Nervous System

Question 1

Consists of the brain and spinal cord, which occupy the dorsal body cavity. The integrating and control center of the nervous system. Interprets sensory input and dictates motor output based on reflexes, current conditions, and past experience.

Answer 1

Central Nervous System (CNS))

Question 2

Part of the nervous system outside the CNS. Consists mainly of nerves that extend from the brain and spinal cord, and ganglia. Spinal nerves carry impulses to and from the spinal cord, and cranial nerves carry impulses to and from the brain. Serve as communication lines that link all parts of the body to the CNS.

Answer 2

Peripheral Nervous System (PNS)

Question 3

The nervous system uses these to monitor changes occurring both inside and outside the body.

Answer 3

Sensory Input

Question 4

The nervous system processes and interprets sensory input and decides what should be done at each moment.

Answer 4

Integration

Question 5

The nervous system activates effector organs—the muscles and glands—to cause a response.

Answer 5

Motor Output

Question 6

Promotes maintenance functions and conserves body energy. “Rest and digest” system, keeps body energy use as low as possible, even as it directs vital “housekeeping” activities like digesting food and eliminating feces and urine.

Answer 6

Parasympathetic Division

Question 7

Mobilizes the body during activity. “Fight-or-flight” system. Evident when individual is excited or in emergency or threatening situations.

Answer 7

Sympathetic Division

Question 8

Craniosacral; Has long preganglionic and short postganglionic fibers; Located in or near the visceral effector organs; Maintenance functions; conserves and stores energy; “rest and digest”.

Answer 8

Parasympathetic Division

Question 9

Thoracolumbar; Has the opposite condition—the preganglionic fibers are short and the postganglionic fibers are long; Lie close to the spinal cord; Prepares body for activity; “fight or flight”.

Answer 9

Sympathetic Division

Question 10

A clear, colorless liquid composed primarily of water that protects the brain and spinal cord from chemical and physical injuries. It forms a liquid cushion that gives buoyancy to CNS structures effectively reducing the brain’s weight by 97%.

Answer 10

Cerebrospinal Fluid

Question 11

A condition wherein something (such as a tumor) obstructs CSF circulation or drainage, CSF accumulates and exerts pressure on the brain. The head enlarges because the skull bones have not yet fused. This causes damage to the brain because accumulating fluid compresses blood vessels and crushes the soft nervous tissue.

Answer 11

Hydrocephalus

Question 12

1. The choroid plexus of each ventricle produces CSF.
2. CSF flows through the ventricles and into the subarachnoid space via the median and
   lateral apertures.
3. CSF flows through the subarachnoid space.
4. CSF is absorbed into the dural venous sinuses via the arachnoid granulations.

Answer 12

Location and Circulatory Pattern of Cerebrospinal Fluid

Question 13

Where is cerebrospinal fluid formed?

Answer 13

Choroid Plexus

Question 14

Consists of the midbrain, pons, and medulla oblongata. Each roughly an inch long, collectively they account for only 2.5% of total brain mass. Its centers produce the rigidly programmed, automatic behaviors necessary for survival. Positioned between the cerebrum and the spinal cord, it also provides a pathway for fiber tracts running between higher and lower neural centers.

Answer 14

Brain Stem

Question 15

Located between the diencephalon and pons. Contains visual (superior colliculi) and auditory (inferior colliculi) reflex centers. Contains subcortical motor centers (substantia nigra and red nuclei). Contains nuclei for cranial nerves III and IV.

Answer 15

Midbrain (Mesencephalon)

Question 16

Bulging brain stem region wedged between the midbrain and the medulla oblongata. Composed of conduction tracts. Contains nuclei of cranial nerves V–VIII.

Answer 16

Pons

Question 17

Run longitudinally as part of the pathway between higher brain centers and the spinal cord.

Answer 17

Deep Projection Fibers

Question 18

Form the middle cerebellar peduncles and connect the pons bilaterally with the two sides of the cerebellum dorsally fibers. Issue from numerous pontine nuclei, which relay “conversations” between
the motor cortex and cerebellum.

Answer 18

Superficial Ventral Fibers

Question 19

Most inferior part of the brain stem that blends imperceptibly into the spinal cord at the level of the foramen magnum of the skull. Contains nuclei of cranial nerves VIII–X and XII. Contains projection fibers. Site of decussation of pyramids.

