Digestive and Circulatory Systems 9. a. Students know how the complementary activity of major body systems provides cells with oxygen and nutrients and removes toxic waste products such as carbon dioxide. & 9. f.* Students know the individual functions and sites of secretion of digestive enzymes (amylases, proteases, nucleases, lipases), stomach acid, and bile salts.

Oxygen molecules move from the air to the alveoli of the lungs and then to the circulatory system

Circulatory System From the circulatory system glucose and oxygen molecules move from the capillaries into the cells of the body where cellular respiration occurs.

The Heart The heart is made up mostly of cardiac muscle tissue, which contracts to pump blood.

O2 and CO2 in the Blood The gas exchange process is reversed for the removal of carbon dioxide from its higher concentration in the cells to the circulatory system and, finally, to its elimination by exhalation from the lungs.

The Digestive System The digestive system delivers nutrients (e.g., glucose) to the circulatory system.

Source of Energy All of our energy comes from the macromolecules in the food we eat. Carbohydrates Lipids Proteins Nucleic Acids

Digestive Enzymes Food proceeds from the mouth through the stomach and through the small intestines). Salivary glands secrete amylase enzymes that change starch into sugar.

Digestive System in the Human Body Stomach acid and gastric enzymes begin the breakdown of protein

Pancreas Secretes amylase enzymes that change starch into sugar. Secretes lipase enzymes to break down fat molecules (which contain 3 fatty acids) to free fatty acids plus diglycerides (which contain 2 fatty acids) and monoglycerides (which contain 1 fatty acid).

Liver Bile secreted by the liver furthers the process of digestion, emulsifying fats and facilitating digestion of lipids. The liver removes toxic materials from the blood, stores them, and excretes them into the bile. The liver also regulates blood glucose. The concentration of sugar in the blood is monitored, and sugar can be stored or pulled from reserves (glycogen) in the liver and muscles

Cross Section of the Small Intestine

Villi in the Small Intestine Digest carbohydrates, fats, proteins and nutrients

Large Intestine Absorbs water and ions

Nucleic Acid Digestion Fat Digestion Carbohydrate Digestion Protein Digestion Nucleic Acid Digestion Fat Digestion Mouth Salivary Amylase (starches into sugars) Stomach Pepsin (proteins into small polypeptides) Small Intestine Pancreatic Amylase Pancreatic Pancreatic nucleases Bile Salts Pancreatic Lipase Large Intestine

Draw a concept map of the enzymes involved in digestion

In case……… Amino acids contained in proteins can also serve as an energy source, but first the amino acids must be deaminated, or chemically converted, in the liver, producing ammonia (a toxic product), which is converted to water-soluble urea and excreted by the kidneys.

Kidneys The water, urea, and salts that remain in the nephron are eliminated as urine.

Kidneys Microscopic nephrons within the kidney filter out body wastes, regulate water, and stabilize electrolyte levels in blood.

The End