Brainstem and reticular formation

Question 1

What are the tree functions of the brainstem?

Answer 1

conduit: info goes to cortex and spinal cord thru brainstem
cranial nerve: head’s version of spinal nn
integrative functions: complex motor patterns, cardiorespiratory control, reflexes

Question 2

What does the STT detect?

Answer 2

pain and temp, some special touch

Question 3

What does PCML pathway detect?

Answer 3

two point touch, vibration, pressure, conscious proprioception

Question 4

What does corticospinal tract detect?

Answer 4

motor

Question 5

What are the three areas of brainstem rostral to obex?

Answer 5

tegmenjtum = tissue ant to ventricle
tectum = post
stuff added onto ant surface

Question 6

What structures are part of the medulla?

Answer 6

obex, pyramidal decussation, olive, cuneate tubercle, gracile tubercle, CNs IX, Xm XII

Question 7

What structures are found in pons?

Answer 7

basal pons, middle cerebellar peduncle, CN V, VI, VII, VIII, superior cerebellar peduncle

Question 8

Structures found in midbrain?

Answer 8

cerebral aqueduct, superior and inferior colliculus, CN II, IV, inferior brachium

Question 9

Where does the caudal medulla extend?

Answer 9

caudal edge of pyramidal decussation to obex

Question 10

Where does rostral medulla extend?

Answer 10

to lateral recess of 4th ventricle

Question 11

Where does caudal pons extend?

Answer 11

lateral recess of 4th ventricle to middle cerebellar peduncle

Question 12

Where does rostral pons extend?

Answer 12

top of middle cerebellar peduncle to vertebral aqueduct

Question 13

What are the types of axons in a spinal n of the spinal cord?

Answer 13

• somatic sensory (paint, temp, mechanoreceptors)
• visceral sensory (GI, blood vessels)
• visceral motor (preganglionic autonomic)
• somatic motor (innervate skeletal mm)

Question 14

What are the special CN functions?

Answer 14

special sensory = hearing, equilibrium

branchial motor = innervate mm derived from pharyngeal arches (larynx, pharynx, jaw, face)

Question 15

How many different types of nerve fibers are in brainstem?

Answer 15

6

Question 16

T/F No CN has all 6 types of axons

Answer 16

T

Question 17

What is the central core of the brainstem?

Answer 17

reticular formation

Question 18

Where does the reticular formation extend?

Answer 18

into cerebrum as hypothalamus

Question 19

What is reticular formation important to regulate?

Answer 19

posture, some stereotypic motor behaviors, regulating internal environment, pain regulation, sleep and wakefulness, emotional tone

Question 20

What are the longitudinal zones of the reticular formation?

Answer 20

1. raphe nuclei
2. medial zone
3. lateral zone

Question 21

What does the raphe nuclei zone produce?

Answer 21

serotonin

Question 22

Where is the source of most ascending and descending projections of neurons?

Answer 22

medial zone

Question 23

What does the medial zone do?

Answer 23

coordinates walking or running

Question 24

Where is the lateral zone prominent?

Answer 24

rostral medulla and caudal pons

Question 25

What is the lateral zone primarily involved in?

Answer 25

CN reflexes and visceral functions

Question 26

What are the two reticulospinal tract? where are they?

Answer 26

medial = pons and lateral = medulla

Question 27

Where does the lateral reticulospinal tract descend?

Answer 27

bilaterally in lateral funiculus

Question 28

Where does medial reticulospinal tract descend?

Answer 28

ipsilateral near MLF and in ant funiculus

Question 29

What is the major alternative to the corticospinal tract in regulating spinal motor neurons?

Answer 29

reticular formation - influences spinal motor neurons directly

Question 30

What does reticular formation regulate?

Answer 30

spinal reflexes

Question 31

Where does the reticulospinal tract receive input from?

Answer 31

cerebral cortex, basal ganglia, substantia nigra, etc

Question 32

Which rhymes motor patterns does the brainstem reticular formation regulate?

Answer 32

gaze centers, mastication, locomotion (pons), heart rate, respiration, swallowing, vomiting

Question 33

What are the gaze centers of reticular formation?

Answer 33

midbrain vertical gaze center and pontine horizontal

Question 34

What are symptoms of sleep bruxism?

Answer 34

tooth grinding or clenching | - sounds, abnormal wear, jaw m discomfort

Question 35

What happens to mm in sleep bruxism?

Answer 35

state of atonia, jaw mm co-contracted, mm of mastication all contracting at same time, increased tone in mm

Question 36

What is the peripheral causes theory of bruxism?

Answer 36

malocclusion results in premature and one-sided contract, jaw movements continue in attempt to reach resting position

Question 37

What is the central causes theory of bruxism?

Answer 37

sleep-related dysfunctions cause bruxism | - input to supratrige minal nucleus may be from basal ganglia, lateral hypothalamus and central nucleus of amygdala

Question 38

where does PAG reticence pain info from?

Answer 38

spinomesencephalic fibers

Question 39

Where does pain signal travel?

Answer 39

PAG to raphe -> posterior horn of spinal cord/ spinal V nucleus

Question 40

What is one way opiates work to control pain?

Answer 40

activate PAG-raphe at multiple levels

Question 41

How can raphe inhibit STT?

Answer 41

directly or indirectly by activating interneurons and can directly inhibit pain afferents

Question 42

Where are centers controlling inspiration, expiration, breathing? heart rate and blood pressure?

Answer 42

pons and medulla | medulla

Question 43

What projections work together to modulate cortical activity?

Answer 43

thalamic intralaminar nuclear projections to cortex and monoamine reticular projections

Question 44

What results in prolonged coma?

Answer 44

bilateral damage to midbrain RF

Question 45

What has a role in sleep-wakefulness cycle?

Answer 45

Ascending reticular activating system

Question 46

What neurochemicals are in the brainstem? hypothalamus? telencephalon?

Answer 46

norepinephrine, dopamine, serotonin histamine acetylcholine

Question 47

How does noradrenergic neurons function in the medulla?

Answer 47

solitary nucleus = memory enhancement | ventrolateral medulla = pain regulation

Question 48

How do noadrenergic neurons in rostral pons function?

Answer 48

locus ceruleus = cortex (arousal) vigilance and attention | - active in attentive situations, moderate while awake and low when sleeping

Question 49

What occurs when norepinephrine is released into trigeminal spinal nucleus and spinal cord?

Answer 49

suppress incoming pain signals

Question 50

What is lost in patients with Parkinson's disease?

Answer 50

locus ceruleus neurons

Question 51

Where are dopamine neurons?

Answer 51

midbrain (substaita nigra and ventral segmental area)

Question 52

What are the two components of schizophrenia?

Answer 52

social withdrawal and hallucinations