Unit 4- Digestive System

Question 1

What are the organs of the GI tract?

Answer 1

Oral Cavity, Pharynx, Esophagus, Stomach, Large Intestine, Small Intestine, and Anus

Question 2

What are the accessory digestive organs?

Answer 2

Parotid Salivary Gland, Teeth, Tongue, Sublingual Salivary Gland, Submandibular Salivary Gland, Liver, Gallbladder, and Pancreas

Question 3

What are the 6 functions of the digestive system?

Answer 3

Ingestion = solid and liquid materials enter oral cavity

Digestion = break materials into smaller structures & molecules

Propulsion = materials swallowed & move through GI tract

Secretion = release of fluids to aid in digestion and protection of GI tract

Absorption = digestion products, water, vitamins, and electrolytes move from GI tract into blood or lymph

Elimination of wastes

Question 4

What structure divides the abdominal cavity into 4 quadrants and what is the purpose of doing so?

Answer 4

Umbilicus (Navel)

Talk about location of organs in the abdominal cavity

Question 5

What are the 4 layers/ tunics of the wall of the GI tract?

Answer 5

1. Mucosa (deepest)
2. Submucosa
3. Muscularis
4. Adventitia or Serosa (superficial layer)

Question 6

Define peritoneum

Answer 6

The serous membrane that lines the
abdominopelvic cavity and many organs included within the cavity

Question 7

Define the peritoneal cavity and give its function

Answer 7

the space between the parietal peritoneum and the visceral peritoneum

allows for movement and expansion of organs

Question 8

What is the difference between parietal and visceral peritoneum?

Answer 8

Parietal- lines cavity
Visceral- lines organs

Question 9

What is the difference between intraperitoneal and retroperitoneal organs?

Answer 9

Intraperitoneal Organ- organ pushes into the abdominal cavity and suspended by peritoneal reflections; surrounded by visceral peritoneum

Retroperitoneal Organ- between parietal peritoneum and posterior wall; no visceral peritoneum

Question 10

What are the organs and or organ systems in the intraperitoneal?

Answer 10

Stomach, Part of Duodenum, Jejunum, Ileum, Cecum, Appendix, and Transverse Colon

Question 11

What are the organs or organ systems in the retroperitoneal?

Answer 11

Most of Duodenum, Pancreas, Ascending and Descending Colon, and Rectum

Question 12

What is a mesentery?

Answer 12

Double-layer reflection of peritoneum formed as an organ pushed into abdominal cavity, wrapping itself in visceral peritoneum

Question 13

What is an omentum?

Answer 13

a double-layer of peritoneum due to an organ becomes “suspended” from another organ/structure as a result of the embryonic rotation of the gut

Question 14

What are the 3 segments of the pharynx?

Answer 14

Nasopharynx- posterior to nasal cavity, conducts air only
Oropharynx- posterior to oral cavity, conducts air, and passage for food and drink
Laryngopharynx- conducts air and passageway for food and drinks to esophagus

Question 15

What is the function of the esophagus?

Answer 15

transport swallowed materials from pharynx to stomach

Question 16

Does the esophagus lie anterior to or posterior to the thoracic/ descending aorta?

Answer 16

anterior

Question 17

Which opening in the diaphragm does the esophagus pass through to reach the stomach? Which esophageal sphincter will you find in this location?

Answer 17

Esophageal hiatus

Inferior Esophageal Sphincter

Question 18

What is the semifluid product that exits the stomach to the duodenum?

Answer 18

chyme

Question 19

What are the regions of the stomach?

Answer 19

Cardia – where esophagus enters stomach
Fundus – dome-shaped superior region
Body – large, central region
Pylorus – funnel-shaped region leading to duodenum
Lesser Curvature – superior concave border (location of lesser omentum)
Greater Curvature – inferior convex border (location of greater omentum attachment)

Question 20

What is the function of the pyloric sphincter?

Answer 20

regulate exiting of chyme into duodenum

Question 21

What is the function of the rugae?

Answer 21

allow stomach to expand when full and return to contracted shape when empty

Question 22

Which is the unique layer of the muscularis of the stomach compared to the rest of the GI Tract and how does this help with the function of the stomach?

