Overview of Brainstem Organisation Flashcards Preview

MD1 Neuroscience > Overview of Brainstem Organisation > Flashcards

Flashcards in Overview of Brainstem Organisation Deck (63)
1

What is the gateway between the spinal cord and higher cortical areas?

Brainstem

2

What are the two major functions of the brainstem?

Reflexive and unconscious behaviour

Modulation of various arousal and conscious states

3

Where is the brainstem located?

In the posterior cranial fossa, extending from the mammillary bodies to the pyramidal decussation caudally.

4

What are the 3 divisions of the brainstem?

Midbrain, pons and medulla

5

What are the two pairs of characteristic bumps on the dorsal aspect of the midbrain?

The superior and inferior colliculi

6

Which part of the brainstem does the cerebellum attach to?

Pons

7

What is the pons limited by?

The 4th ventricle

8

Which parts of the pons form the floor of the 4th ventricle?

The facial colliculi

9

What forms the facial colliculi

Abducens nucleus and fibres of CNVII (facial nerve)

10

What forms the dorsal aspect of the caudal medulla?

Dorsal columns and nuclei, forming the gracile and cuneate tubercles

11

What can be seen on the ventral aspect of the midbrain?

Cerebral peduncles with the interpeduncular fossa in between.

12

What can be seen on the ventral aspect of the pons?

The superior, middle and inferior cerebellar peduncles dorsolaterally attaching to the cerebellum.

13

What can be seen on the ventral aspect of the medulla?

Rostral: Inferior olivary nuclei

Pyramids descending to the pyramidal decussation

14

What is the tectum?

The "roof" of the midbrain - the dorsal part. It refers solely to the colliculi of the midbrain.

15

What forms the roof of the 4th ventricle?

The 4 colliculi, i.e. the tectum.

16

What is the tegmentum?

Where the spinal cord continues up into the brainstem - continous with the spinal cord.

Structures within the tegmentum go to the spinal cord.

These include the cranial nerves and reticular formation.

17

What is the basis?

The basillar pons - the anterior portion of the pons.

Important for descending motor control, e.g. attachments to cerebellum, from cerebellum to other nuclei and tracts important for motor systems.

18

Which part of the brainstem only applies to the colliculi and midbrain?

The tectum

19

Which part of the brainstem is a continuation of the spinal cord that travels throughout the entire brainstem?

Tegmentum

20

What does the tegmentum occupy?

Middle part of the midbrain

Dorsal part of the pons and medulla

21

What does the tegmentum contain?

Nuclei for the cranial nerves and the reticular formation.

22

What is the sole focus of the basis?

Motor control

23

Where do the spinal nerves end?

C2

24

Which spinal cord segment lacks a dermatome?

C1

25

What do the spinal nerves supply?

The body

26

What do the cranial nerves supply?

Somatic and visceral motor and sensory information to head

27

Which cranial nerves also supply visceral sensory and motor innervation to neck, chest and most abdominal organs?

CNIX and X

28

Which side of the brainstem do most cranial nerves exit?

Ventral

29

Which cranial nerve does not exit the brainstem on the ventral surface?

CNIV

30

Which cranial nerves are exclusively motor?

CNIII, IV and VI (control the eye) CNXI and XII

31

Which cranial nerves are exclusively sensory?

CNI, II and VIII

32

Which cranial nerves are mixed?

CNV, VII, IX and X

33

What is the rule of 4 for the cranial nerves?

4 cranial nerves exit the medulla: CNIX-XII

4 exit the pons: CNV, VI, VII, VIII

4 exit above the pons: CNIII, IV

34

Where do the cranial nerve nuclei lie during embryological development?

Adjacent to the ventricular system

35

Which plate do the sensory nuclei develop from?

Alar plate

36

Which plate do the motor nuclei develop from?

Basal plate

37

How are the positions of the cranial nerve nuclei determined?

As the 4th ventricle develops, the alar plate (sensory nuclei) is pushed to the side, now sitting more lateral to the basal plate (motor nuclei).

38

How are cranial nerve nuclei grouped?

Based on function

39

Which nuclei are closer to the midline?

Motor nuclei (motor column)

40

Which nuclei are positioned laterally?

Sensory nuclei (sensory column)

41

How are the sensory and motor nuclei grouped within the brainstem?

Into 3 medial motor columns and 3 lateral sensory columns.

42

What are the 3 motor columns (medial to lateral)?

General somatic motor

Branchial motor

General visceral

43

What are the 3 sensory columns (medial to lateral)?

General and special visceral

General somatic

Special somatic

44

Which nucleus is this?

Spinal trigeminal

45

What is the tegmentum continuous with rostrally?

Certain nuclei in the thalamus

46

What is the tegmentum continuous with caudally?

Intermediate grey of the spinal cord

47

What is the function of the tegmentum rostrally (midbrain and upper pons)?

Mantains alert conscious state.

48

What is the function of the tegmentum caudally (pons and medulla)?

Work together with cranial nerve nuclei and spinal cord to carry out a variety of important motor reflex and autonomic functions. Closer to spinal cord, therefore more spinal cord-like actions.

49

What is the ascending reticular activating system?

Long projection systems from the rostral tegmentum.

50

What 4 different systems does the ascending reticular activating system use?

Noradrenergic (locus cereleus)

Dopaminergic (e.g. substantia nigra)

Serotonergic (dorsal raphe nucleus)

Cholinergic

51

What functions does the caudal reticular formation serve crucial functions in?

Motor reflex and autonomic functions

52

What does the ventrolateral medullary (VLM) reticular formation do?

Regulates the visceral functions of CNX (Vagus): G

I responses (swallowing, vomiting)

Respiratory activities

Rhythm, coughing, hiccupping, sneezing

Cardiovascular responses

53

What is the lateral medullary pontine reticular formation important for?

Chewing

54

What is the region of the reticular formation surrounding the facial nucleus important for?

Crying and smiling

55

What are the 3 major pathways traversing the brainstem?

Ascending pathways:

  1. Dorsal column-medial lemniscus system
  2. Anterolateral system

Descending pathways:

  1. Corticospinal tract

56

Which sensory modality is the dorsal column-medial lemniscus system for?

Fine touch-tactile, vibration

57

Where does the dorsal column-medial lemniscus system decussate?

In the medulla, at the medial lemniscus

58

Which sensory modality is the anterolateral system for?

Pain and temperature

59

Where does the anterolateral system terminate?

In 3 different regions: thalamus, midbrain and reticular formation.

60

What is the function of the corticospinal tract?

Motor

61

Where does the corticospinal tract decussate?

At the pyramids

62

What do the dorsal aspects of the brainstem contain?

Cranial nuclei and reticular formation

63

What do the ventral (basis) aspects of the brainstem contain?

Structures associated with the descending motor tracts (corticospinal tracts).

Midbrain: cerebral peduncles, substantia nigra, red nuclei

Pons: CB nuclei, middle cerebellar peduncle

Medulla: inferior olivary nuclei