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FSU - Anatomy > Exam 4 - Digestive System > Flashcards

Exam 4 - Digestive System Flashcards

1
Q

What are the organs that make up the gastrointestinal tract

A

Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum anus

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2
Q

What are the accessory organs of the digestive tract

A

pancreas, liver, gallbladder, salivary glands

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3
Q

What is another name for the digestive system

A

The alimentary system

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4
Q

What is each area of the digestive tract specialized for

A

Mouth/pharynx: digestion (mechanical and chemical), mastication, lubrication, and propulsion
Esophagus: conduit
Stomach: storage, digestion (churning, proteases, stomach acid)
Small intestine: Digestion and absorption
Large intestine: water and electrolyte balance

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5
Q

List and state the function of the sphincters in the body

A

Upper esophageal: swallowing
Lower esophageal: prevent gastric reflux into esophagus
Pyloric sphincter: partial regulation of gastric emptying, prevents duodenal-gastric reflux
ileocecal sphincter: separates large and small intestine
internal and external anal sphincters: control defication

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6
Q

Functions of accessory organs in relation to digestion

A

Liver: makes bile
Gallbladder: stores bile
Salivary glands: secretes mucous and amylase and saliva
Pancreas: secretes enzymes for digestion into lumen of small intestine

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7
Q

List and state function of cells of the mucousa

A

Surface cells: on villi of crypts of lieberkuhn, increase SA, minor digestive function
Goblet cells: secrete mucous
Stem/progeneter cells: at bottom, differentiate
Enteric endocrine cells: deepest part of crypt, secrete hormones into blood and secrete mucous
Undifferentiated cells: at bottom, turn into any cells

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8
Q

What must occur before food can be assimilated

A

Food must be digested into component molecules and absorbed into the blood/lymph

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9
Q

Carbohydrates: ingestion, digestion, and absorption

A

Ingested: 1/2 daily caloric intake as sugar or disaccharides

Digested:
mouth - amylase
small intestine - 
amylose (1,4): maltose and maltotriose
amylopectin (1,6): alpha limited dextrins
Villi -
lactase: glucose and galactose
Glucoamylase (1,4 gluc bonds)
sucrase-isomaltase
sucrase (1,4)
isomalt (1,4 and 1,6)

Absorption:
lactose: Na+/gluco co-transporter
Fructose: GLUT5
GLUT2: basolat for gluc and galact

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10
Q

Proteins Ingestion, Digestion, and Absorption

A

Ingestion: 1/6 daily caloric intake as protein/large peptides

Digestion: 
stomach - pepsin
small intestine 
trypsin and chymotripsin: oligosacch
minimal carboxypeptidase: individual aa
brush border: multiple peptidase to make individual aa
Absorption: 
apical (2nd active)
aa: Na/aa co-trans
di/tri: H+/peptide co-trans
In cell all made aa
Basolat (passive): aa channel down []
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11
Q

Lipids Ingestion, Digestion and Absorption

A

Ingestion: triglycerides
Digestion: small intestine only (no brush border)
lipase: breaks down on surface only
colipase: holds lipase to fat droplets until free fatty a and monoglyc
emulsification: churning and bile salts break down giant fat droplets into smaller so lipase works better

Absorption:
some: micelles in lumen
all eventually: passive diffusion thru membrane into cell and returned into triglyc

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12
Q

Absorptive process of Lipids

A
  1. Micelle to enterocyte
  2. reform triglyceride
  3. cholomicron
  4. exocytosed basolateral
  5. lacteals
  6. lymph vessels
  7. thoracic duct
  8. subclavian vein
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13
Q

Functions of the GI tract

A

Digestion
Excretion into the feces (via bile)
Water and electrolyte balance (no control)
Defense
Immunological - lymph nodes, mast cells, macrophages
Non-immunological: gastric acid, mucin, peristalsis

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14
Q

What is the source of fluid in the small intestine

A

Secretion by stomach and small intestine

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15
Q

Why is the immune system important to the GI tracct

A

it is all open to the external world which is a very large SA

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16
Q

Digestive Control and examples

A

Coordination of multiple secretory, enzymatic, and motor process (ex. acid in the stomach w/motor activity at the SAME TIME)
Neuronal, hormonal, and paracrine agents (thought of food, one hormone stim other)
Endocrine, neural and paracrine (ENS)

