B. Correct! As air travels through the nasal cavities, it is warmed and humidified.

Transcription

1 Human Anatomy - Problem Drill 20: The Respiratory System Question No. 1 of Which of the following statements about the portion of the respiratory system labeled in the image below is correct? Question #01 (A) The label in the image identifies a portion of the lower respiratory system. (B) The structure labeled in the image warms and humidifies the air. (C) The portion of the respiratory system labeled in the image is not a typical passageway for incoming air during inspiration. (D) The structure labeled in the image is part of both the upper and lower respiratory system. (E) None of the answers is correct. The label in the image identifies the nasal cavities, which are part of the upper respiratory system. B. Correct! As air travels through the nasal cavities, it is warmed and humidified. C. Incorrect! The nasal cavity is the major passageway for inspired air. The nasal cavity labeled in the image is part of the upper respiratory system. Answer B is correct. The upper respiratory tract is primarily a conducting passageway for air to reach the lungs. Air travels through the following structures: nasal cavity, which warms and humidifies the air, and the pharynx (throat), which is a passageway for air and food. The lower respiratory tract is made up of the following structures: (1) larynx (voice box), which is the site of voice production, (2) trachea or windpipe, (3) bronchi, which deliver air to the lungs, and (4) lungs, which contain alveoli, tiny sac-like structures in which gas exchange occurs. (B)The structure labeled in the image warms and humidifies the air.

2 Question No. 2 of The respiratory system is one of the many organ systems in the body. Which of the following statements about the respiratory system is correct? Question #02 (A) The respiratory system plays no role in acid-base balance in the body. (B) The respiratory system is a self-regulated system, with little to no input from the central nervous system. (C) The respiratory system provides for voice production, and the lungs are involved in immunity for the body. (D) The lower respiratory tract extends from the nasal cavity to the lungs. (E) The immune function of the respiratory system includes the presence of immune cells, which are located only in the upper respiratory tract. The respiratory system is involved in acid-base balance because the lungs can alter carbon dioxide levels and the lungs are involved in maintaining blood ph within the normal range. The respiratory center in the brainstem controls rhythmic respiration. C. Correct! The functions of the respiratory system include: (1) The sense of smell (olfaction), (2) voice production, (3) the lungs are involved in immunity and protect us from microorganisms by: cilia, mucus production, coughing reflex, and the presence of immune cells. The lower respiratory tract extends from the trachea to the lungs. Immune cells are located inside the lungs and provide protection for the body against microorganisms. The respiratory system s function is gas exchange, including oxygen uptake and carbon dioxide release in the lungs. The respiratory cycle of breathing brings gas into the lungs during inspiration; oxygen and carbon dioxide are exchanged and then the carbon dioxide is blown off during expiration. The respiratory system is divided into two primary areas: (1) Upper respiratory tract, which includes the nasal cavity and the pharynx, and (2) Lower respiratory tract from the trachea to the lungs. The functions of the respiratory system include: (1) The sense of smell (olfaction), (2) voice production, (3) the lungs are involved in immunity and protect us from microorganisms by: cilia, mucus production, coughing reflex, and the presence of immune cells. (C)The respiratory system provides for voice production, and the lungs are involved in immunity for the body.

3 Question No. 3 of The upper respiratory system includes the pharynx. This key structure is involved in both the respiratory system and the digestive system. Which of the following statements about the pharynx is correct? Question #03 (A) The three divisions of the pharynx are the oropharynx, nasopharynx and the artenypharynx. (B) The pharynx extends from the soft palate to the trachea. (C) The laryngopharynx contains special epithelium that is resistant to damage from mechanical abrasion or chemical damage. (D) The most superior portion of the pharynx is the oropharynx. (E) None of the answers is correct. The pharynx is a tube that connects the nose, mouth and throat, and it is divided into three regions: nasopharynx, oropharynx, and the laryngopharynx. The pharynx extends from the internal nares to the entrances of the trachea and esophagus. C. Correct! The laryngopharynx contains special epithelium that is resistant to damage from mechanical abrasion or chemical damage. The most superior portion of the pharynx is the nasopharynx. Answer C is correct. The pharynx is a tube that connects the nose, mouth and throat, and it is divided into three regions: nasopharynx, oropharynx, and the laryngopharynx. Both the respiratory and the digestive systems share the pharynx, and it extends from the internal nares to the entrances of the trachea and esophagus. The most superior portion of the pharynx is the nasopharynx. This cavity is separated from the oral cavity by the soft palate. Located on the posterior wall of the nasopharynx is the pharyngeal tonsil and the openings of the auditory tubes. (C) The laryngopharynx contains special epithelium that is resistant to damage from mechanical abrasion or chemical damage.

