Chapter 3: Anatomy & Research Methods

Question 1

neuroanatomy

Answer 1

anatomy of the nervous system

Question 2

central nervous system (CNS)

Answer 2

brain and spinal cord

Question 3

peripheral nervous system (PNS)

Answer 3

connects the brain and spinal cord to the rest of the nervous system (it is the nerves outside of the brain/spine)

somatic and autonomic nervous system are part of the PNS

Question 4

somatic nervous system

Answer 4

consists of the axons conveying messages from the sense organs to the CNS and from the CNS to the muscles

Question 5

autonomic nervous system

Answer 5

controls the heart, intestines, and other organs. it has some of its cell bodies within the brain or spinal cord and some in clusters along the sides of the spinal cord

made up of the sympathetic and parasympathetic nervous system

Question 6

sympathetic nervous systems

Answer 6

network of nerves that prepare the organs for a burst of vigorous activity, consists of chains of ganglia just to the left and right of the spinal cord’s central regions (the thoracic and lumbar areas); Sympathetic axons prepare the organs for “fight or flight,” such as by increasing breathing and heart rate and decreasing digestive activity. Because the sympathetic ganglia are closely linked, they often act as a single system “in sympathy” with one another

sweat glands, the adrenal glands, the muscles that constrict blood vessels, and the muscles that erect the hairs of the skin

Question 7

parasympathetic nervous system

Answer 7

called the “rest and digest” system, facilitates vegetative, nonemergency responses; related to, and generally the opposite of, sympathetic activities

parasympathetic ganglia are not linked to one another, they act more independently than the sympathetic ganglia do

also known as the craniosacral system because it consists of the cranial nerves and nerves from the sacral spinal cord

axons release the neurotransmitter acetylcholine onto the organs. Most sympa- thetic nervous system axons release norepinephrine, although a few, such as those onto the sweat glands, use acetylcholine.

decreases heart rate, increases digestive rate, and in general, conserves energy

Question 8

dorsal

Answer 8

toward the back

Question 9

ventral

Answer 9

toward the stomach

Question 10

anterior

Answer 10

toward the front end

Question 11

posterior

Answer 11

toward the rear end

Question 12

superior

Answer 12

above another part

Question 13

inferior

Answer 13

below another part

Question 14

lateral

Answer 14

toward the side, away from the midline

Question 15

medial

Answer 15

toward the midline, away from the side

Question 16

proximal

Answer 16

located close (approximate) to the point of origin or attachment

Question 17

distal

Answer 17

Located more distant from the point of origin or attachment

Question 18

ipsilateral

Answer 18

On the same side of the body (e.g., two parts on the left or two on the right)

Question 19

contralateral

Answer 19

On the opposite side of the body (one on the left and one on the right)

Question 20

coronal/frontal plane

Answer 20

A plane that shows brain structures as seen from the front

Question 21

sagittal plane

Answer 21

A plane that shows brain structures as seen from the side

Question 22

horizontal/transverse plane

Answer 22

A plane that shows brain structures as seen from above

Question 23

spinal cord

Answer 23

part of the CNS within the spinal column; communicates with all the sense organs and muscles except those of the head. It is a segmented structure, and each segment has on both the left and right sides a sen- sory nerve and a motor nerve

contains cell bodies of the motor neurons

sends sensory informa- tion to the brain and receives motor commands from the brain. All that information passes through tracts of axons in the spinal cord.

Question 24

dorsal root ganglia

Answer 24

cell bodies of the sensory neurons are in clusters of neurons outside the spinal cord

ganglia = cluster of neurons outside the CNS
nucleus = cluster of neurons inside the CNS

Question 25

gray matter

Answer 25

the centerof the cord is densely packed with cell bodies and dendrites. Many neurons from the gray matter of the spinal cord send axons to the brain or to other parts of the spinal cord through the white matter

Question 26

white matter

Answer 26

contains myelinated axons

Question 27

hindbrain

Answer 27

posterior part of the brain, consists of medulla, the pons, and the cerebellum.

Question 28

brainstem

Answer 28

medulla and pons, the midbrain, and certain central structures of the forebrain constitute the brainstem

Question 29

medulla

Answer 29

an enlarged extension of the spinal cord

the head and the organs connect to the medulla and adjacent areas by 12 pairs of cranial nerves

cranial nerves originating in the medulla control vital reflexes such as breathing, heart rate, vomiting, salivation, coughing, and sneezing

Question 30

pons

Answer 30

lies anterior and ventral to the medulla; axons from each half of the brain cross to the opposite side of the spinal cord so that the left hemisphere controls the muscles of the right side of the body and the right hemisphere controls the left side

Question 31

cerebellum

Answer 31

large hindbrain structure with many deep folds; contributions to the control of movement, balance, coordination, shifting attention between auditory and visual stimuli, timing, learning, conditioning

Question 32

midbrain

Answer 32

early in development the midbrain is in the middle of the brain, although in adult mammals it is dwarfed and surrounded by the forebrain. Consists of the tectum, tegmentum, superior and inferior colliculus, and substantia nigra

Question 33

tectum

Answer 33

roof of the midbrain

Question 34

superior & inferior colliculus

Answer 34

swellings on each side of the tectum

Both are important for sensory processing—the inferior colliculus for hearing and the su- perior colliculus for vision

Question 35

tegmentum

Answer 35

intermediate level of the midbrain

tectum covers the tegmentum, but the tegmentum covers several other midbrain structures.

