Respiratory Tract Anatomy Quiz

Respiratory Tract Anatomy

• Respiration involves the intake of oxygen and the removal of carbon dioxide, a waste product of cellular metabolism.
• Every cell in a mammal relies on this gas exchange, a crucial function of the cardio-respiratory system.

Nasal Cavity

• The nasal cavity is divided by a septum, although not perfectly symmetrical.
• The hard and soft palate separate it from the oral cavity.
• The posterior nasal cavity connects to the nasopharynx.
• Functions include heating, cleansing, and moisturizing the inhaled air.

Paranasal Sinuses

• These air-filled spaces are located within the skull bones surrounding the nasal cavity.
• They enhance the voice and enable self-hearing.

Larynx

• The larynx (voice box) is a cartilaginous structure.
• Key components include the hyoid bone, epiglottis, vocal cords, and various cartilages (corniculate, cuneiform, thyroid, cricoid, epiglottis).

Phonation

• During exhalation, air passes through the gap (glottis) between the vocal folds.
• Sounds are produced through varying air pressure and vocal fold width.
• The volume and pitch (frequency) of the sound depend on the air pressure and the width of the vocal folds.

Swallowing

• The tongue root propels the epiglottis downwards, closing off the entrance to the larynx.
• Food then travels down the esophagus.
• The vocal folds also close as a safety mechanism during swallowing.
• During coughing, the vocal folds first close, and then suddenly open when the pressure of exhaled air surpasses the laryngeal closing force.

The Lower Airways

• The trachea, or windpipe, is an elastic tube (~12cm long), consisting of C-shaped cartilages connected by elastic membranes.
• It branches into two main bronchi (one for each lung).
• The right lung is divided into three lobes, the left into two lobes, leading to further divisions into smaller bronchi, forming a bronchial tree.

Alveoli

• Alveoli are tiny air sacs in the lungs where gas exchange occurs.
• These sacs are delicate structures embedded in a thin membrane called the air-blood barrier.

Physiology of Breathing

• Breathing involves the negative pressure of the lungs, which sucks air inside.
• Chest expansion happens via the diaphragm (flattens during contraction) and intercostal muscles (lift ribs).
• Auxiliary respiratory muscles also contribute, originating from the cervical (and upper thoracic) spine and connected to the ribs

Inspiration and Expiration

• Inspiration (breathing in) expands the chest cavity, increasing volume and lowering pressure inside the lungs, drawing in air.

• Expiration (breathing out): The chest cavity shrinks due to relaxation of muscles, increasing pressure inside the lungs, forcing air out.

Air Composition

• Air is a mixture of gases, primarily nitrogen, oxygen, carbon dioxide, and trace noble gases.
• Relevant percentages of each gas in the inhaled and exhaled air.

Test your knowledge on the anatomy of the respiratory tract, including the nasal cavity, paranasal sinuses, and larynx. Understand the functions of these structures in gas exchange and phonation. This quiz covers key anatomical components and their roles in the respiratory system.