4 Question No. 4 of A 33-year-old woman is seen by a general surgeon because of trauma she received to the larynx during a car accident. Based on this information, which of the following statements would be correct? Question #04 (A) The car accident could not have damaged the thyroid cartilage in this patient, as it is not part of the larynx. (B) The cricoid cartilage, which normally functions to protect the glottis and the entrance to the trachea, could be damaged in this patient. (C) Either one of the only two types of cartilage that make up the body of the larynx could be damaged in this car accident. (D) Voice production could still be normal in this patient, as the larynx is only a secondary site for this. (E) The site of injury in this patient is normally located superior to the hyoid bone. The thyroid cartilage is the largest cartilage of the larynx and it makes up the majority of the anterior and lateral walls. B. Correct! The cricoid cartilage is a ring of cartilage that is inferior to the thyroid cartilage in the larynx. Both cartilages function to protect the glottis and the entrance to the trachea. C. Incorrect! The body of the larynx is made up of three types of cartilage: thyroid cartilage, cricoid cartilage and the epiglottic cartilage. The larynx, which is also known as the voice box, is the site of voice production. The larynx is inferior to the hyoid bone and is attached to it through the thyrohyoid ligament. The larynx, which is also known as the voice box, is the site of voice production. The larynx extends from the C 4 or C 5 vertebral level to the level of C 7 and is held in position in the anterior neck with a variety of muscles and ligaments. Superior to the larynx is the hyoid bone, and the greater horns of the hyoid bone support the larynx; the lesser horns are connected to the stylohyoid ligaments. The body of the larynx is made up of the thyroid cartilage, cricoid cartilage and the epiglottic cartilage. The thyroid cartilage is the largest cartilage of the larynx and it makes up the majority of the anterior and lateral walls. On its anterior surface is a ridge that is visible and palpable, known as the laryngeal prominence. The thyroid cartilage articulates with the cricoid cartilage and has the following attachments: ligaments attached to the epiglottis and the small laryngeal cartilages. The cricoid cartilage is a ring of cartilage that is inferior to the thyroid cartilage. Both cartilages function to protect the glottis and the entrance to the trachea. This cartilage articulates with small paired arytenoid cartilages and has attachments to the first cartilage of the trachea. (B) The cricoid cartilage, which normally functions to protect the glottis and the entrance to the trachea, could be damaged in this patient.

5 Question No. 5 of Which portion of the larynx is labelled in the image below? Question #05 (A) Cuneiform cartilage. (B) Glottis. (C) Epiglottis. (D) Closed glottis. (E) Vocal fold. The cuneiform cartilage is located on the posterior side of the voice box. The glottis is the passage that extends from the pharynx to the larynx. C. Correct! The epiglottis is labelled in the image. In the image, the glottis is open and the vocal folds are open. The two vocal folds are open in the image and are deep to the epiglottis labelled in the image. The vocal folds of the larynx are flexible, due to the elastic nature of the vocal ligament. Voice production occurs primarily in the larynx, or voice box. Within the voice box is a set of cartilages located at the front of the throat, which contains the vocal folds. The opening and closing of the vocal folds, as air passes through, produces sounds of different quality. The entire larynx vibrates during sound production and the echoing of the sounds occurs in the pharynx, oral cavity, nasal cavity and the paranasal sinuses. (C)Epiglottis.