Question 36

substantia nigra

Answer 36

gives rise to a dopamine-containing pathway that facilitates readiness for movement

Question 37

forebrain

Answer 37

most prominent part of the mammalian brain, consists of two cerebral hemispheres, one on the left and one on the right

each hemisphere is organized to receive sensory information, mostly from the contralateral (opposite) side of the body; controls muscles, mostly on the contralateral side, by way of axons to the spinal cord and the cranial nerve nuclei

consists of thalamus, hypothalamus, cerebral cortex, hippocampus, and basal ganglia

Question 38

limbic system

Answer 38

several interlinked structures that form a border around the brainstem

includes the olfactory bulb, hypothalamus, hippocampus, amygdala, and cingulate gyrus of the cerebral cortex

Question 39

hypothalamus

Answer 39

essential for control of eating, drinking, temperature control, and reproductive behaviors.

Partly through nerves and partly by releasing hormones, the hypothalamus conveys messages to the pituitary gland, altering its release of hormones.

Question 40

amygdala

Answer 40

most central for evaluating emotional information, specially with regard to fear

Question 41

thalamus

Answer 41

pair of structures (left and right) in the center of the forebrain

Most sensory information from a sensory system goes first to the thalamus, which processes it and sends output to the cerebral cortex

cerebral cortex sends information back to the thalamus, prolonging and magnifying certain kinds of input and focusing attention on particular stimuli

Question 42

pituitary gland

Answer 42

endocrine (hormone-producing) gland attached to the base of the hypothalamus

synthesizes hormones that the blood carries to organs through- out the body

Question 43

basal ganglia

Answer 43

group of subcortical structures lateral to the thalamus, include three major structures: the caudate nucleus, the putamen, and the globus pallidus

damage to the basal ganglia impairs movement, as in conditions such as Parkinson’s disease and Huntington’s disease

integrate motivational and emotional behavior to increase the vigor of selected actions

Question 44

nucleus basalis

Answer 44

receives input from the hypothalamus and basal ganglia and sends axons that release acetylcholine to widespread areas in the cerebral cortex

key part of the brain’s system for arousal, wakefulness, and attention

Question 45

hippocampus

Answer 45

large structure between the thalamus and the cerebral cortex, mostly toward the posterior of the forebrain

critical for certain types of memories, especially memories for individual events. It is also essential for monitoring where you are and where you are going.

Question 46

ventricles

Answer 46

four fluid-filled cavities within the brain

Each hemisphere contains one of the two large lateral ventricles

Question 47

cerebrospinal fluid (CSF)

Answer 47

clear fluid similar to blood plasma produced by the ventricles; provides buoyancy to help support the weight of the brain

cushions the brain against mechanical shock when the head moves; provides hormones and nutrition for the brain and spinal cord

Question 48

meninges

Answer 48

membranes that surround the brain and spinal cord.

Although the brain has no pain receptors, the meninges do

Question 49

cerebral cortex

Answer 49

composed of four lobes: frontal lobe, parietal lobe, temporal lobe, and occipital lobe

responsible for the higher-level processes of the human brain, including language, memory, reasoning, thought, learning, decision-making, emotion, intelligence and personality

The cells on the outer surface are gray matter, and their axons extending inward are white matter

Question 50

corpus callosum

Answer 50

the primary commissural region of the brain consisting of white matter tracts that connect the left and right cerebral hemispheres

Question 51

anterior commissure

Answer 51

white matter tract (a bundle of axons) connecting the two temporal lobes of the cerebral hemispheres across the midline

Question 52

laminae

Answer 52

layers of cell bodies that are parallel to the surface of the cortex and separated from each other by layers of fibers

six of them are contained in the cerebral cortex; vary in thickness and prominence

Question 53

columns

Answer 53

organized cortex cells

cells within a given column have similar prop- erties to one another

Question 54

occipital lobe

Answer 54

posterior end of the cortex; main target for visual information

eyes provide the stimulus, and the visual cortex provides the experience

Question 55

parietal lobe

Answer 55

vital for sensory perception and integration; monitors all the information about eye, head, and body positions and passes it on to brain areas that control movement

essential not only for spatial information but also numerical information

Question 56

central sulcus

Answer 56

deep groove in the surface of the cortex

Question 57

postcentral gyrus

Answer 57

receives sensations from touch receptors, muscle-stretch receptors, and joint receptors

Question 58

temporal lobe

Answer 58

lateral portion of each hemisphere, near the temples

primary cortical target for auditory information; left temporal lobe—is essential for understanding spoken language

also contributes to complex aspects of vision, including perception of movement and recognition of faces; emotional and motivational behaviors

