Thursday, March 19, 2009

Reproductive System

The reproductive system allows the passing of genetic information from one generation to the next. The main sex hormone for the male is the testosterone. It is made by the testes. The testes also makes the sperm. The testosterone regulates the production of sperm and the develpment of the male. The testis is stored in epididymis. Sperm mature in the in the epididymis. The vas deferenes then passes through the prostate gland. As he sperm moves it mixes with fluids from several glands. This mix is called semen. To leave the body the semen passes through the uretha. The uretha runs through the penis. The penis is what transfers the semen into the female's body. The female part produces eggs andgives birth to developing individuals. The ovaries are what make the eggs. Estrogen is then released. That is the mai9n female sex hormone. Those are whatregulate the release of eggs and the development of the female. During ovulation, the agg is realesed into the fallopian tube. That tube leads from the into the uterus. If the egg ends up getting fertilized then the embryo enters the uterus. The uterus is the organ in which an embryo develops into a fetus. When the baby is born it passes through through the vagina and squeezes outside the body.

Circulatory System

The circulatory system moves blood throughout the body, to deliver oxygen and nutrients to the cells in the bodyand removes wastes. The circulatory system helps maintain homeostasis. It removes wastes and bringing nutrients to the cells. The right side of the lungs pumps oxygen poor blood to the lungs and the left pumps oxygen- rich blood to the body. The upper chamber is called the atrium and the lower is the ventricle. Valves are located between the two. The valves close to prevent blood from going backwards. That is how you can hear the beating of your heart. It is the valves doing their job. Blood travels through blood vessels. There are three types of them- arteries, capillaries, and veins. Arteries carry blood away from the heart. A capillary allows the exchange of blood cells and blood. A vein takes the blood to the heart. The circulation in which oxygen-rich blood flows between your lungs and heart is pulmonary circulation. The circulation of blood and the rest of the body is called systemic circulation.

Immune System

The immune system fights dideases with several complex defenses. For pathogens to have any danger they have to go through the first line of defense. Many organisma that enter you mouth go through the digestive systme quikly, and any that go through your nose go down with mucus. The outer part of your skin is dead. That makes it hard for the viruses to get into you. Then when yor skin flakes off it takes the viruses and pathogens with it. When your skin is cut then the pathogens get through easier but then the platelets close the seal up, so that they can keep as little as possible pathogens out. The flow of the bloodstream brings cells from the immune system. The immune system is what fights off diseases. the immune system is not controlled by anything. It is just tissues and cells. Macrophages is a cell that engulfs many microorganisms. If only a few enter it is easier to fight off. T cells coordinate the immune system and attack infected cells. B cells is the part of the immune system that makes the antibodies. Antibodies are proteins that attach to specific antigens. When the virus enters it replicates, and that is when the immune system really starts working. it is easier to fight off diseases with the menory B cells. Memory B cells are cells in the immune system that remebers the virus so knows how to work with it.

Digestive System

The digestive system is the break down of food into molecules to be moved into the blood. Food travels through the digestive tact. This includes the, mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, and anus. There are two types of digestion- mechanical and chemical. The chewing of the food id mechanical, and the chemical the nutrients are broken down into molecules. Things called enzymes break down some of the nutrients even smaller for the body. Amino acids are too big for the blood stream so the enzymes break them down. Teeth are different shapes and sizes. The incisors and canines are perfect for the chewing. As you chew saliva mixes in with the food. Saliva includes the enzymes to break down things. After the food has been chewed it leaves the mouth into the esophagus. Then the food gets forced into the stomach. The stomach is attached to the esophagus. The stomach performs mechanical processes to break down the food even more. The enzymes and acid then come out to turn the food into nutrients. After the stomach the food goes to the small intestine. The pancreas is what protects the small intestine. The liver is what comes next. It is what helps with the digestion. The liver makes bile to break up fat, stores mutrients, and breaks down toxins. The bile is temporarily stored in the gallbladder. Then any material not ready to go into the blood stream it goes to the liver. Materials that can't be absorbed are then pushed into the large intestine. It stores compacts and then eliminates indigestible food from the body. The large intestine absorbs most of the liquids and turn it into feces or stool. The last part of the large intestine is the rectum. It stores the feces or stool until it can be released. When it gets released it goes a small opening through the anus.

