Digestive System

Question 1

What does food contain?

Answer 1

water, inorganic salts (Ph, Na, etc.), and major nutrients (carbs, lipids, fats, proteins, etc.)/ micronutrients (vitamins)

Question 2

What are the 6 PRIMARY components of the digestive system?

Answer 2

1. mouth
2. pharynx
3. esophogus
4. stomach
5. small intestine
6. large intestine

Question 3

What are the 2 accessory components of the digestive system?

Answer 3

1. salivary glands
2. liver (with gallbladder, bile duct, haptic portal circulation)
3. pancreas

Question 4

What are the 4 categories of activities in the D.S.?

Answer 4

1. motility- movements of various parts of the digestive tract
2. secretion- secretion into the digestive tract of various juices
3. digestion- the process of breaking up larger molecules into smaller ones
4. absorption- the process whereby the products of digestion are transferred from the inside of the tract into the bloodstream

Question 5

What are the anatomical segments of the digestive tract?

Answer 5

1. Mouth
2. Pharynx
3. Esophagus
4. Stomach= fundus, body, antrum
5. Small Intestine= duodenum, jejunum, ilieum
6. Large Intestine= caecum, colon,rectum, anal canal

Question 6

What is the function of the mouth?

Answer 6

1. receives the food that is placed into it
2. mastication- grinds up and mixes food with saliva
3. preliminary digestion of carbs (salivary amylase)
4. swallowing

Question 7

What is the mouth enclosed by?

Answer 7

lips, cheeks, hard and soft palates, gums part of the tongue and the mucous membrane

Question 8

What is the function of the pharynx?

Answer 8

swallowing

Question 9

What is the pharynx described as in Gray’s Anatomy?

Answer 9

a musculomembranous tube

Question 10

What is the pharynx lined with?

Answer 10

mucous membrane that contains auditory tubes (eustachian tubes), nasal cavity, mouth and larynx

Question 11

How can you swallow?

Answer 11

has a muscle coat (3 constricot muscles) that pull the wall inwards during swallowing= sphincter and partly to promote peristaltic actions

Question 12

What are the 3 segments of the pharynx?

Answer 12

1. nasopharynx
2. oropharynx
3. laryngopharnyx

Question 13

What is the nasopharynx?

Answer 13

air from the nasal cavity enters it through two posterior nasal apertures

Question 14

What is the oropharynx?

Answer 14

opens from the mouth and runs from the soft palette to the epiglottis

Question 15

What is the laryngopharynx?

Answer 15

runs from the upper border of the epiglottis to the lower border of the cricoid cartilage( then continues with the esophagus)

Question 16

What is the point at which the nasopharynx and the oropharynx meet?

Answer 16

pharyngeal isthmus

Question 17

What is closed during swallowing due to the elevation of the soft palette?

Answer 17

pharyngeal isthmus

Question 18

Where is the pharyngeal tonsil found?

Answer 18

in the roof and posterior wall of the nasopharynx

Question 19

What is another name for pharyngeal tonsil?

Answer 19

adenoid

Question 20

What is the pharyngeal tonsil?

Answer 20

It is a mass of lymphoid tissue that increases in size up to 7 yrs old - then atrophies

Question 21

What is the palatine tonsil?

Answer 21

found in the oropharynx

• two masses of lymphoid tissue in its later wall
• often get infected

Question 22

What are the 2 types of tonsils found in the digestive system?

Answer 22

1. pharyngeal tonsil

2. palatine tonsil

Question 23

What are the tonsils considered to be?

Answer 23

MALT= mucosa-associated lymphoid tissue

Question 24

What is the role of the tonsils?

Answer 24

help defend against microbial intruders

Question 25

What is Waldeyer's Ring?

Answer 25

it is a ring of lymphoid tissue that guards the trachea and esophagus against invasion of infectious organisms entering our bodies from the nose and mouth

Question 26

What are the 4 components of Waldeyer's Ring?

Answer 26

1. Lingual Tonsils 2. palatine tonsils 3. pharyngeal tonsil 4. other lymphoid masses of MALT between these groups

Question 27

What are lingual tonsils?

Answer 27

lymphoid nodules in the submucosa of the root of the tongue

Question 28

What is the function of the esophagus?

Answer 28

helps swallowing and connects the pharynx to the stomach

Question 29

What is the anatomical description of the esophagus?

Answer 29

a 10 inch long, thick muscular tube lined with mucous membrane that passes behind the trachea - upper 2/3rds contain skeletal mm. and lower contains smooth mm.

Question 30

What does the esophagus connect?

Answer 30

it connects the pharynx to the stomach

Question 31

What are the 4 functions of the stomach?

