Chapter 24 - Digestive System

Question 1

Major organs of the digestive tract:

Answer 1

oral cavity, pharynx, esophagus, stomach, small intestine, large intestine

Question 2

accessory organs of the digestive system

Answer 2

teeth, tongue, salivary glands, liver, gallbladder, pancreas

Question 3

know the 4 abdominal quadrants and organs within them

Answer 3

Question 4

Integrated processes of digestive system

Answer 4

Question 5

what is the abdominal peritoneum?

Answer 5

Peritoneum - Like a fist in a balloon. All organs are invaginated in peritoneum
Parietal - lines body wall
Visceral - lines organs
Peritoneal cavity - in between layers, sterile
Peritoneal fluid - 7 liters produced and absorbed daily
Ascites - build up of peritoneal fluid

Question 6

what are the types of teeth?
what are each used for?
how many of each do you have?
what are baby teeth called?

Answer 6

incisor - 2, clipping or cutting
- medial incisor
- lateral incisor
canine - 1, tearing
- only 1
premolar - 2, crush, mash, grind
- 1st premolar
- 2nd premolar
molar - 3, crush, grind
- 1st molar
- 2nd molar
- 3rd molar

*deciduous teeth - 20 temporary teeth (2 incisors, 1 canine, 2 molars)

Question 7

mesenteries, lesser omentum, greater omentum

Answer 7

Mesenteries
- Suspended holdings of digestive tract within peritoneal cavity
Lesser omentum
- Between liver and stomach (slide 11)
Greater omentum
- Large adipose sheet over digestive tract
Only attached at top to stomach
- Beer belly - excess adipose in greater omentum.

Question 8

Except for the stomach, what are the layers of the digestive system?

Answer 8

1. Mucosa
2. Submucosa
3. Muscular layer (muscularis externa)
   
   • circular & longitudinal
4. Serosa.

(Stomach and uterus have extra muscle layers)
Enteroendocrine cells

Question 9

what are the types of tissues of the digestive tract?
oral cavity, pharynx, esophagus, anal canal?
stomach, small intestine, most of large intestine?

Answer 9

oral cavity, pharynx, esophagus, anal canal -
- stratified squamous epithelium. Like in skin, for easy replacement
stomach, small intestine, most of large intestine -
- simple columnar epithelium
- enteroendocrine cells secrete hormones for digestive coordination

Question 10

know peristalsis and segmentation

Answer 10

Peristalsis - one way movement of food from mouth to anus.
Segmentation - bulging and constriction cycles to churn the materials. No set pattern

Question 11

what are the salivary glands?

Answer 11

parotid glands - salivary amylase to break down starches
sublingual glands - mucus for buffer
submandibular glands - both

Question 12

know these about saliva…

Answer 12

Saliva
- 1-1.5 liters per day (like 4 coke cans)
- 70% submandibular glands, 25% parotids glands, 5% sublingual glands
- 99.4% water
- 0.6% electrolytes, buffers, glycoproteins, antibodies, enzymes, and wastes
- pH of mouth near 7.0, which is neutral.
- functions: cleaning oral surfaces, moistening, keeping pH, controlling bacteria, dissolving chemicals that stimulate taste buds, initiating digestion of complex carbs.

Question 13

pharynx & esophagus. read through…

Answer 13

Pharynx - 3 parts: nasopharynx (only air), oropharynx (both), laryngopharynx (only food)

Esophagus
Esophageal hiatus - goes through diaphragm
Esophageal sphincter - to prevent stomach acid from entering esophagus

Question 14

what are the 3 phases of swallowing?

Answer 14

Deglutition (swallowing)
3 stages:
buccal - behind tongue
pharyngeal - in pharynx
esophageal phase - in esophagus

Question 15

what are the 3 phases of digestion?

Answer 15

Cephalic Phase
- Thinking → stimulate juice secretions in stomach
Gastric phase
- Juice secretion when food is in stomach
Intestinal Phase
- Further breakdown of material and absorption

Question 16

know parts of the pancreas.
go through the pancreatic enzymes.

