Biology Chapter 41
Chapter 41 vocabulary for Biology 212 with professor John Mayfield.
Terms
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- Essential amino acids
- Amino acids that an animal cannot synthesize itself and must be obtained from food. Eight of these are essential in the human adult.
- Small intestine
- The longest section of the alimentary canal; the principal site of the enzymatic hydrolysis of food macromolecules and the absorption of nutrients.
- Extracellular digestion
- The breakdown of food outside cells.
- Pancreas
- A gland with dual functions: the nonendocrine portion secretes digestive enzymes and an alkaline solution into the small intestine via a duct; the endocrine portion secretes the horomones insulin and glucagon into the blood.
- Peristalsis
- Rhythmic waves of contraction of smooth muscle that push food along the digestive tract.
- Hepatic portal vein
- A large circulatory channel that conveys nutrient-laden blood from the small intestine to the liver, which regulates the blood's nutrient content.
- Ingestion
- A heterotrophic mode of nutrition in which other organisms or detritus are eaten whole or in pieces.
- Intracellular digestion
- The joining of food vacuoles and lysosomes to allow chemical digestion to occur within the cytoplasm of a cell.
- Villus
- A fingerlike projection of the inner surgace of the small intestine. Large numbers of this increase the surface areas of these organs. The plural for this is villi.
- Bile
- A mixture if substances that is produced in the liver, stored in the gallbladder, and acts as a detergent to aid in the digestion and absorptions if fats.
- Cecum
- A blind outpocket of a hollow organ such as an intestine. The plural for this is ceca.
- Absorption
- The uptake of small nutrient molecules by an organism's own by; the third main stage of food processing, following digestion.
- Mastication
- Another word for chewing.
- Pharynx
- An area in the vertebrate throat where air and food passages cross.
- Pepsin
- An enzyme present in gastric juice that begins the hydrolysis of proteins.
- Elimination
- The passing of undigested material out of the digestive compartment.
- Sphincter
- A ringlike valve consisting of modified muscles in a muscular tube, such as a digestive tract; closes off the tube like a drawstring.
- Pepsinogen
- The inactive form of pepsin that is first secreted by specialized (chief) cells located in gastric pits of the stomach.
- Stomach
- An organ of the digestive system that stores food and performs preliminary steps of digestion.
- Vitamins
- Organic molecules required in the diet in very small amounts. These serve primarily as coenzymes or parts of coenzymes.
- Oral cavity
- The mouth of an animal.
- Esophagus
- A channel that conducts food, by peristalsis, from the pharynx to the stomach.
- Rumen
- The first stomach in the digestive system of the cow. When the cow first chews and swallows a mouthful of grass, boluses enter this.
- Liver
- The largest organ in the vertebrate body, producing bile, preparing nitrogenous wastes for disposal, and detoxyifing poisonous chemicals in the blood.
- Colon
- The tubular portion of the vertebrae alimentary tract between the small intestine and the anus; functions mainly in water absorption and the formation of feces. Another term for this is large intestine.
- Epiglottis
- A cartiligious flap that blocks the top of the windpipe, the glottis, during swalling, which prevents the entry of food or fluid into the respiratory system.