Digestive System
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Describe the Digestive System
the system of organs responsible for breaking down food molecules and absorbing nutrients
Describe Digestion
the process of breaking down food into molecules that can be absorbed and used by the body
Describe Nutrients
Molecules that must be absorbed for the body to function properly
Describe the Alimentary Canal
a long, winding tract formed by the organs of the digestive system mouth —> anus 9m (30ft) long
Describe Absorption
the transport of digested nutrients from the digestive system to the circulatory system throughout the entire alimentary canal there is nutrient absorption
Describe Ingestion
the process of taking in food molecules ingestion occurs at the mouth
What does the mouth specialize in?
the digestion of Carbohydrates
Describe the Salivary Glands
contained in the mouth they release a series of substances collectively known as saliva
Describe Saliva
activates taste buds lubricates food so it doesn’t get stuck uses enzymes to begin digestion
Describe Amylase
the most important enzyme in the saliva amylase breaks down starch (carbs) into smaller polysaccharide chains
Describe Chemical Digestion
Digestion using enzymes (or acid)
Describe Mechanical Digestion
Digestion that occurs due to movement of tissue the mouth is the primary site for mechanical digestion, performed by the teeth
Name and describe the two types of teeth
Incisors- sharp teeth used to shred and tear food Molars- flat teeth used to grind food
Describe the Esophagus
the organ responsible for transporting food from the mouth to stomach
Describe a Bolus
the compact ball of food that is formed after food is swallowed
Describe Peristalsis
the use of muscle contractions to move food synchronized contractions
Describe Sphincters
a series of specialized muscles that restrict the movement of food or fluid
Describe the Cardiac Sphincters
located at the bottom of the esophagus and controls how much food enters the stomach name is bc of its location being so close to the heart
Describe the Stomach
the primary site of food storage and specializes in the digestion of protein
What are the two types of cells that line the stomach?
Parietal Cells Peptic Cells (chief cells)
Describe Parietal Cells
they produce Hydrochloric Acids (HCl), commonly called stomach acid also secrete mucus to protect the stomach cells from being digested
Describe Peptic Cells
they release an enzyme called Pepsinogen which becomes activated on acidic conditions to form the enzyme Pepsin Pepsin breaks down proteins into short polypeptide chains
Describe the pH of the stomach
the stomach has a pH of 2, which is extremely acidic and corrosive due to the corrosiveness of the stomach, it also plays an important role in the immune system by dissolving pathogens in the body
Describe Ulcers
a site where the mucus layer breaks down and stomach cells are exposed to HCl