Histology Flashcards
What is the function of the respiratory system?
Supplies oxygen to the blood for delivery to cells throughout the body
Removed carbon dioxide from the blood that has accumulated from tissues of the body
What 3 things does the nasal cavity provide an extensive area for?
Warming, moistening and filtering the inspired air
What is the vestibule?
The most anterior part of the nasal cavity
What type of epithelium lines the vestibule?
Keratinised stratified squamous epithelium
What lines the majority of the conducting part of the respiratory system?
Pseudostratified ciliated columnar epithelium with goblet cells or respiratory epithelium
What lies underneath the respiratory epithelium?
The lamina propria
What is the lamina propria
Band of connective tissue containing seromucsus glands and a rich venous plexus which can quickly engorge with blood and block the nose
What lines the oropharnyx and why?
Non-keratinised stratified squamous epithelium, because it transmits both air and food and most resist abrasion
What are the walls of the larynx made of and how are they lined?
Walls are made of cartilage and muscle and they are lined with respiratory epithelium
What covers the vocal folds and its adjacent structures?
Stratified squamous epithelium
What structures mark the start and end of the trachea?
Continuous with the larynx and divides into the main bronchi
Describe the structure of the trachea
15-20 hyaline C shaped cartilages
The open side of the C is spanned by fibroelastic tissue and smooth muscle (trachealis muscle)
Describe the structure of the wall of the trachea
Respiratory epithelium, then basal lamina, a lamina propria of connective tissue with abundant elastic fibres and a submucosa of loose connective tissue that includes numerous seromucous glands.
Describe the cartilage structure of the bronchi
There are irregular shaped cartilage plates
What is the structure of the walls of the bronchi?
Respiratory epithelium, lamina propria containing a discontinuous layer of smooth muscle seromucous glands
How big is the diameter of a bronchiole?
Less than 1mm diameter
Do bronchioles contain cartilage and glands?
Lack cartilage and glands, but may contain a few goblet cells
As you move down the respiratory tree to the smallest bronchioles, what happens to the epithelium?
Epithelium decreases in height from columnar to cuboidal
What is the lamina propria of bronchioles composed of?
Smooth muscle and elastic and collagenous fibres
What causes the smooth muscle of bronchioles to contract?
Parasympathetic system, histamine and other factors
What are 4 roles of Clara cells?
Stem cells
Detoxification
Immune modulation
Produce surfactant
What are the names of the 2 parts that the respiratory system can be divided up into?
The conducting portion and the respiratory portion
Bronchiole further divided into 2 named bronchiole types, what are these?
Terminal bronchioles followed by respiratory bronchioles
What is the name of the terminal portions of the bronchial tree?
Alveoli
What does surfactant do?
Spreads over the pulmonary surface to reduce the surface tension at the air-fluid interface. Reduces the tendency for alveoli to collapse
What do alveolar macrophages do?
Free cells that phagocytose inhaled particles that may have escapes entrapment by the mucous lining of the airway. They typically migrate my the bronchial tree by the action of cilia, to the pharnyx where they are swallowed.
