Digestive

Question 1

Where is NaHCO3 made?

Answer 1

Pancreas, Small intestines, liver

Question 2

What substance neutralizes chyme as it enters the duodenum?

Answer 2

NaHCO3 (Sodium bicarbonate)

Question 3

Increase of digestive processes is typically signaled by what division of the autonomic nervous system?

Answer 3

Parasympathetic

Question 4

Long digestive reflexes are made by what nervous system?

Answer 4

Central

Question 5

Short digestive reflexes are mediated by what branch of the nervous system?

Answer 5

Enteric

Question 6

What are the effects of gastrin?

Answer 6

Increases stomach contractility and increases HCl secretion

Question 7

What hormone decreases stomach contractility?

Answer 7

CCK

Question 8

What vagal neurotransmitter increases H+ secretion?

Answer 8

Acetylcholine

Question 9

What paracrine signal molecule causes HCl secretion?

Answer 9

Histamine

Question 10

What two things convert pepsinogen to its active form?

Answer 10

HCl
An active pepsin initiating autocatalyzing

Question 11

What organ secretes most of the hydrolytic digestive enzymes?

Answer 11

Pancreas

Question 12

What are the breakdown products of fat before absorption?

Answer 12

Glycerol (monoglyceride), fatty acid

Question 13

What salivary enzyme breaks down starch and glycogen?

Answer 13

Salivary amylase

Question 14

What is the name of the gastric protease and what is its optimal pH range?

Answer 14

1.5-2.5

Question 15

What is the luminal membrane transport mechanism of glucose in the small intestine?

Answer 15

Secondary active transport

Question 16

What sets up glucose absorption?

Answer 16

A sodium concentration gradient

Question 17

What transport mechanism is typically used for monosaccharides at the basolateral membrane?

Answer 17

Facilitated diffusion

Question 18

What are the enzymes used to complete the very last steps of catabolism of carbohydrates and peptides during absorption?

Answer 18

Brush border enzymes

Question 19

What are the cholesterol-based molecules that increase lipid surface area and water solubility for further digestion?

What is this process called?

Answer 19

Bile Salts

Emulsification

Question 20

What are the structures that transport fat breakdown products on the luminal side of absorptive cells

Answer 20

Micelles

Question 21

What is the packing structure of peptides and fats combined that transport those breakdown products across the basolateral membrane?

Answer 21

Chlyomicrons

Question 22

What part of the lymphatic system is responsible for the absorption of fat and protein byproducts?

Answer 22

Lacteals

Question 23

What are the pancreatic proteases and how are they activated?

Answer 23

Trypsin, Chynotrylsin, Procarboxylpeptidase

They are activated by enterochase cleaving their activation peptides

Question 24

What are two advantages humans receive from their microbiome?

Answer 24

Digestive support, with the breakdown of cellulose

Immune support

Question 25

Besides diverting blood away from the digestive system how does stress negatively affect digestion?

Answer 25

Limits motility and rate of HCl production Cortisol causes breakdown of food already stored in the body

Question 26

What are the layers if the alimentary canal from deep to superficial?

Answer 26

Mucosa (lines the lumen) Submocasa (areolar CT) Muscularia externa Serosa

Question 27

What GI activities take place in the oral cavity?

Answer 27

Ingestion, Propulsion, Mechanical Digestion, Chemical Digestion

Question 28

What GI activities take place in the esophagus?

Answer 28

Propulsion

Question 29

What GI activities take place in the stomach?

Answer 29

Propulsion, Mechanical Digestion, Chemical Digestion

Question 30

What GI activities take place in the small intestine?

Answer 30

Absorption, Propulsion, Mechanical Digestion, Chemical Digestion

Question 31

What GI activities take place in the lathe intestine?

Answer 31

Absorption, Defecation

Question 32

What is the main form of movement in the small intestine?

Answer 32

Segmentation

Question 33

What are the methods for regulation of the digestive tract activity?

Answer 33

Autonomous smooth muscle control Mechanical and chemical stimuli (stretch receptors, osmolarity, presence or absence of substrate) GI hormones Extrinsic nerve control (CNS) Intrinsic nerve control locally (ENS)

Question 34

True or False: Visceral smooth muscle is autonomous and has its own pacemaker cellsz

Answer 34

True

Question 35

How does one describe smooth muscle action potentials?

Answer 35

Slow Wave Potential

Question 36

True or False: The force and duration of muscle contraction are directly related to the amplitude and frequency of action potentials

Answer 36

True

Question 37

What are the long reflexes of the GI Tract?

Answer 37

Involve integration with CNS: Alter muscle/gland activity Alter levels of hormone secretion Modify intrinsic activity Coordinate different parts of the GI (ie chewing food increases gastric secretions)

Question 38

What are the short reflexes of the GI Tract?

