Structure of the Vertebrate Nervous System

Question 1

central nervous system (CNS)

Answer 1

the brain and the spinal cord

Question 2

peripheral nervous system (PNS)

Answer 2

connects the brain and spinal cord to the rest of the body

Question 3

Planes of the Brain

Answer 3

Question 4

somatic nervous system

Answer 4

consists of the axons con- veying messages from the sense organs to the CNS and from the CNS to the muscles

Controls voluntary muscles and conveys sensory information to the central nervous system

Question 5

autonomic nervous system

Answer 5

part of the PNS, controls the heart, intestines, and other organs

made up of sympathetic and parasympathetic nervous systemns

Controls involuntary muscles

Sympathetic: Expends energy Parasympathetic:

Conserves energy

Question 6

Anatomical Terms Referring to Directions

Answer 6

Question 7

spinal cord

Answer 7

part of the CNS within the spinal column. The spinal cord communicates with all the sense organs and muscles except those of the head.

Question 8

dorsal root ganglia

Answer 8

clusters of neurons outside the spinal cord, these are the cell bodies of the sensory neurons;

receive sensory input

Question 9

gray matter

Answer 9

H-shaped gray matter in the center of the cord is densely packed with cell bodies and dendrites.

send axons to the brain or to other parts of the spinal cord through the white matter

Question 10

sympathetic nervous system,

Answer 10

network of nerves that pre- pare 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)

prepare the organs for “fight or flight,” such as by increasing breathing and heart rate and decreasing digestive activity

Question 11

parasympathetic nervous system

Answer 11

sometimes called the “rest and digest” system, facilitates vegetative, nonemer- gency responses.

the sympa- thetic nervous system increases heart rate, and the parasym- pathetic nervous system decreases it. The parasympathetic nervous system increases digestive activity, whereas the sym- pathetic nervous system decreases it. The parasympathetic system also promotes sexual arousal, including erection in males

Question 12

three major divisions of the brain

Answer 12

hindbrain, the mid- brain, and the forebrain or hombenceph- alon (hindbrain), mesencephalon (midbrain), and prosen- cephalon (forebrain)

Question 13

hindbrain

Answer 13

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

Question 14

medulla

Answer 14

enlarged extension of the spinal chord; cranial nerves originating in the medulla control vital reflexes such as breathing, heart rate, vomiting, salivation, coughing, and sneezin

Question 15

pons

Answer 15

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 16

brain stem

Answer 16

medulla and pons, the midbrain, and certain central structures of the fore- brain

Question 17

cerebellum

Answer 17

large hindbrain structure with many deep folds; control of movement, and many older text- books describe the cerebellum as important for “balance and coordination.”; but also attention shifting, judgment of timing, etc

Question 18

midbrain

Answer 18

middle of the brain, although in adult mammals it is dwarfed and surrounded by the forebrain;

tectum - roof of the midbrain

superior colliculus and the inferior colliculus - swellings on each side of the tectum; mportant for sensory processing—the inferior colliculus for hearing and the su- perior colliculus for vision

tegmentum - intermediate level of the midbraon

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

Question 19

forebrain

Answer 19

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

Question 20

cerebral cortex

Answer 20

outer portion of the forebrain

Question 21

limbic system

Answer 21

located in the forebrain under the cerebral cortex forming a border around the brain stem; includes:

olfactory bulb

hypothalamus

hippocampus

amygdala

cingulate gyrus of the cerebral cortex

Question 22

thalamus

Answer 22

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

sensory in- formation goes first to the thalamus, which processes it and sends output to the cerebral cortex (except olfactory, which go directly to the cerebral cortex

Question 23

hypothalamus

Answer 23

small area near the base of the brain just ventral to the thalamus;

hypothalamus conveys messages to the pituitary gland, altering its release of hormones

Question 24

pituitary gland

Answer 24

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

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

Question 25

basal ganglia

Answer 25

group of subcortical structures lateral to the thalamus

include three major structures: the caudate nucleus, the putamen, and the globus pallidus

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

critical for learned skills and habits, as well as other types of learning that develop gradually with extended experience

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

Question 26

nucleus basalis

Answer 26

One of the structures on the ventral surface of the forebrain

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 27

Hippocampus

Answer 27

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 28

ventricles

Answer 28

four fluid-filled cavities within the brain. Each hemisphere contains one of the two large lateral ventricles

Toward their posterior, they connect to the third ventricle, positioned at the midline, separating the left thalamus from the right thalamus

Cells called the choroid plexus along the walls of the four ventricles produce cerebrospinal fluid (CSF) -

Question 29

cerebrospinal fluid

Answer 29

a clear fluid similar to blood plasma.

