Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

704 > Reticular Formation and Control of Muscle Activity > Flashcards

Reticular Formation and Control of Muscle Activity Flashcards

1
Q

The RETICULAR FORMATION (RF) is a:

A

network or reticulum of many neurons that comprises the core of the neuroaxis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

It is an __________________ old (early to develop) system that originally was thought to be diffusely organized.

A

ontegenetically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Anatomical studies have shown that instead, the RF is composed of many well defined groups of neurons that receive _____________ from all ascending and descending systems and distribute their axons widely in ______________________ directions.

A

collaterals

caudal and rostral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Consequently, all levels of the CNS are _____________________ either directly or indirectly by way of the reticular formation.

A

interconnected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Nuclei in the reticular formation have a role in: regulating muscle tone for ____________________ during voluntary and reflexive movement; modulating the sense of __________, regulating ___________________________; and coordinating autonomic _________________ and _________________ function.

A

postural control

pain

arousal, sleep, and attention

respiratory

cardiac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

General organization: There are dozens of _____________ and _____________ of the RF. We will only deal with the general organization and a few specific nuclei.

A

nuclei and subdivisions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
  1. ________________________ – largest division
  2. _____________________– thin column of neurons along the midline of the brainstem
  3. Miscellaneous nuclei – _____________________________________________
A
  1. Central Division (Lateral and Medial Zone) – largest division
  2. Raphe Nuclei (Midline Zone) – thin column of neurons along the midline of the brainstem
  3. Miscellaneous nuclei – paramedian pontine RF (PPRF), pedunculopontine nucleus, locus ceruleus, ventral tegmental area.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Central Division –

A

a continuous but diffuse column of neurons, begins as a continuation of the central gray interneuron network of the spinal cord (Lamina X) and ends in the midbrain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Central Division, consists of a __________ medial zone (____________) and a ________________ lateral zone (__________).

A

large (efferent)

smaller (afferent)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Lateral zone – consists of neurons with _____________ dendrites that receive collateral input from _______ sensory and motor information carried by cranial nerves, spinal sensory pathways, and corticospinal, corticobulbar and corticopontine pathways.

A

large

ALL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sensory and ______________ inputs are integrated in the lateral zone. The lateral zone relays this integrated information to the _______________ zone. It also projects to the _____________________, _____________________, _____________________, and _____________________.

A

cortical

medial

cerebrum, cerebellum, thalamus (central median nucleus) and spinal cord.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Medial zone –

A

gives rise to the major efferent pathways from the reticular formation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vital function regulation – nuclei of the medial zone receive input from:

A

1) lateral zone
2) a variety of peripheral receptors, including the carotid body relayed through the solitary nucleus
3) hypothalamus, and
4) prefrontal cortex.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Their (nuclei of the medial zone) role is to regulate vital cardiac and respiratory function through output to ___________________ sympathetic neurons in the ________________ horn of the _____________ spinal cord and preganglionic parasympathetic neurons associated with the _____________________ (cardiac), and to the spinal cord for ______________ control of motor neurons in the spinal cord that regulate _____________________.

A

preganglionic

lateral

thoracic

vagus nerve

somatic

inhalation and expiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Some patients with lesions to the brainstem that involve these regulatory centers have abnormal ________________________ or difficulty ________________________ with hypertension.

A

respiratory patterns

regulating blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Additional reticular nuclei (of medial zone) regulate _______________ and _______________.

A

swallowing

vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Somatic motor activity regulation (of medial zone nuclei) – nuclei in the pons and medulla receive input from the cortex (corticoreticular pathway), cerebellum, vestibular nuclei, and somatosensory areas, via the ___________ zone.

A

lateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Their (nuclei of medial role_somatic motor activity regulation) role is to influence _________ motor neurons for the purpose of regulating __________________________________.

A

lower

postural, reflexive, and voluntary muscle control.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Fibers (of medial zone nuclei in somatic motor regulation) descend in two separate pathways. Both pathways descend ___________________, but then can synapse on interneurons _____________________________. Thus, this influence can be seen ______________.

A

ipsilaterally

both ipsilaterally and contralaterally

bilaterally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Medial (pontine) reticulospinal tract – part of the __________________ system, cell bodies originate in the ____________ RF, descend in ____________ funiculus as part of the MLF to end in the medial parts of the __________________, primarily at a cervical level.

A

medial activation

pontine

ventral funiculus

ventral horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the function of the medial (pontine) reticulospinal tract?

A

Function is to facilitate tonic facilitation of axial or postural flexors along with proximal joint muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Lateral (medulla) reticulospinal tract – part of the lateral activation system, cell bodies originate in the _______________________, descend in the ______________ funiculus to the lateral side of the ventral horn at all levels.

A

pontine (i think it is medulla..??) reticular formation

lateral funiculus

lateral side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the function of the lateral (medulla) reticulospinal tract?

A

Function is to assist the lateral vestibulospinal pathway in tonically facilitating lower motor neurons of the extensors and inhibiting flexors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

This tonic (of lateral RS tract) activity also influences the (y) motor neuron system to assist in the _____________________________.

