Human Lungs Flashcards
Goblet cell function
Secrete sticky mucus, to trap tiny particles in the air. Therefore reducing the chance of infection.
Ciliated epithelial cell function
Has numerous tiny hair-like structures on a membrane called cilia. These waft the mucus up the Airway tube to the back of the throat be swallowed.
What is the function of cartilage / C-rings in the trachea and bronchi ?
To support the trachea and bronchi, holding them open and preventing collapse during inspiration while still allowing the oesophagus to expand.
Where can one find and the Goblet cells, ciliated epithelial cells and smooth muscle ?
Trachea, bronchi and bronchioles
What is the function of Smooth muscle
Adjust the size of the Airways. They can contract, which causes constriction, reducing the diameter of the lumen and restricting airflow to and from the lungs in for example the trachea.
Elastic fibres function
To stretch when inhaling so the alveoli will expand , increasing the surface area. Also to recoil when breathing out to force more air out. They help to prevent the alveoli from bursting
Where can one find elastic fibres?
Trachea bronchi bronchioles and alveoli
Facts about lungs
Lungs are largest organ apart from the skin and the only internal organ to be exposed to the external environment. It’s mass is 1060g.
Facts about alveoli
There are around 50 million of them. The walls are one cell thick and are made of squamous epithelial cells. Capillaries cover the alveoli and are the site of gaseous exchange. The walls of the alveoli expand on breath intake and are no longer wrinkly as seen in microscope photographs
How does gas exchange take place in terms of the process of movement of particles
Simple diffusion
How oxygenated is the blood leaving the alveoli
98 percent
Where does the blood come from before it goes in the alveoli?
From the heart, deoxygenated blood comes through the pulmonary artery before entering the lungs
Where does the blood go after going through the alveoli?
To the heart, oxygenated blood goes through the pulmonary vein exiting the lungs
Why is ventilation important? What are the basics of how this happens?
The air In the lungs needs to be replenished so that fresh supplies of oxygen can be provided and carbon dioxide removed. Lungs are ventilated by the action of intercostal (rib) muscles and the diaphragm, which is a muscular band of tissue that separates the abdomen from the thorax.
Describe inspiration physically
External intercostal muscles contract , pulling the rib cage upwards and outwards. This pulls out the pleural membrane, reduces pressure in the pleural cavity and the inner pleural membrane moves outwards. This pulls on the surface of the lungs and causes the alveoli to expand. The diaphragm contracts pulling it from a dome to a flattened shape.
