BIOL 2402 Exam 3| Full Set Correct
Answers| 2026 Update
Objective 26.1a.1 List and describe the six general functions of the
digestive system - Ans--1. Ingestion: process of digesting and absorbing
nutrients
2. motility: mixing and moving materials through GI tract
3. Secretion: producing and releasing fluid products facilitating digestion
(enzymes, acids, bile)
4. Digestion: mechanical or chemical
5. Absorption: transport of digested molecules (electrolytes, vitamins,
water), from GI to blood or lymph
6. Elimination
Objective 26.1b.2 Identify the six organs that make up the gastrointestinal
(GI) tract - Ans--1. Oral Cavity
2. Pharynx
3. Esophagus
4. Stomach
5. Small intestine
6. Large intestine and anus
Objective 26.1b.3 List the accessory organs and structures - Ans--1.
Salivary glands- create salivary amylase which digests carbohydrates
2. liver- processes, produces proteins, detoxifies
3. pancreas- endocrine (insulin, SS, glucagon) and exocrine (enzymes)
4. teeth and tongue- mechanical digestion
5. gall bladder- concentrates and stores liver secretions (Bile)
Objective 26.1c.4 List and describe the four tunics (layers) that make up the
GI wall - Ans--1. Mucosa (inner lining)
,A. epithelium: simple columnar epi for secretion and absorption and lined
with nonkeratinized stratified squamous epithelium
B. lamina propria: areolar tissue containing blood vessels and nerves
C. Muscularis Mucosae: smooth muscle, contractions that facilitate release
of secretions into lumen and increase contact of materials in lumen with the
mucosa
2. Submucosa
-Consist of areolar and dense irregular CT, blood vessels, lymph vessels,
and nerves, MALT
- Peyer Patches in small intestine
3. Muscularis (Perastalsis)
A. Inner Circular layer- contraction constricting the lumen tube
B. Outer longitudinal layer- cells are oriented lengthwise, contraction
shorting the tube
C. Myenteric Nerve plexus- axons and ganglia between layers, sphincters
4. Adventitia or Serous (Outermost layer)
-Adventitia: areolar CT, found outside peritoneal cavity
-Serous: areolar CT, completely covered by visceral peritoneum, found
within the peritoneal cavity
*Hepatic Portal System- main blood system for intestines
Objective 26.1c.5 Briefly describe the general process of absorption - Ans--
Digested substances are transported from the lumen of GI through the
epithelium
*most nutrients are absorbed into the blood capillaries
*Lipids and lipid soluble vitamins (A,D,E,K) are absorbed into the lymphatic
capillaries
Objective 26.1c.6 Explain the action of the muscularis Tunics - Ans--- Helps
propel within the GI tract
, 1. Peristalsis (moved slowly): alternating contractions of inner and outer
layers
2. Mixing (random): back and forward motion that lack direction, mixes
ingested materials with secretions
Objective 26.1d.7 Describe the structure of the serous membranes
associated with the digestive tract - Ans--1. Parietal Peritoneum (Inside
Surface)
2. Visceral Peritoneum (serous membrane directly on organs)
3. Peritoneal cavity (Space between)- serous fluid to reduce friction
Objective 26.1d.8 Distinguish between intraperitoneal and retroperitoneal
organs - Ans--1. Intraperitoneal (Completely covered): covered by visceral
peritoneum inside the cavtity- stomach, most of small intestine, parts of
large
2. Retroperitoneal( anterolateral portion): outside the peritoneal cavity, only
anterolateral portion is covered with peritoneum- duodenum, pancreas,
kidneys, ascending and descending colon, rectum
Objective 26.1d.9 Explain the function of the mesentery - Ans---Helps
support, suspend, stabilize the intraperitoneal GI organs
- contains blood vessels and nerves
1. Greater omentum
-covers abdominal organs
-extends inferiorly from inferolateral stomach
2. Lesser Omentum
-connects superomedial surface of stomach and proximal duodenum
- connects to liver
Objective 26.1e.10 Identify the type and location of the two main receptors
of the digestive system - Ans--1. Mechanoreceptors: detect stretch or
pressure
- effects the secretion of enzymes and activate the stomach
Answers| 2026 Update
Objective 26.1a.1 List and describe the six general functions of the
digestive system - Ans--1. Ingestion: process of digesting and absorbing
nutrients
2. motility: mixing and moving materials through GI tract
3. Secretion: producing and releasing fluid products facilitating digestion
(enzymes, acids, bile)
4. Digestion: mechanical or chemical
5. Absorption: transport of digested molecules (electrolytes, vitamins,
water), from GI to blood or lymph
6. Elimination
Objective 26.1b.2 Identify the six organs that make up the gastrointestinal
(GI) tract - Ans--1. Oral Cavity
2. Pharynx
3. Esophagus
4. Stomach
5. Small intestine
6. Large intestine and anus
Objective 26.1b.3 List the accessory organs and structures - Ans--1.
