Anatomy/Histology of Respiratory System Flashcards
What are the 6 main functions of the respiratory system?
Airflow
Gas exchange and transport of oxygen and carbon dioxide
Acid-base regulation
Temperature regulation
Immune protection
What is the metabolic function of the respiratory system?
Removal of noradrenaline, prostaglandins and 5-HT
What hormonal activity is present in the lungs?
Angiotensin II is formed from angiotensin I in the lungs
Which is an active process: inspiration or expiration?
Inspiration
How many lobes do each side of the lung have?
Right - 3
Left - 2
What is the transition of epithelial cells down the lung?
Pseudostratified columnar ciliated -> cubodial -> squamous
What part of the lungs has abundant glands?
Upper respiratory tract
What cells decrease in number until the bronchioles?
Goblet cells
When does cartilage stop being found in the respiratory tract?
From the small bronchi onwards
How do tracheal cartilage and bronchi cartilage differ?
Trachea - C-shaped rings
Bronchi - plates
What does smooth muscle in the trachea do?
Joins C-shaped rings
What 2 features of the tract does smooth muscle surround completely?
Bronchi and bronchioles
Which 2 feature is elastic tissue found?
Bronchi and bronchioles
What are the 2 zones in the lungs?
Conducting and Respiratory zone
What is the function of the conducting zone?
Get air in
Warm and moisten air
Clean air
nasal cavity -> terminal bronchioles
What is the function of the respiratory zone?
Gas exchange
Respiratory bronchioles -> alveoli
What is the function of the epiglottis?
Protects lungs from ingested food
What is found in the vestibule of the nasal cavity?
hairs and mucus
What is the function of respiratory mucus?
Filtering, humidifying and adjusting temperature of inspired air
What is the function of turbinate bones in the nasal cavity?
Increase surface area which air flows over
What cells does the mucosa of the nasal cavity contain?
Pseudostratified ciliated columnar respiratory epithelium
Goblet cells
What glands are present in nasal mucosa?
Serous and mucous glands
What is the pharynx?
Passageway that connects nasal and oral cavity
What are the 3 sections of the pharynx?
Nasopharynx
Oropharynx
Hypopharynx
What glands are present in the nasopharynx?
Seromucous glands
What is the lymphoid tissue in the pharynx called?
Waldeyer’s ring
What type of epithelium is present in the oropharynx?
Non-keratinized stratified squamous epithelium
What are the 3 functions of the larynx?
Maintains open passageway for air movement
Prevents swallowed materials from entering trachea
sound production
How many laryngeal cartilages are there?
9 (hyaline and elastic)
What does the first bronchus branching depend on?
Number of lobes
What is the function of the trachea?
Warm, clean and conduct air
What are the 4 layers of the trachea?
Mucosa
Submucosa
C-shaped hyaline cartilage rings
Adventitia
What 3 layers make up the tracheal mucosa?
Epithelium, basement membrane and lamina propria
What 5 cell types are in the tracheal mucosa?
Pseudostratified cilliated columnar cells
Goblet cells
Serous cells
Basal cells
Brush cells
What types of glands are found in the tracheal submucosa?
Mixed seromucous glands
Which primary bronchus is shorter, wider and more vertical?
Right
What does the bronchus lamina propria contain more of?
Elastin and is separated from the SM by smooth muscle
What type of epithelial cells are present in the bronchioles?
Ciliated columnar epithelium
What surrounds bronchioles’ smooth muscle coats?
Fibroelastic connective tissue
What does smaller bronchiole epithelium change to?
Simple cuboidal
What are goblet cells replaced with in terminal and respiratory bronchioles?
Club cells
What is the function of Clara cells?
Divide, differentiate and metabolize toxic chemicals
Produce a component of surfactant
What 4 structures make up the gas exchange region?
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli
What are 4 features of respiratory bronchioles?
Single alveoli in walls
Devoid of goblet cells
Ciliated cuboidal epithelium
Non-ciliated club cells
How many alveolar ducts do respiratory bronchioles divide into?
7
What do alveolar ducts end in?
Alveolar sac which opens to 7 alveoli
What does each alveolus consist of?
Pocket open at one side and lined by squamous pneumocytes (type I and II)
What do alveolar pores allow?
Movement of air between adjacent alveoli
What 3 things does the alveolar wall consist of?
Surface epithelium
Supporting tissue
Blood vessels
What is the function of alveolar macrophages?
Immunity
Keeps alveoli free of dust and debris
What are the 3 functions of Type I Pneumocytes?
Facilitates gas exchange
Maintain ion/fluid balance
Communication with type II cells
What are the 4 functions of Type II Pneumocytes?
Produce and secret pulmonary surfactant - prevents pulmonary collapse
Expresses immunomodulatory proteins
Movement of water
Regeneration of epithelium
What is the pleura?
Thin layer of membrane that holds the lung
What are the 2 layers of the pleura?
Parietal - internal lining
Visceral - externally coats lung
What prevents friction between the pleural layers?
Tiny space that contains a small amount of serous fluid
