Respiratory System Quiz

Respiratory Anatomy

• The respiratory system functions as an air distributor and gas exchanger, filtering, warming, and humidifying air. It influences speech and sense of smell.

Anatomical Division

• Upper respiratory tract (head and neck):
  • Nasal cavity and nose
  • Paranasal sinuses
  • Pharynx
  • Larynx
• Lower respiratory tract (thorax):
  • Trachea
  • Bronchi
  • Lungs

Functional Division

• Conducting zone: Passages that serve only for airflow
  • No gas exchange
  • From nostrils to major bronchioles
• Respiratory zone: Alveoli and other minimal gas exchange regions

The Upper Respiratory Tract

• Nasal cavity:
  • From nostrils (nares)
  • To choanae (posterior region, opening to nasopharynx).
  • Includes nasal septum, nostrils (external nares), sphenoid bone, vomer, and palatine bone; nasal cavity is divided into nasal fossae, each lined with respiratory epithelium that has goblet cells to produce mucus. Vibrissae (stiff hairs) block debris to help filter air.
• Paranasal sinuses: Air-filled spaces in the skull bones surrounding the nasal cavity adding resonance to voice.
• Pharynx: Muscular tube extending from choanae to larynx; divided into three parts: nasopharynx, oropharynx, and laryngopharynx.
• Larynx (voice box): Cartilaginous chamber approximately 4cm long; primarily keeps food and drink out of the airway; evolved additional role of phonation (production of sound) in animals
  • Epiglottis: Flap guarding superior opening of larynx.
  • Thyroid cartilage: Largest cartilage; shaped like shield. Laryngeal prominence ("Adam's apple") is formed from thyroid cartilage.
  • Cricoid cartilage: Ring-like cartilage connecting larynx to trachea.
  • Arytenoid cartilages: Paired cartilages behind thyroid cartilage.
  • Corniculate cartilages: Small, paired cartilages on top of arytenoid cartilages.
  • Cuneiform cartilages: Support soft tissue between arytenoid and epiglottis.

The Nasal Cavity

• Roof: Ethmoid and sphenoid bones
• Floor: Hard palate, maxilla, and palatine bones
• Nasal conchae: Superior, middle, and inferior nasal conchae projecting from lateral walls; create meatus for airflow. Nasal conchae contain erectile tissue, or swell body; venous plexus in inferior concha restricts airflow in one fossa while directing air through other, and this process occurs every 30 to 60 minutes which helps recover from drying.
• Nasal mucosa:
  • Epithelial layer: Ciliated pseudostratified columnar epithelium with goblet cells.
  • Goblet cells: Produce mucus.
  • Cilia: Propel mucus toward pharynx (swallowed).
• Olfactory epithelium: Sensory neurons detecting odors; in small area of nasal cavity roof.

The Pharynx

• Muscular funnel from choanae to larynx
• Three regions:
  • Nasopharynx
  • Oropharynx
  • Laryngopharynx

The Larynx

• Cartilaginous chamber; maintains airway; keeps food out of airway. It is involved in voice production.
• Cartilages: Epiglottic, Thyroid, Cricoid, Arytenoid, Corniculate, Cuneiform

The Lower Respiratory Tract

• Trachea: Rigid tube; 12 cm long and 2.5cm wide; anterior to esophagus, made of hyaline cartilage rings; trachealis muscle adjusts airflow;
• Main bronchi: Trachea branches into right and left main bronchi at level of sternal angle; right bronchus is wider and more vertical; carina is internal ridge at trachea fork.
• Bronchial tree: Branching system of air tubes from main bronchus to 65,000 terminal bronchioles; each branch is narrower. The right bronchus is wider and more vertical for easier foreign body inhalation in that side. The left bronchus is longer, thinner, and more angled.
• Bronchioles: Smallest branches of bronchial tree; 1mm or less in diameter; pulmonary lobule: portion of lung ventilated by one bronchiole; divides into 50 to 80 terminal bronchioles

Alveoli

• Numerous tiny air sacs in lungs; ~150 million in each lung; 70m2 surface area for gas exchange
• Alveolar cells: Squamous (type I), Great (type II), alveolar macrophages
• Respiratory membrane: Thin barrier between alveolar air and blood
• Capillaries surrounding alveoli.

The Pleurae

• Serous membrane surrounding lungs
• Visceral pleura: Inner layer covering lungs
• Parietal pleura: Outer layer lining thoracic cavity
• Pleural cavity: Potential space between visceral and parietal pleura containing pleural fluid (reducing friction).

Test your knowledge on the respiratory system with this quiz that covers both the upper and lower respiratory tracts. Questions explore the functions of various structures and the overall respiratory process. Ideal for students studying human biology or anatomy.