Aphy102 - Marieb - Digestive System

Front 1

Name the six major alimentary canal organs in order.

Back 1

mouth, pharynx, esophagus, stomach, small intestine, large intestine

Front 2

Name the six major accessory digestive organs.

Back 2

teeth, tongue, gallblader, liver, salivary glands and pancreas.

Front 3

What's another name for the alimentary canal?

Back 3

GI tract (gastrointestinal tract)

Front 4

What's another name for the GI (Gastrointestinal) Tract?

Back 4

Alimentary canal

Front 5

What are the six essential activities of digestion?

Back 5

1) ingestion
2) propulsion (swallowing and peristalsis)
3) mechanical digestion (chewing, segmentation)
4) chemical digestion
5) absorption
6) elimination/defecation

Front 6

What word describes the phenomenon of alternate contraction and relaxation of the intestine resulting in distal propulsion of food?

Back 6

peristalsis

Front 7

What word describes nonadjacent segments of the intestine contracting and relaxing, moving food back and forth and resulting in further mixing of food?

Back 7

segmentation

Front 8

Match the arteries to the organs:
1) hepatic artery
2) splenic artery
3) left gastric artery
4) right gastric artery
5) superior mesenteric artery
6) inferior mesenteric artery

Back 8

1) liver
2) spleen
3) stomach (superior portion)
4) stomach (inferior portion)
5) small intestine and large intestine (up until the last third of transverse colon)
6) large intestine (from the end of the transverse colon til the rectum)

Front 9

What system moves nutrient-rich venous blood from the digestive viscera to the liver, where it can be processed?

Back 9

Hepatic portal system

Front 10

What two major nerve plexuses constitute the enteric nervous system?

Back 10

1) submucosal nerve plexus
2) myenteric nerve plexus

Front 11

which nerve plexus is responsible for motility of the GI tract?

Back 11

myenteric nerve plexus (Auerbach's plexus)

Front 12

which nerve plexus regulates glands and smooth muscle in the alimentary canal?

Back 12

submucosal nerve plexus (Meissner's plexus)

Front 13

Which muscle is the primary mover of the lips?

Back 13

orbicularis oris

Front 14

What muscle group is responsible for the movement of the cheeks?

Back 14

Buccinators

Front 15

What structure fastens the tongue to the floor of the mouth and prohibits excessive posterior movement?

Back 15

lingual frenulum

Front 16

What's another word for "gums?"

Back 16

gingivae

Front 17

what do you call your upper lip?

Back 17

superior labia

Front 18

your lower lip is your ____.

Back 18

inferior labia

Front 19

which salivary gland has two big ducts that pump a lot of saliva out right beneath the tongue?

Back 19

submandibular salivary gland

Front 20

What organ is responsible for mixing food with saliva and forming a bolus, as well as positioning food during chewing and forming sounds in speech?

Back 20

tongue

Front 21

what are the four types of papillae present on the tongue?

Back 21

1) filliform papillae
2) fungiform papillae
3) circumvillate papillae
4) foliate papillae

Front 22

which papillae on the tongue provide friction?

Back 22

filliform papillae -- and they DON'T contain taste buds

Front 23

which papillae are scattered widely over the tongue, giving it a reddish hue? Hint -- they DO contain taste buds.

Back 23

fungiform papillae

Front 24

which papillae are located only at the posterior portion of the tongue and only number about a dozen?

Back 24

circumvallate papillae -- oh, and they also contain taste buds

Front 25

what tastebud-containing papillae reside on the lateral aspects of the tongue?

Back 25

foliate papillae

Front 26

what is the major function of the soft palate?

Back 26

to close off the nasopharynx during chewing.

Front 27

What four things does saliva do?

Back 27

1) cleanses mouth (lysozyme)
2) assists in bolus formation
3) moistens and dissolves food chemicals
4) breaks down starches

Front 28

the intrinsic salivary glands scattered throughout the mucosa are called the ____ _____.

Back 28

buccal glands

Front 29

which salivary glands do the most work?

Back 29

extrinsic salivary glands (parotid, submandibular, sublingual)

Front 30

what two secretory cells in the salivary glands release saliva?

Back 30

serous and mucous cells

Front 31

what do serous cells in salivary glands produce?

Back 31

a watery secretion containing lysozyme (disinfectant) and sailvary amylase (dissolves starch). Also includes ions and a wee bit of mucin.

Front 32

what do mucous cells in salivary glands produce?

Back 32

mucus, dummy.

Front 33

is saliva acidic?

Back 33

Yep! Slightly.

Front 34

secretion of saliva is under _________ control.

