Human Body Systems

Darian Joslin and Phillip Ingram

The Digestive System

The function of the digestive system is to digest and absorb food.

The Mouth allows food and air to enter the body and plays a role in speech.

The Esophagus is a tube that leads from the throat to the stomach and helps propel food down to the stomach.

The Stomach is the main storage tank for food in the body and also has digestive enzymes in it that help break down food.

The Small Intestines usually absorb about 90% of the nutrients we get from food.

The Large Intestines absorb water and vitamins and change the food into feces.

The Anus is where the feces exits the body.

The Liver has many essential functions that deal with digestion, metabolism, immunity and the storage of nutrients in the body.

The Pancreas both secretes insulin and glucagon as well as releasing digestive enzymes.

The Gallbladder holds bile that the liver produces untill the digestive enzymes are needed.


Peptic Ulcers: These are holes in the stomach caused by excess stomach acid. Scientists have found that most peptic ulcers are caused by the bacteria Helicobacter pylori. The usual prescriptions are drugs that suppress stomach acid production and to eat foods that are easily digested.

Constipation: This is when too much water is absorbed and the feces takes longer to move out of the body. Poor diet and an inactive life style are the usual causes of constipation. Fiber high foods and exercise are the most common prescriptions.

The Excretory System

The function of the excretory system is to get rid of excess waste and eliminate waste matter,

diseases, and infections.

Nephritis is the inflammation of one or both of the kidneys. It is caused by the inflammation of the first part of the nephron, the glomerulus. Some symptoms are blood in urine and kidney stones.

The Circulatory System

The main function of the circulatory system is to transport blood and other materials throughout the body as well as maintaining homeostasis.

Capillaries are tiny blood vessels that transport blood to and from the cells of the body.

Arteries are blood vessels that carry blood away from the heart, to the rest of the body.

Veins are blood blood vessels that carry blood from the rest of the body back to the heart.


The blood flows through two large veins, known as the inferior and superior vena cava, into the right atrium of the heart. The atrium contracts and blood flows through the right atrium into the right ventricle through the open tricuspid valve. When the ventricle is full the tricuspid valve shuts. As the ventricle contracts the blood flows out of the heart through the pulmonic valve and out the pulmonary artery. Oxygen rich blood flows from the pulmonary vein to the left atrium of the heart. The atrium contracts and blood flows from your left atrium to the left ventricle through the open mitral valve. When the valve shuts the ventricle contracts and blood flows from the heart to the aorta through the aortic valve.

Plasma makes up about 55% of the blood. It is a clear yellow and is 90% water.

The Respiratory System

The main function of the respiratory system is to exchange carbon dioxide for oxygen in the blood.

the alveoli features gas exchange by giving the lungs a big surface area to expand,they have moist thin walls(one cell thick),they have tiny blood vessels called capillaries,oxygen diffuses from the air in the alveoli into the blood,carbon dioxide diffuses from the blood into the air in the alveoli...the gases move by diffusion from where they have a high concentration to where there is a low concentration.

asthma:is one of the disorders.spasms in the lungs or bronchi usually caused by allergies.symptoms could be shortness of breath, help prevent this you usualy are given an inhaler to help you breathe smoothly and etc.

pulmonary embolism:is another disorder of this is whe one or more of the lugs is blocked by a blood clot.chest pain,shortness of breath,cough that may result in blood.medicine is a treatment for that disorder.medicine will help and thin the blood so that it will not clot.this arises by thrombi that originate in the deep venous system of the lower extrimities.

The Skeletal System

Function: Supports movement,protection,blood cell production,calcium storage and endocrine regulation

Bones: Provide support,protection,movement

Ligaments: It connects bone to bone

Muscles: Maintenance of posture and body position

Tendons: Connects muscle to bone

Nerves: Transmits signals to different parts of the body

Osteoporosis: Occurs in old age of humans,hard or can't move things like they used to when young,may only happen when you use something that you haven't used in a while,there is no treatment except calcium

Tendinitis: Injury of tendons,inflammation of pain,rest or ice can help it

The Muscular System

The Muscular System is responsible for the movement of the human body that attaches to the skeletal system.

1.Tight binding in rigor state.the cross bridge is at 45 degree angle relative to the filaments

2. ATP binds to the binding state on the myosin. Then the myosin dissociates from actin

3. The ATPase activity of the myosin hydrolyzes the ATP,ADP and p,remain bound to myosin

4.The myosin head swings over and binds weakly to a new acting molecule. Cross bridge is at 90 degrees relative to the filaments

5. Release of p,initiates the power stroke.the myosin head rotates on its hinge pushing the actin filament past it

6. At the end of the power stroke the myosin head releases ADP and resumes the tightly bound rigor state

1. Tendinitis: A pain or irritation in the tendon,symptoms are pain,there is ways to fix it

2. Poliomyelitis: Like when you can't comb your own hair,you well know when you can't use your muscles in the same way you used to do,there is no fix for this

The Nervous System

The function of the nervous system is to control the body’s function and allow communication between all of the parts.

The central nervous system is responsible for integrating sensory input and responding to stimulus. The brain and the spinal cord are the main components of the organ system.

The peripheral nervous system connects the central nervous system to organs in the body. The peripheral nervous system is made up of 12 cranial nerves, the spinal nerves and roots, as well as the autonomic nerves.

The Reproductive System

The main purpose of the female reproductive system is to produce and protect eggs.

The main purpose of the male reproductive is to produce and inject semen.

Over all the main purpose is to produce offspring.

Spermatogenesis is the process of turning a single diploid spermatogonium into four haploid sperm cells. First the spermatogonia replicates its dna in interphase 1 ending up with two sets of 46 chromosomes. In meiosis 2 the two diploid cells then split into 4 haploid cells.

The first step in Oogenesis is when it goes from ooctyle through ovum splits into 4 and the final one can only be complete from the other 3 which are smaller than the successful one.this happens during time of puberty.there is a difference between male and female.

the 2 major disorders of the reproductive is:

1.chlamydia:is a infection that needs biochemicals from another cell in order to reproduce.women younger and older than 25 years old need to get check up every year.oral antibiotics will be prescribed.

2.herpes:is a sexual transmited disease.there is no cure but there is a treatment that can decrease the likelihood of passing it to someone else