Brainscape's Knowledge GenomeTM

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


See full index

Neurology > Overview Of The Brainstem > Flashcards

Overview Of The Brainstem Flashcards

1
Q

Midbrain (mesencephalon) overview

A

Links the brainstem and forebrain together

Contains cranial nerve nuclei for the following

  • 3
  • 4
  • some of 5

Contains visual and auditory reflex centers, motor function centers, pain transmission centers and visceral functions

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

Pons overview

A

Contains the following cranial nerve nuclei

  • 6
  • 7
  • parts of 5 and 8

Pontine nuclei form a relay station between cerebral cortex, cerebellum and descending motor fibers that travel to all spinal levels

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

Medulla oblongata overview

A

Contains the following cranial nerve nuclei:

  • 9
  • 10
  • 12
  • parts of 5 and 8

Contains ascending and descending tracts that move to and from the spinal cord

Possess essential nuclei for respiratory and HR regulation as well as visceral functions

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

Tegmentum (medial portion) contains

A

Section of the brain stem that is medial to the rectum and base
- is found in all 3 components of the brainstem

Contains all cranial nerve nuclei and reticular formations

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

Base (ventral portion) contains

A

Contains the long pathways or tracts that connect the spinal cord to the cerebrum

Is found in all 3 sections of the brainsteam

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

Tectum (dorsal portion) contains

A

Only found in the midbrain of the brain stem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where is the inferior olivary nucleus located?

A

ONLY in the medulla oblongata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the reticular formation

A

Cell groups found within the tegmentum
- are poorly defined ANS diffuse throughout the tegmentum

Has a rostral and caudal components

1) rostral
- continuous with certain diencephalon nuclei
- function to maintain an alert conscious state in the forebrain
- contains the pontomesencephalic reticular formation

2) caudal
- continuous with intermediate zone fo the spinal cord
- functions to carry out motor/reflex/autonomic functions with cranial nerve nuclei

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

Lateral third of the reticular formation

A

Called the “parvocellular region”
- contains small called nuclei that are responsible for receiving afferent fibers

Found in the pons and medulla

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

Medial third of the reticular formation

A

Called the “magnocellular region”
- functions to give rise to effector fibers

Found in the pons and medulla

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

Midline third of the reticular formation

A

Called the “raphe nuclei”
- they function to secrete serotonin that is wildly distributed throughout the brain and spinal cord

Found in all 3 areas of the brainstem

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

What is locus ceruleus?

A

A group of reticular nuceli that found in the pons and midbrain
- functions to give rise to noradrenergic projections

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

Peduncilopontine nuclei

A

A group of reticular nuclei that is found in the midbrain and pons areas
- functions to project cholinergic neurons to the forebrain

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

Pontomesencephalic reticular formation

A

Pathway which allows for alertness and consciousness of the brain
- found in rostral reticular formation

Projects to the following

  • thalamus (intra laminar nuclei)
  • hypothalamus
  • basal forebrain

damage to the reticular formation, bilateral cerebral cortex or bilateral thalamus can cause coma since it disrupts this pathway

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

Nucleus of the solitary tract (NTS)

A

Is the site in the brainstem where the baroreceptors/chemoreceptors and cardiopulmonary sensory neurons make their 1st synapse

Located in the causal portion of the medulla

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

Central ventrolateral medullary depressor area (CVLM)

A

Relay nucleus for mediating baroreflex and cardiopulmonary reflex

Contains GABAergic neurons that project to RVLM causing a decrease in blood pressure and heart rate

Found in the caudal portion of the medulla

17
Q

Rostral ventrolateral medullary presser area (RVLM)

A

Involved in maintenance of sympathetic tone and communicates with the intermediolateral cell column (IML) via direct monosynaptic projections

Found in the rostral portion of the medulla

18
Q

Intermediolateral cell column (IML)

A

Location of sympathetic preganglionic neurons in the thoracolumbar spinal cord (T1-L2)

Found in spinal column only

19
Q

Nucleus ambiguous (nAmb)

A

Receives direct or indirect projections from the nucleus of solitary tract.

