Why is this system important to our body?
Each organ has its jobs in this system but all together helps protect out body from physical damage and etc.
Skin: is the largest organ in our body. It protects your innards from infection and injuries, help keep you cool or warm, and makes vitamin D. It is made of three layers, the epidermis, the dermis and the subcutaneous layer (hypodermis).
Epidermis- is the outer layer of skin that provides a waterproof barrier and creates our skin tone. It is a sheet made of many cells crowded together. New cells are always being made near the bottom of the epidermis layer. As they move upward, forcing the older cells upward as well, they get more and more flattened. They fill with a tough protein called keratin and then they die, so the top part of the epidermis is made of many flat, dead, cell husks. This keratinized layer is a tough skin barrier that protects you against the outside world.
Eventually, the oldest of the dead cells- the one on the very top layer- fall off. You lose these dead skin cells constantly, even when you're asleep. You actually lose around 40 000 skin cells every minute, but new ones keep getting created and move upward to replace them!
Dermis- Beneath the epidermis is the dermis layer. Unlike the epidermis, the dermis is a connective tissue, meaning its cells are separated from one another by a jelly that contains lots of strong fibers. The dermis contains the skin's sweat glands, blood vessels, hair follicles and nerve endings. Many of these nerve endings go up into the epidermis as well, so both the dermis and epidermis let you feel hear, cold, and touch because of their nerve endings. The dermis is flexible enough to let you move around. If your demir could not get bigger and smaller, you wouldn't be able to bend your arms and legs.
Subcutaneous/ hypodermis- is the innermost layer of skin. It is made up mostly of fat cells and fibrous connective tissue (long, strong, threadlike matter in the body that connects, or fixes, parts together). The fat in this layer helps keep your body warm. Fat cells act like a coat to make sure your body heat stays inside your body. It also keeps extra heat outside your body. The fat acts as a cushion, too. When you bump into an object, the fat protects the underlying muscles and tissue from being hurt. The connect tissue helps connect your skin to the muscles and bones underneath. This helps your skin move when your body does. The hypodermis is useful when you are doing something active.
Skin: is the largest organ in our body. It protects your innards from infection and injuries, help keep you cool or warm, and makes vitamin D. It is made of three layers, the epidermis, the dermis and the subcutaneous layer (hypodermis).
Epidermis- is the outer layer of skin that provides a waterproof barrier and creates our skin tone. It is a sheet made of many cells crowded together. New cells are always being made near the bottom of the epidermis layer. As they move upward, forcing the older cells upward as well, they get more and more flattened. They fill with a tough protein called keratin and then they die, so the top part of the epidermis is made of many flat, dead, cell husks. This keratinized layer is a tough skin barrier that protects you against the outside world.
Eventually, the oldest of the dead cells- the one on the very top layer- fall off. You lose these dead skin cells constantly, even when you're asleep. You actually lose around 40 000 skin cells every minute, but new ones keep getting created and move upward to replace them!
Dermis- Beneath the epidermis is the dermis layer. Unlike the epidermis, the dermis is a connective tissue, meaning its cells are separated from one another by a jelly that contains lots of strong fibers. The dermis contains the skin's sweat glands, blood vessels, hair follicles and nerve endings. Many of these nerve endings go up into the epidermis as well, so both the dermis and epidermis let you feel hear, cold, and touch because of their nerve endings. The dermis is flexible enough to let you move around. If your demir could not get bigger and smaller, you wouldn't be able to bend your arms and legs.
Subcutaneous/ hypodermis- is the innermost layer of skin. It is made up mostly of fat cells and fibrous connective tissue (long, strong, threadlike matter in the body that connects, or fixes, parts together). The fat in this layer helps keep your body warm. Fat cells act like a coat to make sure your body heat stays inside your body. It also keeps extra heat outside your body. The fat acts as a cushion, too. When you bump into an object, the fat protects the underlying muscles and tissue from being hurt. The connect tissue helps connect your skin to the muscles and bones underneath. This helps your skin move when your body does. The hypodermis is useful when you are doing something active.
Hair: The hair on your body serves many purposes. Some hair, such as your eyebrows and nose hair, keep dirt and sweat from entering your body. The hair on your head protects the skin on your head from being hurt from the Sun's harmful rays. Small hairs on your arms and legs work to keep your body temperature about the same. When you are cold, small muscles pull your hair upright, you usually get goose bumps when this happen. When the hair stands up, head is trapped near the body. When you are warm, your hair flattens down so hot air is not trapped near your body.
Hair follicles (it's a place in the epidermis ( layer of skin) that holds the roots of your hair) are the parts of your skin where hair grows. Although the first place you think of hair growing is on your head, you've actually got tiny hairs all over your body. In fact, you've got hair everywhere except the palms of your hands, eyelids, lips and on the bottom of your feet. Hair is alive only at the root, where it's inside your skin. As it grows, the cells form keratin (a protein). Then, as your hair continues to continue growing and pushing, growing and pushing- and you see your hair good because of the sebum oil (glands that produce oils, they can keep you skin moisturized and can make your skin dry if there isn't enough produced. Sometimes when sebum get stuck in the pores ,it can cause acne) that coats each strand as it grows. Your body hair protects your insides from dust and bacteria- like when your nose hair catches airborne debris and stops it from entering your body.
Nails: Your nails are made up of dead cells that have keratin in them. They serve to keep the soft tissue underneath your fingers and toes from getting hurt. They also help you hold and feel objects. At the base of your nail is a light-coloured,half-moon-shaped area. This area is called a lunula. Just under the nail, where the skin wraps over your fingernail is the nail root. It is here in the nail root and lunula that the nail growth takes place as the nail grows in lenth, it is pushed forward to what is called the nail body, or nail plate.
Sweat Glands: Sweat glands are tiny tubes that begin down in your dermis and go right through to your epidermis. This is where the sweat-mostly water with little salt- is released on the surface of your skin and reduces body heat and helps keep you cool. For example when you do something active, like playing a sport, your body uses more energy and gets hotter. Sweat then help keep your body from getting too hot.
**Additional info**
-Skin colour is decided by three factors. The first factor is the amount of melanin(a dark brown to black pigment occurring in the hair, skin, and iris of the eye in people and animals. It is responsible for tanning of skin exposed to sunlight) produced in your epidermis. Melanin ranges in colour from yellow and red to brown and black. People who produce more melanin tend to have darker skin. The second factor that decides skin colour is the amount of carotene. Carotene is a yellow or orange pigment found in the epidermis. Finally, the amount of oxygen in your blood also affects skin colour. If your blood has a lot of oxygen in it, the red blood will give your skin a pink tone. Your skin may look pinker after exercising or when you are hot, too. Even people in the same family can have more or less melanin, carotene, or oxygen in their skin.
-Your sense of touch is greatly controlled by the skin. Inside your dermis are nerve receptors. On most of your body, you have about 1000 nerve receptors on a piece of skin around the size of your fingernail. On your fingertips, there are 3 000 nerve receptors! When these nerve receptors feel pressure or heat, they send message to your brain. If the pressure is too hard, your brain will read the pressure as pain. There are also touch receptors called Meissner's corpuscles. They let your brain know when something is touching your body.
-Your fingerprints have tiny raised ridges on them. These are called friction ridges. You know them as your fingerprints, and they're not only different from finder to finger, but also different from anyone else's. Nobody in the wrold has the same fingerprints you do. Your fingerprints may all look the same to you, but there are actually different types of patterns in them. These patterns are called loops, whorls, and arches. If one of your loops leans to the left, it's a left loop. Same goes for a right-leaning loop. There are also tented arches, double loop whorls and other variations.