From the fourth ventricle, some of it flows into the central canal of the spinal cord, but more goes into the narrow spaces between the brain and the thin meninges, membranes that surround the brain and spinal cord

Cerebrospinal fluid cushions the brain against mechanical shock when the head moves. It also provides buoyancy.

Question 30

meninges

Answer 30

membranes that surround the brain and spinal cord

he brain has no pain receptors, the meninges do, and meningitis—inflammation of the meninges—is painful. Swollen blood vessels in the me- ninges are responsible for the pain of a migraine headache

Question 31

corpus callosum and anterior commissure

Answer 31

Neurons in each hemi- sphere communicate with neurons in the corresponding part of the other hemisphere through two bundles of axons, the corpus callosum and the smaller anterior commissure

Question 32

laminae

Answer 32

A row or layer of cell bodies separated from other cell bodies by a layer of axons and dendrites

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

cerebral cortex contains up to six distinct laminae, some areas are missing certain levels

cells of the cortex are also organized into columns of cells perpendicular to the laminae

Question 33

occipital lobeposterior (caudal) end of the cortex

Answer 33

posterior (caudal) end of the cortex

main target for visual information

posterior pole of the occipital lobe is known as the primary vi- sual cortex, or striate cortex,

Question 34

parietal lobe

Answer 34

between the occipital lobe and the central sulcus

area just posterior to the central sulcus, the postcentral gyrus, or primary somatosensory cortex, receives sensations from touch receptors, muscle-stretch receptors, and joint receptors.

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 35

central sulcus

Answer 35

deep groove in the surface of the cortex

Question 36

postcentral gyrus

Answer 36

area just posterior to the central sulcus

Question 37

temporal lobe

Answer 37

lateral portion of each hemi- sphere, near the temples

primary cortical target for auditory information

in most cases, the left temporal lobe—is essen- tial for understanding spoken language

also contributes to complex aspects of vision, including perception of movement and recognition of faces

also important for emotional and motivational behaviors.

Question 38

Klüver-Bucy syndrome

Answer 38

Previously wild and aggressive monkeys fail to display normal fears and anxieties after temporal lobe damage

Question 39

frontal lobe

Answer 39

containing the primary motor cortex and the prefrontal cortex, extends from the central sulcus to the anterior limit of the brain

posterior por- tion of the frontal lobe, the precentral gyrus, is specialized for the control of fine movements, such as moving a finger

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 40

primary motor cortex

Answer 40

precentral gyrus, also known as the primary motor cortex.

No area in the motor cortex controls just a single muscle. If two muscles usually move together, such as the muscles controlling your little finger and your ring finger, then the brain areas that control one of them largely overlap those that control the other one

Question 41

prefrontal cortex

Answer 41

most anterior portion of the frontal lobe

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

Question 42

three major regions of pre-frontal cortex

Answer 42

posterior portion is as- sociated mostly with movement

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

Question 43

binding problem

Answer 43

large-scale integration problem

question of how various brain areas produce a per- ception of a single object

Question 44

Major Solci/Fissures

Answer 44

Interhemispheric Fissure

Sylvian Fissure (separates temporal from parieatal)

Parieto-occipital Fissure and Calcarine Sulcus (y shaped from temporal, splitting parietal, occipital and temporal)

Central, Postcentral and Precentral Sulci

Question 45

Number of neurons

Answer 45

cerebral cortex: 12 to 15 billion

spinal cord: 1 billion

cerebellum 70 billion

Question 46

cranial nerves

Answer 46

Question 47

postcentral gyrus

Answer 47

primary somatosensory cortex

Primary target for touch sensations and information from muscle-stretch receptors and joint receptors

Question 48

precentral grrus

Answer 48

just posterior to central sulcus

contains the primary motor cortex

Question 49

STRUCTURAL ASYMMETRY

Answer 49

the brain is not symmetrical

The right protrudes in front

The left protrude in back

The right has more volume

The left is larger posteriorly in occipital region

The planum temporale at Wernicke’s area is larger in L hemispehere in 65% of the brains;

11% had a larger surface area in R hemisphere

Question 50

columns

Answer 50

A set of cells perpendicular to the surface of the cortex, with similar properties

Question 51

Tract

Answer 51

A set of axons within the CNS, also known as a projection. If axons extend from cell bodies in structure A to synapses onto B, we say that the fibers “project” from A onto B.

Question 52

Nerve

Answer 52

A set of axons in the periphery, either from the CNS to a muscle or gland or from a sensory organ to the CNS

Question 53

Nucleus

Answer 53

A cluster of neuron cell bodies within the CNS

Question 54

Ganglion

Answer 54

A cluster of neuron cell bodies, usually outside the CNS (as in the sympathetic nervous system)

Question 55

cingulate gyrus

Answer 55

part of limboc system

highly influential in linking motivational outcomes to behavior (e.g. a certain action induced a positive emotional response, which results in learning