Pons

Question 1

Location of the pons

Answer 1

Inferior to midbrain
Superior to medulla

Question 2

What separates the medulla from the pons?

Answer 2

Transverse groove

Question 3

What are the nerves of the transverse groove?

Answer 3

Abducent nerve (Above Pyramid)
Facial (Above Olive)
Vestibulocochlear (Above Olive)

Question 4

What are the surfaces of the pons?

Answer 4

Anterior
Posterior

Question 5

Describe the anterior surface of the pons

Answer 5

Convex

Question 6

Purpose of the basilar sulcus

Answer 6

Contains basilar artery

Question 7

Where is the trigeminal nerve attached?

Answer 7

Attached by two rootlets

Question 8

What is the inferior posterior surface of the pons continuous with?

Answer 8

Upper part of the medulla

Question 9

What is the median sulcus?

Answer 9

Divides the posterior surface of the pons into two halves

Question 10

What is the medial eminence?

Answer 10

Elongated elevation bound by sulcus limitans

Question 11

Where is the facial colliculus?

Answer 11

Lower part of the medial eminence overlying the abducent nucleus

Question 12

What surrounds the facial colliculus?

Answer 12

Facial nucleus axons turned around abducent nucleus

Question 13

What is the superior fovea?

Answer 13

Depression at the lower end of sulcus limitans at the level of facial colliculus

Question 14

Where are the vestibular nuclei?

Answer 14

Lateral to the superior fovea

Question 15

How many parts can the pons be divided into?

Answer 15

Basilar part
Tegmentum

Question 16

What structure divides the pons?

Answer 16

Divided by transversely running fibers of trapezoid body

Question 17

Where is the basilar part of the pons?

Answer 17

Anterior part of the pons

Question 18

How do the contents of the basilar parts vary at each level?

Answer 18

Contents are the same at each level

Question 19

Where is the tegmental part of the pons?

Answer 19

In the dorsal part of the pons
Includes the trapezoid body

Question 20

How do the contents of the tegmentum vary at each level?

Answer 20

Vary in the three levels of the pons

Question 21

What are the components of the basilar part of the pons?

Answer 21

Descending Tracts

Question 22

What are the descending tracts in the basilar part of the pons?

Answer 22

Corticoponto Cerebellar Tract
Corticospinal Tract

Question 23

Characteristics of the corticoponto cerebellar tract

Answer 23

Has numerous transverse pontocerebellar fibers which arise from pontine nuclei

Question 24

Characteristics of the corticospinal tract

Answer 24

Small, separate bundles running longitudinally between the transverse pontine fibers

Question 25

What are the levels of the tegmental part of the pons?

Answer 25

**Lower level**: Level of facial colliculus. **Mid-level**: level of trigeminal nerve. **Upper level**: level of 4 lemnisci

Question 26

Where is the trapezoid body?

Answer 26

Anterior part of the tegmentum

Question 27

What are the fibers of the trapezoid body responsible for?

Answer 27

Arise from cochlear body and are responsible for hearing

Question 28

**Tegmentum in Lower Pons** Components

Answer 28

Nuclei Ascending Tracts

Question 29

**Tegmentum in Lower Pons** Nuclei

Answer 29

Anterior and posterior cochlear nuclei Vestibular nuclei Superior salivatory nucleus Abducent nerve nucleus Facial motor nucleus

Question 30

**Tegmentum in Lower Pons** What encircles the abducent nerve nucleus?

Answer 30

Fibers of facial nerve

Question 31

**Tegmentum in Lower Pons** What does the encircling of the Abducent Nucleus form?

Answer 31

Forms elevation in the floor of 4th ventricle called facial colliculous

Question 32

**Tegmentum in Lower Pons** Describe the pathway of the facial motor neurons

Answer 32

Efferent fibers encircle abducent nucleus Pass antero-laterally Emerge at the groove between pons & olive of medulla

