Anatomy
These are the 5 main intrinsic muscles of the larynx
What are the thyroarytenoid, posterior cricoarytenoid, lateral cricoarytenoid, arytenoids (transverse and oblique), cricothyroid
What are the three ways we can describe voice production?
Pitch, loudness, and quality
How many different types do muscles do we have within the larynx?
5
Posterior and lateral cricoarytenoid
Transverse and oblique arytenoid
Cricothyroid
Thyromuscularis
Thyrovocalis
The larynx is superior to the ___ and anterior to the ___
Where are the sites of vocal fold attachment?
Anteriorly to the thyroid cartilage just below the thyroid notch
Posteriorly to the arytenoid cartilages
List all of the laryngeal control variables
1. laryngeal opposition pressure
2. laryngeal airway resistance
3. glottal size and configuration
4. stiffness
5. effective mass of the VF
What is the difference between extrinsic and intrinsic muscles? (what do they do)
Extrinsic Muscles: attach the larynx to surrounding structures and move the larynx as a unit
Intrinsic Muscles: connect various parts of the larynx together and move laryngeal cartilages relative to each other
What are the biological functions of the larynx?
1. Protecting mechanism: from ‘stuff' getting in and to expel ‘stuff’ out
2. Thoracic Fixation: for bowel and bladder evacuation, childbirth, and emesis (vomiting)
The two laryngeal joints are and they are responsible for
Cricoarytenoid: permits adduction/abduction of the VF in a rocking and gliding motion
Cricothyroid: permits tensing and relaxing of the VF
Explain F0
Fundamental frequency is the cycles per second of our VF
1.The laryngeal muscles are categorized on what two categories?
2. The vibratory patterns of the VF are set by which two types of muscles?
1. Categorized by the affect they have on medial compression and longitudinal tension
2. Tensor and relaxer muscles
What happens to the F0 of men and women as we age and what is the cause?
For females their F0 lowers likely due to menopause
For males their F0 increases due to thinning of the VF
This structure helps protect the airway during swallowing. it does not move on its own
What is the epiglottis
Explain how the myoelastic dynamic theory and the Bernoulli affect relate to the VF
1. Subglottal air pressure builds up below glottis
2. Cover of the VFs open from bottom to top
3. Glottis is open
4. Subglottal pressure decreases
5. At maximum displacement, elasticity of VFs and Bernoulli effect adduct the cover of the VFs back together from bottom to top
These terms are used for closure and opening of the vocal cords
adduction and abduction
Briefly explain laryngeal descent
The larynx if higher up until ~2 years of age and then it descends rapidly through childhood and adolescence to the 3-6/7th vertebrae
What is the skeletal framework of the larynx
hyoid bone
thyroid cartilage
arytenoid cartilages
corniculate cartilages
cricoid cartliages
Explain the three types of vocal attacks, what the laryngeal system is doing during each, and what the VF are doing
Usual: regular speech; respiratory system starts up at the same time as the laryngeal system (build up Psg and engage larynx)
Hard: yelling; respiratory system starts up after the the laryngeal system (VF approximation begins before airflow)
Soft: whisper; respiratory system starts up before the laryngeal system (VF approximate after expiratory airflow)
Explain what each of the muscles does in relation to the VF
ADDuctors:
~lateral cricoarytenoid- rotates arytenoids medially
~oblique arytenoid- pulls the apexes of the arytenoids together
~transverse arytenoid-pulls the arytenoids together
ABductor:
~posterior cricoarytenoid- pulls arytenoids out laterally
Tensors:
~cricothyroid muscles- primary tensor of the VF with two parts; the pars rectus rocks thyroid down toward cricoid (vertical) and the pars oblique slides the thyroid forward (horizontal)
~thyrovocalis: medial muscles of the VF that pulls the thyroid and cricoid cartilages farther apart
Relaxer:
~thyromuscularis- relaxes the VF by pulling the arytenoids towards age thyroid cartilage
What does it mean for our cartilages to ossify and what happen when they do?
Our cartilages begin to stiffen and movement becomes more difficult