Chapter 21, Problem 16RQ

a.

Summary Introduction

To explain: The similarities and dissimilarities between mastication and deglutition.

Introduction: The primary function of the digestive system is the movement of nutrients, water, and ions from the external environment to the internal environment of the body. Mastication and deglutition are the part digestion process.

b.

Summary Introduction

To explain: The similarities and dissimilarities between microvilli and villi.

Introduction: The primary function of the digestive system is the movement of nutrients, water, and ions from the external environment to the internal environment of the body. The digestive system completes its function with the help of four processes- digestion, absorption, secretion, and motility. The cell membrane and the intestine play a major role in the processes of the digestive system.

c.

Summary Introduction

To explain: The similarities and dissimilarities among peristalsis, segmental contractions, migrating motor complex, and mass movements.

Introduction: The motility is the process of movement of material through the GI tract as a result of muscle contraction. The motility fulfills the two purposes of the digestion process. One purpose is the moving of food from the mouth to the anus, and another purpose is the mixing of food mechanically to break it into uniformly small particles. The gastrointestinal tract is mostly composed of single-unit smooth muscles. A different region of GI tracts exhibits different types of contraction.

d.

Summary Introduction

To explain: The similarities and dissimilarities between chyme and feces.

Introduction: The primary function of the digestive system is the movement of nutrients, water, and ions from the external environment to the internal environment of the body. The digestive system completes its function with the help of four processes- digestion, absorption, secretion, and motility. The chyme and feces are formed during the different processes of the digestive system.

e.

Summary Introduction

To explain: The similarities and dissimilarities between short reflexes and long reflexes.

Introduction: Motility and secretion are the two primary regulated functions of the four gastrointestinal processes. The motility is regulated so that the food gets proper time to digest in the intestine. The secretion is regulated so that the appropriate digestive enzymes can break down food for absorption. The enteric nervous system (ENS) regulates motility, secretion, and growth of the digestive tract.

f.

Summary Introduction

To explain: The similarities and dissimilarities among submucosal plexus, myenteric plexus, and vagus nerve.

Introduction: The enteric nervous system (ENS) regulates motility, secretion, and growth of the digestive tract. The enteric nervous system (ENS) works in isolation as well as in association with the central nervous system (CNS).

g.

Summary Introduction

To explain: The similarities and dissimilarities among cephalic, gastric, and intestinal phases of digestion

Introduction: The digestive process is composed of a series of reactions involving digestive hormones and juices as a result of which complex molecules are broken down into smaller ones. The digestion process starts from the oral cavity.