Science Body Essay

   The human body systems work hard and interact with each other in order to maintain a healthy status. To begin with, the respiratory system is an extremely important part of the human body system. The job of the respiratory system is to take in oxygen and expel carbon dioxide. The parts include the nose, the pharynx, the larynx, the trachea, the bronchi, and alveoli. The nose is where oxygen enters and carbon dioxide exits. The nose is the very beginning of the respiratory system. The pharynx is the passage from the mouth to the larynx and the esophagus. The larynx is the area of the throat that contains the vocal cords and produces vocal sounds. The bronchi are one of the two tubes that connect the lungs with the trachea and alveoli are in the lungs. The alveoli are the tiny air sacs where oxygen and carbon dioxide are exchanged. There are 300-350 million alveoli in each lung making a total of about 700 million all together. Alveoli are the parts of the respiratory system that interact with the circulatory system. They give oxygen to the circulatory system through the capillaries and take carbon dioxide from the blood capillaries and expel it out the nose. The circulatory system is also extremely important to human survival. The organs in the circulatory system are in charge of transporting blood throughout your body. The parts of the circulatory system are the heart, veins, arteries, and capillaries. The heart, the main part of the circulatory system, pumps blood to your lungs and the rest of your body. Veins are vessels that carry blood to the heart, and arteries are vessels that carry blood away from your heart to the rest of your body. Except the heart and the lungs, all the other body parts receive their blood supply from the largest artery of the body, the aorta. Capillaries are tiny vessels that allow an exchange between blood and cells throughout the body. Like the respiratory system, the circulatory system interacts with the other body systems also. The capillaries take oxygen away from the alveoli in the lungs and give carbon dioxide to them in exchange. Capillaries also take waste and carbon dioxide away from every cell in the body and give nutrients, so blood interacts with every system. Finally, red blood cells are made in the bone marrow of large bones in the skeletal system.


   The respiratory system and the circulatory system are both very important in order to survive, but eating and digesting food gives our body the energy to perform these tasks. The digestive system breaks down food so your body can use it. The parts of the digestive system include the mouth/saliva and teeth, the pharynx, the esophagus, the stomach, the pancreas, the small intestine, the liver, the gallbladder, the large intestine, the rectum, and the anus. The mouth is the very beginning of food's long journey through the digestive system. Chewing breaks down food into pieces that are small enough to swallow while the saliva changes starch to sugar. The Pharynx is a tube that sends the food to the esophagus. The esophagus uses peristalsis (one-way waves that push the food down) to send the food to the stomach where it breaks it down into chyme using acids, enzymes, and the actions of muscles. The acid also kills any bacteria that are in your food. A lining of mucus prevents your stomach from digesting itself. The pancreas is a very unique part of your body. It sends fluids to the small intestine that neutralize the acids that broke down your food into chyme, in the stomach. It also makes hormones that regulate blood sugar and has enzymes that digest chyme. After leaving the stomach, your food enters the small intestine. The small intestine is covered in villi that absorb all the nutrients in your food and put them into your blood stream for the rest of your body to use. The liver, your largest organ, has lots of jobs to do. It makes bile, stores and filters food, stores extra nutrients and excess sugars, and breaks down toxins such as alcohol. Liver cells take years to replaces themselves so damaging your liver by drinking excessive amounts of alcohol isn't a good idea. The gallbladder takes bile away from the liver and puts it in the small intestine to help break up fats so they can be digested easier. The large intestine takes water out of the food remains and turns it into stool. Fiber keeps the stool soft and keeps it moving. The rectum is the last part of the large intestine, which stores stool or feces until it can be removed from the body. Finally, the anus, an opening at the end of the large intestine, is where the stool is passed out the body. The entire digestive process from mouth to anus takes about 24 hours to complete. For such a huge system it's odd that there is only one interaction that the digestive system has with other systems. The villi in the small intestine interact with the circulatory system when they give the blood nutrients from the food.

   All the actions, voluntary and involuntary in your body are controlled by the nervous system. It gathers information from inside and outside your body and interprets it so your body can react as needed. The main parts of the nervous system are the brain, the spinal cord, and nerves. The brain is your main control center, without it nothing in your body would work. Only four percent of the brain’s cells work, while the rest are kept in reserve. The spinal cord carries information to and from the brain, and it’s like a little bridge. Nerves carry impulses to your spinal cord so they can be sent to the brain. The nervous system interacts with every other system in the body because it controls all the other systems like your digestion, your circulation, and your respiration.

   The urinary system doesn’t seem to play as big of a role in your body but it is just as important as the rest of the systems. The urinary system is in charge of making, storing, and eliminating urine. The parts of the urinary system are the kidney, the ureter, the bladder, and urethra. The kidney is made of numerous tubules known as nephrons. Blood runs through the nephrons and is reduced to urine by the process of filtration, reabsorbtion, and secretion by the nephrons. After the blood is filtered into urine, it travels down the ureter, which is a slender tube that connects the kidney to the bladder. The bladder, which can expand to hold about 400ml of urine, stores the fluid until it can be eliminated from the body. Finally, the urethra is a tube where urine leaves the body. The nephrons in the kidney interact with the circulatory system when they take waste and water out of the blood capillaries.

   There are so many internal systems in your body and the integumentary system is the one that protects all of them. All the organs in the integumentary form a protective covering on the outside of your body. Epidermis, dermis, hair follicles, and nails all work as a living shield for your body. The epidermis is the outmost layer of your skin and it protects your insides from foreign particles. The dermis is the layer under your epidermis that contains your blood vessels, nerves, hair follicles, muscle fibers, oil glands, and sweat glands. Hair follicles grow hair in order to protect your body from UV light and help regulate body temperature. They also keep foreign particles out of mucous membrane openings; also know as your nostrils. The nails protect the tips of your fingers and toes so they can be soft and sensitive. This makes your fingers able to feel texture better. The sweat glands of the integumentary system interact with hormones from the endocrine system to regulate body temperature. Because the nerves and blood capillaries are in the dermis layer of the skin, the integumentary system interacts with the nervous system and the circulatory system. The blood in the dermis also helps regulate body temperature.

   After reading about all the body systems, I was shocked that all this could be happening right inside my body. I had no idea that my brain was controlling other parts of my body without me even knowing, or that the digestive system was so complex. Now I know that there are many parts in my body that are working together non-stop to keep me alive and healthy. Your body is perfectly equipped with many organs and cells in order to overcome everyday problems like burning your hand with hot glue or needing to beat Glenwood and Rifle in a track meet. The human body is truly amazing.