Quiz on Breathing Mechanism and Gas Exchange in the Human Body

What happens to the diaphragm during inhalation?

• It stays in the same position
• It contracts and flattens
• It moves upwards
• It relaxes and curves upwards

Which of the following occurs during exhalation?

• Rib cage moves upwards and outwards
• Air pressure in the thoracic cavity decreases
• Diaphragm contracts
• Intercostal muscles relax

What causes air to enter the lungs during inhalation?

• Decreased air pressure in the thoracic cavity
• Increased air pressure in the thoracic cavity
• Contraction of the alveoli
• Relaxation of the diaphragm

Which structure closes the trachea when swallowing food?

• Bronchus
• Epiglottis
• Pharynx
• Larynx

What is the correct pathway of air during inhalation?

• Nostrils → Larynx → Nasal cavity → Pharynx
• Nostrils → Nasal cavity → Pharynx → Larynx
• Nostrils → Pharynx → Nasal cavity → Larynx
• Nostrils → Nasal cavity → Larynx → Pharynx

Which gas has a higher percentage in exhaled air compared to inhaled air?

• Argon
• Nitrogen
• Carbon dioxide
• Oxygen

What process allows oxygen to move from the alveoli into the blood capillaries?

• Diffusion
• Osmosis
• Active transport
• Filtration

What compound is formed when oxygen combines with hemoglobin?

• Deoxyhemoglobin
• Methemoglobin
• Carboxyhemoglobin
• Oxyhemoglobin

Where does the exchange of gases occur in the respiratory system?

• Pharynx
• Bronchi
• Trachea
• Alveoli

What happens to oxyhemoglobin when it reaches body cells with low oxygen concentration?

• It transforms into carbon dioxide
• It becomes more stable
• It combines with more oxygen
• It decomposes to release oxygen