Chapter 10 Active Learning Review Quiz

13. There are _____ pairs of cranial nerve and ____ pairs of nerves that come from the spinal cord.

12; 31

35. Neuroma

general term for tumor of the nervous system

3. A group of peripheral axons bundled together in an nerium is called a ____.

nerve

4. The two types of cells found in the nervous system are ____ and ____.

nervous; glia

8. The ____ is a place where impulses are passed from one neuron to another.

synapse

39. Dementia

syndrome that include memory loss; short attention span, and reduced intellectual capacity

21. What is a concussion and describe its symptoms.

A concussion is a type of traumatic brain injury resulting from a jolt to the head that bends the brainstem and causes temporary chemical changes in the brain. A concussion can be characterized by changes in thinking or concentration; physical symptoms like headache, nausea, or light sensitivity; a change in mood, and/or changes in sleep.

13. What is a seizure?

A seizure is a sudden burst of abnormal neuron activity that results in a temporary change in brain function. Seizures may be mild, causing subtle changes in the level of consciousness, motor control, or sensory perception, or they may be quite severe, resulting in jerky, involuntary muscle contractions, called convulsions, or unconsciousness.

10. Explain what occurs at a synapse. What are the two ways that neurotransmitter activity is terminated?

A synapse is a place where impulses are transmitted from one neuron to another. Three structures make up a synapse: (1) a synaptic knob, (2) a synaptic cleft, and (3) the plasma membrane of the postsynaptic neuron. The synaptic knob is a tiny bulge at the end of the presynaptic neuron's axon. It contains a neurotransmitter. When a nerve impulse arrives at a synaptic knob, a neurotransmitter is released into the synaptic cleft, which is the space between the synaptic knob and the plasma membrane of the postsynaptic neuron. The plasma membrane of the postsynaptic neuron has protein molecules embedded in it opposite each synaptic knob. These serve as receptors to which neurotransmitters can bind. This binding initiates an impulse in the postsynaptic neuron. The activity of the neurotransmitter can be terminated in two ways: it can diffuse back into the synaptic knob, or it can be metabolized into inactive molecules by specific enzymes.

12. Define dementia.

A variety of degenerative diseases can result in destruction of neurons in the brain. This degeneration can progress to adversely affect memory, attention span, intellectual capacity, personality, and motor control. The general term for this syndrome is dementia.

31. How would you explain why a person is more likely to survive damage to the cerebrum than damage to the brainstem?

Damage to the brainstem could cause loss of sensory, motor, and/or integrative functions. Damage to the brainstem, however, is likely to cause damage to nuclei that include the cardiac, vasomotor, and respiratory centers. Damage to any of these centers would be life-threatening.

1.____ is the name of the nervous system division that includes the nerves that extend to the outlying parts of the body.

Peripheral nervous system

24. Microalgia

act as microbe-eating scavengers and insulate the axons

25. Oligodendrocyte

cells that make myelin for axons in the CNS

22. Schwann Cells

cells that make myelin for axons outside the CNS

37. Parkinson's disease

disease characterized by abnormally low level of dopamine

34 multiple sclerosis

disorder caused by loss of myelin

4. What occurs at the cellular level in multiple sclerosis? What effect does this have on the body?

Multiple sclerosis (MS) is characterized by myelin loss and destruction accompanied by varying degrees of oligodendrocyte injury and death. The result is demyelination of the white matter in the central nervous system. Hard, plaque like lesions replace the destroyed myelin and the affected areas are invaded by inflammatory cells. As the myelin around the axons is lost, nerve conduction is impaired and weakness, incoordination, visual impairment, and speech disturbances occur.

2. Define or explain the following terms: myelin, nodes of Ranvier, and neurolemma.

Myelin is a white, fatty substance formed by Schwann cells that wrap around some axons outside the central nervous system. The nodes of Ranvier are indentations between adjacent Schwann cells. The neurilemma is the outer cell membrane of a Schwann cell.

26. Define neuritis and neuralgia.

Neuritis is the inflammation of peripheral nerves and their branches. Neuralgia is nerve pain.

5. From what type of cells or tissues do neuromas usually develop?

Neuromas do not usually develop directly from neurons, but from glial cells, membrane tissues, and blood vessels in the nervous system.

15. ____ is the part of the autonomic nervous system that regulates effectors during nonstress conditions.

