Chapter 6: The Respiratory System Flashcards
The lungs are located in the ____________, the structure of which is specially designed to perform breathing.
Thoracic cavity
Air enters the respiratory tract through the external nares of the nose and then passes through the nasal cavity, where it is filtered by mucous membranes and nasal hairs (also called __________)
Vibrissae
The _________ resides behind the nasal cavity and at the back of the mouth; it is a common pathway for both air destined for the lungs and food destined for the esophagus,
Pharynx
The _________ lies below the pharynx and is only a pathway for air.
Larynx
___________ is the opening of the larynx.
Glottis
To keep food out of the respiratory system, the opening of the larynx (glottis) is covered by the ___________ during swallowing.
Epiglottis
The larynx contains 2 __________ that are maneuvered using skeletal muscle and cartilage.
Vocal cords
From the larynx, air passes into the cartilaginous ___________.
Trachea
From the trachea, air then passes into one of the two mainstream __________.
Bronchi
In the lungs, the bronchi continue to divide into smaller structures known as ___________.
Bronchioles
The bronchioles then divide further until they end in the tiny balloon-like structures in which gas exchange occurs that are called the ___________.
Alveoli
Each alveoli is coated with __________, a detergent that lowers surface tension and prevents the alveolus from collapsing on itself.
Surfactant
The __________ forms the outside of the thoracic cavity.
Chest wall
Membranes known as __________ surround each lung. Each forms a closed sac against which the lung expands.
Pleurae
The surface adjacent to the lung is the __________, and the outer part is ____________.
Visceral pleura
Parietal pleura
The lungs do not fill passively, and require skeletal muscle to generate the __________ pressure for expansion
Negative pressure
The most important of the required skeletal muscle for lung expansion is the _____________, a thin, muscular structure that divides the thoracic (chest) cavity from the abdominal cavity.
Diaphragm
The space within the sac between the two pleural layers is referred to as the _____________, which contains a thin layer of fluid.
Intrapleural space
We use our diaphragm and _____________ muscles (one of the layers of muscles between the ribs) to expand the thoracic cavity.
External intercostal muscles
As the diaphragm flattens and the chest wall expands outward, the _____________ (the volume of the chest cavity) increases.
Intrathoracic cavity
From the understanding of Boyle’s law, an increase in intrapleural volume leads to a ___________ in intrapleural pressure.
Decrease
The gas in the lungs is initially at the atmospheric pressure, which is now higher than the pressure in the intrapleural space. The lungs will therefore expand into the intrapleural space, and the pressure in the lungs will drop. Air will then be sucked in from a high-pressure environment - the outside world. This mechanism is referred as ________________ because the driving force is the lower (relatively negative) pressure in the intrapleural space compared with the lungs.
Negative-pressure breathing
During exhalation, we can speed up the process by using the ________________ and abdominal muscles, which oppose the external intercostals and pull the rib cage down. This actively decreases the volume of the thoracic cavity.
Internal intercostals muscles
The ___________ prevents the complete collaspe of the alveoli during exhalation by reducing surface tension at the alveolar surface.
Surfactant
The indirect connection of the lungs to the ____________ prevents them from collapsing completely on recoil, like surfactant
Chest wall
_____________ is a disease characterized the the destruction of the alveolar walls.
Emphysema
A ____________ is an instrument used in pulmonology to provide a number of measures quantities within the lungs.
Spirometer
______________ is the maximum volume of air in the lungs when one inhales completely; usually around 6 to 7 liters
Total lung capacity (TLC)
______________ is the volume of air remaining in the lungs when one exhales completely
Residual volume (RV)
______________ is the difference between the minimum and maximum volume of air in the lungs (TLC - RV)
Vital capacity (VC)
______________ is the volume of air inhaled or exhaled in a normal breath.
Tidal volume (TV)
______________ is the volume of additional air that can be forcibly exhaled after a normal exhalation.
Expiratory reserve volume (ERV)
______________ is the volume of additional air that can be forcibly inhaled after a normal inhalation.
Inspiratory reserve volume (IRV)
Ventilation is primarily regulated by a collection of neurons in the medulla oblongata called the ______________ that fire rhythmically to cause regular contraction of respiratory muscles.
Ventilation center
Ventilation center neurons contain _____________ that are primarily sensitive to carbon dioxide concentration.
Chemoreceptors
_____________ or _____________ is when the partial pressure of carbon dioxide in the blood rises.
Hypercarbia
Hypercapnia
As the partial pressure of carbon dioxide in the blood rises (hypercarbia or hypercapnia), the _____________ will increase so that more carbon dioxide is exhaled, causing carbon dioxide levels in the blood falls.
Respiratory rate
___________ is when there is low oxygen concentration in the blood.
Hypoxemia
The capillaries bring deoxygenated blood from the ______________, which original from the right ventricle of the heart.
Pulmonary arteries
The oxygenated blood returns to the left atrium of the heart via the ___________.
Pulmonary veins
Because the entire respiratory tract is highly vascular, it can also be used for ______________, or the regulation of body temperature.
Thermoregulation
Heat - the transfer of thermal energy - is regulated via the body surfaces by _____________ and ______________.
Vasodilation
Vasoconstriction
As capillaries ___________, more blood can pass through these vessel, and a larger amount of thermal energy can be dissipated.
Dilate/Expand
As capillaries ___________, less blood can pass through them, conserving thermal energy.
Contract
The first line of defence in the lungs is the nasal cavity, which has small hairs (____________) that help to trap particulate matter and potentially infectious particles.
Vibrissae
The nasal cavity contains an enzyme called ___________.
Lysozyme
Underlying cilia then propel the mucus up the respiratory tract to the oral cavity, where it can be expelled or swallowed; this mechanism is called the ____________
Mucociliary escalator
The lungs contain ____________ that can engulf and digest pathogens and signal to the rest of the immune system that there is an invader.
Macrophages
Mucosal surfaces contain _________ antibodies that help to protect against pathogens that contact the mucous membranes.
IgA antibodies
____________ release inflammatory chemicals into the surrounding area to promote an immune response when the right substance attaches to the antibodies on the cell surface (allergic reaction).
Mast cells
The respiratory system plays a role in pH balance through the ___________________ system in the blood.
Bicarbonate buffer system
The human body attempts to maintain a pH between ________ and _________.
7.35-7.45
When the pH is lower, and hydrogen ion concentration is higher (__________), acid-sensing chemoreceptors just outside the blood-brain barrier send signals to the brain to increase the respiratory rate.
Acidemia
If the blood is too basic (__________), then the body will seek to increase acidity.
Alkalemia
If the respiratory rate is slowed, then more carbon dioxide will be retained, shifting the buffer equation to the right and producing more hydrogen ions and bicarbonate ions. This results in ________ pH level.
Lower
As the respiratory rate increases, more carbon dioxide is blown off. This will push the buffer equation to the left. Hence, the removal of carbon dioxide causes a shift to the _________ that allows the hydrogen ion concentration to drop back to normal.
Left
