the breathing system (5th Yr)

• What is one benefit of breathing through the nose?

  It filters air with hairs and mucous
• Why is air moistened and warmed in the nose?

  To allow easier diffusion into capillaries
• What is the function of the epiglottis?

  Closes off the trachea when swallowing
• What does the larynx produce?

  Sound by vibrations of vocal cords
• What is the role of the trachea?

  Air passes through it into the bronchi
• What protects the trachea?

  Rings of cartilage
• What is the function of mucous in the trachea?

  To capture harmful bacteria and dust
• What are cilia in the trachea responsible for?

  Upward movement of mucous
• What happens to the bronchi in the lungs?

  They further divide into bronchioles
• What happens to bronchioles during an asthma attack?

  They become restricted
• How do asthma inhalers work?

  By dilating the bronchioles
• What is the primary function of alveoli?

  Gas exchange by diffusion
• What gas enters capillaries from alveoli?

  Oxygen
• What is the process of gas exchange in the lungs?

  Diffusion
• How does oxygen travel in the blood?

  By hemoglobin in red blood cells
• How does carbon dioxide travel in the blood?

  By plasma
• What part of the brain controls breathing rate?

  Medulla oblongata
• What triggers an increase in breathing rate?

  Increased carbon dioxide levels
• What happens to the thoracic cavity during inhalation?

  Its volume increases, pressure decreases
• What is the first step in the inhalation process?

  Brain sends impulse to contract muscles
• What effect does exercise have on breathing rate?

  Increases rate of respiration
• What is the typical nature of exhalation during exercise?

  Becomes more active
• What are common symptoms of asthma?

  Wheezy breathing and breathlessness
• What causes asthma symptoms?

  Dust or allergens
• How can asthma be prevented?

  By avoiding dusty areas and allergens
• What is a common treatment for asthma?

  Bronchodilator
• Describe the process of inhalation in detail.

  • Increased carbon dioxide triggers brain signal
  • Diaphragm contracts and flattens
  • Intercostal muscles contract, rib cage moves up and out
  • Thoracic cavity volume increases, pressure decreases
  • Air is forced in due to pressure difference
• Name a human breathing disorder, its cause, prevention, and treatment.

  • Disorder: Asthma
  • Cause: Allergens (e.g., dust)
  • Prevention: Avoid dusty areas
  • Treatment: Asthma inhaler (widens bronchioles)
• What are three features of alveoli that allow for efficient gas exchange?

  • Thin walled (one cell thick)
  • Large surface area
  • Rich blood supply (capillaries)
• What is the function of the epiglottis?

  To prevent food and water going down the trachea
• What is the function of the larynx?

  To produce sound
• What process is involved in the passage of gas between alveoli and blood?

  Diffusion
• What gas in the blood triggers a deeper, faster breathing rate?

  Carbon dioxide