The structure, function and main disorders of the respiratory system Flashcards
(16 cards)
Nose (Air Passages) – “First Filter”
Function: Warms, moistens, and filters air
Helps with smell (olfaction)
Structure: Hair & mucus trap dust/pathogens
Trachea
Tube with C-shaped cartilage rings to keep airway open
Carries air from nose/mouth to bronchi
Bronchi
Two large branches from trachea, one to each lung
Also supported by cartilage
Carry air into each lung
Bronchial Tree
Bronchi divide into smaller tubes called bronchioles
No cartilage in bronchioles
Lead air to alveoli
Lungs
Pair of organs protected by ribs and pleura
Contain bronchial tree and millions of alveoli
Main site of gas exchange
Alveoli
Tiny air sacs with thin walls surrounded by capillaries
Large surface area for efficient gas exchange
Oxygen diffuses into blood; carbon dioxide diffuses out
Role of Ciliated Epithelial Tissue
Lines airways like trachea and bronchi
Covered in cilia (tiny hairs) that move mucus + trapped particles upward to throat
Respiratory Muscles: Diaphragm
Dome-shaped muscle below lungs
Contracts and flattens to increase chest volume → air in
Respiratory Muscles: Intercostal Muscles
Located between ribs
Contract to expand ribcage during inhalation and relax during exhalation
Ventilation, Gaseous Exchange & Diffusion: Ventilation (Breathing)
Inhalation: diaphragm + intercostal muscles contract → lungs expand → air flows in
Exhalation: muscles relax → lungs recoil → air flows out
Controlled by brain (medulla) responding to CO2 levels
Ventilation, Gaseous Exchange & Diffusion: Gaseous Exchange
Occurs in alveoli
Oxygen moves from alveoli (high concentration) → blood (low concentration)
Carbon dioxide moves from blood → alveoli by diffusion
Ventilation, Gaseous Exchange & Diffusion: Diffusion
Passive movement of gases from areas of higher concentration to lower concentration
Main Respiratory Disorders: Smoking-related
Damages cilia → mucus buildup
Causes chronic bronchitis, lung cancer, and emphysema
Carbon monoxide reduces oxygen transport
Main Respiratory Disorders: Asthma
Airways narrow and swell, producing extra mucus
Causes wheezing, coughing, shortness of breath
Triggered by allergens, exercise, cold air
Main Respiratory Disorders: Chronic Obstructive Pulmonary Disease (COPD)
Long-term airflow obstruction
Includes emphysema (alveoli damaged) and chronic bronchitis
Mainly caused by smoking
Main Respiratory Disorders: Pneumonia
Infection causes alveoli to fill with fluid
Reduces oxygen exchange
Symptoms include cough, fever, difficulty breathing
