Front | Back |
Where are the organs of the digestive
system?
What do they do?
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They are centered around the
gastrointestinal (GI) tract, essentially a
long tube that moves food, water, and
electrolytes from the outside of the body to
the inside.
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What type of energy is our body in
constant need of to fuel the varied
activities of our cells? Where does this
energy originate from?
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ATP: originates from the breakdown of
complex molecules. The origianl source of
those molecules is our food.
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What is our food made of? What type of pathways are these molecules processed for?
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Complex carbs, fats, and proteins: pathways of cellular metabolism and ATP production
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What are the 3 challenges of the digestive system?
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1. must be able to breakdown food from a solid to simple molecules w/out causing damage to the tissues themselves.
2. it must move these molecules from inside the lumen of the gut (outside the body) to the inside of cells and into circulation.
3. it must release large quantities of fluid to aid in the digestive process and then reabsorb that fluid.
4. it must be able to operate literally non-stop (can't fatigue)
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How much fluid a day is put into your guy to help with digestion?
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6-7 liters
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What gets absorbed from carbs, proteins, and fats?
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Carbs- glucose
proteins- amino acids
fats- fatty acids
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What 4 basic processes does digestion involve for any organ of the GI tract?
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1. Digestion
2. Absorption
3. Motility
4. Secretion
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What is digestion?
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The chemical and mechanical breakdown of foods into smaller units that then can be absorbed or transported across the GI wall
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What is absorption?
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The active or passive transfer of substances (molecules) from the lumen of the GI tract, across the gut epithelium, through the extracellular fluid, and into circulation.
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What is motility?
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Movement of material through the GI tract and mechanical mixing to maximize exposure to enzymes and acids
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What is secretion?
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The release of substances that are involved in digestion. Includes enzymes, bile, mucus, bicarbonate solution, water, electrolytes, and acids. Also, hormones and paracrines (signaling substances.
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What is the total length of the GI gract? How much of that makes up the small and large intestine?
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Total= 15 feet
small & large intestine= 13 feet
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What are the major layers of the GI wall?
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Mucosa
Submucosa
Muscularis Externa
Serosa
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What is the mucosa? What makes up the mucosa?
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The mucosa is the inner most layer, with a large surface area. It is made up of the Mucosal Epithelium, the Lamina Propria, & the Muscularis Mucosa
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What is the Mucosal Epithelium?
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For protection, absorption, and secretion.
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