Answer 16

Head, Body, Tail, Pancreatic duct
2 ducts: accessory pd & pancreatic duct
2 parts: endocrine & exocrine
Exocrine secretes pancreatic juice

pancreatic alpha-amylase - breaks down starches
pancreatic lipase - breaks down lipids
nucleases - breaks down RNA or DNA
proteolytic enzyme - breaks down proteins

Question 17

the liver…

Answer 17

• Largest visceral organ (3-4 lbs)
• Has over 200 functions, very important organ for function & health
• Performs essential metabolic and synthetic functions
• bile duct system
  - right & left hepatic duct → join for common hepatic duct
  - Cystic duct from gallbladder
  - Common hepatic duct + cystic duct = common bile duct
  → all into duodenum (specific duct?)

Question 18

the gallbladder…

Answer 18

Gallbladder
Just a storage organ, becomes concentrated with time
Will secrete cck- (cholecystokinin)
Neck, body, and fundus

right + left hepatic duct = common hepatic duct
common hepatic + cystic duct = bile duct

Question 19

Small intestine…

Answer 19

3 parts:
duodenum
Upper parts = jejunum
Lower parts = ileum

Ileocecal valve - there is bacteria in large intestine, valve prevents backflow
Circular folds of jejunum is the plicae circulae?

Question 20

Bowel obstructions

Answer 20

Adhesion, herniation, cancer

Question 21

Large intestine…
what are the pouches of the colon called?
what is the longitudinal band in the large intestine?
what are the 2 upper bends in the colon called?

Answer 21

1. Cecum
2. Colon (largest portion)
   
   • Haustra pouches, only in large intestine
   • Teniae coli is the longitudinal band, only in the large intestine, not small intestine.
   • Know ascending, transverse, descending, and sigmoid colon for exam
   • The bends are right colic flexure (or hepatic flexure) & left colic flexure (or left splenic flexure). Know for exam
     - Sigmoid colon - S shaped, high spot for obstruction since it is more narrow.
3. Rectum - similar epithelium as skin
   - Internal anal sphincter - involuntary smooth muscle
   - External anal sphincter - voluntary skeletal muscle

functions: absorption of water, nutrients, salts, organic wastes, vitamins,
- compaction and storage of feces
- microbiome

Question 22

anal fistula, hemorrhoids, anal fissure

Answer 22

Anal fistula
- When glands become infected → moves through sphincter to surrounding tissue = anal fistula
Hemorrhoids
- Swollen, enlarged veins
- Internal & external hemorrhoids
Anal fissure (different than fistula or piles)
- Tear in the lining of the anus

Question 23

name the parts of the oral cavity

Answer 23

(fauces - like a faucet of some kind)

Question 24

what are the different papillae of the tongue?

Answer 24

fungiform papillae- mushroom-like around whole tongue
Filiform papillae - all the smaller ones
Circumvallate papillae - bigger ones in the back

Question 25

name the muscles of the tongue

Answer 25

(genio means chin)
genioglossus - chin to tongue
geniohyoid - chin to hyoid bone
mylohyoid - ?
hyoglossus - hyoid to tongue
styloglossus - styloid process to tongue
*digastric - not pictured, up underneath chin.

Question 26

name the parts of a tooth

Answer 26

Question 27

name the parts of the pharynx

Answer 27

Question 28

layers of the digestive tract…

Answer 28

Question 29

name the parts of the stomach

Answer 29

Question 30

name the parts of the stomach, part II.
name the muscles, even though they’re not labeled on the image.

Answer 30

fundus (pink)
cardia (green)
body
lesser curvature (upper rim)
greater curvature (lower rim)
pylorus (purple)

circular muscle (external around the body)
longitudinal muscle (aligned with the lesser and greater curvatures)
oblique muscle (internal cutout in image)

Question 31

label the parts of the small intestine.
what is the name of the valve in the below image?

Answer 31

Question 32

know that there is the pancreatic duct (main) and the accessory pancreatic duct…

Question 33

name the parts of the liver

Answer 33

Question 34

name the parts of the gallbladder

Answer 34

Notice that there is the common hepatic duct, and the common bile duct.