Answer 31

1. KEEP food until it is put into the duodenum 2. MIX food with gastric juice (forms chyme) 3. EMPTY chyme in little squirts into the small intestine 4. START protein digestion

Question 32

What is rugae of the stomach?

Answer 32

the folds of the stomach when it is empty

Question 33

What are the 3 main regions of the stomach?

Answer 33

1. fundus 2. body 3. antrum ( the pyloric end empties into the duodenum of the small intestine)

Question 34

What is the cardiac orifice?

Answer 34

where the esophagus opens into the stomach

Question 35

What is the pyloric orifice?

Answer 35

where the stomach opens into the duodenum of the small intestine

Question 36

What are the 2 orifices found in the stomach?

Answer 36

1. cardiac orifice | 2. pyloric orifice

Question 37

What type of epithelium covers the surface of the stomach?

Answer 37

columnar epithelium- secretes thick and protective mucus

Question 38

Where does majority of the gastric juice produced?

Answer 38

in the body and fundus of the stomach

Question 39

What are the 5 types of cells in the stomach?

Answer 39

1. Chief cells (peptic) = exocrine 2. Parietal (oxyntic) cells =exocrine 3. Goblet cells =exocrine 4. Epithelial Cells = exocrine 5. G-Cells =endocrine

Question 40

What do the chief cells in the stomach secrete?

Answer 40

pepsinogen= protein digestion

Question 41

What do the parietal cells in the stomach secrete?

Answer 41

1. HCl- kills ingested bacteria and creates the highly acidic solution needed for pepsin 2. Intrinsic Factor= bind to vitamin B12 in the stomach; aides in the absorption of Vit B12 when it reaches the small intestine

Question 42

What do the Epithelial Cells in the stomach secrete?

Answer 42

secrete alkaline bicarbonate into the mucous layer= assist in protecting the gastric lining from the acid

Question 43

What do the G-Cells secrete?

Answer 43

secrete the hormone Gastrin

Question 44

What is the function of the Small Intestine?

Answer 44

absorb the products of digestion

Question 45

describe the anatomic nature of the small intestines

Answer 45

6-7 meters long; connects the stomach to the large intestine ducts that have pancreatic juice and bile open into the small intestine

Question 46

Why is pancreatic juice key to digestion?

Answer 46

it contains nearly all the enzymes needed for digesting carbs, proteins and fats

Question 47

What are the 3 sections of the small intestine?

Answer 47

1. duodenum 2. Jejunum 3. illeum

Question 48

What does the duodenum contains?

Answer 48

glands of Brunner= alkaline. mucous secretion that neutralizes the acidity of the stomach fluid

Question 49

What are the crypts of Lieberkuhn or intestinal glands?

Answer 49

found between the bill in all parts of the small intestine

Question 50

What is the purpose of intestinal villi?

Answer 50

- are finger-like projections of the mucous membrane | - increase surface area and therefore increase absorption

Question 51

What is the function of the Large Intestine?

Answer 51

absorb fluid and salts (electrolytes) also secrete alkaline mucus

Question 52

What is the function of the teeth?

Answer 52

assist in grinding, cutting and tearing food

Question 53

What are the 4 regions of the large intestine?

Answer 53

1. caecum 2. colon 3. rectum 4. anal canal

Question 54

What is the ileocaecal valve?

Answer 54

a sphincter that controls the one-way passage of the contents of the small intestine into the large intestine

Question 55

What 2 spinsters are involved in defecation?

Answer 55

internal and external sphincters

Question 56

What are 5 accessory structures of the digestive system?

Answer 56

1. teeth 2. tongue 3. salivary glands 4. pancreas 5. liver and gallbladder

Question 57

What is the function of the tongue?

Answer 57

assist in moving the food around the mouth and swallowing; also has sensory receptors involved in tasting food

Question 58

What is deglution

Answer 58

swallowing

Question 59

What is the function of the salivary glands?

Answer 59

discharge saliva into the mouth | serous and mucus cells

Question 60

What is amylase?

Answer 60

an enzyme found in saliva that breaks down large molecules of carbs such as starch

Question 61

What are the 5 functions of saliva?

Answer 61

1. lubricates food (helps in swallowing) 2. Moistens the mucosa of the mouth cavity 3. provides a watery solvent for taste 4. amylase starts the digestion of carbs 5. contains anti-microbial proteins and lysozyme

Question 62

What are the 3 major salivary glands?

Answer 62

1. paired parotids (largest) 2. submandibular 3. sublingual

Question 63

What is the function of the pancreas?

Answer 63

endocrine function= involves Islets of Langerhans exocrine function= involves acinar cells *secrete pancreatic juice into the small intestine

Question 64

What are the 4 enzymes that are found in pancreatic juice?

Answer 64

1. proteases 2. carbohydrate- digesting 3. Lipase 4. Nucleases