Respiratory System

Purpose, Pathway and ProblemsPurpose, Pathway and Problems

Human Respiratory SystemHuman Respiratory System

Purpose:Purpose:

Exchanges gases between air and blood:Exchanges gases between air and blood:Takes in oxygen from environment Takes in oxygen from environment Diffuses ODiffuses O22 to blood (for cellular to blood (for cellular

respiration).respiration).COCO22 diffuses into lungs diffuses into lungsReleases carbon dioxide into env. Releases carbon dioxide into env.

(waste from cellular respiration).(waste from cellular respiration).

Blood Transports Gases Between Lungs and Tissues

Human Respiratory SystemHuman Respiratory System

Pathway: Pathway: Nasal cavityNasal cavity Pharynx Pharynx (Throat)(Throat) Larynx Larynx (Voice Box)(Voice Box) Trachea Trachea (Windpipe)(Windpipe)

BronchiBronchi BronchiolesBronchioles Alveoli Alveoli ((Site of gas exchangeSite of gas exchange))

Exhaled air follows reverse pathway.Exhaled air follows reverse pathway.

PathwayPathway

1.1. Nasal cavity:Nasal cavity:

Air enters nostrilsAir enters nostrils

Filtered by hairs (cilia)Filtered by hairs (cilia)

Warmed/humidifiedWarmed/humidified

PathwayPathway

2. Pharynx (Throat):2. Pharynx (Throat): Intersection where pathway Intersection where pathway for air and food cross. for air and food cross.

PathwayPathway3. Larynx (Voice Box):3. Larynx (Voice Box): Contains muscular Contains muscular

tissue (vocal cords) that vibrate from tissue (vocal cords) that vibrate from passing air.passing air.

4. Trachea (Windpipe): 4. Trachea (Windpipe): Connects larynx to Connects larynx to

bronchibronchi

Rings of cartilage Rings of cartilage maintain shapemaintain shape

5. Bronchi:5. Bronchi: Connects trachea to lungsConnects trachea to lungs

6. Bronchioles:6. Bronchioles: Connect bronchi to alveoliConnect bronchi to alveoli Located within the lungsLocated within the lungs Lined with mucusLined with mucus Lined with ciliaLined with cilia

7.7. Alveoli:Alveoli: Air sacs within the lungAir sacs within the lung 300,000,000 in a person300,000,000 in a person Elastic walls lined with blood vesselsElastic walls lined with blood vessels Site of OSite of O22 and CO and CO22 diffusion diffusion

Breathing:Breathing: Inhalation:Inhalation:

Diaphragm (muscle) contractsDiaphragm (muscle) contracts Chest cavity expands Chest cavity expands Air rushes inAir rushes in

Exhalation:Exhalation: Diaphragm relaxesDiaphragm relaxes Chest cavity contracts Chest cavity contracts Air rushes outAir rushes out

Diseases of the Respiratory SystemDiseases of the Respiratory System Respiratory rate: 10 to 14 inhalations/minute.Respiratory rate: 10 to 14 inhalations/minute.

In one day, an average human:In one day, an average human:

Breathes 20,000 timesBreathes 20,000 times

Inhales 35 pounds of airInhales 35 pounds of air

Most of us breathe in air that is heavily contaminated with Most of us breathe in air that is heavily contaminated with

solid particles, ozone, sulfur oxide, carbon monoxide, solid particles, ozone, sulfur oxide, carbon monoxide,

nitrogen oxides, and many other damaging chemicals.nitrogen oxides, and many other damaging chemicals.

Breathing contaminated air can cause a number of diseases Breathing contaminated air can cause a number of diseases

including asthma, bronchitis, emphysema, and lung cancerincluding asthma, bronchitis, emphysema, and lung cancer

Diseases of the Respiratory SystemDiseases of the Respiratory System Asthma:Asthma: Condition in which breathing is impaired by Condition in which breathing is impaired by

constriction of bronchi and bronchioles, cough, and constriction of bronchi and bronchioles, cough, and thick mucus secretions. The severity and incidence of thick mucus secretions. The severity and incidence of asthma has risen dramatically in recent years, asthma has risen dramatically in recent years, especially in children. May be fatal if not treated.especially in children. May be fatal if not treated.Causes:Causes: Attacks may be precipitated by inhalation of Attacks may be precipitated by inhalation of allergens (e.g.: pollen, cats, and cockroach proteins), allergens (e.g.: pollen, cats, and cockroach proteins), pollutants, infection, or emotional stress.pollutants, infection, or emotional stress.Treatment:Treatment: Alleviates symptoms (e.g.: immuno- Alleviates symptoms (e.g.: immuno-suppressors, bronchodilators), but is not a cure.suppressors, bronchodilators), but is not a cure.

