David Emerine- demerine@uab.edu
Respiratory
Monday Nov 10 EB132 4-5pm
Supplemental Instruction
Larynx
1. Identify these elements of the cartilagnous skeleton/scaffold of the larynx on one of the models of
the larynx.
 Thyroid cartilage
 Cricoid cartilage
 Arytenoid cartilage (paired)
 Corniculate cartilage(paired)**don’t worry for exam
 Cuneiform cartilage (paired)**don’t worry for exam
 Epiglottis/Epiglottic cartilage
ANSWER:
2. Describe the blood supply and nerve supply to the larynx.***don’t worry about blood supply for
this class. Nerve supply is important but wasn’t covered due to time constraints. This is just FYI to all
future healthcare students.
ANSWER:
Blood supply:
 Superficial and deep branches of the Superior thyroid arteryExternal carotid artery
 Inferior thyroid artery Thyrocervical trunkPart I Subclavian a.
Nerve Supply:


External and internal branches of the Superior thyroid nn. – branch form CN X
Recurrent laryngeal nn. Inferior thyroid nn. branch from CN X
3. Describe the difference between the:
 Ventricle and the vestibule of the larynx
 Rima glottides***don’t worry and the glottis of the larynx
 True/vocal cords (vestibular folds) and the false/vocal folds(vocal folds) ***don’t worry about
the true/false terms
ANSWER:
 The ventricles are the narrow slit-like spaces between the superiorly-located false/vocal folds
and the inferiorly located true/vocal cords. The vestibule of the larynx is the space located
inferior to the laryngeal inlet and superior to the false/vocal folds.
 The rima glottidis is the narrow slit-like space between the true/vocal cords which constantly
changes shape during the production of speech. The glottis is a more generic term – that means
“opening of the larynx” and is considered to be the vocal folds and the space between them.
 True vocal cords(vestibular folds) are ligaments that span from the inner surface of the thyroid
cartilage to the arytenoid cartilages AND they form the slit-like opening known as the rima
glottides. In close proximity to the true vocal cords is the Vocalis muscle that assists in the
production of sound along with muscles attached to surfaces of the arytenoid and cricoid
cartilages. The false vocal folds(vocal folds) are superior to the true vocal folds and they do not
move, however they are capable of vibration so they may assist in amplifying lower pitched
tones that are produced in human speech.

 Laryngeal Cartilages (Gilroy p. 570 and Moore p. 1023)
o The larynx consists of nine laryngeal cartilages: three are single (epiglottic,
thyroid, cricoid) and three are paired (arytenoid, corniculate, and
cuneiform).
 Thyroid:
 Largest of the cartilages
 It is composed of two plate-like laminae that fuse on the anterior
side of the cartilage to form a peak, called the laryngeal
prominence, known as the Adam’s apple.
 Its posterior border is elongated both inferiorly and superiorly to
form the superior horn of thyroid cartilage and inferior horn of
thyroid cartilage.
 Cricoid:
 Only laryngeal cartilage to form a complete ring
 Epiglottic cartilage:
 Consists of elastic cartilage, giving flexibility to the epiglottis
 Almost entirely covered in mucosa
 Its stalk projects superiorly and attaches to the posterior aspect of
the tongue, so that during swallowing the epiglottis will move to
cover the respiratory opening, thus keeping food out of the lower
respiratory tubules
 Arytenoid:
 Pyramid shaped
 Anchor the vocal cords
 Corniculate:
 Attach to the apices of the arytenoid cartilages
 Cuneiform:
 Do not directly attach to other cartilages
Thyroid Cartilage
Cuneiform cartilage
 Arterial blood supply to Thyroid gland (Sup./Inf. Thyroid arteries are
branches of what blood vessels???)
o Superior Thyroid Artery arises from the External Carotid
o Inferior Thyroid Artery arises from the Thyrocervical Trunk (from Part 1
of the Subclavian)
 Similarities/Differences: bronchi and bronchioles (Gilroy pp. 110 and
Moore p.115)
Organization of Bronchiole Tree:
o The trachea bifurcates into two primary bronchi, which feed into each lung.
o These primary bronchi branch into secondary lobar bronchi, which supply
each lobe.
o Furthermore, each secondary lobar bronchus branches into tertiary segmental
bronchi, which supply the individual segments of each lobe.
o The right primary bronchus splits into three secondary lobar bronchi, for its
three lobes. The first has three segmental bronchi to supply the superior lobe.
