Exposure to types of radiation is associated with developing skin cancer. The sun can cause sunburn.
Melanin is the dark pigment in the outer layer of skin (epidermis) that gives your skin its normal color. When you're exposed to sunlight, your body protects itself by accelerating the production of melanin. The extra melanin creates the darker color of a tan.
A suntan is your body's way of blocking the sun rays to prevent sunburn and other skin damage. But the protection only goes so far. The amount of melanin you produce is determined genetically. Many people simply don't produce enough melanin to protect the skin well. Eventually, sunlight causes the skin to burn, bringing pain, redness and swelling.
You can get sunburn on cool, hazy or cloudy days. As much as 80 percent of sun rays pass through clouds. Snow, sand, water and other surfaces can reflect sun rays, burning your skin as severely as direct sunlight.
Medications that make your skin especially sensitive to the sun's radiation are known as photosensitizers. When you take them, sun exposure can cause overly reddened "sunburned" skin, hives, swelling, and itchy, scaly skin.
Not everyone will have the same degree of sun sensitivity from these medications. But for some, even short intervals of sun exposure can cause a rash or burn. Those who are more at risk include people with fair skin, light-colored hair, and blue eyes; people who work outside; people who live at higher elevations or near the equator; and people with certain autoimmune diseases, such as lupus.
Dementia is a general term for loss of memory, language, problem-solving, and other thinking abilities that are severe enough to interfere with daily life. Alzheimer's is the most common cause of dementia. Subscribe to E-News to learn how you can help those affected by Alzheimer's.
Risk factors for dementia · age: the older you are, the more likely you are to develop dementia. However, dementia is not a natural part of ageing · genes: in Symptoms include forgetfulness, limited social skills, and thinking abilities so impaired that it interferes with daily functioning. Cognitive: mental decline, confusion in the evening hours, disorientation, inability to speak or understand language, making things up, mental confusion, or inability to recognize common things
Muscular: inability to combine muscle movements or unsteady walking
Also common: memory loss, falling, jumbled speech, or sleep disorder
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.
Answer:The brainstem has an ectodermal origin and is composed of 4 parts: the diencephalon, mesencephalon, pons, and medulla oblongata.
Explanation:
Literally nothing... sorry! lol. you will definitely spot it at the other end in about 24 hours though! no worrys. i swallowed a lego once and i was fine!:)