Back 34

parasympathetic control

Front 35

stemming the flow of mucus can be an action taken by the ______ division, which can result in drymouth.

Back 35

sympathetic

Front 36

food and drink activate chemoreceptors within the oral cavity, stimulating the swallowing center in the ____.

Back 36

pons

Front 37

what two nerves innervate the salivary glands?

Back 37

glossopharyngeal nerve, facial nerve

Front 38

what are primary teeth?

Back 38

primary teeth are your baby teeth -- also called deciduous (think of leaves falling off) or milk teeth (think of babies). They erupt form 6-24 months of age.

Front 39

what are secondary teeth?

Back 39

permanent, adult teeth.

Front 40

how many adult teeth should there be?

Back 40

32

Front 41

primary teeth are replaced by secondary teeth generally by age ___.

Back 41

13

Front 42

which teeth erupt first?

Back 42

incisors (choppers in the front) at about 6 months.

Front 43

which teeth erupt second?

Back 43

molars/premolars, at about 10 months

Front 44

which teeth are the last to erupt?

Back 44

canine (eyetooth)

Front 45

what are the four types of teeth?

Back 45

1) incisor
2) canine
3) bicuspid/premolar
4) molar

Front 46

what are the three main parts of any tooth?

Back 46

1) crown
2) neck
3) root

Front 47

which part of the tooth is the exposed section above the gingiva?

Back 47

crown

Front 48

which part of the tooth is embedded in the jawbone?

Back 48

root

Front 49

which part of the tooth is simply the part where the crown and root join?

Back 49

neck

Front 50

what acellular, brittle material composed of calcium salts and hydroxyapatite crystals is the hardest substance in the body?

Back 50

tooth enamel

Front 51

what are the two main building blocks of tooth enamel?

Back 51

hydroxyapatite crystals, calcium salts

Front 52

what is cementum?

Back 52

calcified connective tissue that covers the root and anchors the root to the periodontal ligament

Front 53

calcified connective tissue that covers the root and anchors it to the periodontal ligament is called _____.

Back 53

cementum

Front 54

what connects the tooth to the alveolus in the jaw?

Back 54

periodontal ligament

Front 55

what does the periodontal ligament do?

Back 55

anchors teeth to the alveolus in the jaw

Front 56

specifically, what kind of synarthroses are the periodontal ligaments?

Back 56

gomphoses

Front 57

what bonelike material lies deep to the enamel and forms most of the tooth?

Back 57

dentin

Front 58

what is the big cavity in the tooth that contains pulp?

Back 58

pulp cavity

Front 59

what is pulp made up of?

Back 59

connective tissue, blood vessels, nerves inside the tooth.

Front 60

what is the root canal?

Back 60

the segment of the pulp cavity that extends into the root.

Front 61

what is the apical foramen?

Back 61

the proximal opening to the root canal.

Front 62

What's another word for your throat (the part that passes both food and air)?

Back 62

pharynx

Front 63

what's the scientific name for swallowing?

Back 63

deglutition

Front 64

what's deglutition?

Back 64

a fancy pants way of saying swallowing

Front 65

deglutition involves how many muscle groups?

Back 65

22

Front 66

what structures/organs are involved in swallowing?

Back 66

tongue, soft palate, pharynx, esophagus

Front 67

what's the muscular tube that transports food (in the form of a bolus) from the laryngopharynx to the stomach via peristalsis?

Back 67

esophagus

Front 68

what's the esophagus?

Back 68

a muscular tube that transports food (in the form of a bolus) from the laryngopharynx to the stomach via peristalsis.

Front 69

what are the four main types of gastric glands found in the stomach?

Back 69

1) mucous neck cells (secrete acid mucus)
2) chief cells (produce pepsinogen)
3) parietal cells (produce HCl and intrinsic factor)
4) enteroendocrine cells (secrete gastrin, histamine, endorphins, serotonin, cholecystokinin (CCK), and somatostatin)

Front 70

what do mucous neck cells do?

Back 70

secrete acid mucus

Front 71

what do chief cells do?

Back 71

produce pepsinogen, which degrades to pepsin. It's also called propepsin

Front 72

what does pepsin do?

Back 72

it breaks down proteins

Front 73

what do parietal cells in the stomach do?

Back 73

secrete HCl and intrinsic factor

Front 74

what important vitamin does intrinsic factor help us digest and absorb?

Back 74

B12

Front 75

what do enteroendocrine cells do?

Back 75

secrete gastrin, histamine, endorphins, serotonin, cholecystokinin (CCK), and somatostatin

Front 76

what are the four major tasks of the stomach?

