Brainstem

Question 1

What are the functions of Brainstem

Answer 1

1. Serves as a conduit for the ascending and descending tracts connecting the spinal cord to the different parts of the higher centers in the forebrain
2. It contains important reflexes centers associated with the control of respiration the cardiovascular system and with the control of consciousness
3. Contains the important nuclei of cranial nerves III through XII

Question 2

What is the structure of medulla oblongata

Answer 2

1. Connects the pons superiorly with the spinal cord inferiorly
2. Junction of the medulla and spinal cord is at the origin, of the anterior and posterior roots of the 1st cervical spinal nerve, which corresponds approximately to the level of the foramen magnum
3. Conical in shape, its broad extremity being directed superiorly
4. Central canal of the SC continues upward into the lower half of the medulla
5. In the upper half of the medulla, it expands as the cavity of the 4th ventricle

Question 3

Medulla Oblongata: Pyramids

Answer 3

Swelling on each side of the median fissure

Question 4

Medulla Oblongata:

Corticospinal fibers

Answer 4

1) Bundles of nerve fibers seen at the pyramids

2) Originate in large nerve cells in the precentral gyrus of the cerebral cortex

Question 5

Anterior External Arcuate Fibers (Medulla Oblongata other fibers)

Answer 5

Emerge from the anterior median fissure above the decussation and pass laterally over the surface of the medulla oblongata to enter the cerebellum

Question 6

Olives (Medulla Oblongata other fibers)

Answer 6

Oval elevations produced by the inferior olivary nuclei located posterolateral to the pyramids

Question 7

Inferior Cerebellar Peduncles ( Medulla Oblongata other fibers)

Answer 7

1. Posterior to the olives

2. Connect the medulla to the cerebellum

Question 8

In the groove between the olive and the inferior cerebellar peduncle emerge the roots of the 1.___ and 2.____ nerves and the cranial roots of the 3.______

Answer 8

1. Glossopharyngeal
2. Vagus
3. Accessory

Question 9

Posterior surface of the superior half of the medulla oblongata

Answer 9

Forms the lower part of the floor of the 4th ventricle

Question 10

Posterior surface of the inferior half of the medulla oblongata

Answer 10

Is continuous with the posterior aspect of the spinal cord and possesses a posterior median sulcus

Question 11

Gracille Tubercle

Answer 11

Elongated swelling on each side of the median sulcus produced by the gracile nucleus

Question 12

Cuneate Tubercle

Answer 12

Lateral to the gracile tubercle is a similar swelling produced by the underlying cuneate nucleus

Question 13

Decussation of the pyramids

Answer 13

The great motor decussation

Question 14

Decussation of the Lemnisci

Answer 14

Great sensory decussation

Question 15

Decussation of the Lemnisci

Answer 15

1. Takes place anterior to the central gray matter and posterior to the pyramids
2. Formed from the internal arcuate fibers (from the nucleus gracilis & nucleus cuneatus)

Question 16

Level of the olives

Answer 16

1. Increased amount of grey matter
2. Presence of the
   * olivary nuclear complex
   * Vestibulocochlear nuclei
   * Glossopharyngeal nuclei
   * Vagus nuclei
   * Accessory Nerve Nuclei
   * Hypoglossal Nerve Nuclei
   * Arcuate Nuclei

Question 17

Inferior Olivary Nuclei

Answer 17

Largest and responsible for the elevation on the surface of the medulla called the olive.

Question 18

What is the function of the olivary nuclei

Answer 18

Associated with voluntary muscle movement

Question 19

Olivary nuclear complex receives fibers from

Answer 19

Spinal cord via the spino-olivary tracts and from the cerebellum and the cerebral cortex

Question 20

Nucleus Ambiguus

Answer 20

Consists of large motor neurons and is situated deep within the reticular formation

Question 21

Central gray matter lies

Answer 21

beneath the floor of the 4th ventricle at this level passing from medial to lateral

• Hypoglossal nucleus
• Dorsal nucleus of the vagus
• Nucleus of the tractus solitarius
• Medial and inferior vestibular nuclei

Question 22

Inferior cerebellar peduncle

Answer 22

Situated in the posterolateral corner of the section on the lateral side of fourth ventricle

Question 23

The spinal tract of the CNV and its nucleus are situated on the

Answer 23

Anteromedial aspect of the inferior cerebellar peduncle

Question 24

Anterior Spinocerebellar tract

Answer 24

Situated near the surface in the interval between the inferior olivary nucleus and the nucleus of the spinal tract of the trigeminal nerve

Question 25

Pons

Answer 25

1. Anterior to the cerebellum and connects the medulla oblongata to the midbrain 2. 1 inch (2.5cm) long

Question 26

Basilar groove

Answer 26

Shallow groove in the midline that lodges the basilar artery

Question 27

Between the pons and the medulla oblongata (medial-lateral)

Answer 27

Abducent, facial and vestibulocochlear

Question 28

The posterior surface is limited laterally by the

Answer 28

Superior cerebellar peduncles and is divided into symmetrical halves by a median sulcus

Question 29

Lateral to the sulcus limitans is the

Answer 29

Area vestibuli produced by the underlying vestibular nuclei

Question 30

Structure of the pons may be studied at two levels

Answer 30

1) Transverse section, through the caudal part, passing through the facial colliculus 2) Transverse section through the cranial part, passing through the trigeminal nuclei

Question 31

Internal structure of the pons and divided by the trapezoid body commonly into

Answer 31

1. The Tegmentum: the posterior | 2. Anterior basal part by the transversely running fibers of the trapezoid body

Question 32

Medial Lemniscus

Answer 32

Situated in the most anterior part of the tegmentum

Question 33

Facial nucleus

Answer 33

Lies posterior to the lateral part of the medial lemniscus

Question 34

The fibers of the facial nerve wind around the

Answer 34

Nucleus of the abducent nerve, producing the Facial Colliculus

Question 35

Medial Longitudinal Fasciculus

Answer 35

1) Situated beneath the floor of the 4th ventricle on either side of the midline 2) Main pathway that connects the vestibular and cochlear nuclei with the nuclei controlling the extraocular muscles (oculomotor, trochlear, and abducent nuclei)

Question 36

Medial Vestibular Nucleus

Answer 36

1) Situated lateral to the abducent nucleus | 2) Close relationship to the inferior cerebellar peduncle

Question 37

Spinal nucleus of the trigeminal nerve

Answer 37

Lie on the the anteromedial aspect of the inferior cerebellar peduncle

Question 38

Trapezoid body is made up

Answer 38

Of fibers derived from the cochlear nuclei and the nuclei of trapezoid body

Question 39

Pontine Nuclei

Answer 39

Small massess of nerve cells at the basilar part of the pons

Question 40

Corticopontine fibers

Answer 40

Forms the main pathway linking the cerebral cortex to the cerebellum