Mcq_mini3_(4)[1] Lung Volume

A spirometer is a device used to measure lung volumes, which are the different amounts of air that can be inhaled or exhaled. The inspiratory reserve volume (IRV), inspiratory capacity (IC), expiratory reserve volume (ERV), and vital capacity (VC) can all be determined using a spirometer. However, the total lung capacity (TLC) cannot be determined by this method because it includes the residual volume (RV), which is the amount of air that remains in the lungs after a maximal exhalation. The spirometer cannot measure the residual volume, so it cannot determine the total lung capacity.

Goblet cells and ciliated epithelial cells are both types of cells found in the respiratory system that help with the production and movement of mucus. Goblet cells secrete mucus, while ciliated epithelial cells have tiny hair-like structures called cilia that help move the mucus along. These cells are found in the nasal cavity, trachea, and bronchi, but not in the alveoli. The alveoli are small air sacs in the lungs where gas exchange occurs, and they do not contain goblet cells or ciliated epithelial cells.

Direct spirometry is a pulmonary function test that measures the volume and flow of air during forced breathing maneuvers. Vital capacity is the maximum amount of air a person can exhale after taking a deep breath. It is one of the values that can be measured using direct spirometry. Therefore, the correct answer is vital capacity.

The patient's lung volume at FRC is approximately 2L. This can be inferred from the fact that the helium concentration in the spirometer falls from 2% to 1% after several minutes. This decrease in helium concentration indicates that the patient's lungs have taken in some of the helium from the spirometer. Since the spirometer initially contains 2L of helium, the fact that the concentration decreases by half suggests that the patient's lungs have taken in 1L of helium, which corresponds to an increase in lung volume of 1L. Therefore, the patient's lung volume at FRC is approximately 2L.

The correct answer is monocytes in circulating blood. Alveolar macrophages are immune cells that play a crucial role in the defense and clearance of pathogens and debris in the alveoli of the lungs. They are derived from monocytes, which are a type of white blood cell found in the circulating blood. Monocytes migrate from the bloodstream into the alveoli and differentiate into alveolar macrophages. These macrophages then reside within the alveoli, where they engulf and remove foreign particles and microorganisms to maintain lung health and function.

only during coughing and forced expiration

The correct answer is surfaces coated with a detergent-like material to facilitate alveolar inflation. This is because the surfactant, which is the detergent-like material, reduces surface tension in the alveoli, allowing them to expand and inflate more easily during inhalation. Without surfactant, the alveoli would collapse and make it difficult for gas exchange to occur in the lungs.

As the respiratory airways decrease in size, there is an increase in the relative amount of smooth muscle. This is because the smooth muscle helps to regulate the diameter of the airways and control airflow. As the airways become smaller, the smooth muscle needs to increase in order to maintain proper control and function. This increase in smooth muscle allows for the airways to constrict or dilate as needed to facilitate efficient respiration.

The function characteristically associated with "respiratory epithelium" is the trapping of particles from passing air for elimination by swallowing. This is because the respiratory epithelium is lined with mucus-producing cells and cilia, which work together to trap and remove particles and foreign substances from the air before it reaches the lungs. This helps to protect the respiratory system from potential harm and maintains its proper functioning.

Oxygen in the inspired air reaches hemoglobin by diffusing across various structures. The layer of surfactant, endothelial cell, and Type I pneumocyte all play a role in this diffusion process. The plasma membrane of the erythrocyte also allows oxygen to diffuse into the red blood cells. However, smooth muscle cells do not directly participate in the diffusion of oxygen to hemoglobin. Therefore, the correct answer is "One or more smooth muscle cells."

The alveoli are tiny air sacs located at the end of the bronchioles in the respiratory tract. They are responsible for the exchange of oxygen and carbon dioxide in the lungs. Unlike the trachea, bronchi, and bronchioles, the alveoli lack smooth muscle. This is because their main function is gas exchange rather than airway constriction or dilation. Smooth muscle is found in the trachea, bronchi, and bronchioles to help regulate the diameter of the airways and control airflow.

