Chapter 14 Part 1

Name the end products of protein, fat, and carbohydrate digestion

Protein: amino acid Fat: fatty acid and glycerol Carbohydrate: monosaccharides (glucose, fructose)

Describe the mechanisms of swallowing, vomiting, and defecation

Defecation: defecation reflex causes walls of rectum to contract and relaxes anal sphincter swallowing: tongue coordinates with soft palate, forcing bolus through vomiting: reverse peristalsis of the stomach

Describe the composition and function(s) of saliva.

A mixture of mucus and serous fluids. Mucus moistens and helps to bind the food together into a mass called a bolus, which makes chewing and swallowing easier. The clear serous portion contains salivary amylase, which begins the process of starch digestion in the mouth.

Name the organs of the Alimentary canal and accessory digestive organs, and identify each on an appropriate diagram or model.

Alimentary Canal: Mouth, Pharynx, esophagus, Stomach, small intestine, and large Intestine. Accessory Organs: Teeth, Salivary glands, Pancreas, liver, Gallbladder.

Identify the overall function of the digestive system as digestion and absorption of foodstuffs, and describe the general activities of each digestive system organ.

Digestive functions: Ingests, digests, absorbs, and defecates. Mouth: Food is masticated and mixed with saliva. Chemical and mechanical digestion begins. Pharynx: Serves as passageway for food and air. Food is propelled down by peristalsis. Esophagus: Runs food from pharynx to stomach. It squeezes the food down to the stomach with peristalsis. Stomach: acts as a temporary storage tank for food as well as a site for food breakdown via chemical (gastric juices) and mechanical processes to produce a heavy cream-like substance called chyme. Located on the left side of the abdominal cavity. Small Intestine: the body's major digestive organ where chemical digestion completes the breakdown of the food and nearly all food absorption occurs via the microvilli. The body's major digestive organ. Site of nutrient absorption into the blood. Muscular tube extending from the pyloric sphincter to the ileocecal valve. Suspended from the posterior abdominal wall by the mesentery. Large intestine: absorption of water dries the indigestible food residue so it can finally be eliminated from the body as feces through the anus. Larger in diameter, but shorter than the small intestine. Frames the internal abdomen.

Describe how the foodstuffs in the digestive tract are mixed and moved along the tract

Food is propelled using Peristalsis (contraction and relaxation of muscles), mixed during Grinding

Describe the function of local hormones in the digestive system

Local hormones Secretin and CCK influence release of pancreatic juice and bile

Name the deciduous and permanent teeth and describe the basic anatomy of a tooth.

The function of teeth is to masticate, or chew, the food - incisors and canines cut and tear the food while molars grind the food. Deciduous teeth - baby teeth - milk teeth - erupt around six months and a complete set of 20 teeth is present by age two Permanent teeth - second set of teeth set deeper under the deciduous teeth - as they enlarge and develop, the roots of the baby teeth are reabsorbed causing them to loosen and fall out around ages 6 - 12 years with all of the permanent teeth but the third molars (wisdom teeth, which erupt around age 17 - 25) having erupted by the end of adolescence ending in a set of 32 teeth although sometimes the wisdom teeth are absent or fail to erupt

State the digestive function of bile

The primary digestive function of bile is to aid in the dispersion and digestion of fat in the lumen of the small intestine.

Explain how villi aid digestive processes in the small intestine.

The villi aid in absorption by increasing the surface area of the intestine and contain specialized cells which transport different types of nutrients into the blood.

list the major enzymes or enzyme groups produced by the digestive organs or accessory glands, and name the foodstuffs on which they act.

sucrase: acts on sucrose; lactase: acts on lactose, diastase: starch