Interaction with internal organs CHAPTER 11 SECTIONS 2,3

TWO KINDS OF DIGESTION In mechanical digestion, foods are physically broken down into smaller pieces. –Where does mechanical digestion happen? –Answers: _____________ In chemical digestion, chemicals produced by the body break foods into smaller chemical building blocks. –Where does chemical digestion happen? –Answers: _____________

Station 1 Mouth 1.Take a mirror. Look at you mouth. 2.Open you mouth and look at you tongue. 3.Find the regions of your tongue 4.Describe your tongue in your journal. 5.Touch your upper pallet (top of mouth) with your tongue and look at your blood vessels on the base of your tongue. You will see the openings to your salivary glands.

Station 1: THE MOUTH The tongue pushes food around, and the teeth break it into smaller pieces. The average person has about 10,000 taste buds and they're replaced every 2 weeks or so. They are called papillae. As a person ages, some of those taste cells don't get replaced and sense of taste diminished. Saliva moistens food and contains the enzyme amylase that begins to digest starch. The Uvula helps with the process of deglutition (swallowing) and production of speech. When you're ready to swallow, the tongue pushes a bit of mashed-up food (called “bolus”) toward the opening of your esophagus.

Draw the tongue (below left). Label the regions of taste. Draw a magnified papillae.

Station 1 Mouth 1.What kind of digestion happens in your mouth? 2.What is the function of the tongue? 3.What is the enzyme in your saliva? What does it break down? 4.What do you call the ball of food once it is chewed and mixed with the saliva and is pushed toward the back of the throat?

Station 2 THE SMALL INTESTINE Once the food has been changed into a thick liquid, the stomach releases a little at a time into the small intestine thru the pyloric valve. Enzymes produced by the gall bladder, the liver, and the pancreas break down the food mixture even more so your body can absorb all the nutrients.

Station 2 THE SMALL INTESTINE: VILLI The lining of the small intestine is covered with millions of finger-shaped structures called villi. The villi absorb nutrient molecules and pass them to blood vessels. The blood vessels carry the nutrients directly to the liver for processing.

9 Figure 24.17b, c Station 2 The small Intestinal Wall

Station 2 Small intestine 1.Draw the small intestine that you have at the lab table 2.Describe the small intestine in detail. You can use the magnifier. 3.What is the function of the lower part of the small intestine? 4.Does the food that you eat go through your small intestine? 5.What are the finger-like structures inside the intestine called? 6.What kind of muscle tissue makes up the large intestine? 7.Does chemical or mechanical digestion occur in the upper part of the small intestines (duodenum)? Explain your answer.

Station 3 LIVER AND GALLBLADDER The liver produces bile, a substance that breaks up fat particles. Bile flows from the liver into the gallbladder, and from the gallbladder into the small intestine. Bile breaks fats into small droplets. These droplets can then be chemically broken down by enzymes produced in the pancreas. The Liver also recycle red blood cells

Station 3 Liver and Gallbladder Draw the liver that you have at the lab table Describe the liver it in detail. You can use the magnifier. What is the function of the liver? Does the food that you eat go to your liver? What is the function of the gallbladder?

Station4 THE LARGE INTESTINE The large intestine is the last section of the digestive system. It contains helpful bacteria that feed on the material passing through. By now, most nutrients are absorbed. All that’s left is water and undigested food such as fiber. As the material moves through the large intestine, water is absorbed into the bloodstream. The remaining material is readied for elimination from the body.

Station 4 Large intestine: COLON AND RECTUM The last section of the large intestine is the sigmoid colon. This is the last chance to absorb water and minerals back into the blood. The large intestine ends in a short tube called the rectum. Here waste is compressed into a solid form and stored until you’re ready “to go”. Waste is removed from the body thru the anus, a muscular opening at the end of the rectum.

The last section of the large intestine is the sigmoid colon. This is the last chance to absorb water and minerals back into the blood. The large intestine ends in a short tube called the rectum. Here waste is compressed into a solid form and stored until you’re ready “to go”. Waste is removed from the body thru the anus, a muscular opening at the end of the rectum. Station 4 Large intestine: COLON AND RECTUM

Station 4 Large intestine 1.Draw the Large intestine that you have at the lab table 2.Describe the Large intestine in detail. You can use the magnifier 3.What is the function of the Large intestine? 4.Does the food that you eat go through your Large intestine? 5.What kind of muscle tissue makes up the large intestine? 6.What are the different regions of the Large intestine? 7.Chemical digestion or Mechanical digestion: Why?

Station 5 Excretory system: Kidneys Function This system collects the waste produced by the cells and removes the waste from the body. This process is called excretion. Helps maintain homeostasis by regulating the amount of water in your body

Station 5 Kidneys:Riñones The major organ of the excretory system We have 2 kidneys Function is to eliminate urea, excessive water and some other waste materials. They function like filters: because when the blood flows through the kidneys, they remove waste

Station 5 Kidney: The waste Our body eliminates carbon dioxide and the water. The excretory system eliminates UREA. Urea is a chemical that comes from the breakdown of proteins in your cells. This is transformed in the kidneys to urine.

Station 5 Kidney Draw the kidney that you have at the lab table Describe the kidney in detail. What is the function of the kidney? To which body system do the kidneys belong? What is the function of this system? What is urea? What two substances does your body lose when you exhale?

Station 6 Digestive system tissue Look under the microscope In your journal draw and label what you see in detail. Complete the Chapter 11-2 and 11-3 R/R on the Digestive System.