Salivary glands- create salivary amylase which digests carbohydrates
2. liver- processes, produces proteins, detoxifies
3. pancreas- endocrine (insulin, SS, glucagon) and exocrine (enzymes)
4. teeth and tongue- mechanical digestion
5. gall bladder- concentrates and stores liver secretions (Bile)
Objective 26.1c.4 List and describe the four tunics (layers) that make up the
GI wall - Ans--1. Mucosa (inner lining)
,A. epithelium: simple columnar epi for secretion and absorption and lined
with nonkeratinized stratified squamous epithelium
B. lamina propria: areolar tissue containing blood vessels and nerves
C. Muscularis Mucosae: smooth muscle, contractions that facilitate release
of secretions into lumen and increase contact of materials in lumen with the
mucosa
2. Submucosa
-Consist of areolar and dense irregular CT, blood vessels, lymph vessels,
and nerves, MALT
- Peyer Patches in small intestine
3. Muscularis (Perastalsis)
A. Inner Circular layer- contraction constricting the lumen tube
B. Outer longitudinal layer- cells are oriented lengthwise, contraction
shorting the tube
C. Myenteric Nerve plexus- axons and ganglia between layers, sphincters
4. Adventitia or Serous (Outermost layer)
-Adventitia: areolar CT, found outside peritoneal cavity
-Serous: areolar CT, completely covered by visceral peritoneum, found
within the peritoneal cavity
*Hepatic Portal System- main blood system for intestines
Objective 26.1c.5 Briefly describe the general process of absorption - Ans--
Digested substances are transported from the lumen of GI through the
epithelium
*most nutrients are absorbed into the blood capillaries
*Lipids and lipid soluble vitamins (A,D,E,K) are absorbed into the lymphatic
capillaries
Objective 26.1c.6 Explain the action of the muscularis Tunics - Ans--- Helps
propel within the GI tract
, 1. Peristalsis (moved slowly): alternating contractions of inner and outer
layers
2. Mixing (random): back and forward motion that lack direction, mixes
ingested materials with secretions
Objective 26.1d.7 Describe the structure of the serous membranes
associated with the digestive tract - Ans--1. Parietal Peritoneum (Inside
Surface)
2. Visceral Peritoneum (serous membrane directly on organs)
3. Peritoneal cavity (Space between)- serous fluid to reduce friction
Objective 26.1d.8 Distinguish between intraperitoneal and retroperitoneal
organs - Ans--1. Intraperitoneal (Completely covered): covered by visceral
peritoneum inside the cavtity- stomach, most of small intestine, parts of
large
2. Retroperitoneal( anterolateral portion): outside the peritoneal cavity, only
anterolateral portion is covered with peritoneum- duodenum, pancreas,
kidneys, ascending and descending colon, rectum
Objective 26.1d.9 Explain the function of the mesentery - Ans---Helps
support, suspend, stabilize the intraperitoneal GI organs
- contains blood vessels and nerves
1. Greater omentum
-covers abdominal organs
-extends inferiorly from inferolateral stomach
2. Lesser Omentum
-connects superomedial surface of stomach and proximal duodenum
- connects to liver
Objective 26.1e.10 Identify the type and location of the two main receptors
of the digestive system - Ans--1. Mechanoreceptors: detect stretch or
pressure
- effects the secretion of enzymes and activate the stomach
