Welcome to the Muscular System

 The muscular system is responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up about half of a person’s body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves. Muscle tissue is also found inside of the heart, digestive organs, and blood vessels. In these organs, muscles serve to move substances throughout the body. The muscular system can be broken down into three types of muscles: skeletal, smooth and cardiac. Skeletal muscles are the only voluntary muscle tissue in the human body and control every action that a person consciously performs. Most skeletal muscles are attached to two bones across a joint, so the muscle serves to move parts of those bones closer to each other. Smooth muscle is found inside of organs such as the stomach, intestines, and blood vessels. It is called a smooth muscle because unlike skeletal muscle, it does not have the same appearance of skeletal or cardiac muscle. The weakest of all muscle tissues, smooth muscles send signals to contract to move substances through the organ. Because smooth muscle is controlled by the unconscious part of the brain, it is known as involuntary muscle as it cannot be controlled by the conscious mind. Finally, the cardiac muscle. The cardiac muscle pumps blood throughout the body.  Like smooth muscles, cardiac muscle tissue is controlled without you knowing. While hormones and signals from the brain change the pace of contraction, cardiac muscle makes itself contract.

Welcome to the Excretory System

In the average lifespan, a normal human being pees almost 3000 times per year. 16-20 ounces of urine can be stored in the bladder of an average adult human being! Some researches reveal that the amount of poop that an average person excretes in his lifetime is about 305 pounds. The urethra of a male is larger in size than that of a female in human beings. Unlike all the other body parts of which skin is a component, excretory system does not have skin as a part of it. Kidney stones most commonly occur in white males with an age of 30 years or more and the largest stone can be as large in diameter as a golf ball. It is estimated that the bladder of an average person takes in 7,850,000,000,000 gallons of fluid and passes it out through the urethra in the normal person’s lifespan. The biggest vein in the body is the vein that leads to the vital excretory organ, the kidney. On average, the kidneys can filter 1.3 liters of blood per minute. The urine is composed of just 5% bile and the other 95% is composed of water. 

Welcome to the Digestive System

The human digestive system is a series of organs that converts food into necessary nutrients that are absorbed into the body and moves the unused waste material out of the body. It is essential to good health because if the digestive system were to stop working, the body will not be able to dispose of waste or nourish itself. The digestion process first starts with chewing. The food is broken down by the teeth so that it is able to safely move down the esophagus. Although the teeth are a part of the skeletal system, they are also very important in digestion. For carnivores, teeth are made to grind and tear meat. For a herbivore, their teeth are flat edged for plants. After the food is broken down into starch by the saliva, you would swallow which pushes the food down into the esophagus. The food is then emptied into the stomach. The stomach acids break down the proteins. The liver creates glycogen from the sugars and carbohydrates and provide energy to the body. It also breaks down any bad chemicals like alcohol, which is detoxified and passed from the body as waste. The remaining materials is passed into the large intestine and mixes with water to create feces which will exit out of the body.

Welcome to the Reproductive system

The Vagina

The vagina is a muscular, hollow tube that extends from the vaginal opening to the uterus. Because it has muscular walls, it can expand and contract. This ability to become wider or narrower allows the vagina to contain something as slim as a tampon and as wide as a baby. The vagina's muscular walls are lined with mucous membranes, which keep it protected and moist. The female reproductive system is designed to carry out several functions. It produces the female egg cells necessary for reproduction, called the ova or oocytes. The system is designed to transport the ova to the site of fertilization. Conception, the fertilization of an egg by a sperm, normally occurs in the fallopian tubes. The next step for the fertilized egg is to implant into the walls of the uterus, beginning the initial stages of pregnancy. If fertilization and/or implantation does not take place, the system is designed to menstruate (the monthly shedding of the uterine lining). Also, the female reproductive system produces female sex hormones that maintain the reproductive cycle.


The Penis

The penis is the most visible part of the male reproductive system. It is primarily used for penetration during the act of sexual intercourse. The penis has three parts; namely, the base, the shaft and the head. The base is the lower part of the penis while the shaft is the cylindrical part of the organ. The head, also known as the glans, is the most sensitive part of the penis. It is also the part where urine and semen comes out. The penis has many blood vessels that fill with blood prior to intercourse. This makes the organ rigid enough for penetration. Ejaculation usually occurs when the penis is inside the vagina, allowing the sperm cells in the semen a means of getting into the female reproductive system for fertilization.

Welcome to the Endocrine System

The endocrine system regulates short-term and long-term activities by sending chemicals throughout the body, it controls development, growth, and daily nessecites. In general, the endocrine system is in charge of body processes that happen slowly, such as cell growth. Faster processes like breathing and body movement are controlled by the nervous system. But even though the nervous system and endocrine system are separate systems, they often work together to help the body function properly.

Welcome to the Nervous System

The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. Vertebrates, animals with backbones and spinal columns have central and exterior nervous system. The central nervous system is made up of the brain, spinal cord and retina. The peripheral nervous system consists of sensory neurons, ganglia (clusters of neurons) and nerves that connect to one another and to the central nervous system.The nervous system is essentially the body’s electrical wiring. It is composed of nerves, which are cylindrical bundles of fibers that start at the brain and central cord and branch out to every other part of the body.

Welcome to the Circulatory System

The circulatory system is one of the main systems in the human body. It is a large web of organs and vessels. The human body relies on this system to deliver nutrients, oxygen and other gases through the blood. This system is made up of three separate structures that work together: the heart, lungs, arteries, veins, coronary and portal vessels. The heart, which is the main organ in the circulatory system, beats about 3 billion times in an averages person's life. About 2,000 gallons of blood travel through the body daily. Without this system, the body would not be able to fight diseases, or maintain a normal body temperature.

Welcome to the Muscular System

 The muscular system is responsible for the movement of the human body. Attached to the bones of the skeletal system are about 700 named muscles that make up about half of a person’s body weight. Each of these muscles is a discrete organ constructed of skeletal muscle tissue, blood vessels, tendons, and nerves. Muscle tissue is also found inside of the heart, digestive organs, and blood vessels. In these organs, muscles serve to move substances throughout the body.

Welcome to the Skeletal System

The skeleton is a group of 206 bones that has 6 major functions. The skeleton provides support for the body's weight, protection for the body's organs, movement, produces red and white blood cells in the bone marrow, stores nutrients such as calcium and iron, and determines how much insulin your body produces. Infants are usually born with 300 to 350 bones and as their body develops some bones fuse together. By the time children are 9 years old they have 206 bones in their body. The skeletal system is a network of ligaments, tendons, and cartilage. It is just one of many systems that helps us function everyday.