CH16 Brainstem Tracts 1

Question 1

What types of vertical tracts are in the brainstem?

Answer 1

• sensory
• autonomic
• motor

Question 2

vertical tracts: synapses or no?

Answer 2

• Some tracts continue through the brainstem without alteration
• Brainstem acts as a conduit

Question 3

The brainstem is divided longitudinally into two sections:

Answer 3

• basilar

- tegmentum

Question 4

Describe and name the additional longitudinal brainstem section (aside from the basilar and tegmentum)

Where is it?

Answer 4

TECTUM

• in the midbrain
• posterior to the tegmentum

Question 5

The tectum includes structures involved in reflexive control of:

Answer 5

• intrinsic and extrinsic eye muscles

- movements in the head

Question 6

important parts of the tectum

Answer 6

• pretectal area
• superior and inferior colliculi

(I think?)

Question 7

Where is the basilar section of the brainstem? What does it primarily contain?

Answer 7

• anterior

- mostly motor

Question 8

Which motor structures does the basilar section contain?

Answer 8

• descending axons from cerebral cortex
• motor nuclei
• pontocerebellar axons

Question 9

Which descending tracts are in the basilar section?

Answer 9

• CST
• corticobulbar
• corticopontine
• corticoreticular

Question 10

Which motor nuclei are in the basilar section?

Answer 10

• SN
• pontine nuclei
• inferior olivary nucleus

Question 11

What is included in the reticular formation?

Answer 11

complex network

• reticular nuclei (and their connections)
• ascending/descending reticular pathways

Question 12

What does the reticular formation do?

Answer 12

• Integrates sensory and cortical information
• Regulates somatic motor activity, autonomic function, and consciousness.
• Modulates nociceptive (pain) information.

Question 13

What are the major reticular nuclei?

Answer 13

• ventral tegmental area (VTA)
• pedunculopontine nucleus (PPN)
• raphe nuclei
• locus ceruleus & medial reticular area

Question 14

Most neurons that produce dopamine are located here

Answer 14

midbrain

Question 15

What are the two production areas of dopamine in the midbrain?

Answer 15

• VTA (part of reticular formation)

- SNpc

Question 16

What happens when the VTA is activated?

Answer 16

produces feelings of pleasure and reward

Question 17

What nucleus does the VTA affect?

Answer 17

nucleus accumbens

Question 18

Why is morphine habit forming?

Answer 18

inhibits inhibitory inputs to the VTA

Question 19

Where is the PPN located?

Answer 19

caudal midbrain

Question 20

Where do ascending axons from the PPN project?

Answer 20

• to the inferior part of the frontal cerebral cortex

- intralaminar nuclei of the thalamus

Question 21

Through which connections does the PPN influence movement?

Answer 21

• Globus pallidus and subthalamic nucleus
• Limbic system
• Reticular areas that give rise to reticulospinal tracts

Question 22

What NT (NM) does the VTA use?

Answer 22

dopamine

Question 23

What NT (NM) does the PPN use?

Answer 23

acetylcholine

Question 24

What NT (NM) do the raphe nuclei use?

Answer 24

serotonin

Question 25

What NT (NM) does the locus ceruleus and medial reticular zone use?

Answer 25

norepinephrine (sometimes epi)

Question 26

What does the ARAS regulate?

Answer 26

consciousness

Question 27

consciousness

Answer 27

awareness of self and surroundings

Question 28

What is the consciousness system?

Answer 28

governs alertness, sleep, and attention

Question 29

What are the brainstem components of consciousness?

Answer 29

- reticular formation | - ARA

Question 30

external medulla: What are the vertical bulges?

Answer 30

pyramids

Question 31

Lateral to the pyramids are two small oval lumps, called

Answer 31

olives

Question 32

Where does CN XII connect to the medulla?

Answer 32

between the pyramid and the olive

Question 33

What does the inferior half of the medulla contain (canal)?

Answer 33

central canal that is continuous with the central canal of the spinal cord

Question 34

anterior component of inferior medulla

Answer 34

descending axons of CST (form the pyramids)

Question 35

What major nerve structures are found in the lower medulla?

Answer 35

cranial nerve structures

Question 36

What happens to the central canal in the upper medulla?

Answer 36

widens to form part of the 4th ventricle

Question 37

Positions of tracts in the rostral medulla compared to the caudal medulla

Answer 37

maintain approximately the same positions except that the medial longitudinal fasciculus is located more posteriorly

Question 38

Where are most CN nuclei found in the rostral medulla?

Answer 38

clustered in the dorsal section

Question 39

What functions does the medulla contribute to?

Answer 39

- controlling eye and head movements - coordinating swallowing - regulation of cardiovascular, respiratory, and visceral activity