The Lungs Flashcards
Path that air takes through the lungs during inhalation and exhalation
-Air is drawn into lungs via trachea due to low pressure in lungs created by increase in volume of thorax as ribs move up and diaphragm moves down
-when diaphragm muscles and muscles between ribs relax volume decreases so pressure rises and air forced out of trachea
How is the trachea divided
Divides into two bronchi carrying air into and from each lung, these branch off into bronchioles ending in alveoli which are the site of gas exchange
Where are goblet cells found and their role
Found in between ciliated epithelial cells lining the airway
-they secrete mucus which traps dirt and pathogens preventing them from entering epithelial tissue
Where are ciliated epithelial cells found and their role
Found lining the walls of airway
-cilia waft mucus up and out of airway to mouth so it can be swallowed into stomach so hydrochloric acid can kill pathogens to reduce the risk of infection
Purpose of smooth muscle in airway tubes
Control diameter of lumen meaning can constrict to reduce air flow if inhaled dust or pollen to limit the amount of this which is inhaled
Purpose of C-shaped cartilage in trachea and bronchi
Provides support and flexibility meaning the airway is kept open
Epithelial cells
Form the outer surface of animals and line cavities and tubes within these animals, work together as a tissue called epithelium
Alveoli adaptations and properties
-consist of squamous epithelial tissue and elastic fibres
-two cell thick walls means short diffusion partway for gases to travel
-large surface area due to shape and millions in the lungs
-numerous capillaries around the alveoli means good blood supply, maintain high concentration gradients for gas exchange
What is the basement membrane
Made of protein fibres in a jelly-like protein carbohydrate matrix that anchors the epithelium to the connective tissue below
