Human Respiratory System A system that provides a large surface area for the diffusion of O2 into the blood, and the diffusion of CO2 out of the blood in order to maintain homeostasis.

Human Respiratory System and Homeostasis Responsible for Obtaining oxygen for cells Ridding the body of waste (carbon dioxide)

Requirements for Respiration Humans require a surface for gas exchange that is big enough for exchange of oxygen and carbon dioxide at a rate to meet organisms metabolic rate. Take place in a moist environment so that oxygen and carbon dioxide are dissolved

Parts of the Respiratory System

Two Main Sections of Respiratory System Upper Respiratory Nasal cavity Pharynx Epiglottis Larynx Trachea Lower Respiratory Bronchii Bronchioles Alveoli/Lungs Diaphragm

Oral and Nasal Cavities Structure - openings through which air enters the system. Nasal cavity is the chamber behind the nose. It contains hairs, cilia, and mucus. Function - the nose and nasal cavities have the following functions: (A) air is cleansed by the mucus, cilia, and hair

Oral and Nasal Cavities (B) air is heated by blood passing through a large number of capillaries just below the mucus membranes. Must be at 37 degrees for optimal performance (C) mucus membranes moisten the air The cleansing, heating, and moistening of the air prevents damage to the delicate lung tissue.

Pharynx Structure - cavity behind the nasal cavity that is common to the respiratory and digestive systems. It contains two lymph glands: adenoids and tonsils. Function - transports air between the nasal cavity/mouth and the trachea.

Larynx (Voice Box) Structure - consists of several pieces of cartilage. Located inside is elastic tissue known as vocal cords. Function - When you breathe there is a gap between cords. When you speak gap closes the vocal cords vibrate as air goes through them producing sound. The pitch of the sound produced depends on the length of the vocal cords. Long length produces low sound, while shorter cord produces a higher sound

Trachea Structure - a tube about 10 to 17 cm long containing rings of cartilage which prevent the tube from collapsing. At the top is located the epiglottis. It is lined with mucus membrane that is ciliated. connects pharynx to the bronchii Function - a connecting tube that leads air to and from the lung by passing through the pharynx to the bronchii. *Epiglottis - prevents liquids or solids from entering the lungs. *Mucus membrane - produces mucus that traps foreign materials that are then swept out of the trachea by the cilia. This material is carried away by food passing down the esophagus.

Bronchii Structure - tubes which branch from the trachea leading into the two lungs. Function - a connecting tube that leads air to and from the lung.

Bronchials Structure - small tubes that branch from the bronchi inside the lungs. Lined with ciliated mucous membrane Function - connecting tubes that lead from the bronchi to the bronchioles.

Bronchioles Structure - yet smaller tubes that branch from the bronchials inside the lung. Function - connecting tubes that lead from the bronchials to the alveoli. Brings air deep into the lungs

Lungs Structure: Protected by the ribs, sternum, and spine. Surrounded by two membranes called pleura. The pleura isolates the lungs and protects the delicate tissue. A lubricating fluid is found between the two layers allowing the lungs to move freely in the chest cavity during breathing. Function - contain a variety of tubes and chambers where gases are exchanged between the lungs and the blood.

Contains thousands of alveoli that inflate with air Humans have 2 lungs Left has 2 lobes and the right has 3 lobes Left lung has 2 lobes making it slightly smaller than right to make room for the heart Contains thousands of alveoli that inflate with air Surface of as typical lung can cover a Tennis court

Lung Systems Vary from species to species, but they all have 3 basic elements: One or two lungs that have a moist respiratory surface Means of forcibly bringing air in contact with lung surface Circulatory system to carry gases between lungs and the other cells of the body

Diaphragm Structure - sheet of muscle that separates the thorax (chest) and abdomen cavities. Function - its movement is responsible for breathing. Inspiration (inhale) - diaphragm contracts Expiration (exhale) - diaphragm relaxes

Alveoli Structure - millions per lung, giving the lungs a very large surface area for gas exchange. They are found at the ends of the bronchioles and are a cluster of microscopic, one cell thick, grape-like air sacs. They are moist and surrounded by capillaries. Function - site of gas exchange between the air in the lungs and the blood in the capillaries. Gas exchange takes place through simple diffusion but 30%occurs through facilitated diffusion

Alveoli of the Lungs

Steps in Gas exchange in Alveolus Oxygen is bought to the surface of an alveolus by inhaling air Oxygen diffuses across the alveolar membrane via concentration gradient and into a capillary. Water is needed at the surface between the alveolus and the capillary to facilitate the diffusion of gases(oxygen and carbon dioxide). At the same time carbon dioxide in the blood diffuses across the membrane and into the alveolus. This happens in the opposite direction to oxygen The carbon dioxide is then sent back up the airway to be expelled to the outside

Process of Breathing Definition - breathing is a mechanical process where gases are exchanged between the lungs and the atmosphere. Breathing is the first step in respiration. Breathing occurs due to changes in the pressure in the thorax or chest cavity of the body. This pressure is controlled by changing the size of the thorax. Two structures responsible for changing the size of the thorax are: ribs and rib muscles (intercostal muscle) diaphragm

