respiratory system Flashcards
what are the basic functions of the respiratory system
- Gas Exchange:
- the exchange of oxygen (O2) and carbon dioxide (CO2) between the body and the external environment. - Oxygen Transport:
- Transports oxygen from the lungs to body tissues via the bloodstream, where it is required for cellular respiration and the production of adenosine triphosphate (ATP) - Carbon Dioxide Removal:
Removes carbon dioxide, a metabolic waste product, from the body during exhalation. Carbon dioxide is transported from body tissues to the lungs via the bloodstream. - Regulation of Acid-Base Balance:
- Helps regulate the body’s pH balance by controlling the levels of carbon dioxide and bicarbonate ions in the blood. - Voice Production:
- Plays a role in voice production through the movement of air past the vocal cords in the larynx. - Sense of Smell:
Provides the sense of smell (olfaction) through the detection of airborne odor molecules by olfactory receptors in the nasal cavity.
list the structures of the conducting zone and their functions
- Nose:
Functions:
- Warms, humidifies, and filters incoming air.
- Detects odors (olfaction). - Nasal Cavities (Nasal Passages):
Functions:
-Conduct air from the nostrils to the pharynx.
-Contain mucous membranes and cilia - Pharynx (Throat):
Functions:
- common passageway for air, food, and liquids.
-swallowing and vocalization. - Larynx (Voice Box):
Functions:
- Produces sound (voice production) through the vibration of the vocal cords.
- Protects the lower respiratory tract during swallowing via the epiglottis. - Trachea (Windpipe):
Functions:
- Conducts air from the larynx to the bronchi.
- Contains C-shaped rings of cartilage to prevent collapse. - Bronchi:
Functions:
- Conduct air from the trachea to the lungs.
- Divide into smaller bronchioles, - Bronchioles:
Functions:
- Conduct air from the bronchi to the alveoli.
- Control airflow and regulate air distribution within the lungs through smooth muscle contraction. - alveolus (alveoli)
list the structures in the respiratory zone and their functions
- Respiratory Bronchioles:
Functions:
- Conduct air from the terminal bronchioles to the alveolar ducts.
- Contain some alveoli along their walls - Alveolar Ducts:
Functions:
- Conduct air from the respiratory bronchioles to the alveolar sacs.
- Consist of thin-walled passages lined with alveoli - Alveolar Sacs (Alveoli):
Functions:
- Site of gas exchange between air and blood.
- Consist of clusters of alveoli surrounded by networks of capillaries.
-Oxygen from inhaled air diffuses into the capillaries, while carbon dioxide from the blood diffuses into the alveoli - Pulmonary Capillaries:
Functions:
-Surround the alveoli and facilitate gas exchange with the bloodstream.
- Carry oxygenated blood away from the lungs and return deoxygenated blood to the lungs.
where is the site of gas exchange in the respiratory system
alveoli
what is the importance of alveoli in relation to an increase surface area for the lungs
Alveoli increase the lung’s surface area, enhancing gas exchange efficiency. Their thin walls and surrounding capillaries facilitate rapid diffusion, adapting to respiratory demands and optimizing lung function for efficient oxygen uptake and carbon dioxide removal, crucial for cellular respiration and maintaining body homeostasis.
how many alveoli are present in adult lungs
300 million
describe the structure of the alveoli
The alveoli are tiny, balloon-like structures located at the end of the respiratory bronchioles in the lungs.
1. Alveolar Epithelium:
The inner lining of the alveoli is composed of a single layer of squamous epithelial cells known as type I alveolar cells. These cells are thin and flat
2. Pulmonary Capillaries:
Surrounds each alveolus. They are in close proximity to the alveolar epithelium, allowing for the efficient exchange of oxygen and carbon dioxide between the air and the bloodstream.
3. Surfactant-Producing Cells:
Type II alveolar cells are specialized cells found interspersed among the type I cells. These cells produce surfactant, a mixture of lipids and proteins that reduces surface tension within the alveoli, preventing their collapse during exhalation.
4. Interstitial Tissue:
The walls of the alveoli providing structural support to the alveoli and facilitates their expansion and contraction during breathing.
5. Alveolar Macrophages:
Scattered throughout the alveolar spaces are alveolar macrophages, specialized immune cells that engulf and remove foreign particles.
describe the anatomy of the lungs within the thoracic cavity including the functions of the pleural sac and intrapleural fluid
The lungs are paired, cone-shaped organs located within the thoracic cavity of the chest.
