Respiratory System

 The respiratory system includes the upper and lower tracts, each with specific structures and functions.

Targets: Understand the anatomy and physiology of the respiratory

سندرس سويا الجهاز التنفسي من منظورين: تشريحي ووظيفي "فسيولوجي"

المحاضرات تفاعلية وممتعة 

سنستخدم فيديوهات حصرية لعرض او مراجعة المعلومات

المراجع المستخدمة:

gray's anatomy

Netter’s Atlas of Human Anatomy 7th Edition

Physiology 6th edition LINDA S. COSTANZO

المقاطع المرئية:

Boards and Beyond

Osmosis

Youtube

Anatomy of the Respiratory System

The respiratory system is divided into the upper and lower respiratory tracts, each with distinct structures and functions.

Upper Respiratory Tract

1. Nose and Nasal Cavity: The primary entry point for air, where it is filtered, warmed, and humidified.
2. Paranasal Sinuses: Air-filled spaces that help lighten the skull and warm and moisten the air.
3. Pharynx (Throat): A muscular tube that serves as a pathway for both air and food.
4. Larynx (Voice Box): Contains the vocal cords and is responsible for sound production. It also protects the trachea by closing during swallowing.

Lower Respiratory Tract

1. Trachea (Windpipe): A tube that connects the larynx to the bronchi, allowing air to pass to the lungs.
2. Bronchi: Two main branches from the trachea that lead into each lung, further dividing into smaller bronchioles.
3. Bronchioles: Smaller airways that lead to the alveoli.
4. Lungs: Two large organs where gas exchange occurs. Each lung contains millions of alveoli.
5. Alveoli: Tiny air sacs where oxygen and carbon dioxide are exchanged with the blood.
6. Diaphragm: A dome-shaped muscle that plays a crucial role in breathing by contracting and relaxing to change the pressure in the thoracic cavity.

Respiratory System Physiology

Structure of the Respiratory System

The respiratory system consists of the nasal cavity, pharynx, larynx, trachea, bronchi, and lungs. These structures facilitate the intake of oxygen and the expulsion of carbon dioxide.

Lung Volumes and Capacities

Lung volumes and capacities measure the different amounts of air the lungs can hold, including tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. These metrics are essential for evaluating respiratory health.

Mechanics of Breathing

Breathing involves the diaphragm and intercostal muscles. Inhalation occurs when the diaphragm contracts, creating negative pressure that draws air into the lungs. Exhalation is usually passive, resulting from muscle relaxation.

Gas Exchange

Gas exchange happens in the alveoli, where oxygen from inhaled air diffuses into the blood, and carbon dioxide from the blood diffuses into the alveoli to be exhaled.

Oxygen Transport in Blood

Oxygen is mainly transported in the blood bound to hemoglobin in red blood cells, with a small amount dissolved in plasma.

Carbon Dioxide Transport in Blood

Carbon dioxide is transported in the blood in three forms: dissolved in plasma, as bicarbonate ions, and bound to hemoglobin.

Ventilation/Perfusion Relationships

Effective gas exchange depends on the matching of ventilation (airflow) and perfusion (blood flow) in the lungs. Imbalances can lead to inefficient gas exchange.

Control of Breathing

Breathing is regulated by the respiratory centers in the brainstem, which respond to chemical and neural signals to adjust the rate and depth of breathing.

Integrative Functions

The respiratory system works with other systems, such as the cardiovascular system, to maintain homeostasis and meet the body’s metabolic demands.

Hypoxemia and Hypoxia

Hypoxemia refers to low oxygen levels in the blood, while hypoxia refers to low oxygen levels in tissues. Both conditions can result from various respiratory or cardiovascular issues.