Chapter 27 - Nervous, Sensory, and Locomotor Systems

Question 0

The integration and commandcenter of the nervous system; the brain and, in vertebrates, the spinal cord.

Answer 0

Central nervous system

Question 1

A communication line madeup of cable-like bundles of neuron fibers (axons and dendrites)tightly wrapped in connectivetissue.

Answer 1

Nerve

Question 2

The network of nerves carrying signals into and out of the central nervous system.

Answer 2

Peripheral nervous system

Question 3

The conduction of signals from sensory receptors to integration centers in the central nervous system.

Answer 3

Sensory input

Question 4

A nerve cell that receives information from sensory receptors and conveys signals into the central nervous system.

Answer 4

Sensory neuron

Question 5

The interpretation of sensorysignals and the formulation of responses within the central nervous system.

Answer 5

Integration

Question 6

A nerve cell, entirely within the central nervous system, that integrates sensory signals and may relay command signals to motor neurons.

Answer 6

Interneurons

Question 7

The conduction of signals from the central nervous system to effector cells.

Answer 7

Motor output

Question 8

A short-lived lymphocyte that has an immediate effect against a specific pathogen; a cell capable of carrying out some action in response to a command from the nervous system.

Answer 8

Effector cells

Question 9

A nerve cell that conveys command signals from the central nervous system to effector cells, such as muscle cells or gland cells.

Answer 9

Motor neurons

Question 10

The part of a cell, such as a neuron, that houses the nucleus and other organelles.

Answer 10

Cell body

Question 11

A short, branched neuron fiber that receives signals and conveys them from its tip inward, toward the rest of the neuron.

Answer 11

Dendrite

Question 12

A neuron fiber that extends from the cell body and conducts signals to another neuron or to an effector cell.

Answer 12

Axon

Question 13

In the nervous system, a cell that protects, insulates, and reinforces a neuron.

Answer 13

Supporting cell

Question 14

A chain of bead-like supporting cells that insulate the axon of a nerve cell in vertebrates. This insulation helps to speed electrical transmission along the axon.

Answer 14

Myelin sheath

Question 15

The voltage across the plasma membrane of a resting neuron.

Answer 15

Resting potential

Question 16

A self-propagating change in the voltage across the plasma membrane of a neuron; a nerve signal.

Answer 16

Action potential

Question 17

__________ is the conveyance of signals by sensory neurons to the CNS from sensory receptors

Answer 17

Sensory input

Question 18

_____________ within the CNS engage in integration, the interpretation of the sensory signals and the formulation of responses.

Answer 18

Interneurons

Question 19

Motor output is the conduction of signals from the integration centers to effectors, such as muscle cells.
(1) Effectors perform the body’s responses.
(2) Motor neurons function in motor output

Answer 19

True

Question 20

_________ are often short, numerous, and highly branched. They receive incoming messages from other cells and convey this information toward the cell body.

Answer 20

Dendrites

Question 21

A(n) ________ on many neurons is a single fiber. Axons conduct signals toward another neuron or toward an effector. Axons can be very long.

Answer 21

Axon

Question 22

T or F?

The spaces between nodes of Ranvier are
the only points on the axon where signals can be transmitted.

Answer 22

True

Question 23

In the human nervous system, signals can travel along a myelinated axon at about 150 meters per second (over 330 miles per hour). A signal from your brain can reach your fingers in a few milliseconds. (T or F?)

Answer 23

True

Question 24

T or F?

A membrane, like a battery, stores energy by holding opposite charges apart.

Answer 24

True

Question 25

The voltage (potential difference) across the plasma membrane of a resting neuron is called _______________.

Answer 25

The resting potential

Question 26

A stimulus is any factor that causes a nerve signal to be generated (T or F?)

Answer 26

True

Question 27

___________ the minimum change in a membrane’s voltage that must occur to trigger an action potential.

Answer 27

Threshold Potential

Question 28

There are five main parts of an action potential (a nerve signal).
(1) A membrane at its resting potential is positively charged on the outside and negatively charged inside.
(2) A stimulus triggers the opening of membrane ion channels, allowing a few ions to enter. If the stimulus is strong enough, a sufficient number of channels open to reach the threshold potential, the minimum change in a membrane’s voltage that must occur to trigger an action potential.
(3) As additional channels open and more ions move in, the interior of the cell becomes positively charged with respect to the outside.
(4) This triggers the closing and inactivation of the channels. Meanwhile, other channels open, allowing the positive ions to diffuse rapidly out, returning the membrane to its resting potential.
(5) An action potential occurs in only a few milliseconds.

Answer 28

Ok

Question 29

An action potential cannot be generated in the regions where a positive charge is leaving the axon. The action potential only spreads to regions of a resting potential.

Answer 29

True

Question 30

Action potentials are all-or-none events. How, then, do action potentials relay different intensities of information to the CNS?

Answer 30

Answer: The frequency of action potentials changes with the intensity of stimuli

Question 31

Synapses can be either __________ or __________.

Answer 31

Electrical; chemical

Question 32

The binding of neurotransmitter to a receptor opens ion channels.