Location:
- The lungs are situated on either side of the mediastinum and are enclosed within the rib cage.
1. Pleural Sac:
Each lung is surrounded by a double-layered serous membrane called the pleura.
- The inner layer (visceral pleura) adheres closely to the surface of the lung.
- The outer layer (parietal pleura) lines the inner surface of the thoracic cavity.
- The space between the visceral and parietal pleurae is called the pleural cavity.
2. The pleural cavity contains a small amount of serous fluid, known as intrapleural fluid (which lubricates the pleural surfaces and reduces friction during breathing)
Functions:
- Creating a lubricated surface that allows the lungs to move smoothly within the thoracic cavity during breathing.
- Maintaining the close apposition of the lung to the chest wall, which helps prevent lung collapse and maintains lung expansion.
- Providing a barrier against the spread of infection or inflammation.
3. Lobes and Fissures:
- Each lung is divided into lobes separated by deep fissures.
- The right lung has three lobes (superior, middle, and inferior lobes) separated by the oblique and horizontal fissures.
- The left lung has two lobes (superior and inferior lobes) separated by the oblique fissure.
4. Bronchial Tree:
- The bronchial tree is a branching network of airways that conducts air into and out of the lungs.
- consists of the trachea, bronchi, bronchioles, and terminal bronchioles.
5. Trachea
- branches into the left and right main bronchi, which further divide into smaller bronchi and bronchioles within the lungs.
6. Alveoli:
- At the distal ends of the bronchial tree are clusters of air sacs called alveoli, where gas exchange occurs. - Each alveolus is surrounded by a network of pulmonary capillaries, allowing for the exchange of oxygen and carbon dioxide between the air and the bloodstream
describe the process of inhalation and exhalation
Inhalation:
1. Muscle Contraction:
a. During inhalation, the diaphragm and external intercostal muscles contract.
b. The diaphragm flattens, and the external intercostal muscles pull the ribs upward and outward.
2. Thoracic Cavity Expansion:
a. Contraction of the diaphragm and external intercostal muscles increases the volume of the thoracic cavity.
b. As the thoracic cavity expands, the pleural pressure decreases, creating a negative pressure gradient between the alveolar pressure and atmospheric pressure.
3. Airflow into the Lungs:
a. The decrease in pleural pressure causes the alveolar pressure to drop below atmospheric pressure.
b. Air moves from an area of higher pressure (atmosphere) to an area of lower pressure (alveoli), filling the lungs with fresh air.
- This process is known as negative-pressure breathing, where the expansion of the thoracic cavity creates a pressure gradient that drives airflow into the lungs.
Exhalation (Expiration):
1. Muscle Relaxation:
a. During exhalation, the diaphragm and external intercostal muscles relax.
b. The diaphragm returns to its dome shape, and the ribs move downward and inward under the force of gravity.
2. Thoracic Cavity Compression:
a. Relaxation of the diaphragm and external intercostal muscles reduces the volume of the thoracic cavity.
b. As the thoracic cavity contracts, the pleural pressure increases, creating a positive pressure gradient between the alveolar pressure and atmospheric pressure.
3. Airflow out of the Lungs:
a. The increase in pleural pressure causes the alveolar pressure to rise above atmospheric pressure.
b. Air moves from an area of higher pressure (alveoli) to an area of lower pressure (atmosphere), expelling stale air from the lungs.
- Exhalation is primarily a passive process driven by the elastic recoil of the lungs and chest wall.
state boyles law and apply it to the movement of air in and out of the lungs
Boyle’s Law states that at a constant temperature, the pressure of a gas is inversely proportional to its volume. (P1V1 = P2V2) where P represents pressure and V represents volume.
Boyle’s Law explains how changes in lung volume during inhalation and exhalation result in corresponding changes in alveolar pressure, creating pressure gradients that drive the movement of air into and out of the lungs.
what must be understood about the pressure exerted by a gas
it is proportional to its temperature and fractional concentration
in a mixture of gases is each pressure exerted independent of that exerted by others
yes
how do you calculate the total pressure of the mixture of gases
the sum of the individual, partial pressures
describe the relationship between gases and liquids
the amount of gas dissolved in a liquid is directly proportional to the partial pressure of the gas (liquid is in equilibrium)
why is the diffusion of gases into liquids presented in partial pressures rather then concentrations
Gases dissolve into liquids based on their partial pressures, following Henry’s Law. Using partial pressures instead of concentrations accurately represents the driving force for gas exchange and facilitates comparisons between different gases dissolved in the same liquid.
