Clinical Kinesiology and Anatomy - Respiratory System

Chapter 11: Respiratory System

Primary Functions:
- Supply oxygen to the body.
- Eliminate carbon dioxide from the body.

Breathing: The process that includes both inhalation and exhalation.
Ventilation: The process of moving air in and out of the lungs.
Respiration: The process of gas exchange, which involves supplying oxygen to and removing carbon dioxide from the tissues of the body.

Definition: The rib cage or thorax includes:
- Sternum
- Ribs
- Costal cartilages
- Thoracic vertebrae
Dimensions: The thoracic cage is wider side-to-side than it is from front to back, and it protects several critical structures:
- Heart
- Lungs
- Aorta and vena cava
- Thymus gland
- Portions of the trachea and esophagus
- Lymph nodes
- Nerves

Movement: Little movement at individual joints.
Elevation and Depression:
- Inhalation: The thoracic cage moves upward and outward, increasing the medial-lateral diameter.
- Exhalation: The thoracic cage moves downward and inward, decreasing the medial-lateral diameter.

Posterior Articulation:
- Costovertebral Joints: Rib articulation with the vertebral body of the vertebra.
- Costotransverse Joints: Rib articulation with the transverse processes of the vertebra.
Anterior Articulation:
- The ribs articulate anteriorly with the sternum via chondrosternal or costochondral joints, which refer to the same connection.

Description: Resembles the motion of a bucket handle, expanding the medial-lateral chest diameter.

Description: Resembles the movement of a pump handle, affecting the anterior-posterior chest diameter.

Upper Airway:
- Nasal cavity
- Oral cavity
- Pharynx
- Larynx
Lower Airway: Includes the following:
- Trachea
- Right and left main stem bronchi
- Lobar bronchi (three right and two left)
- Bronchioles
- Alveoli
Lung Structure:
- Lungs are triangular-shaped, wider, and concave inferiorly, fitting the convex dome shape of the diaphragm.
- The right lung has three lobes (upper, middle, lower) while the left lung has two lobes (upper, lower) to accommodate the heart.

Pleural Cavity: Does not communicate with the outside environment.
Lung Behavior: Lungs communicate with the outside, responding to air pressure changes, indicating that intrathoracic volume and intrathoracic pressure are inversely related.
- Air moves from areas of higher pressure to areas of lower pressure until the pressures equalize.

Diaphragm: Descends as it contracts, increasing intrathoracic volume and decreasing intrathoracic pressure, thus allowing air to move into the lungs.

Diaphragm: Ascends, which decreases intrathoracic volume and increases intrathoracic pressure, expelling air from the lungs.
Rib Movements: Further volume and pressure changes can occur through rib movement.
- External Intercostal Contraction: Can rotate ribs.
- Accessory Muscles: Such as sternocleidomastoid, elevate the thoracic cage.

Inhalation divided into three levels of increasing effort:
1. Quiet Inhalation: Contraction of diaphragm and external intercostals; increases intrathoracic volume and decreases intrathoracic pressure.
2. Deep Inhalation: More forceful muscle contractions than quiet inhalation, increasing volume and allowing more air for gas exchange.
3. Forced Inhalation: Requires accessory muscles for more oxygen due to heightened activity levels.
Exhalation likewise has levels:
1. Quiet Exhalation: Involves relaxation of diaphragm and external intercostals, leading to elastic recoil of thoracic wall and lung tissue.
2. Forced Exhalation: Utilizes internal intercostals pulling ribs down and abdominal muscles compressing the abdominal cavity.

By applying forceful inward and upward thrusts underneath the thoracic cage, abdominal contents push upward against the diaphragm to increase intrathoracic pressure, expelling foreign objects lodged in the airway.

Primary Muscles: Diaphragm and intercostals
- Inhalation: Contraction of diaphragm and external intercostals.
- Exhalation: Relaxation of diaphragm and contraction of internal intercostals.
Accessory Muscles: Include any muscles that attach to the thoracic cage. Some elevate while others depress or stabilize it:
- Key Accessory Muscles: Sternocleidomastoid, scalenes, pectoralis major, quadratus lumborum.

Diaphragmatic vs. Chest Breathing:
- Diaphragmatic: More abdominal movement observed.
- Chest Breathing: More movement in the thoracic cage.
Paradoxical Breathing: When the diaphragm acts but intercostals do not, resulting in the thoracic cage expanding while intercostal spaces contract.
Pursed-Lip Breathing: Involves exhalation through close lips, decreasing airflow thus preventing collapse of airways and extending exhalation for increased gas exchange.

Involves exhalation against a closed glottis, elevating intra-abdominal and intrathoracic pressures; useful during exertions like lifting heavy objects.

Pleurisy: Inflammation of pleura.
Pneumothorax: Results from air or fluid in the pleural cavity, causing lung collapse due to reduced capacity.
Flail Chest: Consequence of multiple rib fractures, limiting lung expansion.
Bronchitis: Inflammation of bronchi, which can be bacterial or viral.
Emphysema: Deterioration of alveolar walls; reduced lung elasticity leads to shortness of breath, where pursed-lip breathing may assist.
Asthma: Results in bronchial spasms that restrict airflow and hinder exhalation due to residual air.
Hyperventilation: Rapid breath expelling excessive carbon dioxide, creating physiological imbalances.
Muscle cramps: Intrinsic factors such as diaphragm spasms or hiccups can cause discomfort.

Joint Degeneration: Limits the mobility of the thoracic cage.
Scoliosis: Reduces lung capacity on the concave side, affecting overall thoracic mobility.