Back 76

1) to hold ingested food
2) to physically and chemically degrade food and deliver chyme to the small intestine
3) to enzymatically digest proteins using pepsinogen, pepsin, and rennin
4) assist in absorption of vitamin B12 (using intrinsic factor)

Front 77

what two types of control mechanisms regulate the release of gastric juice?

Back 77

neural and hormonal

Front 78

secretory events of the stomach involve three phases. what are they?

Back 78

1) cephalic (head. starts when you think "food.")
2) gastric - 3 or 4 hours long, provides most of gastric juices. distension, peptides, and low acidity are the big triggers
3) instestinal - happens once chyme hits the intestine

Front 79

stomach pressure remains constant until roughly how much food is digested?

Back 79

1 liter

Front 80

what two factors result in a constant stomach pressure?

Back 80

1) reflex-mediated relaxation
2) plasticity

Front 81

what three reflex-mediated events occur in the stomach?

Back 81

1) adaptive relaxation (stomach relaxes when food hits esophagus)
2) receptive relaxation (stomach dilates in response to gastric filling)
3) plasticity (intrinsic ability of smooth muscle to exhibit stress-relaxation response)

Front 82

How frequently do peristaltic waves occur in the stomach?

Back 82

every 20 seconds or so (about 3 per minute)

Front 83

where do the most vigorous segmentation and peristalsis occur in the stomach?

Back 83

towards the pyloris

Front 84

Once chyme is created in the stomach, what happens to it?

Back 84

it either slowly leaks into duodenum or gets forced back into stomach for further mixing.

Front 85

What two reflexes regulate gastric emptying?

Back 85

The neural ENTEROGASTRIC reflex,
and the hormonal ENTEROGASTRONE reflex

Front 86

The enterograstric (neural) and enterogastrone (hormonal) reflexes do what, exactly?

Back 86

They inhibit gastric secretion and duodenal filling.

Front 87

What moves more quickly through the duodenum: carbohydrate-rich chyme or lipid-rich chyme?

Back 87

carbohydrate-rich chyme

Front 88

What three structural modifications increase surface area of the small intestine?

Back 88

1) Plicae circulares (circular folds of mucosa and submucosa)
2) Villi - fingerlike extensions of mucosa
3) Microvilli - tiny projections of mucosal cells' plasma membranes

Front 89

What is the "brush border?"

Back 89

It's the border formed by the absorptive microvilli of the small intestine's epithelial cells

Front 90

what do "brush border enzymes" do?

Back 90

they digest both carbohydrates and proteins in the small intestine.

Front 91

What type of epithelium constitutes the small intestine wall?

Back 91

Simple columnar epithelium

Front 92

What type of cell junction is characteristic of cells in the small intestine?

Back 92

Tight junction

Front 93

What type of cells are present in the small intestine that sense the conditions luminal environment and secrete hormones such as cholecytokinin and secretin into the blood?

Back 93

Enteroendocrine cells

Front 94

What do enteroendocrine cells in the small intestine do?

Back 94

They sense the conditions of the luminal environment and secrete hormones such as cholecytokinin and secretin into the blood.

Front 95

What special structure is present in the submucosa of the small intestine (especially the ileum) that is large, ovular, and composed of lymphoid tissue?

Back 95

Peyer's Patch

Front 96

What are the three main functions of the small intestine?

Back 96

1) Neutralization
2) Chemical digestion
3) Absorption

Front 97

What three enzyme in the small intestine digest carbohydrates?
Which two digest proteins?
Which ones get lipids?

Back 97

Carbs - sucrase, lactase, maltase
Proteins - peptidases, proteases
Lipids - Lipases

Front 98

What gets absorbed by the small intestine?

Back 98

Water, electrolytes, and dietary organic molecules

Front 99

What's the largest gland in the body?

Back 99

The liver

Front 100

Name some of the important metabolic functions of the liver?

Back 100

1) production of plasma proteins
2) production of cholesterol and lipoproteins
3) conversion of glucose to glycogen and glycogen storage
4) regulation of blood levels of amino acids
5) processing of hemoglobin for use of its iron (the liver stores iron)
6) conversion of ammonia (poison!) to urea
7) clearing out drugs and poisons
8) regulating blood clotting
9) bile production

Front 101

what does bile do?

Back 101

Bile carries away waste and breaks down fats in the small intestine during digestion.

Front 102

What does bile contain?

Back 102

bile salts, bile pigments, cholesterol, neutral fats, phospholipids, and electrolytes

Front 103

What do the cholesterol derivatives called bile salts do?

