Human Respiratory System Quiz

Biology 8 - Respiratory System

• The respiratory system's function is to supply oxygen to the blood and remove carbon dioxide waste.
• The system oversees gas exchange between the blood and the external environment.
• Oxygen is delivered to all parts of the body by the blood.
• The exchange of gases occurs within the alveoli.
• Passageways to the lungs also warm and humidify the incoming air.

Upper Respiratory Tract

• Includes the nasal cavity, pharynx, epiglottis and larynx.
• Nasal cavity: Moistens air, traps particles, and increases surface area. Olfactory receptors are located here. It has conchae (projections) increasing air turbulence and a hard palate between it and the oral cavity, and a soft palate.
• Pharynx: Muscular passageway from the nasal cavity to the larynx. It has three regions: nasopharynx (superior), oropharynx (middle), and laryngopharynx (inferior). The nasopharynx is the passage for air and the auditory tubes. The oropharynx and laryngopharynx are for both air and food.
• Epiglottis: A flap of cartilage that prevents food from entering the trachea.
• Larynx: Voice box; routes air and food into proper channels. Plays a role in speech, has eight hyaline cartilages and an epiglottis. Vocal cords.
• The larynx contains the thyroid and cricoid cartilage, as well as vocal cords.

Lower Respiratory Tract

• Includes the trachea, bronchi, lungs, and diaphragm.
• Trachea (windpipe): Connects the larynx to the bronchi. Lined with cilia to move mucus and debris away from lungs; has C-shaped hyaline cartilage.
• Bronchi: Branches of the trachea leading to the lungs.
• Lungs: Main organs of gas exchange. Divided into lobes with fissures each. Left lung is two lobes (superior, inferior) right lung is three lobes (superior, middle, inferior)
• Diaphragm: Large, dome-shaped muscle for breathing.

Breathing and Gas Exchange

• Breathing: Two phases:
  • Inspiration (inhale): Diaphragm and intercostal muscles contract, thoracic cavity expands, pressure decreases, air enters the lungs.
  • Expiration (exhale): Diaphragm and intercostal muscles relax, thoracic cavity contracts, pressure increases, air leaves the lungs.
• Gas exchange :
  • Oxygen diffuses from alveoli into the blood.
  • Carbon dioxide diffuses from the blood into the alveoli.
  • This process occurs across the respiratory membrane.

Non-Respiratory Air Movement

• Actions like coughing, sneezing, laughing, crying, yawning, and hiccups.

Events of Respiration (External)

• Oxygen moves from the alveoli to the blood.
• Pulmonary capillaries gain oxygen.
• Carbon dioxide moves out of the blood.
• Carbon dioxide is higher in the blood returning from tissues than the air in the alveoli.
• Blood gives up carbon dioxide at the alveoli.
• Blood leaving the lungs is oxygen-rich and carbon dioxide-poor.

Respiratory Gas Transport

• Oxygen attaches to hemoglobin in red blood cells (oxyhemoglobin).
• A small amount of oxygen is dissolved in blood plasma.
• Most carbon dioxide is transported as bicarbonate ions in the plasma.
• Some carbon dioxide is attached to hemoglobin.

Internal Respiration

• Exchange of gases between blood and body cells.
• Opposite of external respiration.
• Carbon dioxide diffuses out of tissues into the blood
• Oxygen diffuses from the blood into tissues.

Test your knowledge of the human respiratory system with this quiz. It covers key concepts such as gas exchange, the structure of the respiratory tract, and common misconceptions about inhalation and exhalation. Perfect for students studying biology or health sciences!