6 Question No. 6 of Which of the following statements about the portion of the respiratory system labelled in the image is correct? Question #06 (A) The oropharynx is labelled in the image. (B) This portion of the pharynx is separated from the oral cavity by the soft palate. (C) The laryngopharynx is labelled in the image and it is the most superior portion of the pharynx. (D) This portion of the respiratory system contains stratified squamous epithelium. (E) The larynx is labelled in the image. The arrow is pointing to the nasopharynx. B. Correct! The arrow is pointing to the nasopharynx, and it is separated from the oral cavity by the soft palate. C. Incorrect! The nasopharynx is labelled in the image and it is the most superior portion of the pharynx. The laryngopharynx extends from the hyoid bone to the entrance of the esophagus. This is the most inferior portion of the pharynx and is lined with stratified squamous epithelium. The arrow is pointing to the nasopharynx. The larynx is inferior to the structure labelled in the image. The pharynx is a tube that connects the nose, mouth and throat, and it is divided into three regions: nasopharynx, oropharynx, and the laryngopharynx. Both the respiratory and the digestive systems share the pharynx, and it extends from the internal nares to the entrances of the trachea and esophagus. The most superior portion of the pharynx is the nasopharynx. This cavity is separated from the oral cavity by the soft palate. Located on the posterior wall of the nasopharynx is the pharyngeal tonsil and the openings of the auditory tubes. (B)This portion of the pharynx is separated from the oral cavity by the soft palate.

7 Question No. 7 of Which of the following statements is not correct about the bronchi in the respiratory system? Question #07 (A) The left and right main bronchi stem from the trachea, at the carina. (B) The main bronchi have a similar structure to that of the trachea, made up of C-shaped cartilaginous rings. (C) The secondary superior bronchus is outside of the lungs and, therefore, is known as an extrapulmonary bronchus. (D) There are a total of 10 tertiary bronchi in the right lung and 8-9 in the left lung. (E) In the bronchopulmonary segments of the lungs, the tertiary bronchi give rise to the approximately 6500 terminal bronchioles. The left and right main bronchi stem from the trachea, at the carina. The main bronchi have a similar structure to that of the trachea, made up of C- shaped cartilaginous rings. C. Correct! The secondary superior bronchus is located inside the lungs and, therefore, is known as an intrapulmonary bronchus. There are a total of 10 tertiary bronchi in the right lung and 8-9 in the left lung. In the bronchopulmonary segments of the lungs, the tertiary bronchi give rise to the approximately 6500 terminal bronchioles. The left and right main bronchi stem from the trachea, at the carina. The carina is a ridge on the inner surface of the trachea that extends anteroposteriorly, between the two primary bronchi. The left and right primary bronchi are outside of the lungs and are, therefore, known as extrapulmonary bronchi. The main bronchi have a similar structure to that of the trachea, made up of C-shaped cartilaginous rings. As each primary bronchus extends towards the lung, at the hilum of the lung, it branches into the secondary bronchi. The root of each lung is made up of the distal end of the main bronchi and the hilum and is attached to the mediastinum with a meshwork of dense connective tissue. The roots of the lungs are located at T 5 for the right and T 6 for the left. The primary bronchi inside the lungs are known as the intrapulmonary bronchi. Together, the primary bronchi and their branches are known as the bronchial tree. Inside the lungs, the primary bronchi divide into secondary (lobar) bronchi, and then the secondary bronchi divide into tertiary (segmental) bronchi. There are a total of 10 tertiary bronchi in the right lung and 8-9 in the left lung. Each tertiary bronchi supplies oxygen to a specific region of the lung. The lungs themselves are divided into small units, known as bronchopulmonary segments that are named based on the associated tertiary bronchus. (C)The secondary superior bronchus is outside of the lungs and, therefore, is known as an extrapulmonary bronchus.

