Respiratory System - Textbook Flashcards
What does respiration refer to?
all the processes that supply oxygen to the cells of the body for the oxidation of glucose and the process by which wastes are transported to the lungs for exhalation.
How does air enter the respiratory system?
Through the 2 nasal passages or the mouth
What filters the air as it passes through the nasal cavities?
tiny hairs and mucus
What is the Pharynx?
The passage for both food and air
After the pharynx, what is the passage for food and for air?
Food travels through the esophagus
Air travels through the trachea
Describe the trachea
lined with ciliated cells which produce mucus
supported by cartilage rings which keep it open
What is the epiglottis?
a structure that covers the opening of the trachea during swallowing
What is the larynx?
the voice box
Describe the larynx
composed of two thin sheets of elastic ligaments. The vocal cords vibrate as air is forced from the lungs toward the pharynx.
It is protected by a thick band of cartilage commonly known as the Adam’s apple.
What are bronchi?
two tubes that branch off the trachea and go into the lungs.
They have cartilaginous rings.
What are bronchioles?
The smallest passageway of the respiratory tract. They are smaller airways that branch off the bronchi.
They do not contain cartilaginous rings.
What are alveoli?
tiny air sacs in the lung (0.1-0.2mm diameter)
They are surrounded by capillaries
the place where the gases in the air diffuse into the blood according to concentration gradients.
Describe the alveoli
each alveoli are composed of a single layer of cells to allow for a more rapid gas exchange
Has a thin film of lipoprotein coating them.
During inhalation, the alveoli are like little bulb-shaped sacs
During exhalation, they collapse. The lipoprotein layer allows them to pop open during inhalation
What is the pleural membrane?
a thin membrane that covers the outer surface of the lungs and the inner wall of the chest cavity.
It is filled with fluids that reduce the friction between the lungs and the chest cavity during inhalation
What is the relationship of the gas pressures during exhalation?
Gases move from an area of high pressure to low pressure
During exhalation, the pleural pressure (thoracic cavity pressure) is higher than atmospheric pressure so air rushes out of the lungs.
What is the relationship of the gas pressures during inhalation?
Gases move from an area of high pressure to low pressure
During inhalation, the pleural pressure (thoracic cavity pressure) is lower than atmospheric pressure so air rushes into the lungs.
What is the diaphragm?
a band of muscle that separates the chest cavity from the abdominal cavity.
It regulates the pressure in the chest cavity.
When it contracts, the muscle flattens and pulls downward increasing the chest volume.
When it relaxes, it returns to a dome shape due to the force exerted by the organs from the abdomen and the chest volume decreases.
What are intercostal muscles?
The muscles between the ribs.
When they contract, they pull the ribs upward and outward increasing the volume of the chest.
The ribs are hinged to your vertebrae so the contraction of the muscles pulls them up and out.
What is a pneumothorax?
a collapsed lung
It happens when there is a hole in the pleural cavity (gunshot, stabbing)
A hole makes it impossible for the chest cavity to establish pressure differences. When the diaphragm contracts and the rib cage is raised, the pressure inside the chest cavity is reduced. However, much less air is drawn into the lungs. Much of the air flows directly through the hole left by the wound
What controls breathing?
the nerves from the medulla oblongata
How is breathing controlled?
CO2 dissolves in the blood and forms an acid. Should the carbon dioxide accumulate, special chemoreceptors in the medulla oblongata become activated. Once activated, the medulla oblongata relays messages to the muscles of the diaphragm and ribs to begin breathing movements.
What is bronchitis?
The swelling of the bronchii
Caused by bacterial or viral infections, as well as reactions to environmental chemicals. The cause the mucous cells that line the respiratory pathway to secrete more mucus. The irritation may initiate an inflammation response and bring about tissue swelling.
What is emphysema?
an overinflation of the alveoli. Continued overinflation can lead to the rupture of the alveoli.
What is asthma?
a reversible narrowing of the bronchial passage.
It becomes difficult to get air out of the lungs and air pressure builds up.
Where is the partial pressure of CO2 the highest?
highest in the tissues and venous blood
Where is the partial pressure of O2 the highest?
Alveoli and the arterial blood
