Organ Systems Digestive system Organs Esophagus Liver Gall bladder Stomach Large intestine Small intestine Pancreas Appendix Why is it important? Our food and drink must be changed into smaller molecules of nutrients before they can be absorbed into the blood and carried to cells throughout the body. Function: Digestion is the process by which food and drink are broken down into their smallest parts so that the body can use them to build and nourish cells and to provide energy. Movement of food through the system The large, hollow organs of the digestive system contain muscle that enables their walls to move, like a wave These waves of narrowing push the food and fluid in front of them through each hollow organ. The first major muscle movement occurs when food or liquid is chewed up (mastication) and swallowed. Initially we start swallowing by choice, once the swallow begins, it becomes involuntary and proceeds under the control of the nerves (peristalsis). The steps of the digestive system are: 1. 2. Food travels down the esophagus. Food enters the stomach where it stores food and water, mixes up the food, liquid, and digestive juice produced by the stomach, and finally it needs to empty its contents slowly into the small intestine. 3. As the food is digested in the small intestine and dissolved into the juices from the pancreas, liver, and intestine, the contents of the intestine are mixed and pushed forward to allow further digestion. 4. Finally, all of the digested nutrients are absorbed through the intestinal walls. The waste products of this process include undigested parts of the food, known as fiber, and older cells that have been shed from the mucosa. These materials are propelled into the colon, where they remain, usually for a day or two, until the feces are expelled by a bowel movement. Chicken vs. Horse Digestive juices are crucial! 1. 2. 3. 4. Saliva-begins the digestion process (produced by salivary glands) Stomach acid Once the food is in the small intestine it secretes juices to help digest the food The liver produces yet another digestive juice—bile. How is the digestive process controlled? Hormone and Nerve regulators. If you body needs more digestive enzymes to help breakdown your dinner then your nerve and hormone regulators send out a message to the liver or gallbladder to make or secrete enzymes. Cracker Lab: Food vs. Liquid Directions: With your lab partner you need to determine how long it takes for food to travel down the esophagus vs. water. Analyze your data by making a line graph. VS. YOU NEED 1. 2. 3. Stethoscope 6 saltine crackers (3 for you and 3 for your lab partner) Cup of water or liquid (1 for you and your lab partner) FIRST: Make a hypothesis: Which one will take longer? How long will each one take to travel down your esophagus and dump into your stomach? NEXT: Collect Data: You will eat 3 crackers and time all three. Then make a bar graph shoeing the three different data points. Repeat the same procedure for water, drink 3 times and make a bar graph. FINALLY: Write what actually took place. Which one was longer and what were the average times for both. When finished bring it up for a STAMP!! Skeletal System Major Organs: Bones, cartilage, tendons and ligaments. Major Role To provide support for the body, to protect delicate internal organs and to provide attachment sites for the organs. Label the skeleton found on page 9 Circulatory System Major Organs: Heart, blood vessels and blood Major Role The main role of the circulatory system is to transport nutrients, gases (such as oxygen and CO2), hormones and wastes through the body. This is the first system that develops in the body! Embryo can’t grow with out it’s own system transporting materials to the new parts of the body. Muscular System Major Organs: Skeletal muscles and smooth muscles throughout the body. Major Role The main role of the muscular system is to provide movement. Muscle: front and back view Muscles work in pairs to move limbs and provide the organism with mobility. Muscles also control the movement of materials through some organs, such as the stomach and intestine, and the heart and circulatory system. Label the muscle man found on page 9. Endocrine System Major Organs: Many glands exist in the body that secrete endocrine hormones. Among these are the hypothalamus, pituitary, thyroid, pancreas and adrenal glands. Major Role The main role of the endocrine system is to relay chemical messages through the body. In conjunction with the nervous system, these chemical messages help control physiological processes such as nutrient absorption, growth, etc. The hypothalamus is located in the brain, at the base of the optic chiasm. It secretes hormones that stimulate or suppress the release of hormones in the pituitary gland, in addition to controlling water balance, sleep, temperature, appetite, and blood pressure. Thyroid and parathyroids: The thyroid gland and parathyroid glands are located in front of the neck, below the larynx (voice box). The thyroid plays an important role in the body's metabolism. Both the thyroid and parathyroid glands also play a role in the regulation of the body's calcium balance. Lymphatic System Major Organs: Lymph, lymph nodes and vessels, white blood cells, Tand B- cells Major Role: The main role of the immune system is to destroy and remove invading microbes and viruses from the body. The lymphatic system also removes fat and excess fluids from the blood. Nervous System Major Organs: Brain, spinal cord and peripheral nerves. Major Role: The main role of the nervous system is to relay electrical signals through the body. The nervous system directs behaviour and movement and, along with the endocrine system, controls physiological processes such as digestion, circulation, etc. How Good is Your Reaction Time? Visual reaction time: Between you and your lab partner you need one ruler. Place the ruler at the edge of your desk on the 100 mm mark. Your lab partner will be holding the ruler and the subject will place thumb and forefinger on either side of ruler, near, but not touching it. The experimenter asks the subject if they are ready, then within a few seconds releases the ruler as cleanly as possible. Subject grasps ruler as soon as possible after it’s release and holds it against the side of the desk. The experimenter will then read the position of the line the ruler reached by the side of the desk to the nearest whole number and records the results in their lab partners lab book. Make sure you subtract the original 10 mm. You repeat 10 times. When finished you need to calculate the time of reflex by using the formula above the table in your lab book. If the ruler dropped 16.0 cm I would then use the following steps: 1. 2 x 16cm = 32cm 2. 32cm / 980cm/sec² = 0.03265 sec² 3. the square root of 0.03265 sec² = 0.1807 4. 0.1807sec x 1000msec/sec = 180milliseconds visual reaction time Respiratory system Major Organs: Nose, trachea and lungs. Major Role The main role of the respiratory system is to provide gas exchange between the blood and the environment. Primarily, oxygen is absorbed from the atmosphere into the body and carbon dioxide is expelled from the body. Male & Female reproductive System Major Organs: Female (top): ovaries, oviducts, uterus, vagina and mammary glands. Male (bottom): testes, seminal vesicles and penis. Major Role The main role of the reproductive system is to manufacture cells that allow reproduction. In the male, sperm are created to inseminate egg cells produced in the female. Urinary/Excretory System Major Organs: Kidneys, ureters, bladder and urethra Major Role The main role of the excretory system is to filter out cellular wastes, toxins and excess water or nutrients from the circulatory system.