Answer 19

Medulla Oblongata

Question 20

Cardiac center which force and rate of heart contraction; Vasomotor center which changes blood vessel diameter to regulate blood pressure.

Answer 20

Cardiovascular Center

Question 21

Respiratory rhythm and control the rate and depth of breathing.

Answer 21

Respiratory Centers

Question 22

Located dorsal to the pons and medulla. Accounts for about 11% of total brain mass. Second only to the cerebrum in size, occupies the inferior and posterior aspects of the cranial cavity. Protrudes under the occipital lobes of the cerebral hemispheres, from which it is separated by the transverse cerebral fissure.

Answer 22

Cerebellum

Question 23

Superior to the brain stem. Forms the central core of the forebrain and surrounded by the cerebral hemispheres.

Answer 23

Diencephalon

Question 24

Consists of bilateral egg-shaped nuclei, which form the superolateral walls of the third ventricle. Deep, well-hidden brain region that makes up 80% of the diencephalon.

Answer 24

Thalamus

Question 25

Involved in memory processing. Hypothalamus Merging into the midbrain inferiorly, it extends from the optic chiasma (crossover point of the optic nerves) to the posterior margin of the mammillary bodies. Caps the brain stem and forms the inferolateral walls of the third ventricle.

Answer 25

Cerebellum

Question 26

Most dorsal portion of the diencephalon. Forms the roof of the third ventricle

Answer 26

Epithalamus

Question 27

Sensory areas of cerebral cortex are involved in perception of sensory information. Motor areas control execution of voluntary movements. Association areas deal with more complex integrative functions such as memory, personality traits, and intelligence. Basal nuclei help initiate and terminate movements, suppress unwanted movements, and regulate muscle tone. Limbic system promotes range of emotions, including pleasure, pain, docility, affection, fear, and anger.

Answer 27

Cerebrum

Question 28

Localizes and interprets sensory inputs. Controls voluntary and skilled skeletal muscle activity. Functions in intellectual and emotional processing.

Answer 28

Cortical Gray Matter

Question 29

Subcortical motor centers. Help control skeletal muscle movements.

Answer 29

Basal Nuclei (Ganglia)

Question 30

TRANSMIT NERVE IMPULSES ALONG NERVE FIBERS TO OTHER NEURONS.

Answer 30

Neurons

Question 31

MADE UP OF BUNDLES OF NERVE FIBERS.

Answer 31

Nerves

Question 32

CARRY OUT A VARIETY OF FUNCTIONS TO AID AND PROTECT COMPONENTS OF THE NERVOUS SYSTEM.

Answer 32

Neuroglia

Question 33

Consciously Controlled System

Answer 33

Somatic Nervous System

Question 34

Unconsciously Controlled System

Answer 34

Autonomic Nervous System

Question 35

CARRY IMPULSES FROM OTHER NEURONS (OR FROM RECEPTORS) TOWARD THE CELL BODY.

Answer 35

Dendrites

Question 36

TRANSMITS THE IMPULSE AWAY FROM THE AXONAL HILLOCK OF THE CELL BODY AND MAY GIVE OFF SIDE BRANCHES.

Answer 36

Axon

Question 37

ENCLOSED BY SHEATHS OF MYELIN PROVIDED BY SCHWANN CELLS AND ARE MYELINATED FIBERS.

Answer 37

Large Axons

Question 38

The outer layer of myelin.

Answer 38

Neurilemma

Question 39

NARROW GAPS IN THE MYELIN SHEATH BETWEEN SCHWANN CELLS.

Answer 39

Nodes of Ranvier

Question 40

LACK A MYELIN SHEATH AND ARE UNMYELINATED FIBERS.

Answer 40

Small Axons

Question 41

__________ IN THE CNS IS DUE TO MYELIN SHEATHS IN THIS AREA.

Answer 41

White Matter

Question 42

UNMYELINATED NERVE TISSUE IN THE CNS APPEARS __________.

Answer 42

Gray Matter

Question 43

THESE ARE ABLE TO REGENERATE BECAUSE OF THE NEURILEMMA, BUT THE CNS AXONS ARE MYELINATED BY OLIGODENDROCYTES, THUS LACKING NEURILEMMA, AND USUALLY DO NOT REGENERATE.

