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Flashcards in chapter 2: cells and structures Deck (143):
1

Neurons

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

Glial cells

Nonneuronal brain cells that provide structural, nutritional, and other types of support to the brain

Also called glia

3

Synapse

The cellular location at which the information is transmitted from a neuron to another cell

4

Input zone

The part of a neuron that receives information, from other neurons or from specialized sensory structures

5

Dendrite

An extension of the cell body that receives information from other neurons

6

Integration zone

The part of a neuron that initiates nerve electrical activity

7

Cell body or soma

The region of a neuron that is defined by the presence of the cell nucleus

8

Conduction zone

The part of a neuron over which the nerve's electrical signal may be actively propagated

9

Axon

A single extension from the nerve cell that carries action potentials from the cell body toward the axon terminals

Also called nerve fiber

10

Output zone

The part of a neuron at which the cell sends information to another cell

11

Axon terminal

The end of an axon or axon collateral, which forms a synapse on a neuron or other target cell

Also called synaptic bouton

12

Motoneuron

A neuron that transmits neural messages to muscles or glands

Also called motor neuron

13

Sensory neuron

A nerve cell that is directly affected by changes in the environment, such as light, odor, or touch

14

Interneuron

A nerve cell that is neither a sensory neuron nor a motoneuron; interneurons receive input from and send output to other neurons

15

Multipolar neuron

A nerve cell that has many dendrites and a single axon

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Bipolar neuron

A nerve cell that has a single dendrite at one end and a single axon at the other end

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Unipolar neuron

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

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Presynaptic

Referring to the region of a synapse that releases neurotransmitter

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Postsynaptic

Referring to the region of a synapse that receives and responds to neurotransmitter

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Presynaptic membrane

The specialized membrane on the axon terminal of a nerve cell that transmits information by releasing neurotransmitter

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Postsynaptic membrane

The specialized membrane on the surface of a nerve cell that receives information by responding to neurotransmitter from a presynaptic membrane

22

Synaptic cleft

The space between the presynaptic and postsynaptic neurons at a synapse

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Synaptic vesicle

A small, spherical structure that contains molecules of neurotransmitter

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Neurotransmitter

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

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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

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Innervate

To provide neural input to

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Axon collateral

A branch of axon

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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

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Schwann cell

A type of glial cell that forms myelin in the peripheral nervous system

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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

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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

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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

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Lumbar

Referring to the 5 spinal segments that make up the upper part of the lower back

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Sacral

Referring to the 5 spinal segments that make up the lower part of the lower back

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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

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Sulcus

A crevice or valley of a convoluted brain surface

66

Frontal lobe

The mot anterior portion of the cerebral cortex

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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

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Central sulcus

A fissure that divides the frontal lobe from the parietal lobe

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Corpus callosum

The main band of axons that connects the two cerebral hemispheres

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Sagittal plane

Bisects the body into right and left halves

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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

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Medial

Toward the middle

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Lateral

Toward the side

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Ipsilateral

Same side of body

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Contralateral

Opposite side of body

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Superior

Above

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Inferior

Below

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Anterior, rostral

Head end

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Posterior, caudal

Tail end

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Proximal

Near the center

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Distal

Toward the periphery or end of a limb

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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

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Dorsal

Toward or at the back

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Ventral

Toward or at the belly

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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

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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

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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

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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

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medulla

the posterior part of the hindbrain, continuous with the spinal cord

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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

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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