Respiratory SystemTaking in oxygen and getting rid of the carbon dioxide that’s not needed

Methods of Respiration

• Diffusion/Respiratory surfaces

• Gills

• Tracheae

• Air Sacs

• Book Lungs

• Lungs

Diffusion/Respiratory Surfaces

• Single celled organisms• Diffusion Limits their size to small• Respiratory surfaces increase surface area

for gas exchange; they are covered with moist epithelial cells

• Sponges/jellyfish take gases in directly from water

• Flatworms/annelids use outer surface for gas exchange

Gills• Arthropods, fish and amphibians

• Contain blood vessels with a thin epithelial layer

• Can be external (some amphibians) or internal (crabs and fish)

• Water flows over gills in one direction while blood flows in the opposite direction through gill capillaries. This countercurrent flow maximizes oxygen transfer

Tracheae

• Series of tubes that carry air directly to cells for gas exchange

• Spiracles are openings at the body surface that lead to tracheae that branch into smaller tubes known as tracheoles

• tracheae will not function well in animals whose body is longer than 5 cm

• Ex. grasshopper

Air Sacs

• Air sacs are found as tiny sacs off the larger breathing tubes (tracheae) of insects, as extensions of the lungs in birds, and as end organs in the lungs of certain other vertebrates.

• They serve to increase respiratory efficiency by providing a large surface area for gas exchange.

Book Lungs • terrestrial respiratory organ

characteristic of arachnids such as scorpions and spiders.

• Each book lung consists of hollow flat plates.

• Air bathes the outer surface of the plates and blood circulates within them, facilitating the exchange of gases. In most species, adequate gas exchange occurs without any muscular movement to ventilate the lung.

Lungs• In the lungs oxygen is taken into the

body and carbon dioxide is breathed out.

• made of spongy, elastic tissue that stretches and constricts as you breathe.

• The airways that bring air into the lungs (the trachea and bronchi) are made of smooth muscle and cartilage, allowing the airways to constrict and expand.

Where the air goes

• As you breathe air in through your nose or mouth, it goes past the epiglottis and into the trachea.

• It continues down the trachea through your vocal cords in the larynx until it reaches the bronchi.

• From the bronchi, air passes into each lung. The air then follows narrower and narrower bronchioles until it reaches the alveoli.

What happens next?• Within each alveoli, the oxygen concentration is

high, so oxygen passes or diffuses across the alveolar membrane into the pulmonary capillary.

• At the beginning of the pulmonary capillary, the hemoglobin in the red blood cells has carbon dioxide bound to it and very little oxygen.

• The oxygen binds to hemoglobin and the carbon dioxide is released. Carbon dioxide is also released from sodium bicarbonate dissolved in the blood of the pulmonary capillary.

• The concentration of carbon dioxide is high in the pulmonary capillary, so carbon dioxide leaves the alveolus when you exhale and the oxygen-enriched blood returns to the heart.

• Thus, the purpose of breathing is to keep the oxygen concentration high and the carbon dioxide concentration low in the alveoli so this gas exchange can occur!

Lets see the diagram• First the body

breathes in the air which is sucked through the nose or mouth and down through the trachea (windpipe). The trachea is a pipe shaped by rings of cartilage. It divides into two tubes called bronchi. These carry air into each lung.

What does a lung look like?

• Inside the lung, the tubes divide into smaller and smaller tubes called bronchioles. At the end of each of these tubes are small air sacs called alveoli.

Alveoli• Capillaries, which are

small blood vessels with thin walls, are wrapped around these alveoli. The walls are so thin and close to each other that the air easily seeps through. In this way, oxygen seeps through into the bloodstream and carbon dioxide, in the bloodstream, seeps through into the alveoli, and is then removed from the body when we breathe out.

Breathing in and out• The diaphragm is

the muscle that controls the breathing process. As the diaphragm flattens it causes the chest to expand and air is sucked into the lungs. When the diaphragm relaxes, the chest collapses and the air in the lungs is forced out.

Diseases of Respiratory System

• Asthma: The bronchioles constrict, reducing the size of the airways. This cuts down on the flow of air and makes the respiratory muscles work harder.

• Emphysema: The lungs become stiff with fibers and become less elastic, which increases the work of the respiratory muscles.

• Bronchitis: The airways become inflamed and narrower, which restricts the flow of air and increases the work of the respiratory muscles

• Apnea: Breathing slows or stops under a variety of conditions. There are many types of apnea, and they are usually caused by problems in the respiratory centers of the brain.

• Smoke inhalation: Smoke particles coat the alveoli and prevent the exchange of gases.

• Carbon monoxide poisoning: Carbon monoxide binds to hemoglobin more tightly than either oxygen or carbon dioxide, which minimizes the delivery of oxygen to all the tissues of the body, including the brain, the heart and muscles.

Fun Facts!!!!!!!!

• Your lungs contain almost 1500 miles of airways and over 300 million alveoli.

• Every minute you breathe in 13 pints of air. • People tend to get more colds in the winter

because we're indoors more often and in close proximity to other people. When people sneeze, cough and even breathe -- germs go flying

Why do I yawn?

• When you are sleepy or drowsy the lungs do not take enough oxygen from the air. This causes a shortage of oxygen in our bodies. The brain senses this shortage of oxygen and sends a message that causes you to take a deep long breath---a YAWN.

Why do I sneeze?

•  Sneezing is like a cough in the upper breathing passages. It is the body's way of removing an irritant from the sensitive mucous membranes of the nose. Many things can irritate the mucous membranes. Dust, pollen, pepper or even a cold blast of air are just some of the many things that may cause you to sneeze.

What causes hiccups?

• Hiccups are the sudden movements of the diaphragm. It is involuntary --- you have no control over hiccups, as you well know. There are many causes of hiccups. The diaphragm may get irritated, you may have eaten to fast, or maybe some substance in the blood could even have brought on the hiccups

More fun Facts!!!!!!!!!!!!!

• Left lung is smaller to leave room for the heart!

• You breathe over 5000x a day!

If water is made up of hydrogen and oxygen, why can't we breathe underwater?

• Humans cannot breathe underwater because our lungs do not have enough surface area to absorb enough oxygen from water, and the lining in our lungs is adapted to handle air rather than water.