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17
Q

Where is the ENS located and what kinds of neurons does it have

A

The submucosal plexis is between the submucosa and mucosal layers
The myenteric plexis is between the outer longitudinal and next layer in
It is sensory, motor and interneurons

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18
Q

What are the functions of the Enteric Nervous System

A

controls vasoconstriction, secretion of secretory cells, and the mechano and chemoreceptors of the mucosa

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19
Q

Describe the brain-gut axis including descriptions of the innervations of the GI tract by the parasympathetic and sympathetic nervous systems

A

The brain gut axis is two way communication between the GI tract and the brain.
Parasymp is mainly responsible
Vagus nerve to majority acting as th epostgang of parasymp so releases ACh on M2 and M3 receptors
Pelvic Nerve to descending colon and beyond

Symp - no evidence

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20
Q

Describe the types of GI motor activity

A

Churning - mixing
Peristalsis - movement/propulsion forward
Reservior action - prevents anything from entering the small intestine while maintaining low P

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21
Q

Describe how sphincters regulate flow and their interactions with surrounding smooth muscle

A

Proximal stimulation = relaxation

Distal stimulation = contraction

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22
Q

Describe the stages of deglutition

A

Voluntary phase - tongue bushes the bolus towards oropharynx
Pharyngeal phase - soft palate closes off nasopharyns, pharyns and larynx are elevated
succesibe constriction of pharyngeal constrictors: pushes bolus through pharynx to esophagus and pushes epiglottis over larynx
Inferior pharyngeal constrictor contracts and upper esophageal relaxes - bolus enters
Esophageal phase - bolus moved by peristalsis; lower espoh sphincter opens when puper closes

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23
Q

Identify the functional separation for the stomach and duodenum

A

Allows for neutralization of stomach acid and proper functioning of the small intestine

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24
Q

Describe the actions of the internal and external anal sphincters when defecation is desired

A

P in rectum over time-
When fecal enters, increase P due to increase V
triggers reflex to cause rectal relaxation and increased cl (active contraction of rectal smooth, relax of smooth internal anal sphincter)
Skeletal muscles of external anal sphincter contracts due to proximal P on sphincter - involuntary reflex different than other sphincters

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25
Q

Describe the actions of the internal and external anal sphincters when defecation is not desired

A

P in rectum over time-
When fecal enters, increase P due to increase V
triggers reflex to cause rectal relaxation and increased cl (active contraction of rectal smooth, relax of smooth internal anal sphincter)
To defecate, must be voluntary conscious relaxation of external sphincter

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26
Q

Identify the steps necessary for defecation

A

1) relax of external anal sphincter
2) flexion of the hips
3) contraction of abdominal muscles
4) relaxation of the pelvic floor

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27
Q

List the main three functions of the stomach

A

Secretory
Motor
Hormonal

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28
Q

List the secretory products of the stomach (6)

A

Acid, mucous, pepsinogen, bicarbonate, water, intrinsic factor

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29
Q

List the 2 main hormones producted by the stomach

A

gastrin and somatostatin

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30
Q

What are the motor functions and stages of the stomach

A

Functions: secretory, motor, hormonal

1) receiving and providing temporary storage of dietary foods and liquids
2) mixing of food and water with gastric secretory products
3) grinding food so that it is smaller
4) regulating exit of retained material from the stomach into the duodenum

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31
Q

Histology of the stomach (cells)

A

Surface and neck mucus cells
Gastric pit - increase SA of stomach
Gastric Glands - chief cells (pepsinogen secretion), parietal cells (secrete HCl and Intrinsic factor), and enteroendocrine cells ( secrete things into blood)

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32
Q

Steps of acid secretion by parietal cells

A

Use CO2 to make H+
CA to make carbonic acid
then bicarb and H+ ions
Shift where Cl- enters cell w/H+

