PNB 2265 Digestive System Questions With Correct Solutions, Already Passed!!

What are the six major functions of the GI system? - ️️-Ingestion of Nutrients -Mechanical processing -Secretion -Chemical processing -Absorption -Excretion What is unique about ingestion of nutrients compared to the other functions of the GI system? - ️️It is the only one under your conscious control. You choose what to eat and when to eat it- every other function is regulated by the ANS. Why is mechanical processing of food so important - ️️Chewing is so important because it not only prevents choking, but it also increases the surface area of the food, creating more places for digestive enzymes to break them down What is the main reason for secretion of digestive enzymes from accessory glands? - ️️The enzymes break down chemical bonds from complex molecules to simple molecules so that they can be absorbed into the tissues of the body Where does most nutrient absorption occur? - ️️Small intestine, although some water and vitamins can be absorbed in the large intestine as well Once all nutrients are absorbed, where does the bolus travel next? What does it become? - ️️Travels to large intestine. Water soluble waste is excreted as urine through the kidneys, insoluble waste is excreted as feces through the rectum. What is the anatomical term for the digestive system? What structures does it include? - ️️Alimentary canal, includes mouth, esophagus, stomach, small intestine, large intestine, and rectum What is the technical term for food as it travels down the alimentary canal? - ️️Bolus Why is it significant that humans have two openings for the digestive system, as opposed to worms which only have one? - ️️Because we have two, one is used as a portal of entry for nutrients (mouth), while the other is used as a portal of exit of waste (rectum). Worms only have one, which means that the place that they take in food is the same place that they excrete waste from. What are the main accessory organs in the digestive system? - ️️Salivary glands (in mouth), liver, pancreas, gallbladderDifferentiate between the parietal peritoneum and the visceral peritoneum. What is located in between them? - ️️-Parietal: lines walls of abdominal cavity -Visceral: covers the surface of the organs -Peritoneal cavity in between them What is the difference between intraperitoneal organs and retroperitoneal organs? - ️️-Intraperitoneal: Located inside the peritineum (majority of digestive organs) -Retroperitoneal: located outside of the peritneum (kidneys) What is unique about the parietal peritoneum? - ️️It contains many folds in many places, each with a secondary name (ex. in stomach region, greater omentum, major site where fat is deposited) What is ascites and what is it caused by? - ️️When someone has liver failure, they are not creating the plasma proteins that control osmotic balance. Fluid accumulates in in the peritoneal cavity. What are the negative side effects of ascites? - ️️Fluid accumulation in the peritoneal cavity causes abdomen distension, compresses the digestive organs, and forces them upwards towards the diaphragm. This causes shortness of breath and pain. From deep to superficial, what are the four major layers of the alimentary canal? Which layer faces the lumen? Which layer faces the peritoneum? - ️️Deep: outermost, towards peritoneum -Serosa -Muscularis -Submucosa -Mucosa Superficial: innermost, towards lumen and bolus What is the serosa made of and what are its two primary functions? What is another name for the serosa? - ️️Connective tissue, structure and support. Also known as the adventitia What is the muscularis externa composed of? Is contraction of this layer voluntary or involuntary? - ️️Smooth muscle, under involuntary control by the ANS What are the two sub layers of the muscularis externa? Why were they named in this way? - ️️Longitudinal and Circular. Named based on how their muscle fibers are oriented Where is the longitudinal muscularis externa located and how does it function? - ️️It is the outer layer of the muscularis externa, located closes to the serosa. When itcontracts, it shortens the length of the alimentary canal, decreasing the distance that the bolus has to travel Where is the circular muscularis externa located and how does it function? - ️️It is the innermost layer of the muscularis externa, located closest to the lumen where the bolus passes through. When it contracts, it narrows and constricts the radius of the alimentary canal What is located in between the two sublayers of the muscularis externa? What kind of tissue is this and explain why this structure is necessary for contraction. - ️️The myenteric plexus. Because the muscularis externa is under control of the ANS, there must be nerves in the layer that can be innervated in order to produce a contraction. Which pathway (sympathetic or parasympathetic) mainly innervates the myenteric plexus? What type of neurotransmitter is used and what kind of receptors does it utilize? - ️️Parasympathetic- rest and digest. Ach is the neurotransmitter, which binds to muscarinic recpetors in the myenteric plexus