Respiratory Histology Quiz: Trivia

Goblet cells and ciliated epithelial cells are both types of cells found in the respiratory system that help in protecting and maintaining the airways. Goblet cells produce mucus, while ciliated epithelial cells have hair-like projections called cilia that help in moving mucus and trapped particles out of the airways. However, alveoli are tiny air sacs in the lungs where gas exchange occurs, and they do not contain goblet cells or ciliated epithelial cells. Therefore, the correct answer is alveoli.

Surfactant is a complex mixture of phospholipids, carbohydrates, and proteins. It is found in the air-blood barrier interstitium, specifically in the capillary endothelial space. Surfactant helps to reduce surface tension in the alveoli of the lungs, preventing them from collapsing during exhalation and promoting efficient gas exchange. It also plays a role in preventing fluid accumulation in the lungs.

The correct answer is bronchioles. Respiratory (ciliated pseudostratified columnar) epithelium is found in the nasal cavity, trachea, extrapulmonary bronchi, and intrapulmonary bronchi. However, as the bronchioles are smaller airways within the lungs, they are lined with simple cuboidal epithelium instead of respiratory epithelium.

Lamellar bodies which contain surfactant are clearly discernible in type II pneumocytes SURFACTANT REDUCES SURFACE TENSION AT BLOOD-AIR BARRIER from slides 34 & 35 of Moore's ppt-2

The large numbers of alveolar macrophages which migrate into lumens of alveoli are derived from monocytes in circulating blood. Monocytes are a type of white blood cell that circulate in the bloodstream and can differentiate into macrophages when they enter tissues. In the case of the alveoli, monocytes migrate from the blood vessels into the alveolar spaces and differentiate into alveolar macrophages. These macrophages play a crucial role in the immune defense of the lungs by engulfing and removing pathogens, debris, and foreign particles that may enter the alveoli.

The unique feature of the olfactory epithelium is the presence of neurons that are replaced throughout life. Unlike most neurons in the body, which are unable to regenerate, the olfactory neurons have the ability to regenerate and replace themselves throughout an individual's lifetime. This allows for the continuous detection and processing of smells, as the old neurons are constantly being replaced by new ones. This unique characteristic of the olfactory epithelium contributes to the sense of smell and its ability to adapt to different scents over time.

The larynx is characterized by the presence of both skeletal muscle and cartilage. The skeletal muscles in the larynx help control the movement of the vocal cords, allowing for speech and sound production. The cartilage in the larynx, specifically the thyroid cartilage (Adam's apple), provides structural support and protection for the vocal cords and other structures within the larynx. This combination of skeletal muscle and cartilage in the larynx allows for its important functions in respiration and phonation.

Smooth muscle cells are not involved in the process of oxygen diffusion. Oxygen diffuses across the layer of surfactant, endothelial cells, Type I pneumocytes, and the plasma membrane of the erythrocyte to reach hemoglobin. Smooth muscle cells are responsible for regulating the diameter of blood vessels, not for the diffusion of oxygen.

The respiratory epithelium is responsible for trapping particles from the passing air for elimination by swallowing. This is an important function of the respiratory system as it helps to prevent foreign particles from entering the lungs and causing damage. The trapped particles are then eliminated by swallowing, preventing them from reaching the lower respiratory tract.

The surfaces of pulmonary alveoli are coated with a detergent-like material to facilitate alveolar inflation. This surfactant reduces the surface tension in the alveoli, preventing them from collapsing during expiration and allowing for efficient gas exchange.

Alveoli lack smooth muscle. Alveoli are tiny air sacs located at the end of the respiratory bronchioles in the lungs. They are responsible for the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. Unlike the trachea, bronchi, bronchioles, and alveolar ducts, which contain smooth muscle, alveoli are composed of a single layer of epithelial cells and do not have any smooth muscle tissue.

The air 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 to condition the inhaled air. However, it does not generate heat by mitochondria in the basal cells of the respiratory epithelium.

Both respiratory epithelium and olfactory epithelium are pseudostratified epithelia. Pseudostratified epithelia are characterized by the presence of cells of different heights, giving the appearance of multiple layers when in fact there is only one layer. In both respiratory and olfactory epithelium, the cells are arranged in a single layer but appear stratified due to the varying heights of the cells. This arrangement allows for efficient absorption and secretion of substances in both the respiratory and olfactory systems.

skeletal muscle--- because you have voluntary control of it.

Type II pneumocytes are responsible for secreting surfactant, which helps to reduce surface tension in the alveoli and prevent their collapse. They also contain organelles called lamellar bodies, which store and release surfactant. Type II pneumocytes form tight junctions with Type I pneumocytes, creating a barrier that helps to maintain the integrity of the alveoli. Additionally, Type II pneumocytes have the ability to divide and produce both Type I and Type II cells, contributing to the regeneration of the alveolar epithelium. However, they do not phagocytose particulates reaching the alveoli. This function is performed by alveolar macrophages, which are specialized immune cells present in the alveoli.

Intrapulmonary bronchi and bronchioles share the property of association with pulmonary arteries. This means that both the bronchi and bronchioles are closely connected to the network of pulmonary arteries, which supply oxygenated blood to the lungs. This association allows for efficient exchange of oxygen and carbon dioxide between the air in the bronchi and bronchioles and the blood in the pulmonary arteries.

Bronchioles differ from bronchi in all of the following respects except the presence of smooth muscle. Bronchioles are smaller airway passages that branch out from the bronchi, and they do not contain cartilage like the bronchi do. Additionally, bronchioles have a different type of epithelium and lack sub-mucosal glands. However, both bronchioles and bronchi have the presence of smooth muscle, which helps to regulate the diameter of the airways.

Capillaries found within the alveolar septa have several characteristics, including having a larger diameter than most capillaries, having lower pressure than most capillaries, being somatic continuous capillaries, and having transport across the capillary wall using membranous vesicles. However, they do not lack a basement membrane. The basement membrane is a thin, specialized layer of extracellular matrix that provides structural support and acts as a selective barrier in capillaries. Therefore, the correct answer is that they lack a basement membrane.

The correct answer is "larger in diameter than average systemic capillaries." This is because the capillaries of pulmonary alveoli need to accommodate the exchange of gases between the alveolar air and the bloodstream. The larger diameter allows for a greater surface area for gas exchange to occur, ensuring efficient uptake of oxygen and release of carbon dioxide.

To cross the air-blood barrier, both oxygen and carbon dioxide need to diffuse through the alveolar epithelial cells and the endothelial cells of the capillaries. This means that each gas needs to cross two plasma membranes - one in the alveolar epithelial cell and one in the capillary endothelial cell. Therefore, the minimum number of plasma membranes required for this process is 5.