1. c. Describe the effects of aging on body systems.
Respiratory System
SAP4. Students will analyze the physical, chemical, and biological properties of process systems as these relate to transportation, absorption and excretion, including the cardiovascular, respiratory, digestive, excretory and immune systems.
a. Analyze and explain the relationships between the respiratory and cardiovascular systems as they obtain oxygen needed for the oxidation of nutrients and removal of carbon dioxide.
b. Examine various conditions that change normal body functions (e.g. tissue rejection, allergies, injury, diseases and disorders) and how the body responds.
c. Describe the effects of aging on body systems.

2. Introduction
The body uses oxygen for metabolic reactions. These reactions create carbon dioxide. We must constantly bring in oxygen and release carbon dioxide. The respiratory system provides these gas exchanges. It includes the nose, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi and lungs.
Cigarette smoking is the single most preventable cause of death and disability world wide. Smoking disrupts the body’s ability to maintain homeostasis. Turn to page 463 and read Focus on Wellness.

3. Human Respiratory System

4. Organs of the Respiratory System
Upper system – nose, pharynx
Lower system – larynx, trachea, bronchi and lungs
Nose – 2 openings called external nares or nostrils. The internal nose (which includes 4 sinuses) connects to the throat. Pseudostratified ciliated columnar epithelial cells and goblet cells line the nasal cavity. Mucus secreted by goblet cells moistens the air and traps dust particles. Cilia move the dust laden mucus toward the pharynx, at which point it can be swallowed or spit out, thus removing particles from the respiratory tract.

5. Organs of the Respiratory System
Nose continued – Substances in cigarette smoke inhibit movement of cilia. If the cilia are paralyzed, only coughing can remove mucus and dust packages from the airways. This is why smokers cough so much and are more prone to respiratory infections.
Pharynx – throat, lies just posterior to the nasal and oral cavities. The nasopharynx has 2 openings that lead into the auditory (Eustachian) tubes. The middle portion (oropharynx) contain the palatine tonsils. The lowest portion (laryngopharynx) connects with both the esophagus and the larynx.

6. Organs of the Respiratory System
Pharynx continued – Therefore, the oropharynx and laryngopharynx serve as a passage way for air, food and drink.
Larynx – voice box, the thyroid cartilage is also known as the Adam’s Apple which is larger in males due to secretion of male sex hormones during puberty. The epiglottis is a large leaf shaped piece of elastic cartilage. During swallowing the elevation of the larynx causes the epiglottis to move down and form a lid over the larynx closing it off keeping food and drink out of the airways.

7. Organs of the Respiratory System
Larynx continued – Vocal cords produce sounds during speaking. They are ligaments stretched between pieces of rigid cartilage like the strings of a guitar. Air pushed against the vocal cords causes them to vibrate and sets up sound waves in the air in the pharynx, nose and mouth. The greater the air pressure, the louder the sound.
Laryngitis – inflammation of the larynx. The vocal cords are inflamed due to infection or irritants such as smoking and cannot freely vibrate.

8. Organs of the Respiratory System
Trachea – windpipe – anterior to the esophagus. It extends from the larynx to the upper part of the 5th thoracic vertebra where it divides into right and left primary bronchi. It is lined with mucous membrane and is supported by C shaped rings of hyaline cartilage. The mucus provides protection against dust and other unwanted items. Cilia move mucus and trapped particles toward the pharynx. The cartilage gives support so the walls do not collapse and obstruct the air passageway.

9. Organs of the Respiratory System
Bronchi and Bronchioles – the trachea divides into the right and left primary bronchus that goes into each lung. The bronchi branch several times and leads to the bronchioles. Because the airways resemble an upside-down tree with many branches, it is known as the bronchial tree. During exercise epinephrine and norepinephrine are released which dilates (widens) the airways giving better airflow.
Asthma attack – bronchioles goes into spasm and movement of air is constricted causing breathing to be labored. Medication relaxes the bronchioles allowing proper air flow.

10. Organs of the Respiratory System
Lungs – 2 spongy, cone-shaped organs in the thoracic cavity. The lungs are protected by the pleural membrane. The lungs extend from the diaphragm to slightly above the clavicles and lie against the ribs. The broad bottom portion of each lung is its base the narrow top portion is the apex. Due to the space occupied by the heart, the left lung is about 10% smaller than the right lung.

11. Organs of the Respiratory System
Alveoli – a cup shaped outpouching of an alveolar sac. They look like grapes. Around the alveoli are a lush networks of blood capillaries. The exchange of oxygen and carbon dioxide between the air spaces in the lungs and the blood takes place by diffusion across the alveolar and capillary walls, which together form the respiratory membrane. There are roughly 300 million alveoli.

12. Pulmonary ventilation
Pulmonary ventilation is the flow of air between the atmosphere and the lungs. It occurs due to differences in air pressure. We inhale or breathe in when the pressure inside the lungs is less than the atmospheric air pressure. We exhale or breathe out when the pressure inside the lungs is greater than the atmospheric air pressure.
Breathing is called inhalation or inspiration. The muscles of inhalation are the diaphragm and the intercostals, which extend between the ribs. When the diaphragm flattens the lungs expand and fill with air. When you exhale the diaphragm returns to its domed shape.

13. Aging
With advancing age, the airways and tissues of the respiratory tract, including the alveoli, become less elastic and more rigid; the chest wall becomes more rigid as well. The result is a decrease in lung capacity. It can decrease as much as 35% by age 70. Elderly people are more susceptible to pneumonia, bronchitis, emphysema and other pulmonary disorders.

14. Disorders
Asthma – chronic airway inflammation. Affects 3-5% of the U.S. population.
Emphysema – disorder characterized by destruction of the walls of the alveoli which decreases the surface area for gas exchange.

15. Terminology
Heimlich maneuver – first aid procedure to clear the airway of obstructing objects. Performed by applying a quick upward thrust between the navel and lower ribs that causes a sudden elevation of the diaphragm and rapid expulsion of air from the lungs forcing the ejection of the object
Dyspnea – painful or labored breathing
Rhinitis – chronic or acute inflammation of the mucous membrane of the nose