A

sensitivity of stretch reflex activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Raphe Nuclei (Midline Zone) – located in _______________ along the ___________ just anterior to the periaqueductal gray (central gray), many of the neurons use __________________ as their neurotransmitter.

A

brainstem

midline

serotonin (5-HT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

The raphe nuclei receive input from a wide variety of ______________________________________areas. Output consists of ascending and descending pathways.

A

brainstem, cortical, cerebellar and spinal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Ascending pathways (of raphe nuclei) – ___________________ neurons of the raphe play a major role in the reticular activating system that regulates ____________________________. Projection of the neuron pathways is throughout the _____________________________.

A

Serotonergic

arousal, sleep, and mood

cerebrum and brainstem

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Descending pathways (of raphe nuclei) – ________________ neurons modulate __________ input at the level of the “gate” in _________________ of the spinal gray.

A

Serotonergic

pain

dorsal horn

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Modulation of _______________________________ also occurs at the solitary nucleus and spinal trigeminal nucleus.

A

visceral (CN X) and facial (CN V) pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Input from the periaqueductal gray area that are receiving input from ___________________ pathways (part of the anterolateral system) are important in activating this system (descending pathway / pain)

A

spinoreticular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

The raphespinal pathway is a _____________________ tract that provides diffuse activation of ____________ neurons in the ____________ horn and may be involved in influencing motor output during levels of high ______________________.

A

nonspecific

motor

anterior

motivation or arousal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Raphespinal neurons in the ____________ horn influence the __________________ system.

A

lateral

cardiovascular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Paramedian pontine RF –

A

associated with cranial nerves of the extraocular eye muscles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The paramedian pontine RF is located at the level of the facial _____________, surrounding ______________. This was discussed in depth with cranial nerves III, IV, and VI.

A

facial colliculus

surround abducens nucleus

35
Q

pedunculopontine nucleus –

A

an Acetylcholine (Ach) nucleus that is located in the caudal midbrain and projects to parts of the basal ganglia, vestibular nuclei and reticular spinal nuclei.

36
Q

The pedunculopontine nucleus is thought to have a role as a brainstem central pattern generator to induce __________ without __________control. It sends rhythmic impulses to ______________ and ______________ of the basal ganglia.

A

walking

cerebral

caudate and putamen

37
Q

Locus Ceruleus –

A

a major norepinephrine (NE) system that is located in the rostral pontine central gray region.

38
Q

Although the locus ceruleus receives only ____________ input from ________ brainstem nuclei, it sends ______________ ascending and descending connections.

A

restricted

two

widespread

39
Q

In regards to the locus ceruleus, ascending pathways to the thalamus, hypothalamus, basal forebrain and neocortex are involved in the ability to maintain and direct _____________.

A

attention.

40
Q

In regards to the locus ceruleus, the descending ______________ tract provides nonspecific activation of the ___________ neuron pool in the ________ horn, and modulation of _______ information in the _________ horn.

A

cerulospinal

motor

anterior horn

pain

dorsal

41
Q

Ventral Tegmental Area –

A

one of two dopamine (DA) projecting systems in the brainstem (the other is from substantia nigra).

42
Q

Fibers project from the VTA to ___________ and _____________ cortical areas and are believed to play a role in ___________ (decision making) and ______________.

A

limbic AND frontal

cognition AND motivation

43
Q

The projections to the frontal lobe (from the VTA), are balanced with the ________________ pathways. Disturbances in these systems play a role in ____________ and other disorders of cognition and affect.

A

serotonergic

depression

44
Q

The control of __________ activity, whether it is reflex activity, postural shifts, or voluntary movement activity, or some combination of all three, are based on the __________________________________________________.

A

muscle

integrity of both the upper and lower motor neuron components

45
Q

Additionally, systems that modulate the activity of the upper motor neurons, such as _________________________ must be intact (for muscular/ reflex activity to occur)

A

cerebellum and basal ganglia

46
Q

Where are the cell bodies of the lateral corticospinal pathway located?

A

areas 8,6,4,3,1,2,5

47
Q

Where does the lateral cotricospinal pathway terminate?

A

lateral part of contralateral ventral horn; dorsal horn (from 3,1,2,5)

48
Q

The voluntary motor activity is of:

A

of proximal and distal limb musculature, fractionated (fine) motor activityW

49
Q

The fibers (of lateral corticospinal pathway) ending in the ____________ horn are involved in ______________ and _______________ of incoming sensory signals specific to ongoing motor activity.

A

dorsal horn

feedback and modulation

50
Q

Where are the cell bodies of the Anterior (medial) corticospinal pathway located?

A

cell bodies in areas 4,6

51
Q

Where does the Anterior (medial) corticospinal pathway terminate?

A

in medial part of ipsilateral (but notes-contralateral??) ventral horn

52
Q

The voluntary activity of the anterior (medial) corticospinal pathway terminate is of:

A

of axial musculature

53
Q

Where are the cell bodies of the rubrospinal pathway located?