Diseases of the Respiratory SystemDiseases of the Respiratory System Bronchitis:Bronchitis: Inflammation of the mucous membranes of the Inflammation of the mucous membranes of the

bronchi. May present with cough, fever, chest or back bronchi. May present with cough, fever, chest or back pain, and fatigue.pain, and fatigue.Causes:Causes: Associated with smoking, pollution, and bacterial Associated with smoking, pollution, and bacterial or viral infections.or viral infections.

Pneumonia:Pneumonia: Acute inflammation of the lungs. Symptoms Acute inflammation of the lungs. Symptoms include high fever, chills, headache, cough, and chest pain. include high fever, chills, headache, cough, and chest pain. Causes: Causes: Bacterial, fungal, or viral infections.Bacterial, fungal, or viral infections.Treatment:Treatment: Antibiotics or other antimicrobials. Antibiotics or other antimicrobials.

Diseases of the Respiratory SystemDiseases of the Respiratory System Cigarette smoke is one of the worse air pollutants.Cigarette smoke is one of the worse air pollutants.

Over 1 million people start smoking every year.Over 1 million people start smoking every year. Kills about 350,000 people every year in U.S.Kills about 350,000 people every year in U.S. Contains 4000 different chemicals.Contains 4000 different chemicals. Each cigarette smoked subtracts about 5 Each cigarette smoked subtracts about 5

minutes from life expectancy.minutes from life expectancy. Cigarette smoke Cigarette smoke paralyzes ciliaparalyzes cilia in airways, in airways,

preventing them from removing debris and preventing them from removing debris and from protecting delicate alveoli.from protecting delicate alveoli.

Frequent coughing is the only way airways can Frequent coughing is the only way airways can clean themselves.clean themselves.

Cigarette smoke also causes fetal damage, which Cigarette smoke also causes fetal damage, which can result in miscarriage, premature birth, low can result in miscarriage, premature birth, low birth weight, and poor development.birth weight, and poor development.

Diseases of the Respiratory SystemDiseases of the Respiratory System Emphysema:Emphysema: Permanent and irreversible Permanent and irreversible

destruction of alveolar walls, resulting in loss of destruction of alveolar walls, resulting in loss of lung elasticity and gas exchange surface. lung elasticity and gas exchange surface. Symptoms include shortness of breath, difficulty Symptoms include shortness of breath, difficulty exhaling, cough, weakness, anxiety, confusion, exhaling, cough, weakness, anxiety, confusion, heart failure, lung edema (swelling), and heart failure, lung edema (swelling), and respiratory failure.respiratory failure.Causes:Causes: SmokingSmoking, pollution, old age, and infections., pollution, old age, and infections.Treatment:Treatment: Oxygen to help breathing. No cure. Oxygen to help breathing. No cure.

Diseases of the Respiratory SystemDiseases of the Respiratory System Lung Cancer:Lung Cancer: Cancerous growth that invades and Cancerous growth that invades and

destroys lung tissue. Very high fatality rate. destroys lung tissue. Very high fatality rate. Symptoms include bloody sputum, persistent cough, Symptoms include bloody sputum, persistent cough, difficulty breathing, chest pain, and repeated attacks of difficulty breathing, chest pain, and repeated attacks of bronchitis or pneumonia.bronchitis or pneumonia.Causes:Causes: Smoking Smoking (50% of all cases) and pollution (radon, (50% of all cases) and pollution (radon, asbestos). Smokers are 10 times more likely to develop asbestos). Smokers are 10 times more likely to develop lung cancer than nonsmokers.lung cancer than nonsmokers.Treatment:Treatment: Surgery is most effective, but only 50% of all Surgery is most effective, but only 50% of all lung cancers are operable by time of detection. Other lung cancers are operable by time of detection. Other treatments include radiation and chemotherapy.treatments include radiation and chemotherapy.