Chapter 16: The Digestive System

Question 1

6 related processes of digestion

Answer 1

ingestion, mechanical processing, digestion, secretion, absorption, excretion

Question 2

four components of digestive tract

Answer 2

mucosa, submucosa, muscularis externa, and serosa

Question 3

mucosa

Answer 3

-inner lining of digestive tract; example of a mucous membrane
-stratified squamous in areas of high mechanical stress (mouth, pharynx, esophagus, anus)
-forms villi in the small intestine that further increase surface area for absorption

Question 4

submucosa

Answer 4

second layer of loose connective tissue that is immediately deep to the muscularis mucosae; involved in controlling/coordinating contractions of smooth muscle layer and regulation of secretion of digestive glands.

Question 5

Muscularis externa

Answer 5

a band of smooth muscle cells arranged in an inner circular layer and an outer longitudinal layer. (Contractions of these layers propel materials along digestive tract)

Question 6

serosa

Answer 6

serous membrane which covers the muscularis externa along most of digestive tract within peritoneal cavity; does NOT cover oral cavity, pharynx, esophagus, or rectum

Question 7

tongue

Answer 7

-manipulates materials inside mouth
-sensory analysis by touch, temperature, and taste receptors innervated by glossopharyngeal nerve

Question 8

salivary glands

Answer 8

-three pairs: sublingual, submandibular, parotid; each gland produces slightly different saliva
-produce 1-1.5L/day of saliva

Question 9

saliva

Answer 9

-99.4% water, plus mucins and an assortment of ions, buffers, waste products, metabolites, and enzymes
- Helps lubricate the mouth and dissolve chemicals that stimulate taste buds.

Question 10

incisors

Answer 10

blade-shaped teeth found at the front of the mouthuseful for cutting or clipping

Question 11

Canines

Answer 11

are conical, with a sharp ridge line and pointed tip. Used for tearing or slashing.

Question 12

molars

Answer 12

flattened crowns with prominent ridges; used for crushing, mashing, and grinding

Question 13

diaphragmatic hernia

Answer 13

abdominal organs slide into the thoracic cavity through the esophageal hiatus; actually very common, usually goes unnoticed

Question 14

stomach

Answer 14

J-shaped organ located in upper left abdominal quadrant. cardia attaches to esophogus (where it receives food). It has 4 main regions: fundus, cardia, body, pylorus

(When empty ridges/folds called rugae)

Question 15

fundus of stomach

Answer 15

the bulge of the stomach superior to the cardia

Question 16

pepsin

Answer 16

proteolytic enzyme (protein-digesting) derived from pepsinogen

Question 17

gastric lipase

Answer 17

secreted by newborns; initiates the digestion of milk fats

Question 18

gastrin

Answer 18

Secreted by doudenal cells in response to large quantities of incompletely digested proteins.

Question 19

duodenum

Answer 19

1/3 Small Intestine
-segment closest to stomach, curves in a C that encloses the pancreas
-receives chyme from stomach and digestive secretions from the liver/pancreas
10 in

Question 20

jejunum

Answer 20

2/3 Small Intestine
- separated from duodenum by an abrupt bend
-chemical digestion and nutrient absorption occurs here
8 ft

Question 21

ileum

Answer 21

3/3 Small Intestine
the last and longest portion of the small intestine; ends at ileocecal valve
12 ft

Question 22

secretin

Answer 22

Released when pH falls in the duodenum as acidic chyme arrives from stomach.
- Primary role is to increase secretion of bile/buffers by liver/pancreas

Question 23

bile

Answer 23

-secreted by liver
-stored by gallbladder
-consists mostly of water, ions, cholesterol, and bile salts
-released under stimulation of CCK

Question 24

colon

Answer 24

-external pouches called haustra permit distention and elongation
-four segments: ascending, transverse, descending, and sigmoid
-bacteria within colon generate Vitamin K, Biotin, and B5

Question 25

Soft palate

Answer 25

-comprised of five muscles that play essential roles in breathing, phonation, and swallowing
-Separates nasalpharynx and oropharynx

Question 26

Hard palate

Answer 26

-Front bony part of the roof of your mouth
-Separates maxilla and palatine bones

Question 27

Colostomy

Answer 27

a surgical operation in which a piece of the colon is diverted to an artificial opening in the abdominal wall so as to bypass a damaged part of the colon

Question 28

Lactose intolerance

Answer 28

Inability to digest lactose (monosaccharides); symtoms include: bloating, diarhhea

Question 29

Types of hernias

Answer 29

-Diaphragmatic
- Inguinal
-Umbillical
-Femoral
CLINICAL NOTE: pg 593

Question 30

Appendicitis

Answer 30

-Inflammation of veriform appendix
-Obstruction of lumen
-McBurney’s point (1.5-2 inches above illiac crest, right lower quadrant)

Question 31

Peptic Ulcers

Answer 31

-Duodenum ulcers (proximal portion)
-Stomach ulcers
-Most likely duodenal
-More common in males
- pain when stomach is empty

Question 32

Chron’s Disease

Answer 32

-Inflammatory bowel disease
-Chronic inflammation of GI
-Symptoms: Fatigue, weight loss, anemia, diarhhea

Question 33

Peritonitis

Answer 33

Inflammation of membrane lining of GI

Question 34

Gastritis

Answer 34

Inflammation of internal lining of stomach

Question 35

Appendectomy

Answer 35

Surgical removal if appendix

Question 36

Gastroenteritis

Answer 36

-Inflammation of stomach and intestines
-Causes diarhhea, nausea, vomiting

Question 37

Pancreatic Enzymes

Answer 37

-Lipase (Triglycerides to fatty acids)
-Protase (breakdown to polypetide chains)
-Nuclease (nucleic acids)
-Caronhydrase (starches and simple sugars)