Chapter 3 - Anatomy of the Nervous System Flashcards
1
Q
Central nervous system (CNS)
A
The portion of the nervous system within the skull and spine
2
Q
Peripheral nervous system (PNS)
A
The portion of the nervous system outside the skull and spine
3
Q
Somatic nervous system (SNS)
A
The part of the peripheral nervous system that interacts with the external environment
4
Q
Afferent nerves
A
Nerves that carry sensory signals to the central nervous system
5
Q
Efferent nerves
A
Nerves that carry motor signals from the central nervous system to the skeletal muscles or internal organs
6
Q
Autonomic nervous system (ANS)
A
The part of the peripheral nervous system that participates in the regulation of the body’s internal environment
7
Q
Sympathetic nerves
A
Those motor nerves of the autonomic nervous system that project from the central nervous system in the lumbar and thoracic region areas of the spinal cord
8
Q
Parasympathetic nerves
A
Those autonomic motor nerves that project from the brain to the sacral region of the spinal cord
9
Q
Cranial nerves
A
The 12 pairs of nerves extending from the brain (e.g., optic nerves, olfactory nerves, and vagus nerves)
10
Q
Glial cells
A
Several classes of nonneural cells of the nervous system
11
Q
Oligodendrocytes
A
Glial cells that myelinate axons of the central nervous system; also known as oligodendroglia
12
Q
Myelin
A
A fatty insulating substance
13
Q
Myelin sheaths
A
Coverings on the axons of some neurons that are rich in myelin and increase the speed and efficiency of axonal conduction
14
Q
Schwann cells
A
The glial cells that compose the myelin sheaths of PNS axons and promote the regeneration of PNS axons
15
Q
Microglia
A
Glial cells that respond to injury or disease by engulfing cellular debris and triggering inflammatory responses
16
Q
Astrocytes
A
Large, star-shaped glial cells that play multiple roles in the central nervous system
17
Q
Golgi stain
A
A neural stain that completely darkens a few of the neurons in each slice of tissue, thereby revealing their silhouettes
18
Q
Niss1 stain
A
A neural stain that has an affinity for structures in neuron cell bodies
19
Q
Electron microscopy
A
A microscopy technique used to study the fine details of cellular structure
20
Q
Anterior
A
Toward the nose end of a vertebrate
21
Q
Posterior
A
Toward the tail end of a vertebrate or toward the back of the head
22
Q
Dorsal
A
Toward the surface of the back of a vertebrate or toward the top of the head
23
Q
Ventral
A
Toward the chest surface of a vertebrate or toward the bottom of the head
24
Q
Medial
A
Toward the midline of the body
25
Lateral
Away from the midline of the body of a vertebrate, toward the body’s lateral surfaces
26
Superior
Toward the top of the primate head
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Inferior
Toward the bottom of the primate head or brain
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Proximal
Close to something
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Distal
Far from something
30
Horizontal sections
Any slices of brain tissue cut in a plane that are parallel to the top of the brain
31
Frontal sections
Any slices of brain tissue cut in a plane that is parallel to the face; also termed coronal sections
32
Sagittal sections
Any slices of brain tissue cut in a plane that is parallel to the side of the brain
33
Cross section
Section cut at a right angle to any long, narrow structure of the central nervous system
34
Gray matter
Portions of the nervous system that are gray because they are composed largely of cell bodies and unmyelinated interneurons
35
White matter
Portions of the nervous system that are white because they are composed largely of myelinated axons
36
Dorsal horns
The two dorsal arms of the spinal gray matter
37
Meninges
The three protective membranes that cover the brain and spinal cord (singular meninx)
38
Dura mater
The tough outer meninx
39
Arachnoid membrane
The meninx that is located between the dura mater and the pia mater and has the appearance of a gauzelike spiderweb
40
Subarachnoid space
The space beneath the arachnoid membrane, which contains many large blood vessels and cerebrospinal fluid
41
Pia mater
The delicate, innermost meninx