Inhalation (Inspiration) Definition - air enters the lungs Process - there are six steps to the process: (1) rib muscle and diaphragm contract (2) ribs move up and out (3) diaphragm moves down (4) thorax increases in size or volume (5) pressure decreases in the thorax due to increase in volume. The result is lower pressure inside the thorax than outside. (6) air rushes into the lungs

When the above happens it increases the volume of the chest cavity When the above happens it increases the volume of the chest cavity. This creates a low pressure inside the chest. The pressure inside the chest is less than the pressure outside the body. Air rushes into the lungs from the outside The lungs inflate

Exhalation (Expiration) Definition - air leaves the lungs Process - there are six steps to the process: (1) rib muscle and diaphragm relax (2) ribs move down and in (3) diaphragm moves up (4) thorax decreases in size or volume (5) pressure increases in the thorax due to decrease in volume. The result is a higher pressure inside the thorax than outside. (6) air rushes out of the lungs

When this happens it decreases the volume of the chest cavity When this happens it decreases the volume of the chest cavity. This creates a high pressure inside the chest. The pressure inside the chest is greater than the pressure outside the body Air is forced out of the lungs The lungs deflate

Rate of Breathing Breathing is an involuntary response controlled by a section of the brain called the medulla oblongata. This structure sends impulses to the intercostal muscles of the ribs and diaphragm, causing them to contract which produces inspiration. When this impulse stops, the intercostal muscle and diaphragm relax producing expiration. The amount of CO2 in the blood determines the rate of breathing.

aorta leading from the left ventricle of the heart Two sensors located in the circulatory system measure the CO2 content of the blood: carotid artery in the neck aorta leading from the left ventricle of the heart

CO2 Level Rate of Breathing High Fast Slow Low * Breathing rates vary with age and activity.

1. Breathing (previously discussed) Stages of Respiration 1. Breathing (previously discussed)

2. External Respiration Definition - exchange of gases between the alveoli of the lungs and the blood. Process - occurs by diffusion O2 goes into the blood from the alveoli CO2 goes into the alveoli from the blood

3. Gas Transport Definition - transportation of gas between the lungs and body cells. Process - the gases enter the blood and combine with the protein hemoglobin found on the red blood cell (RBC) lung ----> body cells : O2 enters the bloodstream and combines with the hemoglobin forming oxyhemoglobin body cells ----> lung : CO2 enters the bloodstream and combines with the hemoglobin forming carboxyhemoglobin

* CO2 also combines with water on the RBC and in the plasma, this forms carbonic acid.

Gas Exchange

4. Internal Respiration Definition - exchange of gases between the blood and the cells of the body. Process - occurs by diffusion O2 goes into the body cells from the blood CO2 goes into the blood from the body cells

5. Cellular Respiration Definition and Process both covered previously.

Lung Capacity What's the difference between normal breathing and a deep breath? Normal breathing does not use up the full capacity of your lungs. Tidal Volume; the volume of air inhaled and exhaled in a normal breathing movement. About 500mL Inspiratory reserve volume: is the additional volume of air that can be taken in beyond a regular or tidal inhalation. About 2000mL Expiratory reserve volume: is the additional volume that can be forced out of the lungs beyond a regular or tidal exhalation. About 1500mL Vital Capacity is the total volume of gas that can be moved in or out of the lungs. It can be calculated as tidal volume + inspiratory reserve volume+ expiratory reserve volume = vital capacity. About 4L Residual volume: is the amount of gas that remains in the lungs and the passageways of the respiratory system even after a full exhalation. This volume never leaves the respiratory system, if it did the lungs would collapse. About 1500mL

Diseases of the Respiratory System

Bronchitis Definition - inflammation of the bronchial passages. Two forms: Acute - severe form which involves an infection of the air passages. Chronic - less severe form which involves an irritation of the air passages. Symptoms - fever, chest pain, severe coughing and often the secretion of sputum. Causes: infection from coughs and colds Smoking Treatments: Antibiotics Stop smoking

Asthma Caused by the constriction of bronchial passages and swelling of their mucus linings. It is triggered by a hypersensitivity to various agents within an individual’s environment. Can develop at any age Affects can be mild or extremely severe Leading cause of childhood hospitalization in Canada Symptoms – occur in episodes, attack begins with pressure in the chest, feeling of suffocation, with severe bouts of uncontrollable coughing and the secretion of a thick mucous sputum.

What happens during an asthma attack? Airway swells Bronchial muscles tighten Increased mucous is secreted in the airway Common triggers are: colds and chest infections, exercise and sports, exposure to pollen, flowers, grass, plants, trees, exposure to tobacco, dust, cold air, pets mould and mildew

How to manage Asthma Through lifestyle changes and medications Reduce contact with triggers Test for allergens Keep asthma diary Use medications Types of meds used: anti-inflammatory agents: which help prevent attacks by delaying or interrupting inflammation, and they help end attacks Bronchodilators: relax bronchial muscles and open up airways

Pneumonia Caused by the infection in the alveoli resulting in the build-up of fluid in the lungs. Two major forms are bacterial and viral. impairs their ability to take in oxygen so body becomes oxygen starved One of the leading causes of deaths in Canada especially in the elderly Two main types Lobar which affects a lobe of the lung Bronchial which affects patches throughout lungs blood-streaked sputum.

