Brainstem

Question 1

Where is the brainstem located?

Answer 1

Between the cerebrum and spinal cord

Question 2

What are the three components of the brainstem?

Answer 2

Midbrain
Pons
Medulla oblongata

Question 3

What does the brainstem consist of in terms of grey/white matter?

Answer 3

Deep grey matter surrounded by white matter fibre tracts

Question 4

What is the function of the brainstem?

Answer 4

Produces automatic behaviours necessary for survival e.g., breathing

Question 5

Which embryonic structure does the midbrain develop from?

Answer 5

Mesencephalon

Question 6

Which embryonic structure does the pons develop from?

Answer 6

Metencephalon

Question 7

Which embryonic structure does the medulla oblongata develop from?

Answer 7

Myelencephalon

Question 8

How many cranial nerves are there?

Answer 8

12 pairs

Question 9

What is the first cranial nerve?

Answer 9

Olfactory

Question 10

What is the second cranial nerve?

Answer 10

Optic

Question 11

What is the third cranial nerve?

Answer 11

Occulomotor

Question 12

What is the fourth cranial nerve?

Answer 12

Trochlear

Question 13

What is the fifth cranial nerve?

Answer 13

Trigeminal

Question 14

What is the sixth cranial nerve?

Answer 14

Abducens

Question 15

What is the seventh cranial nerve?

Answer 15

Facial

Question 16

What is the eighth cranial nerve?

Answer 16

Vestibulocochlear

Question 17

What is the ninth cranial nerve?

Answer 17

Glossopharyngeal

Question 18

What is the tenth cranial nerve?

Answer 18

Vagus

Question 19

What is the eleventh cranial nerve?

Answer 19

Accessory

Question 20

What is the twelfth cranial nerve?

Answer 20

Hypoglossal

Question 21

Which cranial nerve is the only one to emerge from the posterior aspect of the brain stem?

Answer 21

Trochlear

Question 22

Which cranial nerves are purely sensory?

Answer 22

CN1 - Olfactory

CN2 - Optic

CN8 - Vestibulocochlear

Question 23

Which cranial nerves are purely motor?

Answer 23

CN3 - oculomotor

CN4 - trochlear

CN6 - abducens

CN11 - accessory

CN12 - hypoglossal

Question 24

Which cranial nerves are both sensory and motor?

Answer 24

CN5 - trigeminal

CN7 - facial

CN9 - glossopharyngeal

CN10 - vagus

Question 25

What are the nuclei in the medulla associated with?

Answer 25

Autonomic control Cranial nerves Motor/sensory relays

Question 26

What autonomic nuclei centres are found in the medulla?

Answer 26

Cardiovascular centers Respiratory rhythmicity centers Emesis Coughing Sneezing

Question 27

Which cranial nerves have nuclei in the medulla?

Answer 27

CN8 - vestibulocochlear CN9 - glossopharyngeal CN10 - vagus CN11 - accessory CN12 - hypoglossal

Question 28

Which three relay nuclei are present in the medulla?

Answer 28

Nucleus gracilis Nucleus cuneatus Olivary nuclei

Question 29

What does the nucleus gracilis and nucleus cuneatus do in the medulla?

Answer 29

Relay somatic sensory information to the thalamus

Question 30

What does the olivary nuclei in the medulla do?

Answer 30

Relays information from spinal cord, cerebral cortex, and brainstem to cerebellar cortex

Question 31

What two ridges are visible on the ventral side of the medulla?

Answer 31

Medullary pyramids

Question 32

What are the medullary pyramids formed by?

Answer 32

Large motor corticospinal tracts

Question 33

Where do most fibres decussate?

Answer 33

Medulla-spinal cord junction

Question 34

What features are seen on a Weigert stain of a caudal medulla section?

Answer 34

Ventral horn is smaller Dorsal horn is replaced by trigeminal sensory nucleus Clear decussation of pyramids ventrally

Question 35

What features are seen on a Weigert stain of a mid medulla section?

Answer 35

Dorsal column terminates Prominent gracile and cuneate nuclei

Question 36

What features are seen on a Weiger stain of a rostral medulla section?

Answer 36

Clear medial lemniscus at ventral midline Inferior olivary nucleus Hypoglossal nucleus

Question 37

The pons contains nuclei for which four cranial nerves?

Answer 37

CN5 - trigeminal CN6 - abducens CN7 - facial CN8 - vestibulocochlear

Question 38

Which centres in the pons work with the medulla to maintain respiratory rhythm?

Answer 38

Apneustic and pneumotaxic

Question 39

Which part of the brainstem is the raphe nuclei and reticular activating system found?

Answer 39

Pons

Question 40

What is the tegmentum in the pons?

Answer 40

Dorsal portion of the pons, posterior to medial lemniscus

Question 41

Are sensory fibres located posterior or anterior to motor fibres in the pons?

Answer 41

Posterior

Question 42

What features are observed in a caudal section of the pons?

Answer 42

Trapezoid body between medial lemniscus and pontocerebellar fibers

Question 43

What features are observed in a rostral section of the pons?

Answer 43

Superior cerebellar peduncles are prominent

Question 44

Which nuclei are present in the midbrain?

Answer 44

Red nuclei Cranial nerve nuclei CN3 - occulomotor CN4 - trochlear Substantia nigra

Question 45

Why is the red nucleus called 'red'?

Answer 45

Highly vascularised nucleus

Question 46

What information does the red nucleus receive and what information does it transmit?

Answer 46

Receives from cerebrum and cerebellum Transmits information on subconscious motor commands concerned with muscle tone and posture

Question 47

Where is the substantia nigra located in the midbrain?

Answer 47

Lateral to red nucleus

Question 48

What naturally occurring pigment does the substantia nigra contain?

Answer 48

Melanin

Question 49

What causes the substantia nigra to be darker in colour?

Answer 49

Melanin

Question 50

Which brain stem nucleus contains melanin?

Answer 50

Substantia nigra in the midbrain

Question 51

Which neurotransmitter does the substantia nigra release?

Answer 51

Dopamine

Question 52

What effect does the substantia nigra have on the basal nuclei?

Answer 52

Inhibits the excitatory neurons of the basal nuclei

Question 53

Which three tracts are present in the midbrain?

Answer 53

Motor tracts - pyramidal system Sensory axons - spinothalamic Cerebral peduncles

Question 54

What are the two segments of the midbrain and what separates them?

Answer 54

Anterior (tegmentum) Posterior (tectum) Separated by the cerebral aqueduct

Question 55

Where is the corpora quadrigemina located in the midbrain?

Answer 55

Dorsal surface of midbrain

Question 56

What is the function of the corpora quadrigemina in the midbrain?

Answer 56

Relay center for vision and hearing

Question 57

What two structures make up the corpora quadrigemina?

Answer 57

2 superior colliculi 2 inferior colliculi

Question 58

What sensory process are the two superior colliculi in the corpora quadrigemina of the midbrain involved in?

Answer 58

Vision

Question 59

What sensory process are the two inferior colliculi in the corpora quadrigemina of the midbrain involved in?

Answer 59

Hearing

Question 60

What structures are visible on the caudal section of the midbrain?

Answer 60

Inferior colliculus Periaqueductal grey matter Medial longitudinal fasciculus

Question 61

What structures on the rostral section of the midbrain?

Answer 61

Superior colliculus Red nucleus Substantia nigra Crus cerebri