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Flashcards in Midbrain + Diencephalon Deck (34):
0

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

Alar plates

1

Basal plates develop into what in the adult midbrain?

Edinger-Westphal nucleus
Occulomotor nucleus

2

What are the 3 segment of the midbrain?

Tectum
Tegmentum
Basis pedunculi

3

What is the basis pedunculi? What does it contain?

Anterolateral section of midbrain, Cerebellar peduncle

Substantia nigra and crus cerebri

4

What is the crus cerebri?

Descending motor efferent pathways

5

The rostral limit of midbrain on ventral surface is?

The caudal limit on ventral surface is?

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

Where crus cerebri enter pons

6

Dorsal surface limits of midbrain?

Rostral: rostral limit of superior colliculi

Caudal: caudal limit of inferior colliculi

7

What is the role of the SUPERIOR colliculi?

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)

8

What is the role of inferior colliculus?

Receives auditory input from hindbrain

Sends auditory info to superior colliculus and thalamus

9

What is the role of the red nucleus?

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

10

What is the role of the midbrain locomotor area?

Stimulates pattern generator to unite locomotion

Regulates pattern an speed of movement

11

What is the role of the Periaqueductal grey?

Descending pain modulation

Contains opioid neurones

12

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

Somatic - extraocular muscles

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

13

The medial longitudinal fasciculus gives VESTIBULAR input to which nerves?

III, IV and VI

14

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

Trochlear (IV)

15

Which nerve controls the lateral rectus muscle?

Abducens (VI)

16

Where is the abducens nucleus located?

Hindbrain

17

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

Trochlear

18

Describe the response of visceral motor nerve III

Bilateral response:

Direct light reflex in IPSILATETAL eye

Consensual reflex in CONTRALATERAL eye

(Pupil constriction - parasympathetic)

19

Where does the substantia nigra (SNC) project to?

Striatum

20

Where does the ventral tegmental area project to?
What are these pathways and what are they involved in?

1) ventral striatum - mesolimbic pathway - reward + addiction

2) frontal cortex - mesocortical pathway - memory + arousal

21

What type of neurones are VTA projections?

Dopaminergic

22

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

Schizophrenia

23

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

Parkinson's

24

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

Drug addiction
OCD
ADHD

25

What the 3 main components of the diencephalalon?

Thalamus
hypothalamus
Epithalamus

26

What is the role of the EPITHALAMUS?

Connects limbic system to other brain areas
Contains pineal gland --> melatonin - circadian rhythms

(Also contains habenula)

27

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

GABAergic input to thalamus

Brain wave activity

28

What are the functions of the MEDIAL hypothalamus?

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

29

What are the functions of the LATERAL hypothalamus?

Sleep and wakefulness

30

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

Posterior

31

Which hypothalamic nucleus produces oxytocin?

Paraventricular

32

Which hypothalamic nucleus produces vasopressin?

Supraoptic

33

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

Damage to tegmentum - Occulomotor nucleus and red nucleus

--> inappropriate eye movement and Cerebellar ataxia