Biology 30S Unit Test Review: Digestion

Transcription

1 Bilgy 30S Unit Test Review: Digestin Test utline: Multiple Chice: 10 Questins, 1 mark each. Shrt Answer: 5 Questins (answer 3 f them), 5 marks each. Lng Answer: 2 Lng Answer Questins, 10 marks each. Tasks t be Successful: State the functin f the muth, salivary glands, tngue, teeth, pharynx, esphagus, stmach, small intestine, large intestine, anus, liver, pancreas and gall bladder Knw the structure f teeth (layers), supprting structures Where des prtein digestin take place? What chemicals are required? Where des fat digestin take place? What chemicals are required? What are carbhydrates, prteins, fats, nucleic acids? (Why d we need them? Where d we get them?) Trace a piece f tast frm the muth t the anus Write a brief descriptin f the symptms and treatments fr tw f the fllwing disrders: Anrexia/bulimia, Dysentery, Ulcers, Appendicitis, Malabsrbtin, Diabetes, Liver Cirrhsis. Explain the rle f the liver, pancreas, insulin, glucagns, glycgen and glucse in the regulatin f bld sugar Label a diagram f the digestive system Additinal Questins t Cnsider: 1. Define mechanical digestin. 2. Define chemical digestin. 3. List the structures f the human digestive system that perfrm mechanical digestin. 4. List the structures f the human digestive system that perfrm chemical digestin. 5. What is the fd mass called after it has left the muth? 6. Name the mvements f the esphagus that mve the fd alng t the stmach. 7. What is the name f the ring f muscles that cntrls fd entry int the stmach? 8. What ther functin des this ring f muscle have? 9. What enzyme is active in the stmach? 10. Which structures release this enzyme? 11. What ther secretins are present in the stmach? What are their functins? 12. What is the name f the ring f muscles that cntrls the mvement f fd int the small intestine?

2 13. What is the fd mass called after it leaves the stmach? 14. List, in rder, the three parts f the small intestine. 15. Which is the mst imprtant part f the small intestine? 16. What is the functin f bile? 17. Where is bile made? 18. Where is bile stred befre it enters the dudenum? 19. Why is it imprtant fr the secretins fund in the dudenum t be basic (nt acidic)? 20. What enzymes are active in the small intestine? What d they d? 21. What are tw structural features f the small intestine that make it well adapted fr absrbing nutrients? 22. What is the functin f the cubidal cells f the villi? 23. What is the functin f the capillaries f the villi? 24. What is the functin f the lacteals f the villi? 25. What is the functin f the Krypts f Leiberkuhn? 26. What are the 5 functins f the liver? 27. List in rder, the 6 parts f the large intestine. 28. What are the functins f the large intestine? 29. What happens if nt enugh water is reabsrbed? 30. What happens if t much water is reabsrbed? 31. What type f infrmatin can be fund n a nutritin label? Describe their rle in a healthy diet. What is Insulin? Insulin is a peptide hrmne prduced by beta cells f the pancreatic islets. It regulates the metablism f carbhydrates, fats and prtein by prmting the absrptin f, especially, glucse frm the bld int fat, liver and skeletal muscle cells. In these tissues the absrbed glucse is cnverted int either glycgen via glycgenesis r fats (triglycerides) via lipgenesis, r, in the case f the liver, int bth. Glucse prductin (and excretin int the bld) by the liver is strngly inhibited by high cncentratins f insulin in the bld. Circulating insulin als affects the synthesis f prteins in a wide variety f tissues.

3 Diagram f the Large Intestine: Diagram f Small and Large Intestine:

4 The Digestive System: Pathway and Prcess Digestin begins in the ral cavity, r the muth. The smell f fd triggers the salivary glands in yur muth t secrete saliva, this mistens yur muth. When yu eat the fd the amunt f saliva increases. Once yu start chewing and breaking dwn fd with yur teeth (mechanical digestin), saliva mixes with yur fd and creates blus. The act f swallwing then takes place in the pharynx (a reflex and partially invluntary cntrl). The tngue and sft palate push fd int the pharynx, which clses ff the trachea. The fd then enters the esphagus. Fd is then pushed thrugh the esphagus and int the stmach by means f a series f muscular cntractins called peristalsis. T enter the stmach fd passes by the cardiac sphincter, which allws fr fd t enter the stmach and prevents acid reflux. Once in the stmach, the blus is surrunded by gastric juices (hcl and enzymes) that are secreted by the stmach. The blus begins t be chemically and mechanically digested by the stmach, breaking dwn int a paste like mixture called chyme. Frm here the chyme mves thrugh the pylric sphincter int the small intestine. The first part f the small intestine is the dudenum. It is here that the chyme is further brken dwn by enzymes released by the pancreas and bile frm the liver. CCK is released in the dudenum and causes the gall bladder t release bile that neutralizes the acid in the chyme s it desn t damage the small intestine. Mst f digestin takes place in the small intestine. Peristalsis cntinues t mve the chyme thrugh the small intestine where nutrients are absrbed in the jejunum and ileum by villi n the intestinal wall and int the bldstream. What s left ver frm this pint is cnsidered waste (stl). Stl, r waste left ver frm the digestive prcess, passes thrugh the cln by means f peristalsis, first in a liquid state and ultimately in slid frm. As stl passes thrugh the cln, any remaining water is absrbed. Stl is stred in the sigmid (S-shaped) cln until a "mass mvement" empties it int the rectum. When full, the descending cln empties its cntents int the rectum where the prcess f defecatin can ccur. The stl passes thrugh the anus by means f relaxing the anal sphincter. The stl passes thrugh the anus and int the tilet.

5 Label the Fllwing Diagram Prvide a brief functin f each sectin labeled.