Science

• The integumentary system is the largest organ of the body, equaling 15-20% of our total body mass.
• The skin acts as a barrier to physical, chemical, and biological agents.
• The skin prevents water loss and regulates body temperature.
• The skin transmits the senses of touch, pain, and pleasure and maintains body temperature by secreting sweat.
• The hair lubricates the scalp, which secretes pheromones and cools or warms our heads.
• The nails protect our fingers, which are a major tool used for protecting ourselves and providing ourselves with food, shelter, and sensations.
• The skin leaves us most vulnerable when it is compromised by open wounds, allowing infectious agents into the body.
• The skeletal system supports and protects the body's internal organs.
• The ribs protect the abdominal organs, which are both vulnerable to injury and dangerous to our well being when injured.
• The skull protects our brain which controls all functions of our bodies and minds.
• The skeleton provides the framework and shape to our bodies and also connects to our major muscles to allow movement.
• Bones store minerals such as calcium and create blood cells in the soft bone tissue called marrow.
• Bones can break easily without enough calcium and are subject to such diseases as arthritis; cancers; scoliosis; osteoporosis, gout; bursitis; fractures and breaks; and amputations.
• The human skeleton is made up of 206 bones.
• Cardiac muscles are found in the heart and power the actions that maintain blood flow through our body.
• Smooth, or involuntary muscles are found in the heart and organs, they surround the internal organs and are responsible for their movement such as moving food through the digestive tract.
• Skeletal, or voluntary muscles, are responsible for carrying out the actions and movements caused by messages sent from our brains through our nervous system.
• Skeletal muscles are also responsible for maintaining posture and producing heat.
• When muscles lack appropriate levels of oxygen they can cramp and tear, creating pain.
• Diseases and disorders of the muscular system include muscular dystrophy, fibromyalgia; tendinitis; multiple sclerosis; and muscle strain or sprains; hernias.
• The lymphatic system transports clean fluids in our body back to the blood and drains excess fluids and debris from the tissues and cells of the body.
• The lymphatic system also houses the white blood cells (lymphocytes) involved in protecting our bodies from infection.
• Diseases and disorders specific to the lymphatic system include anemias; leukemia; tuberculosis of the lymph nodes; Hodgkin's disease; and other blood disorders.
• The respiratory system maintains our breathing, supplying the body with oxygen for cellular respiration by collecting oxygen in the lungs and disposing of carbon dioxide by breathing out the waste product.
• The respiratory system also provides our functions of speech and smell.
• The nervous system is composed of the brain, spinal cord, and nerves.
• The central nervous system consists of the brain and spinal cord, while the peripheral nervous system consists of all the nerves that lead into and out of the CNS to other parts of the body.
• The nervous system controls all of the other systems of the body, such as digestion and cardiac rhythm, and responds to internal and external changes, such as activating muscles and breathing.
• The nervous system transmits information to the brain, such as pain and external sensations.
• The endocrine system consists of the pineal gland, pituitary gland, thyroid gland, thymus, adrenal gland, pancreas, ovary, and testis.
• The glands of the endocrine system secrete chemicals called hormones that regulate most of the processes in our bodies such as growth, reproduction, metabolism, and even the control of the amount of glucose in our blood.
• Diseases and disorders of the endocrine system include Type 1 & Type 2 Diabetes, hypoglycemia, Addison's disease, Cushing's syndrome, hyper/hypothyroidism, thyroid cancer, and other active cancers of the endocrine glands.
• The cardiovascular (circulatory) system consists of the heart, blood vessels, and blood.
• The heart, made of cardiac muscle, pumps blood and blood vessels such as arteries and veins, transport the blood to every part of our body providing organs and muscles with nourishment.
• The blood carries oxygen, carbon dioxide, nutrients, waste and more throughout the body.
• The mammary glands produce milk for the newborn.
• The urinary system is also responsible for maintaining the balanced fluid volume in our bodies by regulating the amount of water that is excreted, maintaining the concentrations of electrolytes, and normal pH levels of the blood.
• The reproductive system mainly functions to create human life.
• Eggs are fertilized in the fallopian tube by sperm then travel to the uterus, which provides the site for growth.
• Ovaries produce female sex hormones and eggs.