Sends information directly to the heart and controls rythum

Found in the caudal medulla

20
Q

What’s are the 2 main aggregates of respiratory-related neurons

A

Dorsal respiratory group (DRG)

  • receives input from pulmonary stretch receptors
  • Found in the rostral medulla

Ventral respiratory group (VRG)

  • cVRG subsection contains Expiratory neurons
  • rVRG subsection contains inspiratory neurons
  • botzinger complex contains Expiratory neurons
  • pre-botzinger complex contains pacemaker for respiration
  • all VRG is found in the rostral medulla except the cVRG, this is in the caudal medulla*
21
Q

Descending tracts

A

Long projections that originate from the cerebral cortex and various other centers of the brainstem

Represent motor pathways to the periphery and sensory/motor regulatory pathways for the spinal cord

The following are descending tracts:

  • lateral corticospinal
  • anterior corticospinal tract
  • reticulospinal
  • vestibulospinal
  • tectospinal
  • rubrospinal
22
Q

Reticulospinal tracts specifics

A

Arise from the reticular formation

Contains 3 functionally different fiber systems
- 1st fiber system = mediates motor functions
(Includes lateral reticulospinal and medial reticulospinal tracts)

  • 2nd fiber system = mediates autonomic functions by taking fibers from the ventrolateral medulla and projects to the IML.
  • 3rd fiber system = mediates pain impulses that ascend the spinothalmic tract via two limbs
23
Q

Lateral reticulospinal tract

A

One of the two tracts associated with the 1st fiber system of the reticular formation (motor functions)

Originates in the medulla from the nuecli in the nucleusreticularisgigantocellularis (NRGC)

Projects bilaterally to all levels of the spinal cord to powerfully suppress extension spinal reflex activity (suppresses extension muscles)

24
Q

Medial reticulospinal tract

A

One of the two tracts associated with the 1st fiber system of the reticular formation (motor functions)

Originates in the pons from the nuecli in the nucleus reticularis pontis caudalis (NRPC) and the nucleus reticularis pontis oralis (NRPO)

Project ipsilaterally to the entire spinal cord and functions to promote extensor spinal reflexes (promotes extensor muscles)
* DOES NOT decussate*

25
Q

Third fiber system for reticulospinal tracts specifics

A

Modulates pain impulses that ascend in spinothalamic tract to cerebral cortex

1st limb: consists of enkephalinergic neurons located in the PAG of the midbrain
- neurons project to the serotonergic neurons isn’t he nucleus raphe magnus of the medulla

2nd limb: consists of projections from the raphe magnus neurons to the dorsal horn of the spinal cord where they meet another set of enkephalinergic neurons. This set moves the impulse to primary afferent pain fibers

  • antagonizing this fiber system can help ignore pain for small periods of time*

** the locus ceruleus noraderenrgic neurons follow a similar pathway to also modulate the pain impulses**

26
Q

Lateral and medial vestibulospinal tracts

A

Originate from the vestibular nuclei of the rostral medulla (very close to pons junction)

Lateral:

  • is uncrossed (does not decussate) and descends the entire length of the spinal cord
  • innervates interneurons for motor neurons of ipsilateral trunk extensors and limb extensors
  • primary function = control muscles that maintain upright posture and balance ipsilaterally

Medial:

  • is crossed and uncrossed at the same time (projects bilaterally) * note when they decuss, it is at the medulla level*
  • ends in the cervical spinal cord
  • primary function = adjust the position of the head in response to postural changes (i.e keeps the brain stable and centered while walking or running)
27
Q

Rubrospinal tract

A

Originate from the midbrain and within the nuclei of the red nucleus

Fibers decussate in the midbrain and descend to lateral funiculus of the spinal white matter

Primary function = facilitate flexor motor neurons and inhibit extensor motor neurons

28
Q

Tectospinal tract

A

Originates from the midbrain within nuceli of the superior colliculus in the tectum.

Fibers decussate in midbrain and projects to cervical spinal cord.

Primary function = participates in orientation of head in response to visual(and some auditory) stimuli.

29
Q

Decorticate vs decerebrate posturing

A

Indicators of levels of Brainstem impairment in comatose patients (primarily with herniation syndromes)

Decorticate:

  • excessive action or the rubrospinal tract
  • signifies that above the midbrain is damaged, NOT the midbrain (Supratentorium)
  • cuts off the corticospinal tract

Decerebrate:

  • the Supratentorial pathology has moved down into the caudal portion of the midbrain
  • cuts off the corticospinal tract, as well as all descending cortical systems and the rubrospinal tract
  • results in hyperactivity of extensor muscles on all 4 extremities (since the lateral vestibulospinal tract is active without opposing tracts)
30
Q

Pontine arteries

A

Paramedian branches
- enter pons and supplies medial portion of points

Short circumferential branches
- supply wedge shaped are in the ventrallateral pons (essentially lateral to the paramedian branches)

Long circumferential branches
- supples the rostral pons, caudal midbrain and superior surface of the cerebellum

Neurology (65 decks)

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