Histology Flashcards
Functions of respiratory system?
Supplies Oxygen to the blood for transport around the body
Removes CO2 that has accumulated in the blood from tissues in the body
Phonation
Olfaction
Lungs function in BP control via renin-angiotensin system
Phonation?
Vocalization
Olfaction?
Smelling
Passage of air?
- Enters through the mouth and nose
- Travels via pharynx and larynx into trachea
- Trachea branches into bronchi which convey air to lungs
- Each bronchus divides into smaller bronchi then bronchioles
- Bronchioles terminate into alveolar sacs
What does the nasal cavity provide an area for?
Warming,
Moistening & The air
Filtering
Structure of nasal cavity?
- Initial part (Vestibule) is lined by keratinised, stratified squamous epithelium cells
- Deeper into epithelium keratin is lost
- Further in the epithelium changes to epithelium that lines nearly all of the rest of the conducting part of the respiratory system
What type of epithelium lines the conducting part of respiratory system?
Pseudostratified cliliated columnar epithelium with goblet cells
What is underneath the Respiratory Epithelium?
Lamina propria
Lamina propria?
Band of loose cocnnective tissues containing seromucous glands and thin walled venous sinuses.
What does the oropharynx do?
Transmits both air and swallowed food
Adaptions of oropharynx to transmit air and food?
Must resist abrasion
Lined by non keratinized, stratified, squamous epithelium cells
(as is the anterior surface and upper part of posterior surface of epiglottis)
Structure of larynx?
- Walls are made up of cartilage and epithelium
- Surfaces lined with respiratory epithelium
- Excluding vocal folds and adjacent structures which are covered in stratified squamous epithelium
Placing of trachea?
Continuous with larynx and terminates by dividing into main bronchi
Structure of trachea?
- 15-20 C shaped cartilage rings
- Open side of C is spanned by fibroelastic tissue and smooth muscle
- Wall of trachea covered with respiratory epithelium,backed by basal lamina and lamina propria then submucosa
Walls of bronchus are made up of?
Respiratory epithelium
Lamina propria
Muscularis (Ring of smooth muscle & submucosa)
Bronchioles?
Smaller airways lacking cartilage and glands that are 1mm in diameter
Epithelium as you travel further down bronchioles?
Cuboidal instead of columnar
Smooth muscle of the bronchioles?
Respond to parasympathetic innervation and histamine and other factors by constricting and contracting the diameter of bronchiole.
Plays a significant role in asthma attacks and allergic reactions
Terminal bronchioles structure?
Lined with cuboidal, ciliated epithelium
Contain non ciliated club cells (Clara cells) that project above level of adjacent ciliated cells
Roles of Clara/Club cells?
Stem cells
Detoxification
Immune modulation
Surfactant production
What are terminal bronchioles?
Smallest bronchioles that lack respiratory function (gas exchange)
These branch to give rise to give the first part of respiratory tree that has respiratory function- respiratory bronchioles
What interrupts continuity of respiratory bronchioles?
Alveoli
Cells of alveoli?
Discontinuous Squamous type 1 alveolar cells