42
Cerebrospinal fluid (CSF)
The fluid that fills the subarachnoid space, the central canal, and the cerebral ventricles
43
Central canal
The small cerebrospinal fluid-filled channel that runs the length of the spinal cord
44
Cerebral ventricles
The four cerebrospinal fluid-filled internal chambers of the brain: the two lateral ventricles, the third ventricle, and the fourth ventricle
45
Choroid plexuses
The networks of capillaries that protrude into the ventricles from the pia mater and produce cerebrospinal fluid
46
Blood-brain barrier
The mechanism that impedes the passage of toxic substances from the blood into the brain
47
Ventral horns
The two ventral arms of the spinal gray matter
48
Dorsal root ganglia
Structures just outside the spinal cord that are composed of the cell bodies of dorsal root axons
49
Brain stem
The part of the brain on which the cerebral hemispheres rest; in general, it regulates reflex activities that are critical for survival (e.g., heart rate and respiration)
50
Myelencephalon (medulla)
The most posterior of the five major divisions of the brain; the medulla
51
Reticular formation
A complex network of about 100 tiny nuclei that occupies the central core of the brain stem from the posterior boundary of the myelencephalon to the anterior boundary of the midbrain. Sometimes referred to as "little net" or as the reticular activating system.
52
Metencephalon
One of the five major divisions of the brain; it includes the pons and cerebellum
53
Pons
The metencephalic structure that creates a bulge on the ventral surface of the brain stem
54
Cerebellum
A metencephalic structure that is thought to participate in the storage of memories of learned sensorimotor skills
55
Mesencephalon
One of the five major divisions of the brain; it is composed of the tectum and tegmentum
56
Tectum
The dorsal surface of the midbrain; the roof
57
Inferior colliculi
The structures of the tectum that receive auditory input from the superior olives
58
Superior colliculi
Two of the four nuclei that compose the tectum; they receive major visual input
59
Tegmentum
The ventral division of the mesencephalon; it includes part of the reticular formation, substantia nigra, and red nucleus
60
Periaqueductal gray
The gray matter around the cerebral aqueduct, which contains opiate receptors and activates a descending analgesia circuit
61
Cerebral aqueduct
A narrow channel that connects the third and fourth ventricles
62
Substantia nigra
The midbrain nucleus whose neurons project via the nigrostriatal pathway to the striatum of the basal ganglia; it is part of the mesotelencephalic dopamine system
63
Red nucleus
A structure of the sensorimotor system that is located in the tegmentum of the mesencephalon
64
Diencephalon
One of the five major divisions of the brain; it is composed of the thalamus and hypothalamus
65
Thalamus
The large two-lobed diencephalic structure that constitutes the anterior end of the brain stem; many of its nuclei are sensory relay nuclei that project to the cortex
66
Massa intermedia
The neural structure located in the third ventricle that connects the two lobes of the thalamus
67
Sensory relay nuclei
Those nuclei of the thalamus whose main function is to relay sensory signals to the appropriate areas of cortex
68
Lateral geniculate nuclei
The six-layered thalamic structures that receive input from the retinas and transmit their output to the primary visual cortex
69
Medial geniculate nuclei
The auditory thalamic nuclei that receive input from the inferior colliculi and project to primary auditory cortex
70
Ventral posterior nuclei
A thalamic relay nucleus in both the somatosensory and gustatory systems
71
Hypothalamus
The diencephalic structure that sits just below the anterior portion of the thalamus
72
Pituitary gland
The gland that dangles from, and is controlled by, the hypothalamus
73
Optic chiasm
The X-shaped structure on the inferior surface of the diencephalon; the point where the optic nerves decussate
74
Decussate
To cross over to the other side of the brain
75
Contralateral
Projecting from one side of the body to the other
76
Ipsilateral
On the same side of the body
77
Mammillary bodies
