Digestive Processes Quiz

The document is on the digestive system, a unit in Science and Health Biology 8.
The review covers scientific paper groupings and materials and methodology related to the digestive system.
The theme for the unit is the 5 C's (competence, character, commitment, collaboration, creativity) through academic rigor, growth mindset, and grit.
The digestive system's function includes the breakdown of ingested food, absorption into the blood, transport to tissues for metabolism, production of cellular energy (ATP), and constructive and degradative cellular activities.
Digestion is a catabolic process where large complex molecules (carbohydrates, lipids, proteins, nucleic acids) are broken down into simpler monomers (monosaccharides, glycerol and fatty acids, amino acids, and nucleotides) to be absorbed by the body.
Mechanical digestion involves physically breaking down food into smaller pieces, without chemical changes. Chewing (mastication) is an example.
Chemical digestion involves chemical changes in food. Polymers are broken down into monomers by hydrolysis reactions using enzymes found within digestive juices.
The six processes of digestion are: ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation.
Ingestion is the intake of food into the mouth.
Propulsion moves food along the digestive system (e.g., swallowing, peristalsis).
Mechanical digestion includes mixing food in the mouth, churning in the stomach, and segmentation in the small intestine.
Chemical digestion involves enzymes breaking down food molecules into building blocks (e.g., carbohydrates to simple sugars). Different enzymes are needed for different food types.
Absorption involves the uptake of digested food into the bloodstream or lymph. Food enters mucosal cells first, then into blood or lymph capillaries.
Defecation involves the elimination of indigestible substances as feces.
The digestive system has an alimentary canal (mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus) and accessory organs (salivary glands, teeth, pancreas, liver, gallbladder).
The mouth (oral cavity) includes mastication, mixing with saliva, and initiating swallowing. It also allows for the sense of taste.
Salivary glands produce saliva, a mixture of mucus and serous fluids. Saliva starts starch digestion and dissolves chemicals for taste.
The pharynx serves as a passageway for air and food, using muscle contractions (peristalsis) to propel food to the esophagus.
The esophagus conducts food to the stomach via peristalsis. It's a passageway for food only.
The stomach stores food, breaks it down chemically, and delivers chyme to the small intestine. Its regions include cardiac, fundus, body, and pylorus. Internal folds (rugae) are present for flexibility and increased surface area.
The stomach lining has specialized cells (e.g., mucous neck, chief, parietal, endocrine) producing mucus, enzymes, and hydrochloric acid.
The small intestine (duodenum, jejunum, ileum) is the major digestive organ with folds (plicae circulares) and finger-like projections (villi) enhancing surface area for absorption. The villi lining have absorptive cells with microvilli, which increase the surface area for nutrient absorption. Nutrients enter the bloodstream or lacteals (lymphatic capillaries) to be processed by the liver. Accessory glands aiding the small intestine include the pancreas and liver.
The large intestine (colon - ascending, transverse, descending, sigmoid) absorbs water and eliminates indigestible matter. The cecum is the first part.
The appendix is an accumulation of lymphatic tissue and hangs from the cecum.
The functions of the large intestine include water absorption, waste elimination, and producing vitamins (like vitamin K) through symbiotic bacteria.
The pancreas produces enzymes breaking down all food types. It introduces alkaline fluid with enzymes neutralizing acidic chyme. The pancreas produces endocrine products like insulin and glucagon.
The liver is the largest gland, located under the diaphragm. It produces bile, stored in the gallbladder. Bile aids in fat digestion. Gallstones can impede bile flow.
Nutrients, categorized into carbohydrates, lipids, proteins, vitamins, minerals, and water, are crucial for the body's functions. Malnutrition arises from a lack of proper nutrients or imbalance in amounts.
Diseases of the digestive system include heartburn (acid reflux), ulcers (caused partly by bacteria), Crohn's disease (inflammation of the digestive tract), and colon cancer.