Histology Flashcards
What is the function of the conducting portion of the respiratory tract?
To humidify, cleanse and adjust the temperature of inspired air
What is in the conducting portion of the respiratory tract?
Nasal cavity
Larynx
Trachea
Intrapulmonary region
How is the temperature of inspired air changed?
By the rich vascular supply in the nasal cavity
What is found in the lamina propria of the nasal cavity?
Bowman’s glands
Venous sinuses
Describe the histology of the olfactory region of the nasal cavity
Thick epithelium
No goblet cells
Olfactory cells
Describe the structure of olfactory cells
Bipolar neurones
One dendrite extends to the surface to form a swelling
Non-motile cilia extend parallel with the surface to increase the surface area
Function of the larynx?
Phonation
Prevent substances gaining access to its lumen
What are the three parts of the lumen of the larynx?
Vestibule
Ventricle
Infraglottic cavity
What epithelium are the vocal cords lined with?
Stratified squamous
What does each vocal cord have?
Vocalis muscle
Vocal ligament
What is the trachea supported by?
15-20 C-rings of hyaline cartilage
What are the three layers of the wall of the trachea?
Mucosa
Submucosa
Adventitia
What are the secondary bronchi supported by?
Crescent shaped hyaline cartilage
What is contained in the intrapulmonary region?
Secondary bronchi
Bronchioles
What changes as you go from larger bronchioles to smaller bronchioles?
Goblet cells replaced by Clara cells
What do Clara cells secrete? Purpose?
Surfactant lipoprotein
Prevents walls sticking together during expiration
What is in-between the gaps of hyaline cartilage in the trachea?
Trachealis muscle which is a bundle of smooth muscle and fibroelastic tissue
What are the respiratory muscosa and submucosa adapted to do?
Warm and moisten the air
Trap particles in the mucus
What is contained in the lamina propria of the trachea? Function?
Elastin
Helps in elastic recoil during inspiration and expiration
What is contained in the submucosa? Function?
Serosa-mucous glands
Humidify the air
Diameter of bronchioles?
1mm or less
What are the final branches of the bronchioles called?
Terminal bronchioles
What causes the smooth muscle to contract in the terminal bronchioles?
Parasympathetic stimulation of the vagus nerve
What is in the respiratory portion of the lungs?
Respiratory bronchioles - alveolar ducts - alveolar sacs - alveoli
Epithelium of alveoli?
Type I pneumocytes - squamous cells - permit gas exchange
Type II pneumocytes - produce surfactant
What are alveolar walls supported by?
Elastic and reticular fibres
What do alveolar ducts connect?
Respiratory bronchioles to alveolar sacs
Each sac contains a collection of alveoli
