Laryngeal Neuroanatomy

Question 1

laryngeal function is controlled by..

Answer 1

-PNS and CNS

Question 2

PNS

Answer 2

cranial and spinal nerves

Question 3

CNS

Answer 3

brain and spinal cord

Question 4

white matter

Answer 4

transmits

Question 5

grey matter

Answer 5

processes

Question 6

the cortex

Answer 6

CNS
-outer covering of brain formed by nerve cell bodies
-grey matter
-divided into lobes by central sulcus and lateral fissure
-control of all voluntary movement is located in frontal lobe
-

Question 7

important areas involved in the initiation, planning, and sequencing of all movements:

Answer 7

• primary motor cortex
• premotor cortex
• supplementary motor area

Question 8

sends impulses to mms

Answer 8

primary motor cortex

Question 9

planning, organization of movements

Answer 9

premotor cortex and supplementary motor area

Question 10

cerebrum

Answer 10

CNS

• mass of what matter that forms the bulk of the brain
• consists of many nerve pathways that go up to the cortex and down to other areas

Question 11

areas of grey matter within the cerebrum

Answer 11

• basal nuclei
• thalamus
• hypothalamus

Question 12

basal nuclei structure

Answer 12

• clusters of cell bodies
• grey matter
• putamen, globus pallidius, caudate

Question 13

basal nuclei function

Answer 13

• act as an inhibitory complex for excessive movements

- refines and smoothes movement by inhibiting excessive motor impulses from cortex

Question 14

thalamus

Answer 14

• area of grey matter made of many different clusters of nuclei
• receives motor nerve projections from BG, cerebellum, cortex
• receives sensory info for every sense except smell

Question 15

why is thalamus important for sensory integration?

Answer 15

• if we were aware of all sensory input, it would be too much to process
• distracting
• involved with consciousness, alertness, integration of emotional expression into motor activity (connected to limbic system)

Question 16

cerebullum integrates and regulates…

Answer 16

• movements initiated in other parts of motor system
• contributes to smooth movements
• involved in regulation of balance, posture, muscle tone, coordination of mms groups

Question 17

Similarities and differences cerebrum vs cerebellum

Answer 17

• both have a cover of grey matter (cerebellum has regular cover, cerebrum has sulci and gyro)
• insides both made of white matter with deep grey matter nuclei
• cerebellum is divided into 3 lobes, 2 hemispheres connected by vermis

Question 18

aspects of movement regulated by cerebellum

Answer 18

• force
• speed
• range
• timing
• direction
• amount of displacement

Question 19

periaqueductal grey (PAG) structure

Answer 19

• around liquid grey matter
• diffuse area of grey matter surrounding cerebral aqueduct
• part of ventricular system of brain
• connects 3rd and 4th ventricle
• filled with CSF
• connected to nucleus retroambiguus (NRA)

Question 20

NRA neurons innervate mms of

Answer 20

tongue, pharynx, soft palate, exhalation, larynx

Question 21

PAG function

Answer 21

• coordinates basic respiratory and laryngeal motor patterns necessary for speech
• involved in expression of emotion (linked to limbic lobe)

Question 22

damage in PAG

Answer 22

• results in inability to form a sound (mutism)

- inability to form intent to speak

Question 23

corticospinal tract (CST)

Answer 23

cortex directly to spine

• arises from areas in the frontal and parietal lobes
• fibers run ipsilaterally primarily

Question 24

where does CST decussate

Answer 24

pyramids of medulla

Question 25

CST fibers

Answer 25

80% cross to contralateral side | 20% run ipsilaterally

Question 26

corticobulbar tract (CBT) corticonuclear

Answer 26

cortex to motor nuclei fo specific cranial nerves

Question 27

together CST and CBT form and control...

Answer 27

the direct/pyradmidial system | -controls fine skilled voluntary movements

Question 28

damage to CST/CBT

Answer 28

results in weakness, spasticity to the point of paralysis (maybe)

Question 29

indirect/extrapyramidial tract

Answer 29

circuitous pathway that extends from cortex to brainstem and spinal cord - interconnected with basal ganglia and cerebellum - multisynaptic=interconnected with other brain structures

Question 30

indirect/extrapyramidial tract function

Answer 30

serves to smooth and refine voluntary movement originating in the cortex

Question 31

indirect/extrapyramidial tract damage

Answer 31

causes excessive movements (PD) | -ticks, tremors, rigidity

Question 32

pryamidal and extrapyramidal systems together form...

Answer 32

upper motor neuron (UMN)

Question 33

spinal and cranial nerves form...

Answer 33

the lower motor neuron (LMN) | -aka final common pathway because all the info converges at spinal and cranial nerves

Question 34

3 branches of vagus nerve important for voice

Answer 34

- pharyngeal - superior laryngral (SLN) - recurrent laryngeal (RLN)

Question 35

pharyngeal branch

Answer 35

innervates mms of velum

Question 36

SLN

Answer 36

internal (sensory) and external (motor) branches | -innervates cricothyroid

Question 37

RLN

Answer 37

innervates thyroarytenoid, cricoarytenoid, PCA, and IAs - asymmetrical left and right sides - right side loops around subclavian artery and goes up again - left side loops around aorta

Question 38

vagus nerve damage

Answer 38

longer on left side (more susceptible to damage) | -congestive heart failure can compress nerves causing some dysphonia, affecting vocal function

Question 39

laryngeal reflexes

Answer 39

- important for airway protection | - sensory nerve endings: mucosal layers, joints, mms

Question 40

receptors respond to different stimuli: | and react by...

Answer 40

- touch - movement - vibration - change in air pressure - chemicals -initiating tight reflexive closure of laryngeal valves protecting the airway (cough)

Question 41

two systems controlling vocalization

Answer 41

CBT to nucleus ambiguus (NA) - allows fine control of VOLUNTARY movements - important for purposeful speech and voicing - pathway is not present in other primates

Question 42

emotional pathway

Answer 42

- nerve fibers project between the limbic system>PAG>NA - involved in emotional vocalizations: laughter, crying, screaming, coughing - shared pathways with other primates