Parasympathetic nervous system

11. What is the cause of Parkinson disease? What are some treatment options?

Parkinson disease is a chronic nervous disorder resulting from a deficiency of the neurotransmitter dopamine in certain areas of the brain. The result is misinformation in areas of the brain that normally prevent the skeletal muscles from being overstimulated. Treatment options may include the use of the drug levodopa, or L-dopa, which can be given to increase the dopamine levels in the brain; surgical grafting of normal dopamine-secreting neurons into the brain; or possibly an artificial implant that gives electrical stimulation to the brain, causing it to produce more dopamine.

23. Name and explain the three layers of the meninges.

The dura mater is the tough outer layer that lines the interior of the skull and vertebral canal. The pia mater is the thin innermost membrane covering the brain and spinal cord. The arachnoid mater is the membrane between the dura mater and pia mater. It resembles a cobweb with fluid in its spaces.

6. Define or explain the following terms: epineurium, perineurium, and endoneurium.

The epineurium is a tough, fibrous sheath that covers the entire nerve. The perineurium is a thin, fibrous tissue that surrounds each fascicle in a nerve. The endoneurium is a thin wrapping of fibrous connective tissue that surrounds each axon in a nerve.

17. List and describe the functions of the thalamus.

The thalamus lies above the hypothalamus. It is a dumbbell-shaped section of gray matter. Each end of the dumbbell lies in a lateral wall of the third ventricle. The center section passes from left to right through the third ventricle. The thalamus is composed chiefly of dendrites and cell bodies of neurons that have axons extending up toward the sensory areas of the cerebrum. The thalamus helps produce sensation, its neurons relay impulses to the cerebral cortex from the sense organs of the body, it associates sensations with emotions, and it plays a part in the arousal or alerting mechanism of the brain.

19.dendrite

a highly branched part of the neuron that carries impulses toward the cell body

44. Neuroblastoma

a malignant tumor of the sympathetic nerouc division

20.axon

a single projection that carries nerve impulses away from the cell body

21. Myelin

a white fatty substance that surround and insulates the axon

18. The preganglionic axons of the sympathetic nervous system release the neurotransmitter ____. The preganglionic axons release ____.

acetylcholine; acetylcholine

17. The preganglionic axons of the parasympathetic nervous system release the neurotransmitters ____. The postganglionic release ____.

acetylcholine; norepinephrine

33. Spinal cord

carries messages to and from the brain and the rest of the body; also mediates reflexes

12. The two hemispheres of the brain are almost separate structures except for their lower mid portion, which are connected by a structure called the ____ ____.

corpus callosum

23. Astrocyte

glia cells the help form the blood-brain barrier

11. When too much CSF accumulates in the ventricles, it may lead to a condition called ____, or "water on the brain."

hydrocephalus

41. Meningitis

infection or inflammation of the meninges

36. Multiple neurofibromatosis

inheristed condition casuing multiple benign tumor

6. A ____ is a self-propagating wave of electrical disturbance that travels along the surface of a neuron's plasma membrane.

nerve impulse

9. Acetylcholine and dopamine are examples of what ____.

neurotransmitters

40. Epilepsy

recurring or chronic seizure disorder

29. Hypothalamus

regulates body temperature, water balance, sleep-wake cycle, and sexual arousal

31. Cerebellum

regulates muscle coordination, maintenant of equilibrium and posture

5. The knee jerk reflex is a type of neural pathway called ____.

reflex arc

32. Cerebrum

sensory perception, willed movement, consciousness, and memory are mediated here

30. Thalamus

sensory relay station from various body areas to the cerebral cortex, also involved with emotion and alerting to arousal mechanisms

32. There is a type of medication that inhibits the functioning of acetylcholinesterase (the enzyme that deactivates acetylcholine). Explain the effect this medication would have on the visceral effectors.

Acetylcholinesterase is an enzyme that deactivates acetylcholine. If a medication were given that inhibits the functioning of this enzyme, acetylcholine would remain in the postsynaptic neuron longer, and the stimulus would be prolonged. Because the parasympathetic nervous system uses acetylcholine as its postganglionic neuron neurotransmitter, such a medication would exaggerate the effect of the parasympathetic nervous system on the visceral effectors. See Table 10-3 on p. 270 of the text for an explanation of specific effects.

30. Can you elaborate on why police officers use sobriety tests such as walking along a straight line, touching the tip of the nose with one finger, or maintaining balance with the eyes closed?

Alcohol depresses the central nervous system, including the cerebellum. Functions of the cerebellum include coordinating muscle activity; helping to maintain balance; and helping to make smooth, efficient movement possible. Someone who is under the influence of alcohol has impaired function of the cerebellum (and other parts of the brain), and this condition can be detected by simple tests of motor coordination.