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33
Q

List the purposes for gastric acid

A

Kill pathogens, denature proteins, activate pepsinogen

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34
Q

Describe how acid secretion is regulated including the chemical messengers involved, the source of the secretogues, their pathways of activation, their mechanisms of action, and the stimuli for release of the secretogues

A

Direct control:

1) stimulated by ACh from para
1a) feed-forward to secrete before enters thru Vagus Nerve releasing ACh on M3 (Gq) of parietal cells and ECL
1b) negative feedbacck once in stomach - gastric distention activates vagus to brain and back
2) Gastrin from antrum G cells onto CCKB receptor on body of stomach
2a) stim by vagus nerve stim enteric nervous system releasing GRP
2b) stim by aa/peptide products on apical side to release gastrin and more acid
3) histamine from body endocrine cells (H2 receptor of parietal cell)

Indirect: ACh or Gastrin caused histamine release

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35
Q

Describe the inhibitors of acid secretion including their location of production, their pathways and mechanism for inhibition, and the stimuli for and/or inhibitors of their release (as much as stated in the lecture notes)

A

Somatostatin secreted from D cells by luminal acid or gastrin which then inhibits acid secretion by…

1) Parietal cell Gi receptor to decrease phosphorylation
2) Antagonizes intracellular effects of histamine
3) Indirectly inhibits gastrin and histamine secretion
- -Inhibited by ACh from ENS or Vagus

Prostaglandin inhibits acid secretion by….

1) acts on Gi receptors of parietal cell to directly reduce secretion
2) Indirectly reduce gastrin and histamine secretion

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36
Q

Describe acid secretion during the basal state and during the 3 phases in response to a meal (include all the steps found in each phase and rough percent of total acid secretion thatoccurs in each phase)

A

Basal state: interdigestive - highest at night (pH 3) and lowest in morning (pH 7)

Cephalic: first response to meal, 30% total secretion - feed-forward
activates Vagus nerve to release ACh to stomach

Gastric: second response 50-60% total secretion - distention stom activates local reflexes and the vago-vagal to release ACh on G, ECL, and parietal cells and GRP on G cells. Also digestion of protein

Intestinal- minor phase, 5-10% secretion- protein digestive products stim parietal to release gastric acid

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37
Q

Describe pepsinogens/pepsins where each are made, the stimuli for production of each and the mechanisms of action for the secretogue ,
including their function,

A

Released by chief cells when stimulated by ACh during the cephalic phase and by the vago-vagal reflex due to stom distention and ACh onto cells to release pepsinogen

Pepsinogen will become pepsin only if pH <5 & only active <3.5. Even more active <3

Function: cleaves proteins in middle and not at ends

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38
Q

Role of stomach in carbo and fat digestion

A

None

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39
Q

Describe the components, functions and mechanisms of the gastric diffusion barrier

A

Concentration gradient of H+ so that higher in lumen than cell and interstitial. pH mucous close to 7

All parts: apical mem cells impermeable to H+ and apical w/very tight junctions

All minus gastric glands:
[HCO3-] increase in mucous to protect surface of cells
Mucous gell layer = layer b/t lumen and cells
released by…
1) ACH by enteric mucous cells to secrete
2) Phys or Chem (acid, pepsins, and ethanol) irritation
3) Prostaglandins - cell irritated, releases prost, trigger mucous secretion

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40
Q

Describe the protection against acid mechanisms in the duodenum (2)

A

S cells sensitive to acid, secrete secretin to act in pancrease to stim release of bicarb.