The second has two segmental bronchi that supply the middle lobe. The third
has five segmental bronchi that supply the inferior lobe.
o On the left lung, each of the two secondary bronchi gives rise to five segmental
bronchi, which supply the superior and inferior lobes, respectfully.
o The tissue composition of the wall of each main bronchus mimics that of the
trachea, but as the conducting tubes become smaller, the following changes
occur:
o Supportive connective tissue changes
 The cartilage rings are replaced by irregular plates of cartilage as
the main bronchi enter the lungs. By the level of the bronchioles,
supportive cartilage is no longer present. By contrast, elastin does
not diminish.
o Epithelium changes
 The mucosal epithelium thins as it changes from pseudostratified
columnar to simple columnar and then to simple cuboidal in the
terminal and respiratory bronchioles. Neither cilia nor goblet cells
are present at this point. After the respiratory bronchioles, the
epithelium further simplifies as it turns into single layer of simple
squamous.
o Smooth muscle becomes important
 A layer of smooth muscle first appears in the posterior wall of the
trachea, the trachealis muscle and continues into the large
bronchi. This layer forms helical bands that wrap around the
smaller bronchi and bronchioles and regulate the amount of air
entering the alveoli. The smooth muscle thins as it reaches the
terminal end of the bronchiole tree and is absent around the
alveoli.
Lungs and Bronchial Tree
1.
Name the three vessels that pass through the hilum.
Answer:
Branches of Pulmonary a. and v.
Rt. Lung : Superior Lobar bronchus & Inferior / Middle lobar bronchus
Lft. Lung: Superior / Inferior lobar bronchus
2.
Outline the flow of air into the lungs from the external environment to the deep lung.
Answer:
external nares, nasopharynx, oropharynx, laryngopharynx, primary bronchi,
secondary bronchi, tertiary bronchi, primary bronchioles, terminating
bronchioles, respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli.
3.
Describe the distinguishing features of the left lung.
Answer:
The left lung has an aortic impression, cardiac notch, and two lobes.
4.
The lungs have fissures that separate the lobes; name the fissures.
Answer:
Rt Lung – Horizontal and Oblique fissure
Lft. Lung – Oblique fissure
5.
Map the bronchial tree with respect to each lung and each lobe.
Answer:
The trachea bifurcates into two primary bronchi, which feed into each lung.
These primary bronchi branch into lobar bronchi, which supply each lobe.
Furthermore, each lobar bronchus branches into segmental bronchi, which
supply the individual segments of each lobe. The right primary bronchus splits
into three secondary bronchi. The first has three segmental bronchi to supply the
superior lobe. The second has two segmental bronchi that supply the middle
lobe. The third has five segmental bronchi that supply three inferior lobe. On the
left lung, each of the two secondary bronchus gives rise to five segmental
bronchi, which supply the superior and inferior lobes, respectfully.
Histology of Bronchial Tree
Trachea
1° Bronchi
2° Bronchi
3° Bronchi
1° Bronchiole
Terminating Bronchiole
Respiratory Bronchiole
Cartilaginous rings or
plates
Pseudostratified Ciliated
Columnar Epithelium
Simple cuboidal
Smooth Muscle and
Alveoli-**Alveoli is only in
respiratory Bronchiole
Alveolar duct
Alveolar sac
Alveolar
Bronchioles are lined with simple columnar epithelium
Simple Squamous