08 - NS Diencephalon, Brainstem & Cerebellum

Question 1

What are the components of the diencephalon

Answer 1

Hypothalamus:

Posterior pituitary:

Epithalamus:

Thalamus

Question 2

What does selective attention entail

Answer 2

context, vision, taste, hearing (pain, temp, proprioception, touch/pressure)

Everything but smell!

Question 3

Hypothalamus function

Answer 3

Hypothalamus:
- endocrine regulation
- automatic system regulation (BP, HR, digestion, respiratory, pupil)
- pleasure, fear, rage
- temp regulation
- appetite and thirst

Question 4

Posterior pituitary function

Answer 4

• oxytocin (uterine contractions, lactation)
• vasopressin - ADH (water retenation, vasoconstriction

Question 5

Epithalamus function

Answer 5

• pineal gland (melatonin) - sleep, circadin rhythms, regulated by SCN of hypothalamus

Question 6

Thalamus function

Answer 6

• relay nuclei for memory, motor and sensations to the cerebral cortex
• Memory & emotions (links mammillary bodies to cingulate cortex)
• Motor (determines balance between basal nuclei and cerebellar output to premotor cortex)
• sensations: vision, touch, pain, hearing, pressure, prosterior
• cortical input (inputs from cerebral cortex determine which sensations can or cannot pass to the cortex - selective attention)

Question 7

What are the structures of the brain stem

Answer 7

midbrain, pons and medulla

Question 8

Where do the cranial nerves come from

Answer 8

brainstem
- 4 above pons
- 4 in pons
- 4 below pons

Question 9

Midbrain

Answer 9

contains axons of precentral gyrus
- cerebral peduncles
- corticospinal motor tracts

Question 10

Pons

Answer 10

relay nuclei from cortex to cerebellum via cerebellar peduncle pontine respiratory nuclei
- motor info shared with cerebellum

Question 11

Medulla

Answer 11

pyramidal decussation (corticospinal motor tracts)
- crosses over right side, controls left side vice versa

Question 12

Where are most of the cranial nerve nuclei found

Answer 12

brainstem

Question 13

what are the somatosensory tracts

Answer 13

• cuneate fasciculus
• gracile fasciculus

Question 14

Describe the structures of the midbrain

Answer 14

• tectum (“roof”)
• periaqueductal gray matter (PAG)
• oculomotor nucleus (III)
• medial lemniscus
• red nucleus
• substantia nigra (signals to basal nuclei DA facilitates striatum of basal nuclei)
• fibers of pyramidal tract)
• superior colliculus (visual reflex relay)
• cerebral aqueduct
• reticular formation
• cerebral peduncle
• inferior colliculi (auditory reflex relay)

Question 15

What happens when dopaminergic neurons of the substantia nigra are reduced

Answer 15

Parkinson’s disease
- SN neurons normally prevent activation of inhibitory neurons within the basal nuclei
- loss of the SN results in a decrease of movement due to a net increase of inhibitory neuron activation in the BN

Question 16

Superior Colliculus

Answer 16

vision - coordination of eye movements

Question 17

Inferior Colliculus

Answer 17

Audition - sound localization

Question 18

Periaqueductal grey (PAG)

Answer 18

descending pain modulation

Question 19

Cerebral aqueduct

Answer 19

CSF flow through midbrain

Question 20

red nucleus

Answer 20

motor control

Question 21

medial lemniscus

Answer 21

sensory processing

Question 22

reticular fomation

Answer 22

alertness

Question 23

cerebral peduncles

Answer 23

white matter tracts of motor pathway (pyramidal tract)

Question 24

Substantia nigra

Answer 24

motor control (via basal nuclei)

Question 25

Locate/name structures of the pons

Answer 25

pons

Question 26

pontine nuclei

Answer 26

respiratory center

Question 27

medial lemniscus

Answer 27

sensory processing

Question 28

pyramidal tract

Answer 28

white matter tracts of motor pathway

Question 29

reticular fomation

Answer 29

alertness

Question 30

cerebellar peduncles

Answer 30

white matter tracts that project between the brainstem and cerebellum

Question 31

fourth ventricle

Answer 31

CSF flow

Question 32

Locate/name the structures of the medulla

Answer 32

medulla

Question 33

olivary nuclei

Answer 33

motor control

Question 34

fourth ventricle

Answer 34

CSF flow

Question 35

Choroid plexus

Answer 35

CSF production

Question 36

Medial lemniscus

Answer 36

sensory processing

Question 37

nucleus ambiguus

Answer 37

cardiovascular center

Question 38

solitary nucleus

Answer 38

cardiovascular and respiratory center

Question 39

pyramids

Answer 39

white matter motor tracts (voluntary)

Question 40

Reticular formation

Answer 40

alertness

Question 41

What is the function of the brainstem reticular activating system (RAS)

Answer 41

regulate consciousness, sleep and arousal

Question 41

How does the RAS system work

Answer 41

1. sensory axons synapse on reticular activating system (RAS) neurons in the brain stem - Visual impules - Auditory impulses - Ascending general sensory tracts (touch, pain, temperature, NO olfaction) 2. RAS neurons relay sensory stimuli to the cerebrum through the thalamus 3. the continuous stream of sensory stimuli keeps the cerebrum aroused and alert

Question 41

Vermis

Answer 41

axial control

Question 42

What do descending projections do

Answer 42

from reticular formation nuclei to the spinal cord - help to regulate skeletal and visceral muscle activity

Question 42

Structure of cerebellum

Answer 42

- outer cortex w/groves (fissures) and ridges (folia) - 2 hemispheres w/lobes separate by a central grove anterior lobe primary fissure horizontal fissure posterior lobe vermis

Question 42

lateral hemsphere

Answer 42

appendicular control

Question 43

flocculonodular lobe

Answer 43

eye movements

Question 44

In which way does cerebellar processing and motor control occur

Answer 44

ipsilateral fashion

Question 45

What are the three sensory inputs to cerebellum

Answer 45

1. vision (unfiltered) 2. vestibular (balance) 3. proprioception (position sense) - receptors in joints and muscles (close eyes, position...)

Question 46

What are the major input and output tracts

Answer 46

deep cerebellar nuclei cerebellar peduncles

Question 47

Superior cerebella peduncle

Answer 47

cerebellum to brainstem (muscle tone) and cortex (corrective) from deep nuclei

Question 48

Mid cerebellar peduncle

Answer 48

cortex to cerebellum (motor and visual input)

Question 49

Inferior cerebellar peduncle

Answer 49

proprioceptive & vestibular input to cerebellum

Question 50

CN VIII

Answer 50

Vestibular nerve muscle contractions Cochlear Nerve hearing balance

Question 51

CN XII

Answer 51

hypoglossal nerve - tongue muscle movements

Question 52

CN III

Answer 52

oculomotor nerve - eyeball + eyelid movement