PHYSIOLOGY SPRING LECTURE 22 STUDY GUIDE:
CHAPTER 16 THE DIGESTIVE SYSTEM 1 (P 565 -
597)
QN 1. What is the primary function of the gastrointestinal system? (p. 566)
ANS • The primary function of the gastrointestinal system is to transfer nutrients, water, and
electrolytes from the food we eat to the body’s internal environment.
QN 2. What are the four basic digestive processes? (p. 566)
• Motility: muscular contractions that mix and move forward the contents within the
tract.
• Secretion: consists of water, electrolytes, and specific organic constituents
ANSWERS
important in the digestive process, such as enzymes, bile salts, or mucus.
• Digestion: chemically break down structurally complex foodstuff of the diet into
smaller, absorbable units.
• Absorption: small absorbable units that result from digestion, along with water, vitamins,
and electrolytes, are transferred from the digestive tract lumen into the blood or lymph.
QN 3. How are the following macronutrients broken down in the process of digestion: (p. 566)
CHEMICAL NAME COMMON NAME/DESCRIPTION EXAMPLES/WHAT IT IS FOUND IN
Monosaccharides “one-sugar” molecules Examples: Glucose, fructose,
galactose
ANSWERS
Polysaccharide “many-sugar” molecules Example: Starch- contains amylose
and amylopectin
Glycogen Highly branched polysaccharide Found in: meat
storage form of glucose in muscle
Indigestible dietary Insoluble fiber Found in: plant walls
polysaccharides Example: cellulose
Indigestible dietary Soluble fiber Found in: plant walls
polysaccharides Example: pectin
QN 4. List the accessory digestive organs and their function (p. 569)
• Salivary Glands: Lie outside the oral cavity and discharge saliva through short ducts into the mouth.
ANSWERS
• Exocrine Pancreas: secrete digestive juices into the digestive tract lumen on appropriate neural or
hormonal stimulation.
• Biliary system: composed of the liver and gallbladder; secretes bile into the duodenal lumen.
QN 5. Why are these organs considered exocrine organs? (p. 569)
• These organs are considered exocrine organs because they lie outside the digestive tract and
ANS empty their secretions through ducts into the digestive tract lumen.
6. List the organs in the digestive tract in the order that nutrients would naturally flow through
QN
(p. 570)
• Mouth
• Pharynx
ANSWERS
• esophagus
• stomach
• small intestine
• large intestine
, • anus
QN 7. (p.570)
LAYERS OF THE COMPONENTS FUNCTION CONTAINS
DIGESTIVE
TRACT
ANSWERS
Mucosa Mucous Inner epithelial layer that Exocrine gland cells for the secretion of
membrane serves as a protective digestive juices and endocrine gland cells
for the secretion of blood Bourne GI
surface
hormones epithelial cells specialized for
absorbing nutrients
Lamina Propria Thin middle layer of Houses the gut-associated lymphoid
connective tissue on tissue (GALT), which is important in
which the epithelium defense against disease-causing
rests intestinal bacteria
Muscularis mucosa Sparse outermost layer of N/A
smooth muscle
Submucosa (left intentionally Thick layer of connective Contains the larger blood and lymph
blank) tissue that provides the vessels, both of which send branches
digestive tract with inwards to the mucosal layer and outward
to the surrounding thick muscle layer.
distensibility and
Also, contains a nerve network known as
elasticity
submucous plexus.
Muscularis Externa (left intentionally Major smooth muscle Consists of two layers: an inner circular layer
blank) coat of the digestive tube and an outer longitudinal layer.
Also contains a nerve network known as
myenteric plexus.
Inner circular Run circularly around the Contraction of these fibers decreases
layer tube. the diameter of the tube
Constricts the tube at the
point of
contraction.
Outer longitudinal Shortens the tube Contraction of these fibers decreases
layer the length of the tube
Serosa Covers the Secretes watery, slippery Continuous with the mesentery, which
digestive tract fluid (serous fluid) that suspends the digestive organs from the
lubricates and prevents inner wall of the abdominal cavity.
friction between the
digestive organs and the
surrounding viscera
QN 8. What are the fours ways the digestive function is regulate? (p.571, 572)
REGULATORY MODE TYPE OF ACTIVITY FUNCTION
Autonomous smooth muscle Slow-wave potentials; Also Rhythmic, wavelike fluctuations in
function referred to as basic membrane potential that cyclically bring
the membrane closer to or farther from
electrical rhythm (BER) threshold potential.