The unique feature of the olfactory epithelium is the presence of neurons that are replaced throughout life. Unlike most neurons in the body, which cannot regenerate, the olfactory neurons have the ability to regenerate and replace themselves. This allows for the continuous detection and processing of smells throughout a person's lifetime.

The nasal tissue possesses secretions supplied from goblet cells in the epithelium, secretions from seromucous glands in the subepithelial connective tissues, and venous plexuses at selected places in the subepithelial connective tissues. However, it does not generate heat by mitochondria in the basal cells of the respiratory epithelium.

The laryngeal pharynx is covered with stratified squamous epithelium. This type of epithelium is found in areas that are subject to mechanical stress and friction, such as the skin and the lining of the mouth and throat. The laryngeal pharynx, which is part of the respiratory tract, is responsible for conducting air from the nasal cavity to the larynx. Its location and function make it susceptible to mechanical stress, hence the presence of stratified squamous epithelium to provide protection.

Both respiratory epithelium and olfactory epithelium are pseudostratified epithelia. This means that the cells appear to be layered or stratified, but in reality, all cells are in contact with the basement membrane. This arrangement allows for a larger surface area and increased absorption and secretion.

The correct answer is bronchioles. Respiratory (ciliated pseudostratified columnar) epithelium is found in the nasal cavity, trachea, extrapulmonary bronchi, and intrapulmonary bronchi. However, bronchioles are lined with simple columnar or cuboidal epithelium, not respiratory epithelium.

The larynx is characterized by the presence of both skeletal muscle and cartilage. The skeletal muscles in the larynx help in controlling the tension and position of the vocal cords, allowing for speech and sound production. The cartilage in the larynx, specifically the thyroid cartilage (Adam's apple) and the cricoid cartilage, provide structural support and protection for the vocal cords and other structures in the larynx. Therefore, the larynx is the correct answer as it exhibits the presence of both skeletal muscle and cartilage.

Type II pneumocytes are responsible for the secretion of surfactant, which helps to reduce surface tension in the alveoli. They also contain organelles called lamellar bodies, which store and release surfactant. Type II pneumocytes form tight junctions with Type I pneumocytes, which helps to maintain the integrity of the alveolar wall. They also have the ability to divide and produce both Type I and Type II cells. However, they do not phagocytose particulates reaching the alveoli. This function is primarily carried out by alveolar macrophages.

The question asks for the minimum number of plasma membranes required to cross the air-blood barrier. In the given passage, it is stated that oxygen diffuses from the alveolar cavity into the blood in the alveolar capillaries. This implies that oxygen needs to cross two plasma membranes - one in the alveolar cavity and one in the capillary. Similarly, carbon dioxide diffuses from blood into the alveolar air, requiring it to cross two plasma membranes as well. Therefore, the minimum number of plasma membranes required to cross the air-blood barrier is 5.

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Bronchioles differ from bronchi in all of the listed respects except for the presence of smooth muscle. Bronchioles do not have cartilage, have a different type of epithelium, have Clara cells, and do not have sub-mucosal glands. However, both bronchioles and bronchi have smooth muscle.

To calculate the residual volume of the patient, in addition to the measured lung volume from helium dilution, you need to know the vital capacity. The vital capacity is the maximum amount of air that can be exhaled after a maximal inhalation. By subtracting the vital capacity from the measured lung volume, you can calculate the residual volume, which is the volume of air remaining in the lungs after a maximal exhalation. The other lung volumes and capacities listed are not necessary for this calculation.

Capillaries found within the alveolar septa have a smaller diameter than most capillaries, have lower pressure than most capillaries, are somatic, continuous capillaries, and have transport across the capillary wall using membranous vesicles. However, they do not lack a basement membrane.