Answer 22

The inner oblique muscle layer is not found in the rest of the GI Tract

allows for additional churning/blending of contents with stomach secretions and saliva

Question 23

Does any chemical digestion occur after the small intestine?

Answer 23

Finishes chemical digestion

Question 24

What is the final segment of the small intestine?

Describe the ileocecal valve located in this segment

Answer 24

Ileum- final 10.8 feet

ileocecal valve controls the entry of materials into cecum from the ileum

Question 25

Is both the duodenum and the pancreas retroperitoneal?

Answer 25

Yes

Question 26

What substances enter at the major duodenal papilla?

Answer 26

bile from liver and pancreatic juices

Question 27

List the 3 surface faces that identify the large intestine

Answer 27

Tenia Coli, Haustra, and Omental Appendices

Question 28

From proximal to distal, name the segments of the large intestine, their location within the peritoneum, and their curvatures

Answer 28

1. Cecum- intraperitoneal 2. Ascending Colon- retroperitoneal 3. Hepatic Flexure- curvature at liver 4. Transverse Colon- intraperitoneal 5. Splenic Flexure- curvature at spleen 6. Descending Colon- retroperitoneal 7. Sigmoid Colon- retroperitoneal 8. Rectum- retroperitoneal 9. Anal Canal

Question 29

What is the first segment of the large intestine and what two structures open into this segment?

Answer 29

Cecum Ileocecal valve and appendix

Question 30

What is the difference between the external and internal anal sphincters?

Answer 30

Anal sphincters close off open to anal canal and relax during defecation Internal is involuntary smooth muscle External is voluntary skeletal muscle

Question 31

What are the general functions of the liver? *which one specifically related to the digestion of nutrients

Answer 31

Produces bile*** Detoxifies drugs, metabolites and poisons from blood Stores excess nutrients and vitamins Synthesizes blood plasma proteins Removes debris from blood and recycles worn out blood cells

Question 32

What is the function of bile?

Answer 32

Emulsifies or breaks apart fats to allow for chemical digestion by enzymes

Question 33

What is the function of the gallbladder?

Answer 33

Stores & concentrates bile produced by the liver until needed for emulsification of fat

Question 34

Describe the Biliary Tree

Answer 34

Gallbladder drains in cystic duct (branch 1) and liver drains into common hepatic duct (branch 2, made up of left and right hepatic ducts) Cystic duct + Common Hepatic Duct both drain into Bile Duct Pancreatic Duct and Bile Duct merge and enter the duodenum through the Major Duodenal Papilla

Question 35

What are the general digestive (exocrine) functions of the pancreas?

Answer 35

Secrets pancreatic juices into the duodenum that break down fats and proteins

Question 36

What are the two ducts of the pancreas and where do they drain?

Answer 36

Main pancreatic duct drains into the major duodenal papilla Accessory pancreatic duct drains into the main pancreatic duct

Question 37

What organs form the foregut? What branch of abdominal aorta supplies these organs? What autonomic Nerve Plexus supplies these organs?

Answer 37

GI Tract Organs: Pharynx, Esophagus, Stomach, Proximal Duodenum Accessory Organs: Liver, Gallbladder, Pancreas, and Spleen Supplied by Celiac Trunk Supplied by Celiac Plexus (sympathetic supplied by T5-T9 and parasympathetic supplied by Vagus)

Question 38

What organs form the midgut? What branch of abdominal aorta supplies these organs? What autonomic Nerve Plexus supplies these organs?

Answer 38

Organs: Jejunum, Ileum, Cecum, Appendix, Ascending Colon, and proximal 2/3 of Transverse Colon Supplied by Superior Mesenteric Artery Supplied by Superior Mesenteric Plexus (sympathetic supplied by T8-T12 and parasympathetic supplied by vagus)

Question 39

What organs form the hindgut? What branch of abdominal aorta supplies these organs? What autonomic Nerve Plexus supplies these organs?

Answer 39

Organs: Distal 1/3 of Transverse Colon, Descending Colon, Sigmoid Colon, and Superior Rectum Supplied by Inferior Mesenteric Artery Supplied by Inferior Mesenteric Plexus (sympathetic supplied by L1-L2 and parasympathetic supplied by pelvic splanchnic nerves S2-S4)