Answer 32

True

Question 33

One group of neurotransmitters, called the biogenic amines, is derived from amino acids. They can also act as hormones. Name four of them:

Answer 33

Epinephrine, norepinephrine, serotonin, and dopamine.

Question 34

T or F?

Serotonin and dopamine affect sleep, mood, attention, and learning.

Answer 34

True

Question 35

T or F?

The endorphins are peptides that function as neurotransmitters and hormones, decreasing our perception of pain.

Answer 35

True

Question 36

Name two features common to all vertebrate nervous systems.

Answer 36

Cephalization - the concentration of the nervous
system at the head end

Centralization - the presence of a central nervous system (CNS) distinct from a peripheral nervous system (PNS).

Question 37

What acts as the central communication conduit between the brain and the rest of the body?

Answer 37

The spinal cord

Question 38

What is the master control center of the nervous system?

Answer 38

The brain

Question 39

T or F?

Cerebrospinal fluid cushions the CNS and helps supply it with nutrients, hormones, and white blood cells.

Answer 39

True

Question 40

T or F?

The sensory division of the PNS consists of two sets of sensory neurons. One set brings in information about the outside environment. The other set supplies the CNS with information about the body itself.

Answer 40

True

Question 41

Neurons of the somatic nervous system carry signals to which kind of muscles?

Answer 41

Skeletal muscles

Question 42

T/F?

The somatic nervous system is said to be voluntary because many of its actions are under conscious control.

Answer 42

True

Question 43

The motor neurons of the autonomic nervous system are generally involuntary. Which muscles do they control?

Answer 43

Smooth and Cardiac (and the organs and glands of the digestive, circulatory, excretory, and endocrine systems)

Question 44

The parasympathetic division primes the body for digestion and resting while the sympathetic division is the fight-or-flight response.

Answer 44

True

Question 45

The most extensive portion of the cerebrum.

Answer 45

The thalamus

Question 46

Name the part of the brain whose function:
(1) It sorts data into categories.
(2) It also suppresses some signals and enhances others.
(3) Itthensendsthesortedinformationontothe appropriate higher brain centers for further interpretation and integration.

Answer 46

The thalamus

Question 47

Which part of the brain regulates: (functions) body temperature, blood pressure, hunger, thirst, the sex drive, and fight-or-flight responses, and it helps us experience emotions such as rage and pleasure. It also controls the pituitary gland and the secretion of many hormones.

Answer 47

Hypothalamus

Question 48

T or F?

The brainstem consists of the medulla oblongata and pons

Answer 48

True

Question 49

Which part of the brain provides coordination of body movement and learns and remembers motor responses?

Answer 49

Cerebellum

Question 50

Which part of the brain is the largest and most sophisticated part of our brain.

Answer 50

Cerebrum

Question 51

Which part if the brain:
(1) Its intricate neural circuitry helps produce our most distinctive human traits: reasoning and mathematical abilities, language skills, imagination, artistic talent, and personality traits.
(2) The cortex creates our sensory perceptions by assembling sensory information from many sources.
(3) It also regulates our voluntary movements.

Answer 51

The cerebrum (or cerebral cortex)

Question 52

This part of the brain controls breathing

Answer 52

Pons

Question 53

This part of the brain conducts data to and form other brain centers, helps maintain homeostasis; coordinates body movement.

Answer 53

Brainstem

Question 54

This part of the brain controls breathing, circulation, swallowing, and digestion.

Answer 54

Medulla oblongata

Question 55

The part of the brain that receives and integrates auditory data; coordinates visual reflexes, sends sensory data to higher brain centers.

Answer 55

Midbrain

Question 56

The hindbrain consists of what three parts?

Answer 56

The medulla oblongata, the pons, and the cerebellum

Question 57

The cerebrum, thalamus, and the hypothalamus make up which part of the brain?

Answer 57

Forebrain

Question 58

The brainstem consists of which three parts?

Answer 58

The midbrain, medulla oblongata, and pons

Question 59

This part of the brain performs sophisticated integration; involved in memory, learning, speech, emotions; formulates complex behavioral responses

Answer 59

Cerebrum

Question 60

T or F?

The brainstem filters motor and sensory input.

Answer 60

True

Question 61

The large, central hub of a neuron, called the _________, contains the nucleus and organelles. Short, numerous fibers called __________ receive incoming messages, while a single long fiber called a(n) ___________ conducts signals toward other cells. Neuron ends in any branches, each with a bulb-like ___________ that contains neurotransmitters, which can be used to communicate signals to other neurons.

Answer 61

Cell body; dendrites; axon; synaptic terminal

Question 62

What is the function of the myelin sheath?

Answer 62

It speeds up conduction of signals along an axon.

Question 63

Your nervous system can be divided into two broad subsystems, the __________ and ___________. One of these is made up of nerves that conduct signals to and from the other structures. The other consists of the __________ and __________.

Answer 63

Central nervous system; peripheral nervous system; brain; spinal cord

Question 64

The central nervous system is protected by __________, a liquid that cushions it and supplies it with nutrients, and layers of protective tissue called the __________.

Answer 64

Cerebrospinal fluid; meninges