Brunner’s glands of submucosa secrete bicarb if cells irritated

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41
Q

Describe the glands of pancreas and salivary glands

A

Exocrine pancreas: acinar cells that secrete into lumen of acinus to flow thru ducts
Salivary glands have same organization but w/alveolar cells, not acinar cells

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42
Q

Define acinus

A

Acinus: “grape-like”, the smallest secreting portion of a gland

43
Q

Describe acinar cells

A

specialized for the prod of protein and secretion into lumen

44
Q

Identify the form and function of duct cells

A

Duct cells are for secretion of fluid and transport of electrocytes

45
Q

Identify the product and location of goblet cells

A

Goblet cells (pancreas) localized towards distal/secreting end of the ducts; also for secretion of fluid and transport of electrolytes

46
Q

Identify the product of pancreatic acinar cells and the detailed mechanism/pathways for their release

A

Secrete digestive enzymes into lumen of small intestine

Makes proteins necessary for digestion, packages it up in vesicles, and releases it because of CCK to act on CCKA (Gq) or bc of ACh on M3 (Gq) - increass phosphorylation by PKC to cause vesicles to fuse w/membrane and secrete enzymes into lumen

non-primary: VIP and secretin (Gs) = weak stim of zymogens thru PKA

47
Q

Describe the mechanisms and stimuli for pancreatic and salivary cells to secrete fluid (and NaCl)

A

Stimuli for secretion is ACh and CCK to acinar cells to release a Na/Cl- rich soln.

1) Na/Cl/K co-trans basolat
2) increased intra Cl- drives it apical plus Na+

Primary duct cell bicarb is secretin and it a HCO3-/Cl- exchange

48
Q

Describe the pathways, inhibitors, and stimuli for pancreatic duct cell bicarbonate secretion

A

Most powerful secretion by secretin (Gs) to increase cyc AMP
Also secreted by ACh on M3 (Gq) to PKC to phos CFTR
Inhibited by Substance P

1) Secrete into lumen thru Cl-/bicarb exchanger
2) Lumen more - to drive Na+ thru tight junc, Na+/bicarb in lumen to increase Osm to drive in water,Next, take blood bicarb into cell, CA to make own bicarb, H+ transported by H+ pump and Na/H exchanger

49
Q

Identify where most of the pancreatic fluid is produced (acini or ducts)

A

75% produced in the ducts

50
Q

Identify the purpose of pancreatic bicarbonate production

A

Mainly to neutralize gastric acid, also help solubilize lipids

51
Q

Identify the organ with the highest rate of protein synthesis and secretion

A

Pancreas 1.5 L/day fluid secretion

52
Q

Identify what determines the level of pancreatic secretion

A

A balance between the factors that inhibit and stimulate secretion

53
Q

Identify what types of proteins are secreted by the pancreas

A

More than 20 kinds of proteins secreted - most zymogens, others active

Protesases to digest proteins
Nucleases - to break down RNA and DNA
Amylase: break down carbohydrates
Lipase: fat breakdown

54
Q

Describe pancreatic release of digestive enzymes in the basal state and during the three phases following a meal (include the stimuli and mechanisms employed during each phase and the approximate amount of enzyme released during each phase

A

Cyclic release of enzymes at a low level and then w/trigger there is redundant reg

Cephalic (sight, taste and smell) - feed-forward system, 25% total enzyme release
Vagus Nerve to ENS to cause ACh on M3 of acinar and duct cells

Gastric phase (food in stom) - feed-forward, 10-20% total release
ACh (Main reg via vago-vagal reflex) and Gastrin (weak affin to CCKA receptor)

Intestinal - negative feedback, 50-80% total release;
Gastric acid stim duodenal S cells to release secretin - stim HCO3 and fluid secretion from pancreatic duct cells
Lipids and peptones stim duodenal I cells to release cholecystokinin which stim acinar cells to release digestive enzymes

55
Q

Identify the purpose for redundancy in pancreatic secretion

A

It is a fail safe - digestion is very important so there are a variety of methods to ensure it can be done

56
Q

State the approximate amount of the pancreas that can be removed before maldigestion occurs

A

80-90% can be removed

57
Q

Identify all the functions for saliva that we discussed and be able to explain the function

A

Primary purpose: prevent dehydration of the oral mucosa and provide digestion for mastication and swallowing of ingested food

Also: oral hygine (lysozomes and IGA to kill bacteria and virus), taste, and initiation of carbohydrate digestion

58
Q

Describe the secretory products of each of the different primary salivary glands

A

Parotid salivary gland: serous, mostly ions and water with high amylase
Sublingual: mucinous, more mucous with less amylase
Submandibular: mixture

