Ch. 24 Perceptions and Relays in the Medulla Flashcards Preview

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Flashcards in Ch. 24 Perceptions and Relays in the Medulla Deck (66)
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1
Q

The obex is the part of the fourth ventricle that narrows down to become the ____________ ________.

A

central canal

2
Q

Neurons on the surface of the obex are exposed to the cerebrospinal fluid in the _____ ____________.

A

4th ventricle

3
Q

Neurons on the surface of the obex respond to toxins in the _________________ _________ in the 4th ventricle.

A

cerebrospinal fluid

4
Q

The group of neurons on the ___________ of the ________ that responds to toxins in the cerebrospinal fluid is called the area postrema

A

walls

obex

5
Q

Neurons in the ________ _____________ detect toxins in the cerebrospinal fluid.

A

area postrema

6
Q

Neurons in the area postrema project to the preganglionic parasympathetic neurons in the _________ _________ __________ of the ________ __________ that control the muscles of the stomach

A

dorsal motor nucleus

vagus nerve

7
Q

When they detect toxins in the cerebrospinal fluid neurons in the area postrema initiate vomiting through their projections to the _________ _________ ___________ of the ________ __________.

A

dorsal motor nucleus

vagus nerve

8
Q

The area _____________ is sometimes called the vomiting center.

A

postrema

9
Q

The lateral and anterior spinothalamic tracts carry ________________ sensations through the lateral region of the medulla without synapsing.

A

protopathic

10
Q

Axons in the spinothalamic tracts synapse only in the _____________.

A

thalamus

11
Q

The axons in the fasciculus gracilis and fasciculus cuneatus synapse on ____ in the nucleus gracilis and nucleus cuneatus in the lower medulla

A

second order neurons

12
Q

Just as the fasciculus cuneatus is __________ to the fasciculus gracilis, the nucleus cuneatus is ___________ to the nucleus gracilis.

A

lateral

lateral

13
Q

The axons of the __________ _________ neurons in the nucleus gracilis run ventrad in wide arcs as internal arcuate fibers.

A

secondary sensory

14
Q

Internal arcuate fibers from each __________ ____________ cross in the midline just dorsal to the pyramids and turn rostrad to form the ventral half of the contralateral medial lemniscus.

A

nucleus gracilis

15
Q

The axons of the neurons in the left nucleus gracilis form the ventral half of the ________ _________ _______________ after they cross the midline.

A

right medial lemniscus

16
Q

The axons of the neurons in the nucleus gracilis are _____________ __________ __________ until they cross the midline.

A

internal arcuate fibers

17
Q

Internal arcuate fibers make a right angle turn rostrad toward the thalamus when they enter the _________ ______________.

A

medial lemniscus

18
Q

The ventral half of the left medial lemniscus carries _____________ information from the _________ _________ extremity to the thalamus.

A

epicritic

right lower

19
Q

Axons of __________ _________neurons in the nucleus cuneatus run ventrad in wide arcs, cross the midline, and turn rostrad to form the dorsal half of the medial lemniscus.

A

secondary sensory

20
Q

Axons in the ventral half of the medial lemniscus come from neurons in the _________ __________ and carry epicritic information from the contralateral _________ ____________.

A

nucleus gracilis

lower extremity

21
Q

Axons in the dorsal half of the medial lemniscus come from neurons in the _________ __________ and carry epicritic information from the contralateral _________ ____________.

A

nucleus cuneatus

upper extremity

22
Q

When axons from the nucleus cuneatus cross the midline they are __________ to axons from the nucleus gracilis.

A

dorsal

23
Q

Internal arcuate fibers from the nucleus cuneatus must _________ internal arcuate fibers from the nucleus gracilis before crossing the ____________.

A

cross

midline

24
Q

In the medulla each medial lemniscus is a vertical ribbon of white matter on the __________ side of a pyramid.

A

dorsal

25
Q

Tracts are _________ matter; nuclei are _________ matter; but myelinated tracts usually stain black with silver, iron, or osmium, and nuclei usually do not take these metallic stains.

A

tracts: white
nuclei: gray

26
Q

A decussation is a crossing of right and left tracts en route from one level to another. Thus, the crossing of internal arcuate fibers to form the medial lemniscus is the _______________ of the medial lemniscus.

A

decussation

27
Q

Fibers crossing from one side of the CNS to the other at the same level form a commissure; fibers crossing from one side to the other en route to a different level form a ______________.

A

decussation

28
Q

The nucleus gracilis and nucleus cuneatus continue to contribute to the medial lemniscus up to the level of the __, but the fasciculus ___ disappears by that level.

A

middle medulla

gracilis

29
Q

The nucleus gracilis is on the dorsal surface of the ___________ at the mid-medulla level

A

medulla

30
Q

The nucleus cuneatus is still deep to the _____________ ___________ lateral to the nucleus gracilis at the mid-medulla level.

A

fasciculus cuneatus

31
Q

The medial lemniscus contacts the posterior surface of the _____________ throughout the medulla

A

pyramid

32
Q

The posterior spinocerebellar tract drifts from its position on the _________ side of the lower medulla to a dorsolateral position at the mid-medulla level.

