Module 2: Respiratory System Flashcards
2 anatomical divisions of respiratory system?
- Upper respiratory tract
- Lower respiratory tract
2 functional divisions of respiratory system?
- Conducting zone
- Respiratory zone
What comprises upper respiratory tract?
Nasal cavity, nose, sinuses, pharynx, (larynx)
What comprises lower respiratory tract?
Trachea, bronchi, bronchioles, alveolar ducts, alveoli
What is delineated by the conducting zone?
Airways from pharynx, larynx, and trachea -> terminal bronchioles
What is delineated by the respiratory zone?
Respiratory bronchioles, alveolar ducts, and alveolar sacs, alveoli
Role of nasal cavity?
Warming (highly vascularised), humidifying (secretes mucus), and filtering (secretes mucus) of inspired air
What is the nasal cavity?
Large space above and behind the nose; where air first flows in, at rest
What is inside the nasal cavity?
Curved shelves of bone called conchae, which are lined with respiratory epithelium that secretes mucus
What is respiratory epithelium?
Type of pseudostratified columnar ciliated epithelium
Where is the pharynx located?
Located posteriorly to nasal and oral cavities
Tissues of pharynx that are involved in immune surveillance?
3 pairs of tonsils
Role of pharynx?
Allows both food and air to pass (so, digestive and respiratory)
What is the larynx?
Short tube; voice box (contains vocal folds)
Structure of larynx?
Short tube comprised of cartilage structures connected by ligaments and muscles; epiglottis located at entrance
Role of epiglottis?
Flap of cartilage that directs air through the larynx into the trachea, and food/liquid into the esophagus
What is the trachea?
‘Windpipe’; links upper airways to lungs
Location of trachea?
Runs anteriorly to esophagus, down neck into chest
Structure of trachea?
C-shaped rings of cartilage (which help keep the airway open) connected by smooth muscle
What are the primary bronchi?
The two tubes which split from the trachea and carry air into the lungs
Difference between primary, secondary, and tertiary bronchi?
Primary bronchi = entry of lungs
Secondary bronchi = entry of lobes
Tertiary bronchi = smallest bronchi
What are bronchioles?
Smallest airways of respiratory tract; smaller branches of bronchi
What are the most distal bronchioles referred to?
Respiratory bronchioles
Role of alveolar ducts?
Connect respiratory bronchioles to alveoli
What are alveoli?
Thin-walled, elastic buds at the end of the respiratory tree; where gas exchange occurs
What is the diaphragm?
Large thin muscle separating thoracic cavity from abdominal cavity
What happens when the diaphragm contracts?
Moves downward -> increases volume of thoracic cavity -> lower pressure -> air drawn into lungs
What happens when the diaphgram relaxes?
Recoils upward -> decreases volume of thoracic cavity -> higher pressure -> air forced out of lungs