Question 59

frontal lobe

Answer 59

containing the primary motor cortex (precentral gyrus) and the prefrontal cortex

Separate areas are responsible for different parts of the body, mostly on the contralateral (opposite) side but also with slight control of the ipsilateral (same) side

Question 60

precentral gyrus (primary motor cortex)

Answer 60

specialized for the control of fine movements; No area in the motor cortex controls just a single muscle

Question 61

prefrontal cortex

Answer 61

Neurons in the prefrontal cortex have huge numbers of synapses and integrate an enormous amount of information

regulates our thoughts, actions and emotions through extensive connections with other brain regions

Question 62

functions of the prefrontal cortex

Answer 62

posterior portion is associated mostly with movement. The middle zone pertains to working memory, cognitive control, and emotional reactions. anterior zone of the prefrontal cortex is important for making decisions, evaluating which of several courses of action is likely to achieve the best outcome

people with damage to the pre- frontal cortex have trouble on the delayed-response task, in which they see or hear something, and then have to respond to it after a delay.

Question 63

binding problem

Answer 63

question of how various brain areas produce a perception of a single object

binding occurs if you perceive two sensations as happening at the same time and in approximately the same place

Question 64

ablation

Answer 64

removal of a brain area, generally with a surgical knife

Question 65

lesion

Answer 65

made when surgical removal is difficult, usually for tiny structures below the surface of the brain

Question 66

stereotaxic instrument

Answer 66

device for the precise placement of electrodes in the brain

By consulting a stereotaxic atlas (map) of a species’ brain, a researcher aims an electrode at the desired position relative to landmarks on the skull. ; drills a small hole in the skull, inserts the electrode (insulated except at the tip), lowers it to the target, and passes an electrical current just sufficient to damage that area.

Question 67

transcranial magnetic stimulation (TMS)

Answer 67

application of magnetic stimulation to a portion of the scalp, can stimulate neurons in the area be- low the magnet, if the stimulation is sufficiently brief and mild. With stronger stimulation it inactivates the neurons, producing a “virtual lesion” that out- lasts the magnetic stimulation itself

procedure enables researchers to study behavior with some brain area active, then inactive, and then active again

Question 68

optogenetics

Answer 68

using light to control a limited population of neurons

nvestigator can control the ex- citation or inhibition of one type of neuron in a small brain area with millisecond accuracy.

Question 69

electroencephalograph (EEG)

Answer 69

records electrical activity of the brain through electrodes— ranging from just a few to more than a hundred—attached to the scalp ; Electrodes glued to the scalp measure the average activity at any moment for the population of cells under the electrode. The output is then amplified and recorded.

Question 70

evoked potentials/responses

Answer 70

same device used for an EEG can also record brain activity in response to a stimulus

Question 71

magnetoencephalograph (MEG)

Answer 71

measures the faint magnetic fields generated by brain activity

recording identifies the approximate location of activity to within about a centimeter; has excellent temporal resolution, showing changes from one millisecond to the next

can identify the times at which various brain areas respond and thereby trace a wave of brain activity from its point of origin to the other areas that process it

Question 72

positron-emission tomography (PET)

Answer 72

provides a high- resolution image of activity in a living brain by recording the emission of radioactivity from injected chemicals

first, the person receives an injection of glucose or some other chemical containing radioactive atoms. Because the most active brain areas increase their use of glucose, tracking the levels of glucose tells us something about brain activity. When two detec- tors record gamma rays at the same time, they identify a spot halfway between those detectors as the point of origin of the gamma rays. A computer uses this information to determine how many gamma rays came from each spot in the brain and therefore how much of the radioactive chemical is located in each area

most radioactivity are presumably the ones with the most active neurons.

requires exposing the brain to radioactivity, a poten- tial hazard

Question 73

functional magnetic resonance imagine (fMRI)

Answer 73

modified version of MRI based on hemoglobin (the blood protein that binds oxygen) instead of water

Researchers set the fMRI scanner to detect the amount of hemoglobin with oxygen. When a brain area becomes more active, two relevant changes occur: First, blood vessels dilate to allow more blood flow to the area. Second, as the brain area uses oxygen, the percentage of hemoglobin with oxygen decreases. An fMRI scan responds to both of these processes; requires a comparison task

Researchers often examine the mean results for a group of participants, ignoring important differences among individuals

Question 74

phrenology

Answer 74

relating skull anatomy to behavior

issues: skull shape does not match brain anatomy, based many conclusions on small numbers of people who apparently shared some personality aspect and a similar bump on the skull.

Question 75

computerized axial tomography (CT/CAT scan)

Answer 75

physician injects a dye into the blood to increase contrast in the image, and then places the person’s head into a CT scanner. X-rays are passed through the head and recorded by detectors on the opposite side. The CT scanner is rotated slowly until a measurement has been taken at each angle over 180 degrees. From the measurements, a computer constructs images of the brain.

Question 76

magnetic resonance imaging (MRI)

Answer 76

applies a powerful magnetic field to align all the axes of rotation, and then tilts them with a brief radio frequency field.

When the radio frequency field is turned off, the atomic nuclei release electromagnetic energy as they relax and return to their original axis. By measuring that energy, MRI devices form an image of the brain