CHAPTER 16 THE DIGESTIVE SYSTEM 1 (P 565 -
597)
QN 1. What is the primary function of the gastrointestinal system? (p. 566)
ANS • The primary function of the gastrointestinal system is to transfer nutrients, water, and
electrolytes from the food we eat to the body’s internal environment.
QN 2. What are the four basic digestive processes? (p. 566)
• Motility: muscular contractions that mix and move forward the contents within the
tract.
• Secretion: consists of water, electrolytes, and specific organic constituents
ANSWERS
important in the digestive process, such as enzymes, bile salts, or mucus.
• Digestion: chemically break down structurally complex foodstuff of the diet into
smaller, absorbable units.
• Absorption: small absorbable units that result from digestion, along with water, vitamins,
and electrolytes, are transferred from the digestive tract lumen into the blood or lymph.
QN 3. How are the following macronutrients broken down in the process of digestion: (p. 566)
CHEMICAL NAME COMMON NAME/DESCRIPTION EXAMPLES/WHAT IT IS FOUND IN
Monosaccharides “one-sugar” molecules Examples: Glucose, fructose,
galactose
ANSWERS
Polysaccharide “many-sugar” molecules Example: Starch- contains amylose
and amylopectin
Glycogen Highly branched polysaccharide Found in: meat
storage form of glucose in muscle
Indigestible dietary Insoluble fiber Found in: plant walls
polysaccharides Example: cellulose
Indigestible dietary Soluble fiber Found in: plant walls
polysaccharides Example: pectin
QN 4. List the accessory digestive organs and their function (p. 569)
• Salivary Glands: Lie outside the oral cavity and discharge saliva through short ducts into the mouth.
ANSWERS
• Exocrine Pancreas: secrete digestive juices into the digestive tract lumen on appropriate neural or
hormonal stimulation.
• Biliary system: composed of the liver and gallbladder; secretes bile into the duodenal lumen.
QN 5. Why are these organs considered exocrine organs? (p. 569)
• These organs are considered exocrine organs because they lie outside the digestive tract and
ANS empty their secretions through ducts into the digestive tract lumen.
6. List the organs in the digestive tract in the order that nutrients would naturally flow through
QN
(p. 570)
• Mouth
• Pharynx
ANSWERS
• esophagus
• stomach
• small intestine
• large intestine
, • anus
QN 7. (p.570)
LAYERS OF THE COMPONENTS FUNCTION CONTAINS
DIGESTIVE
TRACT
ANSWERS
Mucosa Mucous Inner epithelial layer that Exocrine gland cells for the secretion of
membrane serves as a protective digestive juices and endocrine gland cells
for the secretion of blood Bourne GI
surface
hormones epithelial cells specialized for
absorbing nutrients
Lamina Propria Thin middle layer of Houses the gut-associated lymphoid
connective tissue on tissue (GALT), which is important in
which the epithelium defense against disease-causing
rests intestinal bacteria
Muscularis mucosa Sparse outermost layer of N/A
smooth muscle
Submucosa (left intentionally Thick layer of connective Contains the larger blood and lymph
blank) tissue that provides the vessels, both of which send branches
digestive tract with inwards to the mucosal layer and outward
to the surrounding thick muscle layer.
distensibility and
Also, contains a nerve network known as
elasticity
submucous plexus.
Muscularis Externa (left intentionally Major smooth muscle Consists of two layers: an inner circular layer
blank) coat of the digestive tube and an outer longitudinal layer.
Also contains a nerve network known as
myenteric plexus.
Inner circular Run circularly around the Contraction of these fibers decreases
layer tube. the diameter of the tube
Constricts the tube at the
point of
contraction.
Outer longitudinal Shortens the tube Contraction of these fibers decreases
layer the length of the tube
Serosa Covers the Secretes watery, slippery Continuous with the mesentery, which
digestive tract fluid (serous fluid) that suspends the digestive organs from the
lubricates and prevents inner wall of the abdominal cavity.
friction between the
digestive organs and the
surrounding viscera
QN 8. What are the fours ways the digestive function is regulate? (p.571, 572)
REGULATORY MODE TYPE OF ACTIVITY FUNCTION
Autonomous smooth muscle Slow-wave potentials; Also Rhythmic, wavelike fluctuations in
function referred to as basic membrane potential that cyclically bring
the membrane closer to or farther from
electrical rhythm (BER) threshold potential.