59
Q

Describe the role salivary duct cells play in the final saliva composition that enters the mouth

A

Salivary duct cells alter what was secreted by the acinar cells to create a hypotonic saliva rich in KHCO3 and low in NaCl

Acinar stim to secrete by ACh on M3 (Gq) to make an isotonic saline of Cl- and Na+ (too salty)
Duct cells absorb Na+ and Cl- and secrete K+ and HCO3-

60
Q

Identify when salivary secretion is lowest and how much it can be increased of basal rates

A

During sleep it is at its lowest of 0.5 ml/day but it can increase 10 fold

61
Q

Identify the main regulator of salivary secretion

A

The parasympathetic nervous system

62
Q

Identify the pathways for parasympathetic control of salivation including stimuli for activation, location of salivatory nuclei and nerves involved

A

Para activates:

1) projects thru glossopharyngeal to parotid gland
2) Facial to submandibular and sublingual

Symp activates:
1) adrenal gland and release of epine - mior effect

63
Q

Identify the effect of sympathetic activation on salivation

A

It causes salivation

64
Q

Identify how stress can induce a dry mouth

A

Draw mouth causes parasympathetic withdraw causing dry mouth

65
Q

Identify where most digestion occurs

A

Most digestion occurs in the small intestine

66
Q

Identify the purpose of digestion

A

To break things down to an absorbable size so we can get the proper nutrients

67
Q

Secretion and absorption of water

A

Interstitial epi cells are polar which is important for transporting accross the membrane

Secretion: 8.5L/day to small; absorbs 6.5 L/day and K+, Na+ and HCO3-

Colon gest 2L day, absorbs 1.9L and Na+ and Cl=

68
Q

Absorption of Sodium in different parts of intestinal tract

A

Na+ abs in small and large intestine coupled w/Cl- usually
Mainly absorbed by vili expi in small and surface epi colon

Na+ to blood - via Na/K pump on basolat of epi
Jejunum & some ileum: co-trans dependent on electrogenic process in vilus epi (Na/H exchanger - H+ in lumen abs Na+ so cell keep pH at optimum level)
Ileum and prox dependent on parallel abs of Cl- (Counter trans Na/H and Cl-/HCO3-; H and HCO3- to lumen)
Distal colon: ENaC channels

69
Q

Absorption of Cl- in diff parts of intestinal tracts

A 
Small and large intestine - linked to Na+ reabs
Voltage dependent Cl- absoprtion
Na+ electrogenic absorption = negative lumen = draw Cl- in
Distal colon (ENaC) and some in ileum w/co-trans
70
Q

Identify the sources of protein that is digested and absorbed in the GI tract

A

70-90g/day of protein from diet

Other sources: endogenous enzymes, mucus, and sloughed epithelial cells

71
Q

Identify the locations of macronutrient absorption and the relative importance of each location

A

Duodenum - most important
Jejunum - semi important
Ileum - only important to fats

72
Q

Describe the mechanism for absorption of fat soluble vitamins

A

Vit A, D, E & K absorbed same way as lipids
Embedded into fats we consume, liberated as fats in lumen, simple diffusion across apical mem.
In enterocyte, goes into chylomicron and trans to liver to store it or release it in the blood

73
Q

Describe the mechanism for absorption of water soluble vitamins

A

Most (B and C - not B12) facilitated diffusion or thru 2nd active trans (w/Na+) similar to ions, aa, and sugars

74
Q

Describe the mechanism for absorption of Vit b12

A

Large and charged molecule that cannot go thru a channel

1) Bound to intrinsic factor in stomach, travels to ileum
2) Enterocytes of ileum have receptors for intrinsic factor
3) Binds and is endocytosed by receptor mediated endocytos
4) B12 liberated, intrinsic factor digested (in enterocyte)
5) In blood, transcolablbin 2 bound to B12
7) taken up by cells that need to divide (B12 necessary for thymine repro)

75
Q

Describe the absorption of trace minerals and, in particular, iron

A

Iron - most needed; bound to heme from meat and easily absorbed into enterocyte

Ionized iron (ferric Fe3 and Ferrous Fe2)