3. Name and give the function of the three types of glial cells.

Astrocytes, meaning star cells, have threadlike branches that attach to neurons and to small blood vessels, holding these structures close to each other. They also form a two-layer structure called the blood-brain barrier (BBB), which separates blood and nervous tissues, thereby protecting vital brain tissue from harmful chemicals that might be circulating in the blood. Microglia act as microbe-eating scavengers. They surround the microbes, draw them into their cytoplasm, and digest them. Oligodendrocytes hold nerve fibers together and also produce the fatty myelin sheath that envelops nerve fibers located in the brain and spinal cord.

2.____ is the name of the nervous system divisions that include the brain and spinal cord.

Central nervous system

24. What is the function of cerebrospinal fluid? Where and how is it produced?

Cerebrospinal fluid (CSF), along with the meninges, helps protect the cells of the central nervous system.It forms continually from fluid filtering out of the blood in a network of brain capillaries known as the choroid plexus and into the ventricles.

27. What is the cause of tic douloureux? What is the cause of Bell palsy?

Compression or degeneration of the fifth cranial nerve, the trigeminal nerve, may result in trigeminal neuralgia or tic douloureux. Compression, degeneration, or infection of the seventh cranial nerve, the facial nerve, may result in Bell palsy.

14. ____ are skin surface areas supplied by a single spinal nerve.

Dermatomes

10. ____, ____, and ____ are the three membranes that make up the meninges.

Dura mater, arachnoid layer, pia mater

7. What causes gray matter to be gray and white matter to be white?

Gray matter is tissue composed primarily of cell bodies and unmyelinated axons and dendrites and appears gray in color. White matter has nerve fibers usually covered by a myelin sheath; myelin is a white, fatty substance.

7. ____ conduction is the term that describes the impulses as it "jumps" around the myelin.

Saltatory

1. Name the three types of neurons classified according to the direction in which the impulse is being transmitted. Define or explain each of them.

Sensory neurons, also called afferent neurons, transmit impulses to the spinal cord and brain from all areas of the body. Motor neurons, also called efferent neurons, transmit impulses from the brain and spinal cord to muscle and glandular epithelial tissue. Interneurons, also called central or connecting neurons, conduct impulses from sensory neurons to motor neurons.

16. ____ is the part of the autonomic nervous system that regulates effectors during the "flight or fight" response.

Sympathetic nervous system

19. List and describe the functions of the cerebellum.

The cerebellum, containing both white and gray matter, is the second largest part of the brain. It lies under the occipital lobe of the cerebrum. The cerebellum helps produce smooth coordinated movements and maintain equilibrium and normal posture.

20. Give the general functions of the cerebrum. What are the specific functions of the occipital and temporal lobes?

The general functions of the cerebrum include maintaining consciousness, thinking, memory, sensation, emotions, willed movement, vision, hearing, and normal speech. The occipital lobe helps you identify and understand specific visual images. The temporal lobe interprets incoming nervous signals from the ear as specific sounds.

16. List and describe the functions of the hypothalamus.

The hypothalamus is located below the thalamus. The stalk attaching the pituitary gland, the posterior pituitary gland, and the side walls of the third ventricle are all extensions of the hypothalamus. Functions of the hypothalamus include the regulation of heartbeat; constriction and dilation of blood vessels; contractions of the stomach and intestines; production of some hormones released by the posterior pituitary gland; secretion of hormones that impact the function of the anterior pituitary gland; regulation of body temperature, water balance, sleep cycles, control of appetite, and control of many emotions involved with pleasure, fear, anger, sexual arousal, and pain.

8. Explain how a reflex arc functions. What are two types of reflex arc?

The impulse conduction in a reflex normally starts in a receptor. Receptors are the beginning of dendrites of a sensory neuron. The nerve impulse that is generated by stimulation of the receptor travels along the length of the sensory neuron's dendrite to its cell body located in the posterior root ganglion. The axon of the sensory neuron travels from the cell body and ends near the dendrites of another neuron in the spinal cord. The impulse moves across the synapse to the dendrites of a motor neuron. The impulse moves across the dendrite, cell body, and axon of the motor neuron until it reaches the structure called an effector, an organ that puts the nerve signals "into effect." Effectors are muscles or glands. Muscle contraction or gland secretions are the only two kinds of reflexes. There are two kinds of reflex arcs: a two-neuron reflex that uses a sensory neuron and motor neuron, and a three-neuron reflex that uses a sensory neuron, an interneuron, and a motor neuron.

