Brainstem Organization

Question 1

The brainstem extends from

Answer 1

the mamillary bodies to the pyramidal decussation

Question 2

The pyramidal decussation marks

Answer 2

the decussation of the motor pathways

Question 3

What are the ‘bumps’ of the dorsal membrane?

Answer 3

Superior and inferior colliculi

Question 4

Along the floor of the 4th ventricle lie

Answer 4

facial colliculi formed by abducens nucleus and VII fibres

Question 5

The medula conists of

Answer 5

dorsal columns and nuclei (gracile and cuneate tubercles)

Question 6

What comprises the ventral aspect of the midbrain?

Answer 6

Cerebral peduncles

Question 7

What are the cerebral peduncles made of?

Answer 7

White matter tracts coming down from the motor cortex

Question 8

What comprises the ventral pons?

Answer 8

Cerebellar peduncles (white matter tracts attaching to the cerebellum)

Question 9

What comprises the ventral medulla?

Answer 9

olives (more lateral) and pyramids (more medial)

Question 10

What is the tectum?

Answer 10

Roof of the 3rd and 4th ventricles - comprises the dorsal aspect of the midbrain (superior and inferior colliculi)

Question 11

What is the tegmentum?

Answer 11

Continuous with the spinal cord; lies between the cerebral aqueduct (dorsally) and the pons (ventrally)

Question 12

The tegmentum contains

Answer 12

cranial nerve nuclei, nerve fibres connected to the cranial nerve nuclei including the reticular formation

Question 13

What is the importance of the basilar region of the brainstem?

Answer 13

Descending motor control - corticospinal tracts; range of nuclei, some of which control these descending fibres via attachments to the cerebellum

Question 14

General somatic nerves innervate

Answer 14

skeletal muscle and skin

Question 15

General visceral nerves innerate

Answer 15

viscera - smooth muscle, glands, blood vessels

Question 16

Spinal nerves end at

Answer 16

C2 (there is no C1 dermatome)

Question 17

Which cranial nerves are exclusively motor?

Answer 17

III, IV, VI, XI, XII

Question 18

Which cranial nerves are exclusively sensory?

Answer 18

I, II, VIII

Question 19

Which cranial nerves are mixed?

Answer 19

V, VII, IX, X

Question 20

Sensory nuclei develop from which plate?

Answer 20

Alar

Question 21

Motor nuclei develop from which plate?

Answer 21

Basal

Question 22

The general function of the reticular activating system is

Answer 22

regulating function of cranial nerves

Question 23

The rostral reticular activating system is important in

Answer 23

controlling alertness and conscious state

Question 24

The caudal reticular activating system is important in

Answer 24

regulation of survival reflexes, motor reflexes, autonomic functions, breathing, heart rate

Question 25

How does the rostral reticular activating system function?

Answer 25

long projection systems ascending into the forebrain (cortex) defined by neurotransmitters

Question 26

Noradrenergic ARAS projections start from which nucleus?

Answer 26

locus ceruleus

Question 27

Dopaminergic ARAS projections start from

Answer 27

substantia nigra (important in movement)

Question 28

Serotonergic ARAS projections originate from

Answer 28

dorsal raphae nucleus (important in mood and addiction)

Question 29

The ventrolateral medullary reticular formation is responsible for

Answer 29

caudal - reflexes; regulates visceral functions of vagus X such as swallowing, vomiting, respiration (rhythm, coughing, hiccuping, sneezing), and cardiovascular responses

Question 30

Locked-in syndrome generally affects

Answer 30

the ventral pons

Question 31

The substantia nigra is found

Answer 31

in the ventral midbrain (basis)

Question 32

The red nuclei are found

Answer 32

in the ventral midbrain (basis)

Question 33

The cerebellar nuclei are found

Answer 33

in the ventral pons (basis)