Digestive System

Question 1

What are the accessory digestive organs?

Answer 1

Liver, Pancreas, Gallbladder, Salivary glands

Question 2

What is peristalsis?

Answer 2

An organized contraction and relaxation of smooth muscle that propels through the alimentary canal in one direction

Question 3

What is segmentation?

Answer 3

Contractions of smooth muscle that moves chyme back and forth within the canal to allow mixing and further breakdown

Question 4

What are the layers of the alimentary canal? What are their basic functions

Answer 4

Lumen, mucosa (lines lumen), submucosa (support layer), muscularis externa (muscle layer), serosa (outer layer)

Question 5

In which of the 4 main layers of the alimentary canal would you expect to find an epithelium?

Answer 5

Mucosa and serosa

Question 6

What are the 3 sublayers of the mucosa?

Answer 6

1. epithelium 2. lamina propria 3. Muscularis externa

Question 7

Characteristic of the Submucosa

Answer 7

Highly vascularized and nutrient absorbent

Question 8

What is the submucosal nerve plexus?

Answer 8

controls secretions of glands & muscularis mucosa contractions

Question 8

What is the submucosal nerve plexus?

Answer 8

Controls secretions of glands and muscularis mucosa contractions

Question 9

What is the muscularis externa made up of?

Answer 9

2 layers of smooth muscle: circular and longitudinal

Question 10

What is the myenteric nerve plexus and where is it found?

Answer 10

Controls peristalsis and segmentation; found within the muscularis externa

Question 11

What is the enteric nervous system?

Answer 11

Controls the smooth muscle and glands of alimentary canal; “brain in the gut”; made of 2 nerve plexuses

Question 12

What is the serosa made of?

Answer 12

Simple squamous epithelium + a thin loose areolar CT

Question 13

What type of epithelium would you expect to find lining the oral cavity?

Answer 13

Stratified squamous

Question 14

What is rough surface found on the tongue called?

Answer 14

Filiform papillae

Question 15

What is the lingual frenulum?

Answer 15

Fold of mucosa layer that connects the tongue to the floor of the mouth

Question 16

What are the primary salivary glands?

Answer 16

Parotid gland, submandibular gland, sublingual gland

Question 17

What are the types of permanent teeth?

Answer 17

Incisors, Canines, Premolars, molars

Question 18

What are the regions of a tooth? Where are they found?

Answer 18

Crown: part above gum line
Neck: contained within gum tissue
Root: contained within bone

Question 19

What part of the tooth provides nutrients and sensation?

Answer 19

Pulp

Question 20

Enamel is the…

Answer 20

… hardest substance in the body

Question 21

What is the periodontal ligament?

Answer 21

Dense CT that attached cement of tooth to bony socket

Question 22

What is the function of the pharynx?

Answer 22

Connects oral cavity to esophagus and nasal cavity

Question 23

What are the parts of the pharynx?

Answer 23

Oropharynx, laryngopharynx, Nasopharynx

Question 24

What is the epithelium of the oropharynx and the laryngopharynx?

Answer 24

Stratified squamous

Question 25

Characteristics & Function of Esophagus

Answer 25

connects pharynx to stomach; stratified squamous; mucous glands secrete mucus to lubricate bolus of food

Question 26

What is the muscularis externa layer of the esophagus made up of?

Answer 26

Upper 1/3: skeletal muscle Middle 1/3: skeletal & smooth muscle Lower 1/3: smooth muscle

Question 27

What is the outer layer of the esophagus?

Answer 27

Adventitia

Question 28

What absorption takes place in the stomach?

Answer 28

Limited to water and alcohol

Question 29

What is the lining mucosa epithelium of the stomach? What else is found here?

Answer 29

Simple columnar; Cells that produce bicarbonate-buffered mucus & the lining is dotted with gastric pits

Question 30

What are the rugae of the stomach?

Answer 30

"wrinkles", folds of mucosa that increase SA and allow stomach to expand.

Question 31

What are the sphincters of the stomach and what are their functions?

Answer 31

Cardiac sphincter: prevents food from moving back into esophagus Pyloric Sphincter: controls the release of chyme into duodeum

Question 32

What are the layers of the muscularis externa in the stomach?

Answer 32

1. oblique 2. circular 3. longitudinal

Question 33

What are the specialized cells found in the gastric pits of the stomach? What are their functions?