15. List and describe the functions of the medulla oblongata.

The medulla oblongata is an enlarged, upward extension of the spinal cord. It lies just inside of the cranial cavity above the foramen magnum. It contains both white and gray matter. The cardiac, respiratory, and vasomotor centers are located in the medulla oblongata. Impulses from these centers control heartbeat, respiration, and blood vessel diameter, which is important in the regulation of blood pressure.

9. Explain what occurs during a nerve impulse. What is saltatory conduction?

The membrane of each resting neuron has a slight positive charge on the outside and a slight negative charge on the inside. This occurs because there is normally an excess of sodium ions on the outside of the membrane. When a section of the membrane is stimulated, its sodium channels open and sodium rushes inward. The inside of the membrane temporarily becomes positive, and the outside becomes negative. Although this section of the membrane immediately recovers, the electrical disturbance stimulates sodium channels in the next section of the membrane to open. A self-propagating wave of an electrical disturbance, called a nerve impulse, travels in one direction across the neuron's surface. If the traveling impulse encounters myelin, it simply "jumps" around the myelin. This "jumping" of the impulse down the axon is called saltatory conduction.

18. Describe the function of the pineal gland (body).

The pineal gland receives sensory information about the strength of light seen by the eyes and adjusts its output of the hormone melatonin.

22. List and describe the function of the spinal cord.

The spinal cord is about 17 to 18 inches long. It lies inside the spinal column and extends from the occipital bone down to the bottom of the first lumbar vertebra. The H-shaped core of the spinal cord consists of gray matter and is composed mainly of dendrites and cell bodies of neurons. Columns of white matter form the outer portion of the cord and bundles of myelinated nerve fibers, called spinal tracts, make up the white columns. The spinal cord functions as the primary reflex center of the body.

29. Explain the structure and function of the parasympathetic nervous system.

The structure of the parasympathetic nervous system begins with the parasympathetic preganglionic neurons. They have dendrites and cell bodies in the gray matter of the brain and the sacral section of the spinal cord. The preganglionic parasympathetic neurons extend some distance from the spinal cord before terminating in the parasympathetic ganglion located close to the visceral effectors they control. The dendrites and cell bodies of the parasympathetic postganglionic neurons lie in these outlying parasympathetic ganglia with their short axons extending into the effector organs. Both the pre- and postganglionic neurons use acetylcholine as their neurotransmitter. The function of the parasympathetic nervous system is to slow heartbeat, increase peristalsis of the digestive system, and increase the secretion of digestive juices.

28. Explain the structure and function of the sympathetic nervous system.

The structure of the sympathetic nervous system begins with the sympathetic preganglionic neurons. They have dendrites and cell bodies in the gray matter of the thoracic and upper lumber segments of the spinal cord. The axon leaves the spinal cord in the anterior root of a spinal nerve. It enters the spinal nerve but soon leaves it to extend to and through a sympathetic ganglion and terminate in a collateral ganglion. It synapses with several postganglionic neurons whose axons extend to terminate in the visceral effectors. The preganglionic neurons use acetylcholine as their neurotransmitter and the postganglionic neurons use epinephrine. The function of the sympathetic nervous system is to prepare the body for emergency situations, the "fight-or-flight" response. It causes the heart to beat faster and blood vessels to constrict, increases blood pressure, dilates blood vessels to skeletal muscles, and increases secretion of sweat glands and adrenal glands.

14. List two possible causes of Alzheimer disease.

There is some evidence that Alzheimer disease has a genetic basis. Other evidence indicates that environmental factors may play a role. The exact cause of Alzheimer disease is not known at this time.

25. How many nerve pairs are generated from the spinal cord? How many nerve pairs are generated from each section of the spinal cord? How are these nerves named? What is a plexus?

Thirty-one nerve pairs are generated from the spinal cord. Eight pairs are attached to the cervical section, twelve pairs are attached to the thoracic section, five pairs are attached to the lumbar section, five pairs are attached to the sacrospinal section, and one pair is attached to the coccygeal section. Spinal nerves have no special name, but rather a letter and number identify each; for example, C1 indicates the pair of nerves from the first segment of the cervical part of the cord. A plexus is a network of intersecting or braided branches from several spinal nerves.

38. CVA

cessation of blood flow to the brain; a stroke

42. Tic doulourex

compression or degeneration of the fifth cranial nerve

43. Bell palsy

compression or degenration of the seventh cranial nerve

28. Midbrain

part of the brainstem that contains tlays for visual and auditory impulses

27. Pons

part of the brainstem that is conduction pathway between the brain and the body; influences respiration

26. Medulla oblongata

part of the brainstem the brainstem that contains cardiac, respiratory, and vasomotor centers