1) Only co-trans w/H+ for Fe2, so Fe3 broken down
2) In cell, ferrus binds mobile ferrin
3a) stay
3b) some ionized iron passive trans across basolat and bind to transferrin to take Fe to cells that need it
4) equilibrium in free iron and bound
5) Once absorbed, no mechanisms to get rid of it

76
Q

What would happen with high iron (in blood) and transferrin mostly bound

A

the free iron in blood is higher than free iron in the cell, so iron would not leave

77
Q

Define hepatobiliary

A

Of the liver and gallbladder

78
Q

Describe the blood flow of the liver following the movement of blood from the heart to the liver and back to the heart by all pathways

A

Portal system w/hepatic sinusoid as the capillary of the liver

1) Heart –> aorta –> hepatic artery (O2 rich) –> hepatic sinusoid –> central vein –> hepatic vein –> vena cava –> heart
2) Heart –> aorta –> small intestines (O2 poor) –> hepatic portal veins –> hepatic sinusoid –> central vein –> hepatic vein –> vena cava –> heart

79
Q

Describe a portal acinus, what it is, how to outline one, the significance of them, and the zones

A

Functional division of the liver that is diamond in shape w/two axis - 1) b/t central veins, 2- b/t portal triads

Zone1: closest to portal triad (most O2)
Zone II: middle
Zone III: closest to central vein (least O2)

80
Q

Identify the cell types found in the liver and their location and function and which are the most numerous//Identify the location of hepatocytes specialized for different functions and identify what those general functions are for the different locations

A

Hepatocytes: most common
periportal hepato - zone I - oxidative metabolism
pericentral hepato - zone III - conjugation rxns and other detoxifying

Endothelial cells (line sinusoids, veins, and arteries)
Kupffer cells in sinusoids (mixed macrophages)
Stellate cells - b/t hepato and sinusoid (store Vitamin A)

81
Q

Identify the functions of bile and where it is produced

A

Bile is produced in the liver
primary funct: emulsify fats
other: assist in diluting and neutralizing gastric acid and excreting substances for excretion in the feces

82
Q

Describe the flow of bile from the liver to the duodenum, including the important ducts/canaliculi, where it is stored and how it gets to the storage site, how it gets from the storage site to the duodenum, where the bile enters the duodenum and what structure regulates the entry of bile into the duodenum

A

1) made in hepatocytes
2) secreted apical mem to bile canaliculi
3) interlobar bile ducts (ducts in portal triads)
4) Right and left hepatic ducts
5) common bile ducts
6a) cystic duct (branch to gallbladder)
6b) Sphincter of Odi - to duodenum if it is open ie if there is fat in the duct

83
Q

Describe the functions of the gallbladder

A

1) storage reservior (30-50ml/bile)

2) concentrative function ([] bile made by liver)

84
Q

Describe bile secretion including where the bile salts secreted by the liver come from, the proportion that escapes recycling, what the bile salts are made from, and whether the bile salts are recycled more than once during a meal

A

Most bile salts reabsorbed by Na+/coupled transporters & sent to liver via portal vein and absorbed by hepato
95% recycled and reused during digestion of one meal
Liver makes new bile by uptake of cholesterol and production of cholesterol

85
Q

Identify what gives bile, urine and feces their color and why feces is brown but urine is yellow

A

Bilirubin is a product of heme which is fairly non-polar so hard to get rid of in kidney
Liver makes it watersoluble and send it out thru bile
Makes urine yellow and in intestinal tract, cholanic bacteria break it down which is why feces is brown

86
Q
  1. Identify what is secreted by duct cells and describe how it is secreted (refer back to the pancreas file) and what the stimulus for secretion is (hormone and what stimulates that hormone) Describe the secretion of bile including what stimulates production in the hepatocyte, where it is stored, how it is concentrated, the stimulus for secretion (hormone and what stimulates that hormone), and how the hormone causes secretion
A

Duct cells secrete a bicarbonate rich fluid in response to secretin, which is stimulated by the acid in the duodenum