Causes of pneumonia Infection by bacteria, viruses, mycoplasma, fungi and other infectious agents and some chemicals

Types Bacterial pneumonia Viruses occurs in lobar pneumonia is caused by an invasion of streptococcus pneumonia. Can get a vaccination to provide long term protection Viruses usually attacks upper respiratory, but they also cause many forms of pneumonia. Is less serious then other forms and last for long periods of time

Mycoplasma pneumonia: Walking Pneumonia caused by small free living agents of disease in humans. Have characteristics of both bacteria and viruses. Patients require a long recovery period and can be weak for a long time Symptoms - fever, pain in the chest while breathing, cough, and sshortness of breath, shivering, chills, headache, delirium (confusion), severe bad breath, muscle pain, weakness, blue lips and nail beds from lack of oxygen in the blood

Treatments The best approach to treating pneumonia depends on a number of factors, including your age and general health, the organism or organisms involved, and the setting — community or health care — where the infection developed. Medication Antibiotics are used to treat bacterial pneumonia. Antivirals Fever reducers Cough medicine Hospital admission

Cancer Cancer is the uncontrollable multiplication of cells. Cancer may occur in any part of the body, and therefore in any part of the respiratory system.

Lung Cancer Uncontrolled and invasive growth of abnormal cells in lungs and is the leading cancer killer of both men and women in North America Carcinoma Malignant tumour grows abnormal cells that continue to multiply and take over healthy cells. Death is caused by difficulty in breathing, or cancer moving out of lungs And into brain or other body parts

87% of lung cancer is due to smoking(Carcinogens) Causes 87% of lung cancer is due to smoking(Carcinogens) Another cause is exposure to radon an element used in radiotherapy(12%) symptoms Chronic cough, coughing up blood, weigh loss los of appetite, shortness of breath chest pain and fever without cause

Effects of Lung Cancer Treatments Death but not by difficulty breathing. Death is normally caused by the cancer moving out of lungs an into other body parts such as the brain Treatments Radiation and chemotherapy if not too far advanced

Emphysema A progressive disease in which the tissues of the lungs lose their elasticity, and therefore the volume of air that the lungs are able to handle continually decreases. Alveoli are distended and their walls are so damaged that the surface available for gas exchange is reduced and less oxygen is available to the brain and tissues The deterioration in the lungs is permanent and irreversible.

Symptoms - severe coughing, shortness of breath, and wheezing; developing into difficulty in breathing. It sometimes results in disability and death. Treatments: reduce or eliminate smoking exercise, some drugs help to keep alveoli working and supplemental oxygen

Influenza A viral infection of the respiratory tract, especially the trachea. Commonly called flu. Reduces a person’s resistance making them susceptible to further infections such as pneumonia. Symptoms - sore throat, nasal discharge, fever, chills, headache, aching of muscles and joints, upset stomach

Treatments: Treat symptoms — . Rest until the flu is fully resolved, especially if the illness has been severe Fluids — Drink enough fluids so that you do not become dehydrated. Acetaminophen (such as Tylenol® and other brands) can relieve fever, headache, and muscle aches. Cough medicines are not usually helpful; cough usually resolves without treatment.

Common Cold A viral infection of the upper respiratory tract. Symptoms - sneezing, headaches, sore throat, nasal discharge

Pleurisy Inflammation of the pleura membranes that surrounds the lungs. Most cases are due to infections, and many are associated with pneumonia. Symptoms - sharp pain brought on by breathing and coughing. Patient breaths shallowly.

Treatments Use an anti-inflammatory medicine, such as ibuprofen (Motrin) or aspirin, to reduce the pain and inflammation. You may have less pain if you lie on the side that hurts. Avoid exerting yourself or doing anything that would cause you to breathe hard. Call your doctor or go to your hospital's emergency department if you can't breathe deeply or cough because of severe pain

Carbon Monoxide Poisoning Definition - Carbon monoxide is a chemical compound consisting of one atom of carbon and one atom of oxygen (CO). It is an odorless and tasteless gas. Source - It is produced when organic compounds are burned with an insufficient air supply. Effects - When inhaled, it combines with the hemoglobin on the RBC, preventing absorption of oxygen.

Symptoms - symptoms are normally mild and include nausea, headache, or fatigue. Excessive inhalation can be more serious, even fatal. Treatment - remove the individual from the source of CO. Perform mouth to mouth resuscitation if necessary.

Emphysema The swelling and scarring of alveoli in the lung resulting in loss of elasticity( cannot inflate and deflate) of the alveoli. This causes some of them to burst resulting in decrease of surface area for gas exchange Difficulty in breathing Causes of emphysema Smoking Other agents Treatments for emphysema Stop smoking Drugs to make alveoli work Extra oxygen