Midbrain + Diencephalon

Question 0

Basal plates develop into what in the adult midbrain?

Answer 0

Edinger-Westphal nucleus

Occulomotor nucleus

Question 1

The red nucleus and substantia nigra descend from what in development?

Answer 1

Alar plates

Question 2

What are the 3 segment of the midbrain?

Answer 2

Tectum
Tegmentum
Basis pedunculi

Question 3

What is the basis pedunculi? What does it contain?

Answer 3

Anterolateral section of midbrain, Cerebellar peduncle

Substantia nigra and crus cerebri

Question 4

What is the crus cerebri?

Answer 4

Descending motor efferent pathways

Question 5

The rostral limit of midbrain on ventral surface is?

The caudal limit on ventral surface is?

Answer 5

Exit of crura cerebri and (caudal limit of) mammillary bodies

Where crus cerebri enter pons

Question 6

Dorsal surface limits of midbrain?

Answer 6

Rostral: rostral limit of superior colliculi

Caudal: caudal limit of inferior colliculi

Question 7

What is the role of the SUPERIOR colliculi?

Answer 7

Receives visual, auditorium and somatosensory input

Produces motor response to direct head and eyes towards stimulus.
- (Projects to colliculospinal tract to cervical SC to control neck muscles)

Question 8

What is the role of inferior colliculus?

Answer 8

Receives auditory input from hindbrain

Sends auditory info to superior colliculus and thalamus

Question 9

What is the role of the red nucleus?

Answer 9

Motor nucleus, associated with cerebellum 
Parvocellular and magnocellular output
Important in development 
Corticospinal more important in adults 
 ( also has high iron content = red)

Question 10

What is the role of the midbrain locomotor area?

Answer 10

Stimulates pattern generator to unite locomotion

Regulates pattern an speed of movement

Question 11

What is the role of the Periaqueductal grey?

Answer 11

Descending pain modulation

Contains opioid neurones

Question 12

What do the somatic motor and visceral motor components of the Occulomotor nerve innervate?

Answer 12

Somatic - extraocular muscles

Visceral - sphincter and ciliary muscles (pupil constriction: parasympathetic)

Question 13

The medial longitudinal fasciculus gives VESTIBULAR input to which nerves?

Answer 13

III, IV and VI

Question 14

Which is the only cranial nerve to exit from dorsal surface?

Answer 14

Trochlear (IV)

Question 15

Which nerve controls the lateral rectus muscle?

Answer 15

Abducens (VI)

Question 16

Where is the abducens nucleus located?

Answer 16

Hindbrain

Question 17

Which nerve has a crossed pathway and innervates the superior oblique muscle?

Answer 17

Trochlear

Question 18

Describe the response of visceral motor nerve III

Answer 18

Bilateral response:

Direct light reflex in IPSILATETAL eye

Consensual reflex in CONTRALATERAL eye

(Pupil constriction - parasympathetic)

Question 19

Where does the substantia nigra (SNC) project to?

Answer 19

Striatum

Question 20

Where does the ventral tegmental area project to?

What are these pathways and what are they involved in?

Answer 20

1) ventral striatum - mesolimbic pathway - reward + addiction
2) frontal cortex - mesocortical pathway - memory + arousal

Question 21

What type of neurones are VTA projections?

Answer 21

Dopaminergic

Question 22

What disorder is caused by loss of dopaminergic pathways from VTA to frontal cortex?

Answer 22

Schizophrenia

Question 23

What disorder is caused by loss of dopaminergic pathway from SNC to striatum?

Answer 23

Parkinson’s

Question 24

What disorders are caused by loss of dopaminergic pathway from VTA to ventral striatum?

Answer 24

Drug addiction OCD ADHD

Question 25

What the 3 main components of the diencephalalon?

Answer 25

Thalamus hypothalamus Epithalamus

Question 26

What is the role of the EPITHALAMUS?

Answer 26

Connects limbic system to other brain areas Contains pineal gland --> melatonin - circadian rhythms (Also contains habenula)

Question 27

Another structure in the diencephalic is the reticular nucleus. What is it's role?

Answer 27

GABAergic input to thalamus Brain wave activity

Question 28

What are the functions of the MEDIAL hypothalamus?

Answer 28

- Autonomic - Endocrine - Homeostasis - Survival behaviours (reproduction, feeding, defence etc)

Question 29

What are the functions of the LATERAL hypothalamus?

Answer 29

Sleep and wakefulness

Question 30

Is there a neural connection between the hypothalamus and the anterior pituitary or posterior pituitary?

Answer 30

Posterior

Question 31

Which hypothalamic nucleus produces oxytocin?

Answer 31

Paraventricular

Question 32

Which hypothalamic nucleus produces vasopressin?

Answer 32

Supraoptic

Question 33

What causes Benedikt's sydrome? What does it cause?

Answer 33

Damage to tegmentum - Occulomotor nucleus and red nucleus --> inappropriate eye movement and Cerebellar ataxia