Answer 38

Involves the enteric nervous system: Within the GI Tract Coordinates local activity but can involves the extrinsic nerve because they are linked

Question 39

What does the myenteric plexus control?

Answer 39

Motility of the stomach

Question 40

What does the submucosal plexus control?

Answer 40

Gastral secretions?

Question 41

What is a paracrine signal?

Answer 41

Affects neighboring cells instead of entering the bloodstream

Question 42

What is a gastrointestinal peptide?

Answer 42

Digestive hormones that excite or inhibit motility or secretions and act on the brain to trigger hunger or satiety

Question 43

What is the term for chewed food mixed with saliva?

Answer 43

Bolus

Question 44

What is saliva made of?

Answer 44

97-99% water Digestive enzymes; salivary amylase and salivary lipse Mucus Lysozyme and IgA (antibacterials)

Question 45

What three glands secrete salvia?

Answer 45

Parotid Sublingual Submandibular

Question 46

What is the difference between the simple and acquired salivary reflex?

Answer 46

Simple: Ingested food triggers barioreceptors and chemoreceptors, triggers salivary center of medulla Acquired: Thought of food triggers cerebral cortex, triggers same

Question 47

What is the difference between nervous centers for control of saliva

Answer 47

PSNS - larger volume, watery, enzyme rich SYMP - smaller volume, more mucus

Question 48

What structures are involves in swallowing?

Answer 48

Tongue, Soft Palate, Pharynx, Esophagus

Question 49

What is the difference between the two deglutition (swallowing) reflexes?

Answer 49

Buccal phase - voluntary Pharyngeal-esophageal - Involuntary

Question 50

How does food enter the stomach?

Answer 50

Through the gastroesophageal sphincter

Question 51

What is food called after it is mixed with gastric juices in the stomach?

Answer 51

Chyme

Question 52

Besides pepsin, what hormone does the stomach produce and what is its purpose?

Answer 52

Intrinsic factor; the absorption of vitamin B12

Question 53

What are the 4 phases of gastric motility?

Answer 53

Gastric Filling Storage Mixing Emptying

Question 54

True or False. The most peristaltic contractions happen during gastric storage.

Answer 54

False. Little mixing occurs here

Question 55

What causes gastric mixing?

Answer 55

Chyme is propelled by the muscular antrum against the closed pyloric sphincter

Question 56

What are the exocrine stomach secretions?

Answer 56

Mucus - to protect walls from acid HCl - from parietal cells Intrinsic factor - from parietal cells Pepsinogen and gastric lipase - from Chief cells, becomes pepsin in stomach

Question 57

What hormones inhibit and stimulate gastric acid secretion, respecitively

Answer 57

Somatostatin and Gastrin

Question 58

What are the breakdown components of proteins?

Answer 58

Peptides then amino acids

Question 59

What are the stimulations of the 3 phases of gastric juice secretion?

Answer 59

Cephalic (thought if food, stimulation of taste receptors - vagal nerve) Gastric (stomach distention activates stretch receptors, rising pH and caffeine activate chemoreceptors and G cells) Intestinal (presence of low pH stimulates gastrin release)

Question 60

What are the inhibitory impulses of the Gastric Phases?

Answer 60

Cephalic (depression causes cerebral cortex to block stimulation) Gastric (excessive acidity, emotional upset causes SNS to override PSNS) Intestinal (distention of duodenum, irritants in chyme stimulate entero-gastric reflex)

Question 61

Which controls the rate of stomach emptying: the stomach or the duodenum?

Answer 61

Both

Question 62

How long does it take the stomach to empty?

Answer 62

4 hoursish

Question 63

What are the gastric factors that increase gastric emptying?

Answer 63

The amount of chyme in the stomach (empties at proportional rate) Fluidity if chyme Signaling from vagus nerve Gastrin

Question 64

What are the dudoenal factors that decrease gastric emptying?

Answer 64

Fatty chyme High acidity (chyme has to be complete neutralized) Hypertonicity Distention

Question 65

What are the hormonal mechanisms that inhibit gastric motility?

Answer 65

Chloecystokinin (CCK) and secretin

Question 66

What is the name of the reflex that closes the pyloric sphincter as the duodenum fills?

Answer 66

Enterogastric Reflex

Question 67

Activities of the digestive system are stimulated by what?

Answer 67

Intrinsic nerve plexi hormones parasymp. impulses symp. impulses the contents of the GI tract

Question 68

Salivary glands contain enzymes for the breakdown of what substance?

Answer 68

Polysaccharides

Question 69

Is lactase secretes by the pancreas?

Answer 69

No

Question 70

What does the gastroileal reflex do?

Answer 70

Moves chyme into the colon

Question 71

What does CCK do?

Answer 71

Causes the gallbladder to contract, releasing stored bile

Question 72

What does secretin cause?

Answer 72

Pancreas to release fluid rich in bicarbonate