Brainstem and cranial nerves

Question 1

What is the brain composed of?

Answer 1

Brain is comprised forebrain, midbrain and hindbrain

Question 2

What forms the brainstem?

Answer 2

Midbrain
Pons
Medulla

Question 3

What passes through the brainstem?

Answer 3

All ascending and descending pathways pass through the brainstem

Many synapse here in relay nuclei or arise directly from or synapse in other brainstem nuclei

Question 4

How is the cerebellum connected to the brainstem?

Answer 4

Cerebellum connected to brainstem by 3 cerebellar peduncles (white fibre tracts)

Question 5

What nuclei are in the brainstem?

Answer 5

Contains nuclei of 9 of the 12 pairs of cranial nerves – III to XII (except XI)

Question 6

What is the internal structure of the brainstem?

Answer 6

Base
Tegmentum
Tectum roof
Ventricular system

Question 7

What are the more detailed components of the brainstem (posterior)?

Answer 7

Pineal gland
Superior colliculus
Inferior colliculus
Dorsal columns
Trochlear nerve

Question 8

What are the more detailed components of the brainstem (anterior)?

Answer 8

Optic chiasm
Pituitary stalk
Mammillary body
Cerebral peduncle
Medullary pyramids
Pyramidal decussation

Question 9

Cerebral peduncles – descending tracts what are these?

Answer 9

Corticospinal and corticobulbar

Question 10

Label this diagram of the midbrain.

Answer 10

*cranial nerves III and IV emerge at this level

Question 11

What are components of the pons?

Answer 11

Pontine nuclei, transverse fibres and descending pathways

Cranial nerves V, VI, VII & VIII emerge at this level

Question 12

Label this diagram of the pons.

Answer 12

Middle cerebellar peduncle

4th ventricle

Question 13

What cranial nerves emerge at from medulla?

Answer 13

Cranial nerves IX, X & XII emerge from medulla

Question 14

Label this diagram of the open (upper) medulla.

Answer 14

Question 15

Label this diagram of the closed (lower) medulla?

Answer 15

Question 16

What type of continuation is the medulla?

Answer 16

Rostral continuation of spinal cord

Question 17

Which motor pathway has fibres which cross at the medulla?

Answer 17

Corticospinal

Question 18

Describe the surfaces of the medulla.

Answer 18

Anterior surface has pyramids (descending tracts)

Posterior surface has dorsal columns
Posterior surface divided into open and closed

Question 19

What does the closed (lower) medulla have?

Answer 19

Closed has extension of central canal of spinal cord
Canal widens to form 4th ventricle in open medulla

Question 20

What does CNS blood supply come from?

Answer 20

anterior and posterior arterial systems

Question 21

Anterior arterial system is derived from which vessels?

Answer 21

Internal carotid system

(Most of the cerebral hemispheres)

Question 22

Posterior arterial system is derived from which vessels?

Answer 22

Vertebrobasilar

(brainstem)

Question 23

What is the brainstem blood supply split into?

Answer 23

Circle of Willis
Vertebrobasilar system

Question 24

What are these cranial nerves on the brainstem?

Answer 24

Question 25

What are the 2 types of nuclei in the brainstem?

Answer 25

Efferent (motor) nuclei Afferent (sensory) nuclei

Question 26

Do you understand/ remember some of this diagram?

Answer 26

Y/N

Question 27

How can cranial nerves be grouped?

Answer 27

according to their functional components

Question 28

What are the groups of the cranial nerves according to their functional components? (7)

Answer 28

General somatic afferent (GSA) General somatic efferent (GSE) General visceral afferent (GVA) General visceral efferent (GVE) Special somatic afferent (SSA) Special visceral afferent (SVA) Special visceral efferent (SVE)

Question 29

What are General visceral efferent (GVE)?

Answer 29

Fibres are the preganglionic parasympathetic neurons to cranial, thoracic and abdominal viscera

Question 30

What are General visceral afferent (GVA)?

Answer 30

Fibres carry sensation from viscera of head, neck, thorax and abdomen

Question 31

What are General somatic efferent (GSE)?

Answer 31

Fibres innervate skeletal muscles

Question 32

What are General somatic afferent (GSA)?

Answer 32

Fibres carry general sensation from skin, muscles, joints of head and neck

Question 33

What are Special visceral efferent (SVE)?

Answer 33

Innervate skeletal muscles of the jaw, face, larynx and pharynx

Question 34

What are Special visceral afferent (SVA)?

Answer 34

Fibres carry taste sensation

Question 35

What are Special somatic afferent (SSA)?

Answer 35

Fibres carry special senses of hearing and balance

Question 36

What nerves emerge from the pons?

Answer 36

Cranial nerves V-VIII

Question 37

What cranial nerves emerge from the midbrain?

Answer 37

Cranial nerves II & IV

Question 38

What does the anterior aspect of midbrain have?

Answer 38

mammillary bodies, cerebral peduncles, medullary pyramids

Question 39

What does the posterior aspect of midbrain have?

Answer 39

pineal gland, colliculi, dorsal columns