Q.1 Which structure is the primary site of gas exchange in the respiratory system?
Trachea
Bronchi
Alveoli
Pleura
Explanation - Alveoli are tiny sacs within the lungs where oxygen and carbon dioxide are exchanged between air and blood.
Correct answer is: Alveoli
Q.2 Which cartilage prevents food from entering the trachea during swallowing?
Cricoid cartilage
Thyroid cartilage
Epiglottis
Arytenoid cartilage
Explanation - The epiglottis acts as a flap that closes over the glottis during swallowing, preventing aspiration.
Correct answer is: Epiglottis
Q.3 The trachea bifurcates into the right and left bronchi at which vertebral level?
T2
T4/T5
T7
T10
Explanation - The trachea divides into the primary bronchi at the level of the sternal angle, around T4/T5 vertebra.
Correct answer is: T4/T5
Q.4 Which lung has three lobes?
Left lung
Right lung
Both lungs
Neither lung
Explanation - The right lung has three lobes: superior, middle, and inferior, whereas the left lung has only two lobes.
Correct answer is: Right lung
Q.5 The respiratory membrane consists of alveolar epithelium, basement membrane, and:
Endothelium of capillaries
Smooth muscle cells
Bronchial cartilage
Ciliated columnar cells
Explanation - The thin respiratory membrane allows efficient gas exchange between alveolar air and capillary blood.
Correct answer is: Endothelium of capillaries
Q.6 Which muscle is the primary muscle of inspiration?
Intercostal muscles
Sternocleidomastoid
Diaphragm
Scalene muscles
Explanation - The diaphragm contracts and flattens during inspiration, increasing thoracic volume for lung expansion.
Correct answer is: Diaphragm
Q.7 The nasal cavity is divided into two parts by the:
Palate
Nasal septum
Turbinates
Nares
Explanation - The nasal septum, composed of bone and cartilage, divides the nasal cavity into left and right passages.
Correct answer is: Nasal septum
Q.8 Which structure is also known as the 'voice box'?
Trachea
Larynx
Pharynx
Bronchus
Explanation - The larynx contains the vocal cords and is commonly referred to as the 'voice box'.
Correct answer is: Larynx
Q.9 Which pleura covers the surface of the lungs?
Parietal pleura
Visceral pleura
Costal pleura
Diaphragmatic pleura
Explanation - The visceral pleura is tightly adhered to the lungs, whereas the parietal pleura lines the thoracic cavity.
Correct answer is: Visceral pleura
Q.10 Which sinus is located within the cheekbones?
Frontal sinus
Maxillary sinus
Ethmoidal sinus
Sphenoidal sinus
Explanation - The maxillary sinuses are the largest paranasal sinuses, located within the maxilla (cheekbone).
Correct answer is: Maxillary sinus
Q.11 Which bronchus is more vertical and wider, making it more likely for aspirated objects to enter?
Left bronchus
Right bronchus
Both equally
Neither
Explanation - The right primary bronchus is shorter, wider, and more vertical, making it a common site for aspirated foreign bodies.
Correct answer is: Right bronchus
Q.12 Which structure connects the pharynx to the trachea?
Esophagus
Bronchus
Larynx
Pleura
Explanation - The larynx serves as a passage between the pharynx and trachea, as well as housing the vocal cords.
Correct answer is: Larynx
Q.13 Which type of epithelium lines the trachea?
Simple squamous
Stratified squamous
Pseudostratified columnar ciliated
Transitional
Explanation - The trachea is lined with pseudostratified columnar ciliated epithelium containing goblet cells for mucus secretion.
Correct answer is: Pseudostratified columnar ciliated
Q.14 Which nerve provides motor innervation to the diaphragm?
Vagus nerve
Phrenic nerve
Intercostal nerve
Glossopharyngeal nerve
Explanation - The phrenic nerve (C3-C5) controls diaphragmatic movement, essential for breathing.
Correct answer is: Phrenic nerve
Q.15 The conducting zone of the respiratory system includes all EXCEPT:
Trachea
Bronchi
Bronchioles
Alveoli
Explanation - The conducting zone only transports air; alveoli belong to the respiratory zone where gas exchange occurs.
Correct answer is: Alveoli
Q.16 Which tonsil is also known as the adenoids?
Palatine tonsil
Pharyngeal tonsil
Lingual tonsil
Tubal tonsil
Explanation - The pharyngeal tonsils, located in the nasopharynx, are commonly called adenoids.
Correct answer is: Pharyngeal tonsil
Q.17 Which part of the pharynx connects to the nasal cavity?
Oropharynx
Nasopharynx
Laryngopharynx
Hypopharynx
Explanation - The nasopharynx lies posterior to the nasal cavity and connects it to the oropharynx.
Correct answer is: Nasopharynx
Q.18 Which structure marks the beginning of the lower respiratory tract?
Pharynx
Larynx
Trachea
Bronchi
Explanation - The larynx is considered the starting point of the lower respiratory tract.
Correct answer is: Larynx
Q.19 Which blood vessels surround alveoli for gas exchange?
Arteries
Capillaries
Veins
Arterioles
Explanation - Pulmonary capillaries form a dense network around alveoli for efficient gas exchange.
Correct answer is: Capillaries
Q.20 Which structure separates the nasal cavity from the oral cavity?
Uvula
Hard palate
Soft palate
Tonsils
Explanation - The hard palate forms the bony separation between the nasal and oral cavities.
Correct answer is: Hard palate
Q.21 Which lung is smaller and has a cardiac notch?
Right lung
Left lung
Both lungs
Neither lung
Explanation - The left lung is smaller due to the presence of the heart and has a distinct cardiac notch.
Correct answer is: Left lung
Q.22 Which part of the larynx produces sound?
Epiglottis
Arytenoid cartilages
Vocal cords
Thyroid cartilage
Explanation - The vocal cords vibrate when air passes through, producing sound.
Correct answer is: Vocal cords
Q.23 The trachea is reinforced by what kind of cartilage?
Elastic cartilage
Fibrocartilage
Hyaline cartilage
Articular cartilage
Explanation - C-shaped rings of hyaline cartilage prevent tracheal collapse while allowing flexibility.
Correct answer is: Hyaline cartilage
Q.24 Which structure serves as the common passage for air and food?
Trachea
Pharynx
Esophagus
Bronchus
Explanation - The pharynx acts as a shared pathway for both respiratory and digestive tracts.
Correct answer is: Pharynx
Q.25 Which cavity contains the lungs?
Abdominal cavity
Thoracic cavity
Cranial cavity
Pelvic cavity
Explanation - The thoracic cavity, bounded by the rib cage and diaphragm, houses the lungs and heart.
Correct answer is: Thoracic cavity