Nervous System

The nervous system responds to the body and enviroment; controls all functions of your body. The nervous system is broken down in two parts. The first one is your central nervous system. This one is your brain and spinal cord. This one responds to any messages you systems coming from the other part of the nervous system, the peripheral nervous system. This one includes all of the parts except for the brain and spinal cord. It connects all the parts of the bdies to the CNS. The PNS uses specialized structures called nerves to carry the information. In fast electrical energy nuerons carry these messages. Those fast moving messages are called impulses. The neurons have dendrides, which are especially short extensions of the cell. Dendrides are what brings the information in to the neurons. Axons are what takes them away. Sensory neurons collect information of what is going on in and outside of your body. Receptors are what detect the changes. The neuron that sends impulses to the tissue glands from the spinal cord are motor neurons. Almost all of the neurons that are under the somatic nervous system are under conscious control. They control voluntary movemonts such as writing and smiling. The autonomic nervous system does things you don't think about, like digesting food. Its manin roll is to keep everything in balance. Sympathetic nervous system and the parasympathetic work together in the autonomic system to keep a stable internal enviroment called homeostasis. The largest and main organ in the nervous system is the brain. It does invountary things and voluntary things. The largest part of the brain is called the cerebrum. It holds your voluntary movements in there. It is where most of your memories are kept. It divodes into two hemispheres. The left side controls the right and the right controls the left. The second largest part of your brain is the cerebellum. It lies below the cerebrum. This is what keeps your form. Such as when you lose your balnce, it sends messages. The medulla is what connects to the spinal cord. You can't live without it. The medulla controls invountary actions, such as blood pressure and heart rate. It recieves information from the receptors to send out impulses if your body is too cold or warm.

Muscular System

The muscular syatem is smooth muscle for movement in internal organs; cardiac muscle is found only in the heart; skeletal muscle which works with the skeletal system for movement of the bones. There are three types of muscles. They are the smooth muscle, cardiac muscle, and skeletal muscle. The smooth muscle is found in in the digestive tract. It is also found in blood vessels. Cardiac muscle is only to be found in your heart. Skeletal muscle is what helps you move and is attached to your organs. When you want to move signals sound from your brain to your skeletal cells. After the signal is sent then your muscles contract or get shorter. Tendons are what connect muscle to bone. Muscles often work in pairs. Most of the time one of the muscles straightens your body and the other bends. The one that bends is called the flexor and extenser is the one that straightens your body. A great way to strengthen the skeletal muscle is by doing resistance excercise. To strengthen your muscle then you can do aerobic excercise.

Skeletal System

The skeletal system forms redblood cells; stores calcium and phosphorus; provides shape, support, protection, and movement. The average adult body has 206 bones. Your bone work with muscles to help you move. The also help you keep a stable homeostasis by storing minerals and creating blood cells. The bone looks simple and useless but it is made up of tissues. They are made of connective and minerals. There are two type of bone tissues. If you can't see any visible spaces then it is a compact bone. The bone that has visible openings is called a spongy bone. Spongy bone provides most of the strength and support. Before your bone becomes hard it is a soft tissue called cartilage. When babies are born they don't have a lot bones. As you get older and bigger your cartilage is replaced by strong bones. Two places where your cartilage never gets replaced is in the ear and and the end of your nose. A place where tow or more bones meet is called a joint. A joint lets you move when your muscles contract. Fixed joints let no movement or barely any movement at all. There are three types of joint, gliding, ball-and-socket, and hinge. Then, joits are held together by ligaments. Ligaments are strong elastic bands of connective tissue. Ligaments connect the bone to a joint.