Anatomy and Physiology: Respiratory System

Introduction to the Respiratory System

• Comprises anatomy and physiology of the respiratory system.
• Involves processes of inhalation, exhalation, and gas exchange.
• Includes transportation of oxygen and carbon dioxide in the blood.

Breathing and Respiration

• Respiration involves gas exchange among the atmosphere, blood, and cells.
• Requires three processes: ventilation (breathing), external respiration (pulmonary), and internal respiration (tissue).
• The cardiovascular system aids in gas transportation.

Components of the Respiratory System

• Divided into two structural parts: upper respiratory system (nose, pharynx) and lower respiratory system (larynx, trachea, bronchi, lungs).
• Functionally split into conducting zone (airways) and respiratory zone (gas exchange sites).

Upper Respiratory Tract

• Nose and nasal cavity produce mucus for immune functions.
• Filters, warms, and moistens inhaled air; contributes to speech and smell.
• Pharynx serves as a passageway for air and food, houses tonsils for immune action.
• Pharyngeal tonsils (adenoids) can affect sleep apnea when swollen.

Upper Respiratory Tract Inflammation

• Rhinitis: inflammation of nasal mucosa can lead to sinusitis.

Lower Respiratory Tract

• Conducting zone cleanses, warms, and humidifies air.
• Respiratory zone, including respiratory bronchioles and alveoli, is where gas exchange occurs.

Larynx

• Connects pharynx and trachea; contains vocal folds for sound production.
• Important structures include:
  • Thyroid cartilage (Adam's apple)
  • Cricoid cartilage (ring-shaped)
  • Glottis (lumen of larynx)
  • Epiglottis (closes glottis during swallowing).

Larynx Inflammation

• Laryngitis causes vocal fold swelling, leading to hoarseness or limited voice.

Trachea and Bronchi

• The trachea connects larynx to primary bronchi; features C-shaped cartilage.
• Divides into right (wider, shorter) and left bronchi entering respective lungs.
• Bronchi branch into lobar bronchi and smaller airway structures.

Lungs

• Paired thoracic organs, protected by pleural membranes.
• Pleural cavity contains fluid for lubrication; assists lung expansion and recoil.
• Each lung has lobes divided into segments; infections typically do not spread across segments.

Alveoli

• Terminal structures for gas exchange surrounded by rich capillary networks.
• Contain two pneumocyte types:
  • Type I: thin cells for gas exchange.
  • Type II: secrete surfactant to facilitate lung inflation.

Blood Supply to the Lungs

• Blood enters via pulmonary and bronchial arteries; exits via pulmonary and bronchial veins.
• Ventilation-perfusion coupling redirects blood flow from poorly to well-ventilated areas.

Upper Respiratory Disorders

• Cilia dysfunction from smoking leads to mucus accumulation.
• Pleurisy: inflammation of pleurae causing pain and possible pleural effusion (fluid accumulation).

Respiratory Physiology

• Pulmonary ventilation involves air movement due to pressure changes from respiratory muscle activity.
• Inhalation (inspiration) and exhalation (expiration) are key phases of breathing.

Boyle’s Law

• Describes the inverse relationship between gas volume and pressure, governing inhalation and exhalation mechanics.

Diaphragm in Breathing

• The diaphragm is the primary muscle for inhalation, adjusting its position during breathing cycles.

Pressures in Pulmonary Ventilation

• Atmospheric pressure (Patm) at sea level is 760 mm Hg.
• Intrapulmonary pressure (Ppul) varies with breathing; intrapleural pressure (Pip) remains negative to facilitate lung expansion.

Explore the intricate details of the respiratory system in this quiz. Learn about the anatomy, physiology, and the processes of inhalation, exhalation, and gas exchange. Perfect for students and professionals seeking to understand how oxygen and carbon dioxide function within the body.