Question 33

**Tegmentum in Lower Pons** Ascending Tracts

Answer 33

Medial Lemniscus (Gracile and Cuneate Tracts) Spinal Lemniscus (Anterior and Lateral Spinothalamic Tracts) ANTERIOR SPINOCEREBELLAR TRACT Spinal Tract and Nucleus

Question 34

**Tegmentum in Lower Pons** Purpose of the spinal tract

Answer 34

Carries pain and temperature sensations of face and scalp

Question 35

**Tegmentum in Mid-Pons** Nuclei

Answer 35

Trigeminal motor nucleus Trigeminal sensory nucleus

Question 36

**Tegmentum in Mid-Pons** Location of Trigeminal Motor Nucleus

Answer 36

Medial in position

Question 37

**Tegmentum in Mid-Pons** What do the axons of the Trigeminal Motor Nucleus form?

Answer 37

Form the motor root of trigeminal nerve which passes along mandibular nerve

Question 38

**Tegmentum in Mid-Pons** Location of the Trigeminal Sensory Nucleus

Answer 38

Lateral in position

Question 39

**Tegmentum in Mid-Pons** Names of Ascending Tracts

Answer 39

Medial, Trigeminal, Spinal and Lateral Lemnisci Anterior Spinocerebellar Tract

Question 40

What is the upper tegmentum composed of?

Answer 40

Lateral Lemniscus Spinal Lemniscus Trigeminal Lemniscus Medial Lemniscus Anterior Spinocerebellar Tract

Question 41

**Tegmentum in Upper-Pons** Location of Lateral Lemniscus

Answer 41

Most lateral lemniscus

Question 42

**Tegmentum in Upper-Pons** What fibers does the Lateral Lemniscus contain?

Answer 42

Ascending fibers carrying hearing sensations from both ears (mainly opposite side)

Question 43

**Tegmentum in Upper-Pons** Where does the Lateral Lemniscus end?

Answer 43

Auditory Area in Temporal Lobe

Question 44

**Tegmentum in Upper-Pons** Location of Spinal Lemniscus

Answer 44

Medial to lateral lemniscus

Question 45

**Tegmentum in Upper-Pons** What fibers does the Lateral Lemniscus contain?

Answer 45

Band of ascending fibers

Question 46

**Tegmentum in Upper-Pons** What sensations does the Spinal Lemniscus carry?

Answer 46

Pain, temperature and touch from opposite side of body

Question 47

**Tegmentum in Upper-Pons** Location of the Trigeminal Lemniscus

Answer 47

Medial to Spinal Lemniscus

Question 48

**Tegmentum in Upper-Pons** What sensations does the Trigeminal Lemniscus carry?

Answer 48

Touch, pain and temperature from the opposite side of the face and scalp

Question 49

**Tegmentum in Upper-Pons** Location of Medial Lemniscus

Answer 49

Most medial lemniscus

Question 50

**Tegmentum in Upper-Pons** What sensations does the Medial Lemniscus carry?

Answer 50

Carrying proprioceptive sensations from the opposite side of the body

Question 51

Primary blood supply of the pons

Answer 51

Basilar Artery

Question 52

Which branches of the basilar artery supply the medial part of the basis pontis?

Answer 52

Paramedian Pontine Branches

Question 53

Which branches of the basilar artery supply the lateral part of the basis pontis?

Answer 53

Long and short circumferential pontine branches

Question 54

Which branches of the basilar artery supply the tegmentum?

Answer 54

Paramedian pontine branches Long circumferential pontine branches and superior cerebellar artery (cranial part) Long circumferential pontine branches and anterior inferior cerebellar artery (caudal part)

Question 55

What is the venous drainage of the pons?

Answer 55

Basilar Venous Plexus Inferior Petrosal Sinus

Question 56

What are the effects of extensive pontine haemorrhage?

Answer 56

Pin point pupil Hyperpyrexia Quadriplegia