Assignment 6 - AP2 PDF

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AP2 Assignment 6

Name _____________________Nike Howard__________________________ Refer to chapters 23 & 24 in your textbook to answer the following questions. Answer in your own words. 1. What is propulsion? How is peristalsis related to propulsion? Propulsion is when you voluntary swallow your food and it moves down the alimentary canal and combine with peristalsis is when the walls of the muscles involuntary contracts and relax to push the food down. 2. Briefly explain what happens in cellular respiration, and what its function is. The reactions from citric acid, glycolysis, and oxidative phosphorylation create reaction to intake fuels like glucose and breakdowns them. It’s function is to release energy to create ATP. cellular respiration is a form of cell catabolism . Here cell coverts food into usable energy in the form of ATP. It releases stored energy in glucose molecules and covert it in a form of energy that can be used by cells. In this process glucose is broken down into six molecules of carbon dioxide in the presence of molecular oxygen. Energy released is preserved as ADP and free phosphate into ATP. In this process , one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound. Cells require fuel and an electron acceptor which drives the chemical process of turning energy into a useable form.

3. Define deglutition. Briefly describe the role of the following structures in the deglutition process. It means swallowing. a. Tongue: Food first hits the tongue and turns into bolus and swallowing next. Tongue helps to round the food that is chewed. Bolus is placed over posterodorsal surface of the tongue. Anterior part of tongue is retracted and depressed. Posterior part of tongue is elevated and retracted against the hard palate. This pushes the bolus backward into the pharynx. Forceful contraction of tongue against the palate produces a positive pressure in posterior part of oral cavity .this pushes food into pharynx.

b. Uvula and soft palate : The soft palate and uvula moves superiorly when swallowing, which triggers the nasopharynx to close so that food dose not enter the nasal cavity. Uvula blocks the nasal cavity when a person is eating or drinking. Soft palate have muscles and tissues that makes bolus flexible and mobile. c. Epiglottis: Food is moved posteriorly into esophagus after the epiglottis closes off the larynx. Epiglottis prevents the food from entering the respiratory tract by

folding backward to cover the entrance of the larynx. It stays open during breathing. d. Pharynx: When food reaches the pharynx, sensory receptors in the oropharynx are stimulated and transmitted by cranial nerves V, IX, and X. The swallowing center in the medulla oblongata produces the deglutition reflex and causes progressive contraction of the pharyngeal muscles to continue to propel the food bolus.

4. What are the functions of the following GI structures? a. Mesentery: The mesentery attaches intestines to the wall of the abdomen. This keeps the intestines in place, preventing it from collapsing down into pelvic area.

b. Mesocolon: Mesocolon connects the abdominal cavity to pelvic cavity and attaches colon to the abdominal wall.

c. Greater omentum Fat deposition having varying amounts of adipose tissue Immune contribution having milky spots of macrophage collections Infection and wound isolation Limiting spread of intraperitoneal infections

d. Falciform ligament The ligament which attaches the liver to the front abdominal wall, and separates the liver into the left medial lobe and right lateral lobe.

5. What is the inflammatory GI tract condition that is common in adolescence? What events lead to this condition and why is it common in adolescence? Exact cause is unknown Family history of IBD Genetic disorders

Environmental factors such as intestinal helminth infection Immunological disorders such as production of inflammatory cytokines , interleukins , chemokines and TNF-alpha Smoking Use of NSAIDS Genetic factors and family history plays the role for higher incidence of IBD in adolescence....