Chapter 9 Nervous System

1. What makes up the nervous system?

-brain -spinal cord -nerves -ganglia -nerve, blood, connective tissue

8. What are the three basic parts of a neuron?

-cell body -one or more dendrites -a single axon

4. What are the two main subdivisions of the nervous system?

-central nervous system -peripheral nervous system

30. What are the four parts of the human brain?

-cerebrum -diencephalon -brain stem -cerebellum

26. What are some examples of reflexes that take place in the body?

-coughing -sneezing -reactions to painful stimuli

29. What three layers make up the meninges, starting with the outer layer?

-dura mater -arachnoid -pia mater

7. What are the two subdivisions of the autonomic nervous system?

-sympathetic -parasympathetic

44. How many pairs of spinal nerves are present in the human body?

31

42. How long is the spinal cord?

43-46cm(approximately 17-18 inches)

VI

Abducens eye movement

XI

Accessory contraction of trapezeous and sternocleidomastoid muscles

46. What is the difference between ascending tracts and descending tracts of the spinal cord?

Ascending-carry sensory impulses from the body part to the brain Descending-carry motor impulses from the brain to muscles and glands

37. List and explain the functions of the three control centers located in the medulla.

Cardiac center-adjusts the heart rate and contraction strength to meet body needs Vasomotor center-regulates blood pressure by effecting changes in blood vessel diameter Respiratory center-acts with the centers in the pons to regulate the rate, rhythm, and depth of breathing

45. What are the functions of the spinal cord?

Conduction pathway for impulses going to and from the brain and serves a reflex center

VII

Facial sf from taste receptors on anterior two thirds of tongue mf to muscles of facial espression,lacrimal glands, salivary glands

Control Center

Function

IX

Glossopharyngeal sf from taste receptors on posterior one tbird of tongue mf to muscles used in swallowing and to salivary glands

XII

Hypoglossal contraction of muscles of tongue

Cranial Nerve

Name Function

III

Oculomotor movement of of eyes and eyelids

I

Olfactory sense of smell

V

Opthalmic branch sf from cornea,skin of nose,forehead,scalp Maxillary branch sf from cheek,nose,upper lip,teeth Mandibular branch sf from skin mandible,lower,lip,teeth

II

Optic vision

IV

Trochlear movement of eyes

VIII

Vestibulocochlear hearing and equilibrium

21. What happens to sodium ions when a neuron receives a stimulus?

allows them to move inside the cell, then potassium ions move outside the cell

25. What is a reflex?

an automatic, involuntary response to some change, either inside or outside the body

10. somat/o

body

43. What surrounds the spinal cord?

bone, meninges, and CSF

c. Mixed nerves:

both type of fibers

27. What makes up the central nervous system?

brain and spinal cord

b. Parasympathetic:

brings bodys systems back to normal state after an emergency situation by slowing the heart&breathing rate, decreasing blood pressure&blood flow to skeletal muscled

10. What is the function of an axon?

carry impulses away from the cell body

a. Afferent (sensory) neurons:

carry impulses from peripheral sense receptors to the CNS

39. What are ventricles?

cavities in the brain

20. What is a resting membrane?

cell membrane of a nonconducting or resting neuron

3. cerebell/o

cerebellum

4. cerebr/o

cerebrum

a. Thalamus:

channels the impulses to the appropriate region of the cortex for discrimination, localization, and interpretation

40. What is the function of cerebrospinal fluid?

clear fluid that forms as a filtrate from the blood in specialized capillary networks, the choroid plexus within the ventricles of the brain

a. Sensory nerves:

contain only afferent fibers-long dendrites of sensory neurons

28. What bones surround and protect the brain?

cranium

b. Integrative functions:

decisions are made based on the sensory input

a. Sensory functions:

detect changes that occur in and outside of the body then converts stimuli as an impulse and transmitted into the brain

19. What is the function of neuroglia?

do not conduct nerve; instead they support, nourish, and protect the neurons

________ 1. An axon transmits impulses toward a neuron cell body.

false

________ 5. The CNS is made up of cranial nerves and spinal nerves.

false

________ 9. Sensory nerves contain only efferent fibers.

false

________ 7. The pons functions in body coordination, posture, and balance.

false cerebellum

________ 3. A myelin sheath is formed around axons within the CNS by Schwann cells.

false dendrites

________ 7. The spinal cord extends from the base of the skull to the fourth lumbar vertebra.

false first

________ 5. The central sulcus divides the cerebrum into two hemispheres.

false longitudinal fissure

________ 2. Gray matter is made up of myelinated fibers.

false white

41. What is the starting point and ending point of the spinal cord?

foramun magnum at the base of the skull to the level of the first lumbar vertebra

32. What five lobes make up the cerebral hemisphere?

frontal lobe, pariental lobe, occipital lobe, temperal lobe, insula or island of Reil

7. gli/a

glue

5 cephal/o

head

52. What are some examples of body functions controlled by the autonomic nervous system?

heart rate, breathing rate, blood pressure, body temperature, and other visceral activities that work together to maintain homeostasis

12. What makes up the white matter in the central nervous system?

is made of axons connecting different parts of grey matter to each other.

