex. White matter mostly transmits information
94
Neural tube
An embryonic structure with subdivisions that correspond to the future forebrain, midbrain, and hindbrain
95
Forebrain
The frontal division of the neural tube, containing the cerebral hemispheres, the thalamus, and the hypothalamus
96
Midbrain
The middle division of the brain
97
Hindbrain
The rear division of the brain which contains the cerebellum, pons, and medulla
98
Telencephalon
The anterior part of the fetal forebrain, which will become the cerebral hemispheres in the adult brain
99
Diencephalon
The posterior part of the fetal forebrain, which will become the thalamus and hypothalamus in the adult brain
100
Brainstem
The region of the brain that consists of the midbrain, the pons, and the medulla
101
Nucleus
A collection of neuronal cell bodies within the central nervous system (e.g., the caudate nucleus)
102
Tract
A bundle of axons found within the central nervous system
103
Pyramidal cell
A type of large nerve cell that has a roughly pyramid-shaped cell body and is found in the cerebral cortex
104
Cortical column
One of the vertical columns that constitute the basic organization of the cerebral cortex
105
Basal ganglia
A group of forebrain nuclei, including the caudate nucleus, globes pallidus, and put amen, found deep within the cerebral hemispheres
106
Caudate nucleus
One of the basal ganglia; it has a long extension or tail
107
Putamen
One of the basal ganglia
108
Limbic system
A loosely defined, widespread group of brain nuclei that innervate each other to form a network
109
Amygdala
A group of nuclei in the medial anterior part of the temporal lobe
110
Hippocampus
A medial temporal lobe structure that is important for learning and memory
111
Fornix
A fiber tract that extends from the hippocampus to the mammillary body
112
Cingulate gyrus
A strip of cortex, found in the frontal and parietal midline, that is part of the limbic system and is implicated in many cognitive functions
113
Olfactory bulb
An anterior projection of the brain that terminates in the upper nasal passages and, through small openings in the skull, provides receptors for smell
114
Thalamus
The brain regions that surround the third ventricle
115
Hypothalamus
Part of the diencephalon, lying ventral to the thalamus
116
Superior colliculi
Paired gray matter structures of the dorsal midbrain that process visual information
117
Inferior colliculi
Paired gray matter structures of the dorsal midbrain that proces auditory information
118
Tectum
The dorsal portion of the midbrain consisting of the inferior and superior colliculi
119
substantia nigra
a brainstem structure that innervates the basal ganglia and is the source of all dopaminergic projections
120
reticular formation
an extensive region of the brainstem (extending from the medulla through the thalamus) that is involved in sleep and arousal
121
cerebellum
a structure located at the back of the brain, dorsal to the pons, that is involved in the central regulation of movement
122
pons
the portion of the brainstem that connects the midbrain to the medulla
123
medulla
the posterior part of the hindbrain, continuous with the spinal cord
124
meninges
the three protective membranes – dura mater, pia mater, and arachnoid – that surround the brain and spinal cord
125
dura mater
the outermost of the three meninges that surround the brain and spinal cord
126
Pia mater
The innermost of the three meninges that surround the brain and spinal cord
127
Arachnoid
The thin covering of the brain that lies between the dura mater and pia mater
128
Cerebrospinal fluid (CSF)
The fluid that fills the cerebral ventricles
129
Meningitis
An acute inflammation of the meninges, usually caused by a viral or bacterial infection
130
Meningioma
A noninvasive tumor of the meninges
131
Ventricular system
A system of fluid-filled cavities inside the brain
132
Lateral ventricle
A complexly shaped lateral portion of the ventricular system within each hemisphere of the brain
133
Choroid plexus
A specialized membrane lining the ventricles that produces cerebrospinal fluid by filtering blood
134
Third ventricle
The midline ventricle that conducts cerebrospinal fluid from the lateral ventricles to the fourth ventricle
135
Fourth ventricle
The passageway within the pons that receives cerebrospinal fluid from the third ventricle and releases in to surround the brain and spinal cord
136
Stroke
Damage to a region of brain tissue that results from the blockage or rupture of vessels that supply blood to that region
137
Blood-brain barrier
The mechanisms that make the movement of substances from blood vessels into brain cells more difficult than exchanges in other body organs, thus affording the brain greater protection from exposure to some substances found in blood
138
Computerized axial tomography (CAT/CT)
A noninvasive technique for examining brain structure through computer analysis of X-ray absorption at several positions around the head
139
Magnetic resonance imaging (MRI)
A noninvasive technique for examining brain structure that uses magnetic energy to generate images that reveal some structural details in the living brain
140
Functional MRI (fMRI)
Magnetic resonance imaging that detects changes in blood flow and therefore identifies regions of the brain that are particularly active during a given task
141
Positron emission tomography (PET)
A technique for examining brain function that combines tomography with injections of radioactive substances used by the brain
142
Transcranial magnetic stimulation (TMS)
A noninvasive technique for examining brain function that applies strong magnetic fields to stimulate cortical neurons, in order to identify discrete areas of the brain that are particularly active during specific behaviors
143
Magnetoencephalography (MEG)
A passive and noninvasive technique for examining brain function that measures the tiny magnetic fields produced by active neurons, in order to identify regions of the brain that are particularly active during a given task
