Circulatory Systems

1. By clicking on this link, you can watch a short video of what happens to the food you eat as it passes from your mouth to your intestine. Along the way, note how the food changes consistency and form. How does this change in consistency facilitate your gaining nutrients from food? 2. Visit this site for an overview of digestion of food in different regions of the digestive tract. Note the route of non-fat nutrients from the small intestine to their release as nutrients to the body. 3. Watch this animation to see how swallowing is a complex process that involves the nervous system to coordinate the actions of upper respiratory and digestive activities. During which stage of swallowing is there a risk of food entering respiratory pathways and how is this risk blocked? 4. Watch this animation that depicts the structure of the stomach and how this structure functions in the initiation of protein digestion. This view of the stomach shows the characteristic rugae. What is the function of these rugae? 5. Watch this animation that depicts the structure of the small intestine, and, in particular, the villi. Epithelial cells continue the digestion and absorption of nutrients and transport these nutrients to the lymphatic and circulatory systems. In the small intestine, the products of food digestion are absorbed by different structures in the villi. Which structure absorbs and transports fats? 6. By watching this animation, you will see that for the various food groups—proteins, fats, and carbohydrates—digestion begins in different parts of the digestion system, though all end in the same place. Of the three major food classes (carbohydrates, fats, and proteins), which is digested in the mouth, the stomach, and the small intestine? 7. Watch this video to see the structure of the liver and how this structure supports the functions of the liver, including the processing of nutrients, toxins, and wastes. At rest, about 1500 mL of blood per minute flow through the liver. What percentage of this blood flow comes from the hepatic portal system? 33. Explain how the enteric nervous system supports the digestive system. What might occur that could result in the autonomic nervous system having a negative impact on digestion? 34. What layer of the alimentary canal tissue is capable of helping to protect the body against disease, and through what mechanism? 35. Offer a theory to explain why segmentation occurs and peristalsis slows in the small intestine. 36. It has been several hours since you last ate. Walking past a bakery, you catch a whiff of freshly baked bread. What type of reflex is triggered, and what is the result? 37. The composition of saliva varies from gland to gland. Discuss how saliva produced by the parotid gland differs in action from saliva produced by the sublingual gland. 38. During a hockey game, the puck hits a player in the mouth, knocking out all eight of his most anterior teeth. Which teeth did the player lose and how does this loss affect food ingestion? 39. What prevents swallowed food from entering the airways? 40. Explain the mechanism responsible for gastroesophageal reflux. 41. Describe the three processes involved in the esophageal phase of deglutition. 42. Explain how the stomach is protected from self-digestion and why this is necessary. 43. Describe unique anatomical features that enable the stomach to perform digestive functions. 44. Explain how nutrients absorbed in the small intestine pass into the general circulation. 45. Why is it important that chyme from the stomach is delivered to the small intestine slowly and in small amounts? 46. Describe three of the differences between the walls of the large and small intestines. 47. Why does the pancreas secrete some enzymes in their inactive forms, and where are these enzymes activated? 48. Describe the location of hepatocytes in the liver and how this arrangement enhances their function. 49. Explain the role of bile salts and lecithin in the emulsification of lipids (fats). 50. How is vitamin B12 absorbed? 30. Describe how metabolism can be altered. 31. Describe how Addison’s disease can be treated. 32. Explain how glucose is metabolized to yield ATP. 33. Insulin is released when food is ingested and stimulates the uptake of glucose into the cell. Discuss the mechanism cells employ to create a concentration gradient to ensure continual uptake of glucose from the bloodstream. 34. Discuss how carbohydrates can be stored as fat. 35. If a diabetic’s breath smells like alcohol, what could this mean? 36. Amino acids are not stored in the body. Describe how excess amino acids are processed in the cell. 37. Release of trypsin and chymotrypsin in their active form can result in the digestion of the pancreas or small intestine itself. What mechanism does the body employ to prevent its self-destruction? 38. In type II diabetes, insulin is produced but is nonfunctional. These patients are described as “starving in a sea of plenty,” because their blood glucose levels are high, but none of the glucose is transported into the cells. Describe how this leads to malnutrition. 39. Ketone bodies are used as an alternative source of fuel during starvation. Describe how ketones are synthesized. 40. How does vasoconstriction help increase the core temperature of the body? 41. How can the ingestion of food increase the body temperature? 42. Weight loss and weight gain are complex processes. What are some of the main factors that influence weight gain in people? 43. Some low-fat or non-fat foods contain a large amount of sugar to replace the fat content of the food. Discuss how this leads to increased fat in the body (and weight gain) even though the item is non-fat. 31. What is suggested by the presence of white blood cells found in the urine? 32. Both diabetes mellitus and diabetes insipidus produce large urine volumes, but how would other characteristics of the urine differ between the two diseases? 33. Why are females more likely to contract bladder infections than males? 34. Describe how forceful urination is accomplished. 35. What anatomical structures provide protection to the kidney? 36. How does the renal portal system differ from the hypothalamo–hypophyseal and digestive portal systems? 37. Name the structures found in the renal hilum. 38. Which structures make up the renal corpuscle? 39. What are the major structures comprising the filtration membrane? 40. Give the formula for net filtration pressure. 41. Name at least five symptoms of kidney failure. 42. Which vessels and what part of the nephron are involved in countercurrent multiplication? 43. Give the approximate osmolarity of fluid in the proximal convoluted tubule, deepest part of the loop of Henle, distal convoluted tubule, and the collecting ducts. 44. Explain what happens to Na+ concentration in the nephron when GFR increases. 45. If you want the kidney to excrete more Na+ in the urine, what do you want the blood flow to do? 46. What organs produce which hormones or enzymes in the renin–angiotensin system? 47. PTH affects absorption and reabsorption of what? 48. Why is ADH also called vasopressin? 49. How can glucose be a diuretic? 50. How does lack of protein in the blood cause edema? 51. Which three electrolytes are most closely regulated by the kidney?