2. gangli-

knot

15. What is the neurilemma, and what is its function?

layer of cells that surrounds a nerve fiber in the peripheral nervous system and in some cases produces myelin

b. Hypothalamus:

maintaining homeostasis because it regulates many visceral activities, serves as a link between the nervous and endocrine systems bc it regulates secretion of hormones from the pituitary gland

34. What functions are controlled by the cerebral cortex?

memory, language, reasoning, intellingence, personality, and all the other factors that we associate with human life.

36. What structures make up the brain stem?

midbrain, pons, medulla oblongata

1. act-

motion

38. What is the function of the cerebellum?

motor area of the brain that mediates subconscious contractions of skeletal muscles

3. What is an effector? What are two types of effectors?

muscles and glands, they can cause an effect in response to directions from the nervous system

6. neur/o

nerve

47. What makes up the peripheral nervous system?

nerves that branch out from the brain and spinal cord

49. What is the makeup and function of the autonomic nervous system?

nerves that connect the CNS to the visceral organs such as the heart, stomach, and intestines. Mediates conscious activities

48. What is the makeup and function of the somatic nervous system?

nerves that go to the skin and muscles and is involved in concious activities

b. Motor nerves:

only have efferent fibers-long axons of motor neurons

a. Sympathetic:

preparing the body for stressful or emergency situations

9. -tion

process of

16. What is the function of oligodendrocytes?

produce myelin

31. What is the function of the corpus callosum?

provides the communication pathway between the two halves

9. What is the function of a dendrite?

receive impulses from other neurons and transmit impulses to the neuron cell body

23. What is a synapse?

region of communication between two neurons

c. Motor functions:

sends signal to muscles causing them to react

8. -lemma

sheath, covering

14. Describe the appearance of a node of Ranvier.

short spaces between segments of myelin in a myelinated nerve fiber

54. How is memory affected as the nervous system ages?

short term memory seems to be affected more than long term memory

b. Autonomic nervous system:

supplies motor impulses to cardiac muscle, smooth muscle, and glandular epithelium

a. Somatic nervous system:

supplies motor impulses to the skeletal muscles

33. Where is the cerebral cortex located? What makes up the cerebral cortex?

the outermost portion of the cerebrum, neruon cell bodies and unmyelinated fibers

17. Why can't nerve fibers in the central nervous system regenerate?

there is no neurilemma

c. Interneurons:

they form the connecting link between the afferent and efferent neurons

22. Describe how a nerve impulse is propagated along the length of a neuron through an action potential.

threshold stimulus causes a localized action potential on the membrane. The rest of the membrane is in the resting condition. The action potential stimulates the next point. This continues point by point in a domino fashion

24. How is a nerve impulse transmitted across a synapse?

through the presynaptic neuron, postsynaptic nerve, synaptic vesicles inside the synaptic knob

8. syn-

together, with

b. Efferent (motor) neurons:

transmit impulses from the CNS to effector organs such as muscles and glands

a. Afferent (sensory) division:

transmits impulses from peripheral organs to the CNS

b. Efferent (motor) division:

transmits impulses from the CNS out to the peripheral organs to cause an effect or action

_______ 10. The body has 12 pairs of cranial nerves.

true

_______ 10. The sympathetic division of the autonomic nervous system prepares the body for fight or flight.

true

________ 1. The function of a neuron is to transmit nerve impulses.

true

________ 2. Neuroglia support and protect neurons.

true

________ 3. Myelin is a white fatty substance that surrounds nerve fibers.

true

________ 4. Sneezing is an example of a reflex.

true

________ 4. Synapse is the name of the region of communication between two neurons.

true

________ 6. The cerebral cortex consists of gray matter.

true

________ 6. The hypothalamus functions in the regulation of body temperature.

true

________ 8. The autonomic nervous system supplies motor impulses to visceral organs.

true

________ 8. The peripheral nervous system provides a communication network between the central nervous system (CNS) and the body.

true

________ 9. Nerves that carry both sensory and motor fibers are known as mixed nerves.

true

X

vagus sf from pharynx, larynx, esophagus,and visceral sm fibers to muscles of pharynx and larynx am fibers to heart, smooth muscles, and glands to alter gastric motility, heart rate, respiration, and blood pressure

13. What makes up the gray matter in the central nervous system?

which has a pinkish-grey color in the living brain, contains the cell bodies, dendrites and axon terminals of neurons, so it is where all synapses are

11. What is a myelin sheath?

white, fatty substance that surrounds many nerve fibers