R1 - Respiratory Systems Flashcards
What are the main structures of the respiratory system?
Upper Respiratory Tract (nasal passages, pharynx, larynx, epiglottis, trachea), Lower Respiratory Tract (bronchi, bronchioles, alveoli, pleural membranes), Muscles for Breathing (diaphragm, intercostal muscles).
Why do we need to breathe?
To take in oxygen for cellular respiration (energy production) and to remove carbon dioxide, a waste product of cellular respiration.
What are the four stages of respiration?
- Breathing – Inhalation (inspiration) and exhalation (expiration). 2. External Respiration – Gas exchange between air and blood in the lungs. 3. Internal Respiration – Gas exchange between blood and body tissues. 4. Cellular Respiration – Energy-releasing chemical reactions in cells.
What are the three requirements for respiration?
- Concentration gradients (for gas exchange). 2. Moist environment (oxygen & carbon dioxide dissolve). 3. Large surface area (maximizes gas exchange).
What is the function of the nasal passages?
They warm, moisten, and clean incoming air using mucus and cilia.
What does the pharynx do?
Serves as a passageway for both air and food.
What is the function of the larynx (voice box)?
Contains vocal cords that produce sound when air passes through.
Longer cords → lower sound. Shorter cords → higher sound.
What does the epiglottis do?
A flap of cartilage that closes over the trachea when eating to prevent food from entering the airway.
What is the glottis?
The opening to the trachea.
What is the trachea made of?
Semicircular cartilage rings (to prevent collapse) and is lined with cilia and mucus.
What are bronchi?
Branches of the trachea that enter each lung; contain cartilage rings for support.
What are bronchioles?
Smaller branches within the lungs that lack cartilage rings but are lined with mucus and cilia.
What are alveoli, and what is their function?
Tiny air sacs in the lungs that allow gas exchange with capillaries; they are only one cell thick.
What is the pleural membrane?
A thin, double-layered membrane that surrounds the lungs and connects them to the body.
What is the role of the diaphragm in breathing?
A dome-shaped muscle that contracts to pull air into the lungs and relaxes to push air out.
What do intercostal muscles do?
Found between the ribs, they work with the diaphragm to expand and contract the chest during breathing.
How many alveoli are in an average pair of human lungs?
About 480 million alveoli.
What is the difference between external and internal respiration?
• External respiration: Gas exchange between air and blood in the lungs. • Internal respiration: Gas exchange between blood and body tissues.
What is a concentration gradient, and why is it important for respiration?
A difference in gas concentration between two areas, which drives diffusion of oxygen and carbon dioxide.
How does mucus help in the respiratory system?
It traps dust, bacteria, and debris, preventing them from reaching the lungs.
What is the function of cilia in the respiratory tract?
Tiny hair-like structures that move mucus and trapped particles out of the airways.
What is the role of goblet cells in the respiratory system?
Goblet cells produce mucus, which helps trap particles and moisten the airways.
How does the rib cage assist in breathing?
Expands and contracts along with the diaphragm to create pressure changes that allow airflow.
What happens to the diaphragm during inhalation?
It contracts and moves downward, creating space for air to enter the lungs.
What happens to the diaphragm during exhalation?
It relaxes and moves upward, pushing air out of the lungs.
Why is a moist environment important for gas exchange?
Oxygen and carbon dioxide must dissolve in moisture before diffusing across cell membranes.
What is the difference between inspiration and expiration?
• Inspiration: Air enters the lungs (inhalation). • Expiration: Air exits the lungs (exhalation).
What is the function of the pleural membrane?
It reduces friction between the lungs and chest wall during breathing.
How does smoking affect the respiratory system?
It damages cilia, increases mucus production, and can lead to lung diseases like emphysema and cancer.
How does oxygen travel from the alveoli to the blood?
Oxygen diffuses from high concentration in alveoli into the low concentration in capillaries.
What role do capillaries play in the lungs?
They surround alveoli and allow gas exchange between air and blood.