Answer 33

Parietal cells: produce and secrete HCl and GIF which necessary for vitamin b12 absorption in the SI Chief Cells: produce and secrete pepsinogen and gastric lipase Enteroendocrince cells: release hormones Undiff. Stem Cells: replaced every 3-7 days

Question 34

What is pepsin? How is it created?

Answer 34

Pepsin breaks down proteins in food. It is created when pepsinogen mixes with HCl

Question 35

Characteristics & Functions of the Small Intestine

Answer 35

Simple columnar; site of most absorption and chemical digestion

Question 36

What are the segments of the SI?

Answer 36

Duodenum, Jejunum, Ileum

Question 37

What do the circular folds of the SI do?

Answer 37

Increase SA and force chyme to spiral through the small intestine which slows it down allowing for increased absorption of nutrients

Question 38

Characteristics of Villi

Answer 38

Made of absorptive cells (enterocytes); Have capillaries (absorb proteins & carbs) and Lacteals (absorb fat)

Question 39

What are absorptive enterocytes made of?

Answer 39

Lots of mitochondria because absorption of nutrients requires energy

Question 40

What are the specialized cells found in the mucosa of the SI? What are their functions?

Answer 40

Absorptive enterocytes; Goblet cells (secrete mucus); enteroendorcine cells (secrete hormones to control the release of other substances); Intestinal crypts (between villi, produce intestinal juice); Paneth cells (secrete enzymes to destroy unwanted bactera)

Question 41

What are the inputs to the duodenum?

Answer 41

Stomach contributes chyme, gallbladder adds bile; Pancreas adds digestive enzymes, pancreatic juice

Question 42

Chyme enter duodenum from stomach and activates enteroendocrine cells... the presence of fats stimulates the release of ____.

Answer 42

CCK: signals release of store bile to break down fats for better absorption.

Question 43

Chyme enter duodenum from stomach and activates enteroendocrine cells... the presence of acids stimulates the release of ____.

Answer 43

Secretin: signals release of pancreatic juice to neutralize acids

Question 44

Label the Gross Anatomy of the Large Intestine

Answer 44

add: epipolic appendages, teniae colie; haustra; ascending colon, transverse colon, descending colon, sigmoid colon

Question 45

What type of epithelium would you expect to find lining the large intestine?

Answer 45

Simple columnar

Question 46

What are the specialized cells of the LI? What are the functions?

Answer 46

Colonocytes: absorb water & electrolytes Goblet Cells: secrete mucus Intestian crypts: stem cells are replaced every 7 days

Question 47

What are the sphincters in the anal canal? What are the characteristics of each?

Answer 47

External Anal Sphincter: skeletal muscle, voluntary control | Internal Anal Sphincter: smooth muscle, involuntary control

Question 48

Where is bile produced?

Answer 48

Liver;

Question 49

What does the hepatic portal vein of the liver do?

Answer 49

Gathers blood from digestive organs and transports it to the liver

Question 50

What does the hepatic artery proper of the liver do?

Answer 50

Provides oxygen-rich blood to the liver

Question 51

What does the inferior vena cava of the liver do?

Answer 51

removes blood from liver after it has been processed

Question 52

What does each portal triad contain? What does each part do?

Answer 52

Bile duct (transports bile out of lobule); Portal venule (transports nutrient-rich blood into lobule); Portal arteriole (transports oxygen-rich blood into the lobule)

Question 53

What is the primary cell of the liver?

Answer 53

Hepatocytes

Question 54

What is the role of liver sinusoids? Where are they found?

Answer 54

Between plates of hepatocytes; Site where arterial and venous blood mix (gives hepatocytes access to oxygen & nutrients) and carried to the central vein

Question 55

What does the central vein do?

Answer 55

Drains blood from sinusoids out of liver

Question 56

What are stellate macrophages?

Answer 56

Move through sinusoids to destroy unwanted microorganisms

Question 57

What is the path of the bile in the liver?

Answer 57

Bile moves from hepatocytes to bile canaliculus to bile ducts

Question 58

What does the gallbladder do?

Answer 58

Stores and concentrates bile

Question 59

What is the exocrine function of the Pancreas?

Answer 59

Acinar cells produce and secrete pancreatic juices

Question 60

What is the endocrine function of the pancreas?

Answer 60

Beta cells produce insulin & alpha cells produce glucagon

Question 61

What is the mesentery?

Answer 61

Double-sided serous membrane that suspends organs within abdominal cavity

Question 61

What is the mesentery?

Answer 61

Double-sided serous membrane that suspends organs within abdominal cavity

Question 62

What are Ulcers?

Answer 62

Crater-like erosions of the mucosa