Answer 43

Peripheral Neurons

Question 44

Usually have several dendrites and one axon. Most neurons in the brain and spinal cord are of this type, as well as all motor neurons.

Answer 44

Multipolar Neurons

Question 45

Have one main dendrite and one axon. They are found in the retina of the eye, the inner ear, and the olfactory area (olfact = to smell) of the brain.

Answer 45

Bipolar Neurons

Question 46

Have dendrites and one axon that are fused together to form a continuous process that emerges from the cell body.

Answer 46

Unipolar Neurons

Question 47

Small cells that phagocytize bacterial cells and cellular debris.

Answer 47

Microglial Cells

Question 48

Form myelin in the brain and spinal cord.

Answer 48

Oligodendrocytes

Question 49

Near blood vessels andsupportstructures,aid in metabolism, and respond to brain injury by filling in spaces.

Answer 49

Astrocytes

Question 50

Cover the inside of ventricles and form choroid plexuses within the ventricles.

Answer 50

Ependyma

Question 51

The myelin-producing neuroglia of the peripheral nervous system.

Answer 51

Schwann Cells

Question 52

Flat cells that surround the cell bodies of neurons of PNS ganglia.

Answer 52

Satellite Cells

Question 53

Begins at the base of the brain and extends as a slender cord to the level of the intervertebral disk between the first and second lumbar vertebrae.

Answer 53

Spinal Cord

Question 54

Consisting of the brain, spinal cord, and nerves—constantly receives signals about changes from the external environment and within the body. It then processes the information, decides what action needs to occur, and sends electrical and chemical signals to the cells, enabling proper response. It also powers our ability to learn, feel, create, and experience emotion. It is the most complex of all body systems.

Answer 54

Nervous System

Question 55

This reward system is attributed to neurons that release the neurotransmitter _________ in areas of the brain called the ventral tegmental area (VTA), the nucleus accumbens, and the amygdala.

Answer 55

Dopamine

Question 56

Responsible for this “feel good” reward system.

Answer 56

Neurotransmitters

Question 57

The branch of medical science that deals with the normal functioning and disorders of the nervous system.

Answer 57

Neurology

Question 58

With a mass of only 2 kg (4.5 lb), about 3% of total body weight.

Answer 58

Nervous System

Question 59

With sensory (afferent) and motor (efferent) components.

Answer 59

Peripheral Nervous System

Question 60

Consists of a variety of different receptors as well as sensory neurons.

Answer 60

Sensory System

Question 61

Conducts nerve impulses from the CNS to muscles and glands.

Answer 61

Motor System

Question 62

Consists of neurons that conduct impulses from cutaneous and special sense receptors to the CNS, and motor neurons that conduct impulses from the CNS to skeletal muscle tissue.

Answer 62

Somatic Nervous System

Question 63

Contains sensory neurons from visceral organs and motor neurons that convey impulses from the CNS to smooth muscle tissue, cardiac muscle tissue, and glands. The motor part of the ANS consists of the sympathetic division and the parasympathetic division.

Answer 63

Autonomic Nervous System

Question 64

Consists of neurons in enteric plexuses that extend the length of the GI tract. Many neurons of the enteric plexuses function independently of the ANS and CNS. Sensory neurons of the ENS monitor chemical changes within the GI tract and stretching of its walls, whereas enteric motor neurons govern contraction of GI tract organs, and activity of the GI tract endocrine cells.

Answer 64

Enteric Nervous System

Question 65

Cluster of neuronal cell bodies located in the PNS; closely associated with cranial and spinal nerves.

Answer 65

Ganglion

Question 66

Cluster of neuronal cell bodies located in the CNS.

Answer 66

Nucleus

Question 67

Bundle of axons that is located in the PNS.

Answer 67

Nerve

Question 68

Bundle of axons that is located in the CNS.

Answer 68

Tract

Question 69

Composed primarily of myelinated axons.

Answer 69

White Matter

Question 70

Contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia. It appears grayish, rather than white, because the Nissl bodies impart a gray color and there is little or no myelin in these areas.

Answer 70

Gray Matter

Question 71

Like muscle fibers, neurons are electrically excitable. Excitable cells communicate with each other by graded potentials or action potentials. Graded potentials allow communication over short distances only whereas action potentials allow communication over long distances. When an action potential occurs in a neuron (nerve cell).

Answer 71

Nerve Action Potential