2- VM Respiratory System Flashcards
What type of cartilage is found in the epiglottis? What type of epithelium covers the anterior surface of the epiglottis and why?
Elastic.
Non-cornified stratified squamous (may change to ciliated pseudostratified columnar at lower end) because this surface is subject to abrasion during swallowing of food bolus.
What type of epithelium lines the larynx? Why?
Respiratory epithelium (ciliated pseudostratified columnar with goblet cells) because this surface normally comes in contact with air only.
The glands located between the epithelium and cartilage of the larynx are ______ glands.
Mixed glands (mucous and serous).
What type of epithelium lines the lumen of the trachea?
Respiratory epithelium - ciliated pseudostratified columnar with goblet cells
What type of cartilage makes up the tracheal rings?
Hyaline cartilage
C rings of the trachea are incomplete posteriorly, and a band of smooth muscle connects the two ends of the cartilage rings. What is the name of this muscle? During what activity does this muscle contract?
Trachealis muscle.
Coughing causes it to contract, constricting the tracheal muscle lumen and increaseing the force of air flow.
What type of tissue is prominent in the submucosa between the tracheal epithelium and cartilage?
Mucous and seromucous glands.
You have a patient with COPD as a result of bronchitis. How might you control excessive secretions in a patient who is coughing up sputum?
Urge the pt to cough.
A suction catheter may be passed into the trachea to remove secretions. This also stimulates the pts cough reflex. In addition to bronchodilation, beta 2 adrenergic agents increase the rate of particle transport by the ciliated epithelium to improve clearance of airway secretions.
What is an alveolar sac? What cell types are present in the walls of an alveolar sac? What type of connective tissye supports the wall of an alveolar sac?
Clusters of alveoli that open into a common air space. (like a round foyer with open doorways to several rooms - the alveoli).
Type I and type II pneumocytes and alveolar macrophages are present.
Elastic tissue (passive recoil of elastic fibers contribute sto exhalation)
What is the function of the smooth muscle cells at the openings of alveolar duct alveoli?
The smooth muscle serves as a sphincter, regulating alveolar air movements.
Within the epithelium of all bronchioles are _____ cells. What are thse and what are some purported funcitons of these cells?
Club cells.
Functions may include:
- secreting a protective material to protect bronchiolar epithelium
- degrading inhaled toxins
- serving as stem cells
What happens to the smooth muscle fibers of the bronchiols upon stimulation by the sympathetic division of the ANS? What effect does sympathetic stimulation have on the blood vessels in lung tissue?
Smooth muscle fibers: relax to produce bronchodilation
Blood vessels: vasoconstrict
Normally, what substance coats the surface of the alveoli? What cells are the source of this substance?
Surfactant - type II pneumocytes
What are the morphological components of hte blood-gas barrier?
Type I pneumocutes, fused basal laminae of type I pneumocytes and capillary endothelial cells, capillary endothelial cells, erythrocyte plasma membrane alveoli.
What histological structure is common to respiratory bronchiles and distal structures?
Alveoli.
