Body Systems
I. Circulatory system A. JOB: body’s transport system B. Blood contains red and white blood cells, platelets, and plasma C. Heart contracts and relaxes about 70 times/min. D. Blood vessels: From one human adult, end to end, would wrap the world 2.5 times (about 60,000 miles) 1. Arteries carry blood from heart to body 2. Veins carry blood from body to heart 3. Capillaries are where exchange of nutrients, waste, and oxygen occurs
II. Digestive System JOBS: breaks down foods into protein, vitamins, minerals, carbohydrates, and fats Broken down food is used for energy, growth, and cell repair PATHWAY: mouth, esophagus, stomach, duodenum, small intestine, large intestine The liver and pancreas produce chemicals that the digestive system uses to break down food The villi in small intestines is where food is absorbed into the bloodstream
III. Endocrine System JOB: controls mood and emotion, growth, development, tissue function, and metabolism B. Glands make hormones Examples: hypothalamus, pituitary, thyroid, parathyroid, adrenal, reproductive glands C. Hormones are chemical messages which are sent through the body
IV. Excretory System A. JOB: performs the process of removing wastes from the body B. PARTS: 1. kidneys remove waste from the blood, produce urine 2. lungs remove carbon dioxide from the blood to exhale 3. skin sweats 4. liver breaks down fats 5. large intestine removes solid waste from the body
V. Immune System JOB: The body’s defense against infectious organisms and other invaders Phagocytes: chew up invading organisms Leukocytes: make antibodies that remember previous invaders and destroy them quickly Lymph vessels: transport leukocytes Antigens: foreign substances invading the body
VI. Muscular System JOB: Create movement B. TYPES: skeletal (attached to bones), smooth (in your organs), cardiac/heart C. Voluntary muscles: you decide when they move D. Involuntary muscles: automatically done because of hormones or brain signals E. Over 630 muscles in the adult body F. Fibers in muscles cells make them contract and relax
VII. Nervous System A. JOB: senses, thinking breathing, remembering, laughing, pain, movement B. Central Nervous System (CNS) brain spinal cord C. Peripheral Nervous System (PNS) carries nerve impulse from CNS to muscles and glands 1. Nerves are threadlike 2. Nerves can be up to 3 feet long 3. Nerves send electric and chemical messages throughout the body
VIII.Reproductive System JOB: the organs that are involved with producing egg or sperm and conceiving and carrying babies
IX. Respiratory System JOBS: to bring oxygen to the body, deliver oxygen to the blood, remove carbon dioxide from the blood B. Pathway: mouth/nose, trachea, bronchi, alveoli (air sacs) C. Muscles in the diaphragm pull down, allowing the lungs to fill with air D. Blood flows past the air sacs, picks up oxygen and drops off carbon dioxide. We exhale the carbon dioxide when we breathe out.
X. Skeletal System A. JOB: 1. Shapes the body 2. Protects vital organs a. Brain - skull b. Heart - ribs c. Spine - vertebrae 3. Makes movement B. Infants have over 300 bones. They fuse together to make 206 in the adult human C. Bones are made of living bone cells D. Bone Marrow fills the hollow cavity inside bones and makes white and red blood cells
Review Questions What are the main jobs of each of the systems? What are the names and functions of each of the three types of blood vessels? What is the path of food through the digestive system? What purpose do the liver and pancreas serve for the digestive system? What are five main parts of the body that work as part of the excretory system? What is their function? Describe the difference between a leukocyte and a phagocyte and tell how they travel through the body. What are three types of muscles in the body? Examples? Describe the difference between an involuntary and a voluntary muscle. Which parts of the nervous system are considered CNS and PNS? Describe nerves? What is the pathway that air travels to get to the body’s cells? What is bone marrow and where can it be found?