The pair of spherical nuclei that are located on the inferior surface of the hypothalamus
78
Telencephalon
The most superior of the brain’s five major divisions
79
Cerebral cortex
The layer of neural tissue covering the cerebral hemispheres of humans and other mammals
80
Neurons
Cells of the nervous system that are specialized for the reception, conduction, and transmission of electrochemical signals
81
Multipolar neuron
A neuron with more than two processes extending from its cell body
82
Unipolar neuron
A neuron with one process extending from its cell body
83
Bipolar neuron
A neuron with two processes extending from its cell body
84
Interneurons
Neurons with short axons or no axons at all, whose function is to integrate neural activity within a single brain structure
85
Nuclei
The DNA-containing structures of cells; also, clusters of neuronal cell bodies in the central nervous system (singular nucleus)
86
Ganglia
Clusters of neuronal cell bodies in the peripheral nervous system (singular ganglion)
87
Tracts
Bundles of axons in the central nervous system
88
Nerves
Bundles of axons in the peripheral nervous system
89
Fissures
The large furrows in a convoluted cortex
90
Sulci
Small furrows in a convoluted cortex
91
Gyri
The cortical ridges that are located between fissures or sulci
92
Longitudinal fissure
The large fissure that separates the two cerebral hemispheres
93
Cerebral commissures
Tracts that connect the left and right cerebral hemispheres
94
Corpus callosum
The largest cerebral commissure
95
Central fissure
The large fissure that separates the frontal lobe from the parietal lobe
96
Lateral fissure
The large fissure that separates the temporal lobe from the frontal lobe
97
Frontal lobe
The most anterior of the four cerebral lobes
98
Parietal lobe
One of the four cerebral lobes; it is located just posterior to the central fissure
99
Temporal lobe
One of the four major cerebral lobes; it lies adjacent to the temples and contains the hippocampus and amygdala
100
Occipital lobe
The most posterior of the four cerebral lobes; its function is primarily visual
101
Precentral gyrus
The gyrus located just anterior to the central fissure; its function is primarily motor
(plural: precentral gyri)
102
Postcentral gyrus
The gyrus located just posterior to the central fissure; its function is primarily somatosensory
(plural: postcentral gyri)
103
Superior temporal gyri
The plural of superior temporal gyrus
104
Neocortex
Six-layered cerebral cortex of relatively recent evolution; it constitutes 90 percent of human cerebral cortex
105
Pyramidal cells
Large multipolar cortical neurons with a pyramid-shaped cell body, an apical dendrite, and a very long axon
106
Stellate cells
Small star-shaped cortical interneurons
107
Columnar organization
The functional organization of the neocortex in vertical columns; the cells in each column form a mini-circuit that performs a single function
108
Hippocampus
A structure of the medial temporal lobes that plays a role in various forms of memory
109
Limbic system
A collection of interconnected nuclei and tracts that ring the thalamus
110
Amygdala
A structure in the anterior temporal lobe, just anterior to the hippocampus; plays a role in emotion
111
Cingulate cortex
The cortex of the cingulate gyri, which are located on the medial surfaces of the frontal lobes
112
Cingulate gyri
Large gyri located on the medial surfaces of the frontal lobes, just superior to the corpus callosum
(singular: cingulate gyrus)
113
Fornix
The major tract of the limbic system; it connects the hippocampus with the septum and mammillary bodies
114
Septum
A midline nucleus of the limbic system, located near the anterior tip of the cingulate cortex
115
Basal ganglia
A collection of subcortical nuclei (e.g., striatum and globus pallidus)
116
Caudate
The tail-like structure that is part of the striatum
117
Putamen
A structure that is joined to the caudate by a series of fiber bridges; together the putamen and caudate compose the striatum
118
Striatum
A structure of the basal ganglia that is the terminal of the dopaminergic nigrostriatal pathway
119
Globus pallidus
A structure of the basal ganglia that is located between the putamen and thalamus
