Respiratory Anatomy

Question 1

What is derived from the 1st pharyngeal pouch?

Answer 1

Auditory tube

Tympanic cavity

Eardrum

Pharyngeal fistula and tube

Question 2

What is derived from the 2nd pharyngeal pouch?

Answer 2

Supra tonsillar fossa

Palatine tonsil

Question 3

What is derived from the 3rd pharyngeal pouch?

Answer 3

Parathyroid glands

Thymus gland

Question 4

What nerves correspond to each pharyngeal arch?

Answer 4

Arch 1: trigeminal nerve (5)

Arch 2: facial nerve (7)

Arch 3: glossopharyngeal nerve (9)

Arch 4 and 6: vagus nerve

Question 5

Internal laryngeal vs external laryngeal nerves

Answer 5

Internal laryngeal
- supplies sensory from the focal folds up in the larynx

External laryngeal
- supplies sensory to the cricothyroid

note that the recurrent laryngeal nerve (AKA inferior) supplies sensation and motor to everything below the cricothyroid

Question 6

Development of the diaphragm

Answer 6

Develops from 4 embryonic structures:

1) Septum transversum
- develops all the diaphragm not from any of the below structures (central tendon)

2) pleuroperitoneal membrane
- generates the posterior-lateral borders of the diaphragm

3) dorsal mesentery of esophagus
- generates the Crura of the diaphragm

4) muscular in growth from lateral body walls of somites 3-5
- muscles of the diaphragm innervated by via the phrenic nerve

Question 7

Eventration of the diaphragm

Answer 7

Half the diaphragm has defective musculature and allows the intestines to indirectly herniate into the thoracic cavity

Caused by failure of muscle tissues to extend into the pleuroperitoneal membranes (NOT a defect in the membrane itself)

this is in contrast to CDH, where the membrane does not develop and allows direct herniation of the bowls into the lateral borders of the thoracic cavity

Question 8

What structures make up the upper respiratory tract?

Answer 8

Nasal cavity

• w/ 4 sinuses
• w/ 3 concha and vomer bone

Pharynx

Larynx

Question 9

What structures make up the lower respiratory tract?

Answer 9

Trachea

Primary bronchi
- w/ secondary and tertiary as well

Lungs
- w/ bronchioles and alveoli

Question 10

3 types of nasal concha

Answer 10

Inferior meatus
- contains the nasolacrimal duct and also is its own separate structures

Middle meatus

• contains the ethmoidal bulla
• contains the semilunar hiatus to connect w/ frontal sinus, anterior ethmoidal cells and maxillary sinuses

Superior meatus
- contains posterior ethmoidal sinuses

note that middle and superior meatus are connected

Question 11

Refresher of the laryngeal muscles

Answer 11

Cricothyroid muscle
- tightens vocal folds

Vocalis muscle
- tightens vocal folds

Thyroartyenoid muscle
- adducts vocal folds

Transverse artyenoid muscle
- adducts vocal folds

Posterior cricoarytenoid muscle

• abducts the vocal folds
• ONLY one to abduct

Lateral cricoarytenoid muscle
- adducts the vocal codrds

Question 12

Types of lung pleura

Answer 12

Parietal pleura

• innervated by intercostal (lateral portion of lung) and phrenic nerve (medial portion of lung)
• outermost layer of the lung
• somatic afferent and sensitive to pain, temp and touch/pressure

Visceral pleura

• innervated by autonomic nerves
• innermost layer attached to the lung
• visceral afferent only sensitive to stretch

Question 13

Anatomical locations of the lung lobes

Answer 13

Superior lobe (right)

• anterior = above clavicle -> 3rd intercostal space
• lateral (midaxillary) = above clavical -> 4th intercostal space

Superior lobe (left)

• anterior = above clavicle -> 5th intercostal space
• lateral (midaxillary) = above clavicle -> 4th intercostal space

Middle lobe (right)

• anterior = 4th-> 5th intercostal space
• lateral (midaxillary)= 5th -> 7th intercostal space

Inferior lobes

• anterior = 5th -> 6th intercostal space
• posterior = below the scapula

Question 14

Pump handle and Bucket handle motions of the ribs

Answer 14

Pump handle  (ribs 1-6)
- move anterior/posteriorly primarily 

Bucket handle (ribs 7-10)
- move laterally primarily 

• movement of the diaphragm is associated with verticals movement of all ribs*

Question 15

Types of lymph nodes in the lungs (from deep -> proximal to the trachea)

Answer 15

1) bronchopulmonary lymph nodes (hilar lymph nodes)
- drain lymph from all parts of the lungs (often site of malignancy)

2) inferior tracheo-bronchial nodes (cardinal nodes)
- drain lymph from all parts of the lungs EXCEPT left superior lobe.
- usually comes second in line after hilar lymph nodes

3) superior tracheo-bronchial nodes
- drains all lymph
- next after cardinal nodes

• left superior lobe eventually drains to the left bronchmediastinal trunk and to the thoracic duct*
• all other parts of the lung eventually drains to the right lymphatic duct*

Question 16

Posterior intercostal arteries

Answer 16

Upper posterior intercostal arteries
- 2 of them and arise from superior intercostal artery

Lower posterior intercostal arteries
- 2 of them and arise from descending aorta

• all supply the intercostal muscles*

Question 17

Anterior arteries w/ respect to what parts of the thoracic cavity they supply

Answer 17

Anterior intercostal arteries
- supply’s intercostal spaces 1-6

Musculophrenic arteries
- supply intercostal spaces 7-9

Superior epigastric arteries
- supplies abdominal walls

• lateral thoracic artery runs along the mid axillary line to supply serratus muscles*

Question 18

Venous drainage

Answer 18

Anterior intercostal veins
- drain into internal thoracic -> brachiocephalic veins

Posterior intercostal veins

• drain into azygos system
• lower left (7-11 intercostal spaces) drain into hemiazygos vein
• upper left (1-6 intercostal spaces) drain into accessory hemiazygos veins
• entire right side empties into main azygos vein