The human body has 12 organ systems each of which contain several specific organs working together to perform specific functions in the body.
1. The digestive system functions to absorb nutrients from the foods we eat and to eliminate indigestible waste. Ingested food must be broken down and processed to make the nutrients available for the tissues. The portion that is not digested is eliminated from the body in the form of feces.
2. The integumentary system includes the skin, hair, nails and exocrine glands. The integumentary system forms the external body covering and protects deeper tissues from injury. It houses important touch, pain and temperature receptors along with sweat glands and oil glands, and synthesizes vitamin D.
3. The nervous system allows for fast specific communication between the body and the brain. Both conscious and unconscious sensory information is gathered about the state of our external and internal environments. This information is gathered by sensory receptor cells and sent to the central nervous system for processing. The central nervous system includes the brain and the spinal cord. The central nervous system integrates and processes this information and then forms a response. These motor commands then travel from the central nervous system to the peripheral nervous system. Motor neurons will innervate muscles and glands that will then carry out the motor commands from the central nervous system.
4. The cardiovascular system functions to circulate blood around the body through blood vessels. The heart is the organ of the cardiovascular system that creates the pressure needed to pump the blood through the vessels. Red blood cells circulate throughout the body delivering oxygen to cells and tissues, while picking up carbon dioxide. When these red blood cells pass by the lungs, they release carbon dioxide and pick up oxygen.
5. The respiratory system includes the network of airways that allows for gas exchange. The respiratory system takes in oxygen and expels carbon dioxide.
6. The skeletal system consists of bones, cartilage, tendons and ligaments. The skeletal system works as a support structure for your body. It gives the body its shape, allows for movement, makes blood cells, provides protection and stores minerals.
7. The muscular system is composed of specialized cells called muscle fibers. Their predominant function is contractibility. The muscular system includes cardiac muscle that powers the muscular contraction of the heart. It also includes the smooth muscle that enables substances to be moved through the body. Skeletal muscle attach to bones allowing for purposeful movements under conscious control
8. The immune system, defends the body against physical injury and protects us from pathogens that may cause harm. The immune system includes a variety of defenses against viruses, bacteria, fungal infections, and parasites.
9. The lymphatic system is comprised of a network of lymphatic vessels that carry a clear fluid called lymph. the white blood cells of the immune system can travel though the lymph and the blood protecting us from infection that can cause illness and disease. The key functions of the lymphatic system:
• Drains excess fluids and proteins from tissues all around the body and returns them back into the bloodstream.
• Removes waste products produced by cells.
• Fights infections.
• Absorbs fats and fat-soluble vitamins from the digestive system and transports these into the bloodstream.
10. The endocrine system influences the functions of the body by using hormones. Glands from the endocrine system secrete hormones that regulate many processes like growth, metabolism, and reproduction. The endocrine system works together with the nervous system to maintain homeostasis.
11. The reproductive system allows us to make offspring. It functions to produce egg and sperm cells, to transport and sustain these cells, and to nurture the developing offspring.
12. The urinary system, also known as the renal system, produces, stores and eliminates urine, the fluid waste excreted by the kidneys. The kidneys make urine by filtering wastes and extra water from blood. Urine travels from the kidneys through two thin tubes called ureters and fills the bladder.
All of these anatomical layers increase in their complexity. All of the organ systems come together to create the total organism. This brings us to the organism level or anatomical organization. It takes all of these levels of organization to create a really awesome YOU! You are multifaceted, elegant and complex. Now, aren’t you amazing!?