If no need - bile diverted to gallbladder where 90% H2O removed so it is concentrated by absorbing Na/Cl thru counter (h/Na and Cl/HCO3-), then CA convert CO2 and H2O of lumen by CA

If need - I cells of duocenum secrete cholecystokinin, increse plasma CCK, acts on CCKA receptors to cause gallbladder contraction, increase bile flow to common bile duct and increase flow into duodenum. CCK also on sphincter of Odi to cause relax and increase flow into duodenum

87
Q

Other functions of the liver

A

Biotransformations - metabloize compounds
Take sub across basolat mem of blood into cell to be chemically degraded
2 phases of transformation follow so it will be taken up
Phase 1: oxidize chem rxn using p-450 enzymes (drugs, bile acid synthesis, vitamin activation)
Phase 2: ROH and conjugates another molecule (large polar group)

88
Q

Which stimulates ventilation to blow off excess Co2?

a) increased H+ from volatile sources
b) increased H+ non-volatile sources
c) both
d) neither

A

c) both

89
Q

Vomiting causes loss of (H+ or HCO3-) while diarrhea causes loss of (H+ or HCO3-)

A

H+ vomit, HCO3- diarrhea

90
Q

Which of the following are true of bicarbonate? Choose three.

a. It is freely filtered.
b. It is bound to proteins.
c. It is reabsorbed.
d. It is not reabsorbed.
e. It can be secreted.
f. It cannot be secreted.

A

freely filtered, reabsorbed, can be secreted

91
Q

Water and CO2 come into tubular cells and are converted into bicarbonate and hydrogen ions. What is the fate of the bicarbonate and hydrogen ions?

A

Bicarb moved to blood, H+ secreted into the tubule

92
Q

If the blood is acidic, the kidneys will respond by (choose three):

a. reabsorbing less bicarbonate
b. reabsorbing more bicarbonate
c. breaking down glutamate
d. not breaking down glutamate
e. make new bicarbonate
f. not make new bicarbonate

A

reabsorbing more bicarbonate, breaking down glutamate, make new bicarb

93
Q

T or F Nueronal input is required for function of the ens

A

false

94
Q

The __symp/para_NS_ stimulates secretions and increases mobility in the GI tract

A

para

95
Q

___ acts in the brain to induce satiety

A

Cholecystokinin

96
Q 
Source of agents:
ACh
Histamine
Gastrin
Somatostatin
Secretin
Cholecystokinin (CCK)
A 
ENS: ACh 
ECL: Histamine
G: Gastrin
D: Somatostatin
S: Secretin
I: Cholecystokinin (CCK)
97
Q 
ID the G protein each agent is linked to:
ACh
Histamine
Gastrin
Somatostatin
Prostaglandins
Secretin
Cholecystokinin (CCK)
A 
ACh - Gq
Histamine - Gs
Gastrin - Gq
Somatostatin - Gi
Prostaglandins - Gi
Secretin - Gs
Cholecystokinin (CCK) - Gq
98
Q

Which of the following stimulate parietal cells to produce acid? Choose three.

a. Histamine
b. Gastrin
c. Somatostatin
d. Prostaglandins
e. Acetylcholine

A

Histamine, Gastrin and ACh

99
Q

Acetylcholine from the enteric nervous system is stimulatory to all of the following except:

a. Chief cells
b. Mucus cells
c. ECL cells
d. Parietal cells
e. Somatostatin
f. Acinar cells
g. Duct cells

A

Somatostatin

100
Q

Acidic conditions in the lumen of the small intestine _____________ the release of somatostatin and prostaglandins.

a. stimulate
b. inhibit

A

a - stimulate

101
Q

Which of the following does prostaglandin inhibit the secretion of? Circle all that apply.

a. acid
b. histamine
c. gastrin
d. mucus cells

A

acid, histamine, and gastrin

102
Q

What is the main secretagogue for duct cells?

A

secretin

103
Q

Gastrin has a/an (stim/inhib) effect on ECL and parietal cells

A

stimulatory

104
Q

Acidic chyme in the duodenum (stim/inhib) the release of secretin and CCK

A

stimulates

FSU - Anatomy (10 decks)

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