A

lateral

33
Q

The lateral cuneate nucleus becomes prominent dorsolateral to the nucleus __________ and deep to the posterior spinocerebellar tract at the mid-medulla level

A

cuneatus

34
Q

The cuneocerebellar tract merges with the ____________ _________________ tract to form the restiform body at the mid-medulla level.

A

posterior spinocerebellar

35
Q

The bulge on the lateral side of the middle and upper medulla is called the __________.

A

olive

36
Q

The inferior olivary nucleus is wavy ribbon of _________ matter inside the olive

A

gray

37
Q

The inferior olivary nucleus receives tendon stretch information from the contralateral side of the body through the _________-___________ _________ and messages from the ipsilateral red nucleus of the midbrain through the central tegmental tract.

A

spino-olivary tract

38
Q

The central tegmental tract carries messages from the _______ ___________ of the ____________ to the ipsilateral ____________ __________ __________ of the ___________.

A

red nucleus
midbrain
inferior olivary nucleus
medulla.

39
Q

It is a bit unfortunate that the tract that should have been called the rubro-olivary tract is called the __________ _______________ ________.

A

central tegmental tract

40
Q

The central tegmental tract enters the _____________ __________ ___________ on its dorsal (or posterior surface.

A

inferior olivary nucleus

41
Q

The spino-olivary tract enters the inferior olivary nucleus on its ____ side

A

convex lateral

42
Q

The spino-olivary tract tells the ____________ __________ __________ how an action was carried out.

A

inferior olivary nucleus

43
Q

The central tegmental tract tells the _____________ _________ __________ what the action was intended to be .

A

inferior olivary nucleus

44
Q

The ___________ _________ __________ compares intention and action and communicates that comparison to the contralateral cerebellum.

A

inferior olivary nucleus

45
Q

Information from the inferior olivary nucleus allows the contralateral _____________ to better assist the ipsilateral cerebral cortex the next time the action is performed.

A

cerebellum

46
Q

The contralateral cerebellum will inform the ipsilateral red nucleus of its intentions and the red nucleus will inform the ipsilateral inferior olivary nucleus of those intentions through the ___________ ______________ _________.

A

central tegmental tract

47
Q

The cerebellum to ______ __________ to _____________ ________ _________ to cerebellum circuit is responsible for the simpler aspects of motor learning

A

red nucleus

inferior olivary nucleus

48
Q

The right side of the cerebellum projects to the ________ red nucleus which projects to the _______ inferior olivary nucleus which projects to the ________ side of the cerebellum

A

left
left
right.

49
Q

The body part whose performance is subject to the cerebellar learning circuit is ipsilateral to the participating side of the cerebellum but contralateral the participating _____ ________ and ____________ __________ __________.

A

red nucleus

inferior olivary nucleus

50
Q

The inferior olivary nucleus projects to the contralateral side of the ____________ through the restiform body.

A

cerebellum

51
Q

The olivocerebellar tract leaves the medial side of the inferior olivary nucleus and joins the contralateral ____________ _______.

A

restiform body

52
Q

The restiform body is formed by the union of the ________________ ________, the posterior spinocerebellar tract, and the cuneocerebellar tract.

A

olivocerebellar tract

53
Q

The olivocerebellar tract curves dorsad to join the _____________ ____________________ _______ and cuneocelebellar tract to form the restiform body.

A

posterior spinocerebellar tract

54
Q

The region ventral to the hypoglossal nucleus, dorsal motor nucleus of the vagus, and solitary nucleus and dorsal to the ____________ ________ nucleus and ___________ ____________ ________ is the reticular formation of the medulla.

A

inferior olivary

central tegmental tract

55
Q

The medullary reticular formation contains neurons whose axons form the __________ _____________________ _________.

A

lateral reticulospinal tract

56
Q

The most easily assigned function of the medullary reticular formation is the stimulation of the lower motor neurons for the ___________ of the _________ ____________ during absent-minded walking.

A

flexion

lower extremity

57
Q

Most of the other ___________ in the medullary reticular formation have short axons that create a neural network.

A

neurons

58
Q

The neural network of the _____________ formation gets its name from the Latin word for net: reticulum.

A

reticular

59
Q

The neural network of the _____________ formation gets its name from the Latin word for net: reticulum.

A

reticular

60
Q

The nucleus ambiguus is embedded in the ________________ ________________ ventromedial to the ___________ ___________________ nucleus.

A

reticular formation

spinal trigeminal

61
Q

The inferior olivary nucleus is _______________ to the reticular formation

A

ventral (or anterior)

62
Q

The inferior olivary nucleus projects to the ________________ side of the cerebellum via the ________________ _________.

A

contralateral

restiform body

63
Q

The inferior olivary nucleus receives information from the _______ ____________ of the midbrain via the _____________ __________________ ____________.

A

red nucleus

central tegmental tract

64
Q

The red nucleus receives information from the __________________ side of the cerebellum via the _____________ ______________ ______________.

A

contralateral

superior cerebellar peduncle

65
Q

The medial lemniscus is ____________ to the inferior olivary nucleus

A

medial

66
Q

Each medial lemniscus carries _____________ information from the ___________________ side of the body to the ______________.

A

epicritic
contralateral
thalamus