8 Question No. 8 of Normal breathing involves the re-expansion of alveoli after exhalation to continue with gas exchange in the lungs. Which of the following statements about the reexpansion of lung alveoli is correct? Question #08 (A) Alveoli re-expand after exhalation, purely based on the strong elastic nature of the alveolar wall. (B) The presence of pulmonary surfactant plays a major role in the re-expansion of alveoli in the lungs. (C) Pulmonary surfactant in the alveoli makes the lungs harder to inflate. (D) The polar head of a surfactant molecule faces towards the air inside the alveoli. (E) None of the answers are correct. The presence of surfactant increases lung compliance and makes the lungs easier to inflate, as well as preventing the lungs from collapsing at the end of expiration. B. Correct! The presence of pulmonary surfactant plays a major role in the re-expansion of alveoli in the lungs. C. Incorrect! Pulmonary surfactant increases lung compliance and makes the lungs easier to inflate, by decreasing surface tension. The surfactant polar head adsorbs into the liquid/ water covering of the alveoli. Answer B is correct. Pulmonary surfactant is a phospholipid, similar to those found in a lipid bilayer surrounding human cells. It is made by pneumocytes in the lungs. Pulmonary surfactant has two components: (A) A polar (water-loving) head, (B) A nonpolar (water-fearing) tail. The surfactant polar head adsorbs into the liquid/ water covering of the alveoli. The surfactant nonpolar tail faces towards the air inside the alveoli. Surfactant adsorbed into the liquid layer on the alveoli decreases surface tension. This increases lung compliance and makes the lungs easier to inflate, as well as preventing the lungs from collapsing at the end of expiration. (B)The presence of pulmonary surfactant plays a major role in the reexpansion of alveoli in the lungs.

9 Question No. 9 of The muscles of respiration are stimulated into action by the respiratory center in the brainstem. Which of the following statements about the muscles of respiration is correct? Question #09 (A) During quiet breathing, the diaphragm is the major muscle involved in the breathing cycle. (B) The internal intercostal muscles are active during quiet and deep breathing movements. (C) Contraction of the diaphragm decreases the volume of the lungs. (D) As the diaphragm contracts during inspiration, the pressure within the alveoli is increased above atmospheric pressure. (E) None of the answers are correct. A. Correct! During quiet breathing, the diaphragm is the major muscle involved in the breathing cycle. During deep or laboured inspiration, the external intercostal muscles are involved, along with the diaphragm. The internal intercostal muscles are not involved in quiet breathing but are recruited during deep exhalation. C. Incorrect! As the diaphragm contracts, the volume of the chest cavity and lungs increases. When the diaphragm contracts (flattens), there is an increase in chest volume and a subsequent decrease in pressure inside the alveoli. Answer A is correct. The pressure of a gas is inversely related to its volume. The volume of the chest cavity (and subsequent pressure) is changed by contraction of the diaphragm. The diaphragm is a dome-shaped muscle below the lungs. When the diaphragm contracts (flattens), there is an increase in chest volume and a subsequent decrease in pressure. When the diaphragm relaxes, this decreases the chest volume, which leads to an increase in pressure. During quiet breathing, the diaphragm is the major muscle involved in the breathing cycle. During inspiration (inhalation), the volume of the chest cavity is increased; this is caused by the diaphragm contracting. During deep or laboured inspiration, the external intercostal muscles are involved, along with the diaphragm. During inspiration, the pressure within the alveoli is reduced below atmospheric pressure, and this change in pressure causes air to flow into the lungs. (A)During quiet breathing, the diaphragm is the major muscle involved in the breathing cycle.

10 Question No. 10 of The components of the respiratory system form early during human development. Which of the following statements about the development of the respiratory system is correct? Question #10 (A) The lungs develop from the mesoderm germinal layer. (B) At the 12 th week of development, a shallow pulmonary groove appears in the midventral floor of the pharynx. (C) The lung buds are present by the 4 th week of development. (D) The alveoli are completely developed by the 6 th month of human development. (E) None of the answers are correct. The lungs develop from the endoderm germinal layer. By the 3 rd week of development, a shallow pulmonary groove appears in the midventral floor of the pharynx. C. Correct! By the 4 th week of development, the groove gives rise to a tube, which will form the trachea, and at the end of the tube are the lung buds. Beyond the 6 th month and for a certain period after delivery of the baby, alveoli develop from the bronchioles. Answer C is correct. The lungs develop from the endoderm germinal layer. By the 3 rd week of development, a shallow pulmonary groove appears in the midventral floor of the pharynx. By the 4 th week of development, the groove gives rise to a tube, which will form the trachea, and at the end of the tube are the lung buds. As development continues past the 4 th week, the lung buds continue to develop and elongate. After 4 months of development, the lung tissue becomes vascularised and, eventually, the terminal pouches give rise to the respiratory bronchioles and alveolar ducts. At the end of the 6 th month of development, there are approximately one million terminal branches. Beyond the 6 th month and for a certain period after delivery of the baby, alveoli develop from the bronchioles. (C)The lung buds are present by the 4 th week of development.