Back 103

1) emulsify fat
2) facilitate fat and cholesterol absorption
3) Help solubilize cholesterol
4) Stimulate liver to produce bile

Front 104

What is the chief bile pigment?

Back 104

bilirubin -- a waste product of heme

Front 105

When do cholesterol gallstones develop?

Back 105

When bile contains too much cholesterol and not enough bile salts. Also, certain proteins that inhibit or promote cholesterol crystallization play a role

Front 106

What happens when bile contains too much cholesterol and not enough bile salts, and proteins are present that promote cholesterol crystallization?

Back 106

Cholesterol gallstones develop.

Front 107

What color is the gallblader?

Back 107

The gallbladder is green.

Front 108

What are the three major functions of the gallbladder?

Back 108

1) Storage of bile
2) Concentration of bile by absorbing water and ions
3) Releasing bile via the cystic duct which merges into the bile duct

Front 109

What happens when acidic, fatty chyme enters the duodenum?

Back 109

1) The duodenum secretes cholecystokinin and secretin into the bloodstream
2) Secretin, along with bile salts in the bloodstream, signal the liver to produce bile more rapidly
3) Vagal stimulation and the cholecystokinin cause gallbladder to contract, secreting bile into the duodenum

Front 110

What two exocrine secretions are produced by the pancreas? What do they do?

Back 110

1) Acinar cells secrete pancreatic juice -- break down all sorts of food
2) Bicarbonate -- neutralizes stomach acid in duodenum

Front 111

What are the endocrine cells of the pancreas called?

Back 111

Islets of Langerhans

Front 112

What do the islets of langerhans do?

Back 112

The Islets of Langerhans produce insulin, glucagon, and somatostatin.

Front 113

What two types of bacteria live in the large intestine?

Back 113

1) Those that survived the small intestine and enter the cecum.
2) Those entering via the anus

Front 114

What four things do colon bacteria do?

Back 114

1) Colonize the colon
2) Ferment indigestible carbohydrates
3) Release irritating acids and gases (flatus)
4) Synthesize B complex vitamins and vitamin K

Front 115

What is the major purpose of the colon?

Back 115

Propelling feces toward the anus.

Front 116

What makes the colon different from the rest of the digestive organs?

Back 116

It doesn't really digest anything (besides enteric bacteria), and it's actually not necessary for human life (though it sure helps).

Front 117

Distension of the rectal walls caused by feces does what two things?

Back 117

It stimulates contraction of the rectal walls and relaxes the internal anal sphincter.

Front 118

What's a "mass movement?"

Back 118

A mass movement is basically a giant peristaltic contraction that strips an area of the colon of its contents.

Front 119

What provents feces from being passed with gas?

Back 119

Three valves of the rectum stop it.

Front 120

Where does the word feces come from?

Back 120

The latin 'faex,' meaning dregs.

Front 121

What is feces composed of?

Back 121

water, undigested food residues, digestive secretions, bacteria

Front 122

The reddish-brown color of feces comes from what?

Back 122

The reddish brown hue comes from bacterial action on bilirubin, which creates stercobilin.

Front 123

What is responsible for the odor of feces?

Back 123

Bacterial action produces smelly stuff like:
Indoles
Skatoles
Mercaptans
All of these are rich in sulfur. Bacteria also produce hydrogen sulfide.

Front 124

Define "hydrolysis."

Back 124

A chemical reaction that uses water to break down a compound.

Front 125

What enzymes digest carbohydrates throughout the digestive system?

Back 125

Salivary amylase, pancreatic amylase, brush border enzymes

Front 126

Where does protein digestion begin?

Back 126

In the stomach.

Front 127

What is the pH level of the stomach?

Back 127

1.5-2.5

Front 128

What enzymes in the small intestine digest proteins?

Back 128

Pancreatic enzymes trypsin, chymotrypsin, carboxypeptidase.

Brush border enzymes aminopeptidases, carboxypeptidases, dipeptidases

Front 129

How are lipids absorbed?

Back 129

They combine with proteins and extrude chylomicrons, then enter lacteals and enter circulation via lymph.

Front 130

How are glycerol and short chain fatty acids absorbed?

Back 130

They enter capillary blood in the villi and travel via the hepatic portal vein using bile salts and pancreatic lipase.

Front 131

How are nucleic acids digested?

Back 131

Membrane-bound enzymes in epithelial cells of the ileum break the nucleotides into their constituent components and absorb them. Pancreatic ribonuclease and deoxyribonuclease breaks them down and they travel to the liver via the hepatic portal vein.