The human body is made up of 12 systems. The Commonwealth of these systems gives us a whole organism. There are no important or unimportant systems. Each system is necessary, and each of them is important. If we have a problem with one system
soon we will have problems with the others.
Actually, everything in the body is in a constant state of movement and change. It is constantly being broken down and rebuilt. Everything is in the process of becoming something
else. Our systems cannot function separately. They are all interconnected and dependent on each other. Some of the same organs even belong to more than one system. For example, the long bones appear in both the skeletal and the lymphatic systems, since in
addition to providing the support they also manufacture blood cells. The ovaries appear in both the hormonal and the reproductive systems since they produce both hormones and ova. These human body systems are merely useful ways of classifying and studying
the structure and function of the body. All together they function and interact with each other and with the surroundings to produce a conscious, living human being.
1. Cardiovascular system: the blood circulation
with heart, arteries, and veins. Heart Pumps blood through blood vessels; blood carries oxygen and nutrients to cells and carbon dioxide and waste away from cells and helps regulate acid-base balance, temperature and water content of body fluids; blood components
help defend against disease and repair damaged blood vessels
2. Digestive system: Organs of the gastrointestinal tract, a long tube that includes the mouth, pharynx (food tubes), stomach, small
and large intestines, and anus; also includes accessory organs that assist in digestive processes, such as salivary glands, liver, gallbladder, and pancreas. Achieves physical and chemical breakdown of food absorbs nutrients; eliminates solid wastes.
3. Endocrine system: Hormone-producing glands--pineal gland, hypothalamus, pituitary gland, thymus, thyroid gland, parathyroid glands, adrenal glands, pancreas, ovaries and testes--and hormone-producing
cells in several other organs. Regulates body activities by releasing hormones (chemical messengers transported in blood from endocrine gland or tissue to target organ.
4. The excretory system including skin: eliminating
wastes from the body
5. Immune system: defending against disease-causing agents
6. Hematopoietic system: The
bodily system of organs and tissues involved in the production of blood.
7. Lymphatic system: a subset of the circulatory system, has a number of functions, including the removal of interstitial
fluid, the extracellular fluid that bathes most tissue. It also acts as a highway, transporting white blood cells to and from the lymph nodes into the bones, and antigen-presenting cells to the lymph nodes.
system: moving the body with muscles, structural support, and protection through bones
9. Central nervous system: Brain, spinal cord, nerves. Generates action potentials (nerve
impulses) to regulate body activities; detects changes in the body's internal and external environments, interprets changes, and responds by causing muscular contractions or glandular secretion
10. Reproductive system: the
- Female Reproduction System: Components: ovaries and associated organs--uterine tubes, uterus, vagina and mammary glands. Functions: Gonads produce oocytes that unite to form
a new organism; gonads also release hormones that regulate reproduction and other body processes; associated organs transport and store gametes; mammary gland produces milk.
- Male Reproduction System: Components: Testes and associated organs--epididymides,
ductus, deferens, seminal vesicles, prostate, and penis. Functions: Gonads produces sperm that unites to form a new organism; gonads also release hormones that regulate reproduction and other body processes; associated organs transport and store sperm
11. Respiratory system: the organs used for breathing, the lungs. Through respiration, we exchange gases with our environment. Our cells require a continuous supply of oxygen (O2) in order to obtain energy from food
molecules. Cells would also die if they were not able to get rid of the carbon dioxide (CO2) they produce.
12. Sensory system: Eyesight