(4)	+Breathing+&+gas+exchange

**Breathing**: inhaling of Oxygen and exhaling of Carbon Dioxide **Exchange of gases**: the movement of oxygen & carbon dioxide between the alveoli to the capillaries (oxgyen = alveoli to capillaries & carbon dioxide = capillaries to alveoli). **Respiration**: when cells break down glucose and turn this glucose into energy. Breathing is the active, mechanical process some animals use to draw in oxygen rich-air and to push out carbon dioxide-rich air.
 * Definition: **

**Gas exchange** in general is a process in biology where gases contained in an organism is transfered or exchanged with gases from the atmosphere. How gas echange work in a human body is that we inhale the oxygen (atmosphere gas) and it is transfered in to our blood to be convert in to energy. Gas exchange happens in the lung of our body, In unicellular organisms the respiratory surface and gas-exchange is governed by Fick's law. ** Two types of Muscles: **
 * Thoracic diaphragm** - a dome-shaped muscle that is located right under the ribcage. In breathing, these muscles help by contracting and reducing the chest cavity therefore creating suction.
 * Intercostal muscle** - are muscles that are located in between the ribs, they also help expanding and shrinking the chest cavity during breathing.

When you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. This increases the space in your chest cavity, into which your lungs expand. The intercostal muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale. When you breathe in, the air will be carried through the nose and into the trachea. The trachea will then split into two tubes (called bronchi) that are connected to the lungs. Then the tubes will be spreaded out in smaller branches of bronchioles. When the air is inside the lungs, the two types of muscles, diaphramg and intercostal muscles will contract and flatten therefore reducing the pressure and expanding the area inside the lungs. When you breathe out, air is forced out of the lungs. Now, the two types of muscles will relax and move up and the lungs will contract
 * Written sequence of what occurs: **

Air moves from high pressure to low pressure So by enlarging out lungs volume it is actually lowering out lungs pressure, which then higher pressure atmosphere air then moves into lower pressure lungs, which is the reason why our body inhale in air. The same things goes to other way around, when we exhale our lungs is actually increasing the lung pressure which then force the air to go out of the lungs and into the lower pressure atmosphere.

The main functions of the respiratory system.is to: Ventilation is also called breathing, and what breathing really is is when the co-ordination of the diaphragm and surrounding muscles cause air to flow into and out of the alveoli. The process has already been explained, but 2 vocabulary words that weren't used were inspiration and expiration. Inspiration: When the diaphragm contracts by flattening and pulling downwards while the intercostal muscles contract and pull the ribs upwards and outwards. This increases the volume in the thoracic cavity and lungs, reducing the air pressure. In order to equalize the air pressure, air rushes into the lungs and into the alveoli.
 * Ventilate the lungs
 * Take the oxygen from the air into the bloodstream
 * Produce carbon dioxide and water vapour as a waste product.
 * Maintain and steady the acid base of the blood

Expiration: It is the opposite of inspiration, and is a passive process. The diaphragm and intercostal muscles relax, allowing the diaphragm to move upwards and the intercostal muscles let the rib cage relax to the resting state. The volume of the thoracic cavity then decreases, and this causes an increase in pressure above the atmospheric pressure. In order to equalize the air pressure, air is forced out of the lungs/alveoli.

Works Cited: "THE RESPIRATORY SYSTEM." Anatomy T.V. N.p., n.d. Web. 22 Feb. 2012. <[] StudyGuide.aspx?guideid=26&nextID=17&maxID=0&customer=primal>. "Ambulance Technician Study." Respiratory System. Nixon Mcinnes, 20 Apr. 2009. Web. 22 Feb. 2012. <[] respsystem.html>.

The diffusion of gases is from an area of high concentration to an area of low concentration. When the air is in the bronchioles, it travels into millions of tiny sacs called alveoli. Then, the oxygen would travel to other tissues inside the body that needs it. While our body uses oxygen, it also creates carbon dioxide, which we do not need. The oxygen will be exchanged for the carbon dioxide inside the alveoli. When we exhale, the carbon dioxide would travel back up to the trachea and out of our nose of mouth.
 * What gases are exchanged? **

8 Liters of oxygen are inhaled in a minute for most adults, and 10 Liters of oxygen are inhaled in a minute for children. How much oxygen our body use to function in a minute: When sleeping: 0.1 Liters When standing: 0.3 Liters When walking: 0.57 Liters When running: 1.6 Liters media type="youtube" key="EFCj9STCvdI" height="315" width="420" Rap about the Respiration: media type="youtube" key="1w848pp7Adc?version=3" height="360" width="640"
 * How much gas is actually used? **
 * Video of Gas Exchange**