The Brainstem

Question 1

What is the basilar circus?

Answer 1

Shallow sulcus where the basilar artery runs

Question 2

What is the bulbopontine sulcus?

Answer 2

The line between the pons and the medulla

Question 3

What is the anterior median fissure?

Answer 3

The line down the front of the medulla

Question 4

What happens at the decussation of pyramids?

Answer 4

80% of descending corticospinal fibres cross over the midline

Question 5

What is the ventral lateral sulcus?

Answer 5

The groove dividing the pyramid and the olive- it is where the rootlets of the hypoglossal nerve exit

Question 6

What are the two main divisions of the midbrain?

Answer 6

Dorsal tectum and ventral tegmentum

Question 7

What is the medulla?

Answer 7

Conical continuation of the spinal cord within the skull, beginning at the foramen magnum.

Question 8

Where does the dorsal tectum lie?

Answer 8

Dorsal to the aqueduct of the midbrain and the fourth ventricle

Question 9

Where does the ventral tegmentum lie?

Answer 9

Ventral to the aqueduct of the midbrain and the fourth ventricle

Question 10

What is the interpeducular fossa?

Answer 10

The space between the crus cerebri

Question 11

What are the cerebral peduncles/crus cerebri?

Answer 11

A large collection of fiber bundles in the ventral midbrain, which originate in the cerebral cortex

Question 12

What are mammillary bodies?

Answer 12

Small round bodies, located on the undersurface of the brain that, as part of the diencephalon, form part of the limbic system

Question 13

What is a pyramid?

Answer 13

An elongated swelling (eminence) marking the position of the underlying fibres passsing from the cerebral hemisphere to the cord, the corticospinal tracts

Question 14

What is the decussation of the pyramids?

Answer 14

Diagonally oriented bundles of fibres crossing the fissure, where 80% of corticospinal fibres corss the midline to enter the opposite lateral white column of the spinal cord

Question 15

What is the olive?

Answer 15

A swelling (eminence) caused by the presence of the underlying inferior olivary nucleus and is concerned with the control of movement

Question 16

What is the inferior cerebellar peduncle?

Answer 16

A thick bundle of white matter passing into the cerebellum whihc forms the posterolateral margin of the medulla

Question 17

What is the tectum?

Answer 17

The midbrain dorsal to the aqueduct, it is made up of the colliculi (aka the corpora quadrigemina)

Question 18

What is the tegmentum?

Answer 18

The midbrain ventral to the aqueduct, it is made up of nerve fibres entering and leaving the cerebral hemispheres, nerve nuclei etc

Question 19

What is the superior colliculi?

Answer 19

Part of the visual system concerned with eye reflexes

Question 20

What is the inferior colliculi?

Answer 20

Part of the autitory system concerned with the reflex of looking towards a loud noise

Question 21

What is the superior cerebellar peduncle?

Answer 21

A fibre bundle passing from the cerebellum to the midbrain

Question 22

What is the pineal gland?

Answer 22

An endocrine gland that synthesises melatonin whihc modulates sleep patterns in both circadiam and seasonal cycles

Question 23

What does the inferior brachium do?

Answer 23

Conveys auditory information from the medial geniculate body to the inferior colliculi

Question 24

What does the superior brachium do?

Answer 24

Conveys visual information form the lateral geniculate body to the superior colliculi

Question 25

What is the gracile tubercle?

Answer 25

A round swelling on either side of the medulla midline overlying the gracile fasciculus

Question 26

What is the gracile fasciculus involved in?

Answer 26

Involved in carryin fine touch, vibration, two-point discrimination and proprioception from the lower limb

Question 27

What is the cuneate tubercle?

Answer 27

A swelling lateral to the gracile tubercles, overlying the cuneate fasciculus

Question 28

What is the cuneate fasciculus invovled in?

Answer 28

Involved in carrying fine touch, vibration, two-point discrimination and proprioception from the upper limb

Question 29

What cranial nerve nuclei does the tegmentum carry ?

Answer 29

Carries the nuclei of: Abducens (6) Facial (7) Trigeminal (5- motor division- muscles of mastication) Glossopharyngeal (9) Vagus (10) Accessory (11) Hypoglossal (12)

Question 30

What is the floor of the 4th ventricle called?

Answer 30

Rhomboid fossa

Question 31

What connects the third anf fourth ventricles

Answer 31

The cerebral aqueduct runs through the midbrain and interconnects the third and fourth ventricles

Question 32

What is the substantia nigra?

Answer 32

A black band of nerve cells overlying the crus cerebri (cerebral peduncles), ventro-lateral to the red nucleus on each side

Question 33

What is the red nucelus?

Answer 33

A circular mass of grey matter ventro-lateral to the cerebral aqueduct, often appears pink

Question 34

The nuclei underlying the gracile and cuneate tubercles are called the dorsal column and are a major relay site for which pathway?

Answer 34

Dorsal column sensory pathway aka dorsal column medial lemniscal system

Question 35

What is Bell's Palsy?

Answer 35

Acute unilateral inflammation of the facial nerve (lower motor neurone) Symptoms: Pain behind ear Paralysis of facial muscles Failure to close the eyes Signs: Absent corneal reflex Hyperacusis (certain sounds heard unpleasantly loudly) Lodd of taste on anterior 2/3s pf tongue

Question 36

What is Bulbar Palsy?

Answer 36

Impairment of the functions of the cranial nerves that arise from the medulla (Nerves 9-12). Caused by motor nuerone disease and Guillain-Barre syndrome Symptoms: Dysphagia (difficulty swallowing) Slurring of speech Dysphonia (difficulty forming sounds) Excess saliva- dribbling Signs: Wasting and fasciculating tongue Absent gag reflex

Question 37

What is central pontine myelinoysis?

Answer 37

Destruction of myelin in the pons- occurs when low sodium levels are corrected too quickly Symptoms: Confusion Balance problems Dysphagia (difficulty swallowing) Hallucinations Reduced consciousness Slurred speech Tremor and weakness in the face or limbs