Respiratory System Anatomy Quiz

The Structure of the Lower Respiratory Tract I

• The larynx is the gateway to the lower respiratory tract (LRT).
• The larynx has several key arteries: internal carotid artery and superior laryngeal artery.
• The trachea, thyroid cartilage, cricoid cartilage, thyrohyoid membrane and superior thyroid artery are also components of the larynx.
• The thoracic cage is crucial for respiration and contains 12 ribs on each side and 3 layers of flat muscles.
• The sternum, composed of the manubrium, body, and xiphoid process, forms the anterior part of the thoracic cage.
• The three flat muscle layers in the thoracic cage include: external intercostal muscle, internal intercostal muscle, innermost intercostal muscle.
• The main blood vessels are located along the lower border of each rib.

Rib Articulation

• The anterior end of each rib comprises costal cartilage, providing flexibility and elasticity to the rib cage.
• Each rib articulates posteriorly with thoracic vertebrae.
• The majority of ribs have three articulations with the vertebral column.

Rib Movement

• Rib movement includes two inter-related movements:
  • Superior and anterior movements
  • Lateral shaft elevation

Surface Anatomy

• The sternum's movement during respiration is described as "pump handle" and "bucket handle" movements.

Identifying Structures of the Thorax

• A, B, and C refer to different sections on the lateral chest view, specifically showcasing the three lateral lung lobes.

Location of Middle Lobe of the Right Lung

• The middle lobe of the right lung lies between the 4th and 6th rib.

Trachea

• The trachea extends from the larynx to the carina.
• The carina is where the trachea divides into the right and left main bronchi.

Anatomy of the Trachea

• The trachea branches into primary bronchi, which further divide into secondary bronchi.
• The trachea contains tracheal cartilages, with a carina (internal ridge) situated at the bifurcation point.

Venous Drainage

• Venous drainage, associated with the respiratory tract, includes brachiocephalic, accessory hemiazygos, and azygos veins.

Main Bronchi

• The right main bronchus is narrower and more vertical than the left.

Bronchial Tree

• The bronchial tree divides into lobular bronchi, segmental bronchi, and terminal bronchioles.

Lung Hilum

• The pulmonary artery is superior to the main bronchus in the left hilum but anterior to the main bronchus in the right hilum.

Right Lung

• The right lung has three lobes (superior, middle, and inferior) separated by fissures (horizontal and oblique).

Left Lung

• The left lung has two lobes (superior and inferior) separated by an oblique fissure, and contains a lingula analogous to the right middle lobe.

Segmental Branches

• Segmental bronchi and branches serve different sections of the lungs, enabling targeted airflow for effective ventilation.

Lung Lobes

• The right lung has three lobes: apical, anterior, and posterior in the superior, two segments (medial and lateral) middle and 5 segments (apical, anterior, posterior, medial, and lateral) in the inferior lobe.
• The left lung has two lobes: apical-posterior and anterior in the superior and the lingula, with two sections (superior and inferior), and 4 (apical, anterior, posterior, and lateral) in the inferior segment.

Acinus

• The acinus is the portion of the lung distal to a terminal bronchiole.
• A first-order respiratory bronchiole supplies the acinus.

Alveoli

• A lung contains approximately 30,000 acini.
• An acinus has a diameter of approximately 3.5 mm.
• The acinus is vital for gas exchange as all respiratory bronchioles have alveoli in their walls.
• Alveolar epithelium is composed of type I pneumocytes (90-95%) and type II pneumocytes (5-10%).

Respiratory Bronchioles

• Respiratory bronchioles are the first airways able to conduct gas exchange.
• Respiratory bronchioles are lined with ciliated cuboidal epithelium.
• Respiratory bronchioles contain Clara cells (secretory cells)

Terminal Bronchioles

• Terminal bronchioles are the smallest conducting airways.
• They're progressively smaller airways that branch from the bronchi.

Sensory Dermatomes

• Sensory dermatomes are specific segments of skin innervated by spinal nerves (T2-T12).