A

cell bodies in the Red Nucleus

54
Q

Where does the rubrospinal pathway terminate?

A

in lateral part of contralateral ventral horn, cervical region primarily

55
Q

The voluntary activity of the Rubrospinal pathway is:

A

voluntary (fractionated) activity of distal UE musculature, primarily flexors of the digits

56
Q

Where are the cell bodies of the Tectospinal pathway located?

A

cell bodies in superior colliculus

57
Q

Where does the tectospinal pathway terminate?

A

in the medial part of contralateral ventral horn, cervical region primarily

58
Q

The tectospinal pathway controls coordination of the:

A

neck movements with eye movements, reflexive turning toward stimulus

59
Q

Where are the cell bodies of the Lateral Vestibulospinal pathway located?

A

cell bodies primarily in Lateral Vestibular nucleus

60
Q

Where does the Lateral Vestibulospinal pathway terminate?

A

in ipsilateral ventral horns of all levels, but heavier in lower thoracic through sacral levels

61
Q

The lateral Vestibulospinal pathway is facilitory to:

A

extensor lower motor neurons as response to head movement

62
Q

Where are the cell bodies of the Medial Vestibulospinal pathway located?

A

cell bodies in Medial and Inferior vestibular nuclei

63
Q

Where does the Medial Vestibulospinal pathway terminate?

A

bilaterally in ventral horn of cervical and upper thoracic cord

64
Q

The Medial Vestibulospinal pathway is facilitory to:

A

to ipsilateral lower motor neurons of neck, inhibitory to contralateral lower motor neurons of neck, facilitory to extensors of upper extremities

65
Q

Where are the cell bodies of the Lateral (medullary) reticulospinal pathway located?

A

cell bodies in medullary reticular formation

66
Q

Where does the Lateral (medullary) reticulospinal pathway terminate?

A

in lateral part of ventral horn on interneurons effecting bilateral segmental LMNs

67
Q

The Lateral (medullary) reticulospinal pathway functions primarily to facilitate:

A

functions primarily to facilitate flexor LMNS and thus decrease the activity of extensor LMNs

68
Q

Where are the cell bodies of the Medial (pontine) reticulospinal pathway located?

A

cell bodies in pontine reticular formation

69
Q

Where does the Medial (pontine) reticulospinal pathway terminate?

A

terminate in medial part of ventral horn on interneurons effecting bilateral segmental LMNs, primarily in the cervical region

70
Q

The Medial (pontine) reticulospinal pathway functions to facilitate:

A

functions to facilitate extensors of the UE bilaterally

71
Q

The brainstem pathways function to help in maintaining static and reactive ___________ through ___________ input, through ascending sensory information that is entering the _________________, or through cerebellar influences via the red nucleus, vestibular nuclei, and reticular formation.

A

posture

vestibular

reticular formation

72
Q

This influence is mediated by activity on both the _______ motor neuron and ______ motor neurons, mostly through _______________ connections

A

α

γ

interneuronal

73
Q

Voluntary motor activity is dependent on the _________.

A

cortex

74
Q

The main pathway for necessary to generate volitional movement is via the ________________________ tract, which is receiving information from _______________________________________ and _______________________________________under the modulatory influence of cerebellum and basal ganglia.

A

lateral corticospina

area 6 (premotor and supplementary motor cortical regions) AND area 4 (primary motor cortex)

75
Q

Running parallel to this pathway is the __________________________ pathway (area 6 to pontine and medullary reticular nuclei).

A

corticoreticulospinal

76
Q

Thus, area 6 is serving three functions:

A
  1. direct corticospinal fibers, 2. direct input to are 4, and
  2. indirect corticoreticulospinal fibers.
77
Q

Anticipatory postural responses (preparatory postural responses prior to voluntary limb movements) are prepared through the __________________ projections from the __________________ motor cortex. Influence from these cortical regions onto the _________________ pathways is important for regulating the __________________ of these pathways.

A

corticospinal

supplementary

reticulospinal

excitability

78
Q

______________ and ______________ Posture as an example of changes in descending control over motor activity

A

Decerebrate

Decorticate

79
Q

Decerebrate posture –

A

when brainstem pathways are disconnected from the cortex by a midbrain lesion caudal to the red nucleus.

80
Q

In decerebrate posture, lateral vestibulospinal tract maintains tonic activity over _____________ of the __________________ extremities.

A

extensors

upper and lower

81
Q

In decerebrate posture, reticulospinal tracts are ____________ of influence from cortex due to lesion. This lets the vestibulospinal pathways maintain their activity without ________________ activity of the reticulospinal paths. ___________ influence from rubrospinal tract is also lost. The resultant posture is ____________________________________.

A

devoid

antagonistic

Flexor

extension of both the upper and lower extremities.

82
Q

Decorticate posture –

A

when lesion is above the level of the red nucleus, rubrospinal influence on UE flexors causes flexor posture in UE, while extensor tone is still dominant in LE.

83
Q

The resultant of decorticate posture is:

A

flexion at the elbow in UE with extension of the LE.

704 (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions