Children are fascinated by the workings of the digestive system: they relish crunching a potato chip, delight in making “mustaches” with milk, and giggle when their stomach growls. As adults, we know that a healthy digestive system is essential for good health because it converts food into raw materials that build and fuel our body cells. Show
Functions of the Digestive SystemThe functions of the digestive system are:
Anatomy of the Digestive SystemThe organs of the digestive system can be separated into two main groups: those forming the alimentary canal and the accessory digestive organs.
Organs of the Alimentary CanalThe alimentary canal, also called the gastrointestinal tract, is a continuous, hollow muscular tube that winds through the ventral body cavity and is open at both ends. Its organs include the following: MouthFood enters the digestive tract through the mouth, or oral cavity, a mucous membrane-lined cavity.
PharynxFrom the mouth, food passes posteriorly into the oropharynx and laryngopharynx.
EsophagusThe esophagus or gullet, runs from the pharynx through the diaphragm to the stomach.
StomachDifferent regions of the stomach have been named, and they include the following:
Small IntestineThe small intestine is the body’s major digestive organ.
Large IntestineThe large intestine is much larger in diameter than the small intestine but shorter in length.
Accessory Digestive OrgansOther than the intestines and the stomach, the following are also part of the digestive system: TeethThe role the teeth play in food processing needs little introduction; we masticate, or chew, by opening and closing our jaws and moving them from side to side while continuously using our tongue to move the food between our teeth.
Salivary GlandsThree pairs of salivary glands empty their secretions into the mouth.
PancreasOnly the pancreas produces enzymes that break down all categories of digestible foods.
LiverThe liver is the largest gland in the body.
GallbladderWhile in the gallbladder, bile is concentrated by the removal of water.
Physiology of the Digestive SystemSpecifically, the digestive system takes in food (ingests it), breaks it down physically and chemically into nutrient molecules (digests it), and absorbs the nutrients into the bloodstream, then, it rids the body of indigestible remains (defecates). Activities Occurring in the Mouth, Pharynx, and EsophagusThe activities that occur in the mouth, pharynx, and esophagus are food ingestion, food breakdown, and food propulsion. Food Ingestion and Breakdown Once food is placed in the mouth, both mechanical and chemical digestion begin.
Food Propulsion – Swallowing and Peristalsis For food to be sent on its way to the mouth, it must first be swallowed.
Activities of the StomachThe activities of the stomach involve food breakdown and food propulsion. Food Breakdown The sight, smell, and taste of food stimulate parasympathetic nervous system reflexes, which increase the secretion of gastric juice by the stomach glands
Food Propulsion Peristalsis is responsible for the movement of food towards the digestive site until the intestines.
Activities of the Small IntestineThe activities of the small intestine are food breakdown and absorption and food propulsion. Food Breakdown and Absorption Food reaching the small intestine is only partially digested.
Food Propulsion Peristalsis is the major means of propelling food through the digestive tract.
Activities of the Large IntestineThe activities of the large intestine are food breakdown and absorption and defecation. Food Breakdown and Absorption What is finally delivered to the large intestine contains few nutrients, but that residue still has 12 to 24 hours more to spend there.
Propulsion of the Residue and Defecation When presented with residue, the colon becomes mobile, but its contractions are sluggish or short-lived.
Practice Quiz: Digestive System Anatomy and PhysiologyHere’s a 10-item quiz about the study guide. Please visit our nursing test bank page for more NCLEX practice questions. 1. All of these are among the four tunics found throughout the digestive tract EXCEPT: A.
Mucosa 1. Answer: B. Glandulosa
2. Which of the following are functions of the tongue? Select all that apply. A. Crucial organ for speech 2. Answer: E. All of these are functions of the tongue
3. Each quadrant of the adult mouth holds ___ incisors, ___ canines, ___ premolars, and ___ molars. A. 1, 2, 3, 2 3. Answer: D. 2, 1, 2, 3
4. Which of these is NOT a pair of salivary glands? A. Parotid 4. Answer: C. Submucosal
5. Which statement about the esophagus is TRUE? Select all that apply. A. It is a cartilaginous
tube. 5. Answer: D. It has upper and lower sphincters.
6. All of these structures are matched with the correct description EXCEPT: A. Cardiac region: the area closest to the small intestine 6. Answer: A. Cardiac region: the area closest to the small intestine
7. The saliva does NOT contain: A. Amylase 7. Answer: D. Hydrochloric acid
8. Which statements best describe mechanical digestion? Select all that apply. A. It breaks large food particles into smaller ones. 8. Answer: A. It breaks large food particles into smaller ones.
9. The greatest volume of gastric secretion occurs during: A. Cephalic phase 9. Answer: B. Gastric phase
10. Which of the following produce gastrin? A. Mucous neck cells 10. Answer: D. Endocrine cells
[sc name=”Anatomy and Physiology”] What are the effects of aging on the digestive system?Our digestive system moves food through our bodies through a series of muscle contractions. As we age, this process can slow down. When that happens, more water from the food is absorbed into the body, which can lead to constipation. Staying hydrated is very important to help prevent constipation.
What are the effects of aging on the digestive system quizlet?As a person ages, the digestive system goes through several changes: motility is decreased, goblet cells and glands tend to secrete less with age; decline in the defenses of the digestive tract of older people makes them more sensitive to outside influence, tooth enamel becomes thinner (causes pain),..
Which change in the digestive system is common for older adults?Digestive Problems as You Age. Constipation. One of the most common things we see, certainly as people are getting into their 60s and 70s, may be a change in bowel habits, predominantly more constipation," says Ira Hanan, MD, associate professor of medicine at the University of Chicago Medical Center.
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