Breathing In (Inhalation)
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.
As your lungs expand, air is sucked in through your nose or mouth. The air travels down your windpipe and into your lungs. After passing through your bronchial tubes, the air finally reaches and enters the alveoli (air sacs).
Through the very thin walls of the alveoli, oxygen from the air passes to the surrounding capillaries (blood vessels). A red blood cell protein called hemoglobin (HEE-muh-glow-bin) helps move oxygen from the air sacs to the blood.
At the same time, carbon dioxide moves from the capillaries into the air sacs. The gas has traveled in the bloodstream from the right side of the heart through the pulmonary artery.
Oxygen-rich blood from the lungs is carried through a network of capillaries to the pulmonary vein. This vein delivers the oxygen-rich blood to the left side of the heart. The left side of the heart pumps the blood to the rest of the body. There, the oxygen in the blood moves from blood vessels into surrounding tissues.
(For more information on blood flow, go to the Health Topics How the Heart Works article.)
Breathing Out (Exhalation)
When you breathe out, or exhale, your diaphragm relaxes and moves upward into the chest cavity. The intercostal muscles between the ribs also relax to reduce the space in the chest cavity.
As the space in the chest cavity gets smaller, air rich in carbon dioxide is forced out of your lungs and windpipe, and then out of your nose or mouth.
Breathing out requires no effort from your body unless you have a lung disease or are doing physical activity. When you're physically active, your abdominal muscles contract and push your diaphragm against your lungs even more than usual. This rapidly pushes air out of your lungs.
The animation below shows how the lungs work. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.
I think its the name of the tape used to seal the packet.
Gender refers to the socially constructed differences between women and men, while the term ‘‘sex’’ is a reference to the biological and physical differences between males and females. Gender draws attention to the socially unequal distinction between femininity and masculinity. Femininity is used to describe characteristic behaviors and emotions of females and masculinity refers to the distinctive actions and feelings of the male sex. In studies of gender and sports, the concept of gender is analytically distinguished from that of sex even though the two are often used synonymously in everyday language and thought. Not all the differences between females and males are biological. But historically, ideas about the implications of biological differences between women and men have served to justify the exclusion or limited inclusion of women in sports. Such views reflect an ideology of biological determinism, where it is claimed that men, and not women, are inherently strong, aggressive, and competitive and, therefore, better suited to sports.
