Clin Med - GI Intro 2

drraythe's version from 2016-03-14 20:25


Question Answer
**What are the 3 substances which turn ON the acid receptor in the stomach?Gastrin
Which cells secrete HCl?Parietal cells
What cells secrete pepsinogen?Chief cells
Which cells secrete bicarb in the stomach?Mucus cells
What are the 2 phases of secretion in the stomach? What triggers each phase to begin?(1) Cephalic (triggered by the PNS, w/ ACh)
(2) Gastric (triggered by gastrin, a hormone secreted by G cells in the pyloric antrum of the stomach, duodenum & the pancreas)
The vomiting center in the brain can be triggered/stimulated by many different things, but what are the actual neurotransmitters which make it work?Dopamine
What does the chemoreceptive trigger zone usually respond to & how is it able to do this?Usually responds to toxins & drugs. It is able to respond to them bc it has LIMTED protection by the BBB so it's more sensitive to things in the blood
Direct stimulation to vomiting center can come from what sources? (5)CRTZ (chemoreceptive trigger zone)
The higher CNS
Vestibular center
GI tract
Abdominal organs/Peritoneum (if they are irritated they can trigger vomiting)
Explain the physiology of vomiting, starting w/ what the vomiting center tells the GI to do 1stGI motility is 1st inhibited
Initiate retrograde contraction in SI & antral relaxation (portion of the pylorus opening into the body of the stomach)
Shortening of intra-abdominal esophagus
Dilation of cardia & LES (lower esophageal sphincter)
Rhythmic inspiratory movements w/ closed glottis (so you don't aspirate)
Abdominal contractions
↑ intra-abdominal & intrathoracic pressures
Forceful expulsion
What’s a parasitic worm that can make you puke till you die?Physaloptera
What are a few initial thoughts of what might be the matter if there is Hematemesis?Ulceration
If an animal is vomiting a lot, why might you look under the tongue?Linear foreign bodies can get caught under there, esp. for cats
What are the 2 types of poop blood?Melena (black, upper GI)
Hematochezia (lower, fresh red blood)
When you vomit, what GI contents are you losing?Gastric & duodenal contents!!!
***Does vomiting cz you to have a metabolic alkalosis or acidosis?***ACIDOSIS***!!! This is bc altho you lose some stomach acid, you ALSO lose a lot of BILE, which is very basic-you lose more base (bile) so then you are overly acidic (acidotic)
***When does vomiting cz a metabolic alkalosis? What KIND of alkalosis?The ONLY TIME this happens is when there is a ↑ GI obstruction. Then the Bile can't come out bc something is blocking it, so you just lose stomach acid. Bc of this, it's a hypochloremic metabolic alkalosis
**What's probably even more worrying than the acid-base changes in a case of profuse vomiting?MASSIVE WATER LOSS! You can get hypovolemic pretty quick.
(WHY does a ↑ GI block cz a HYPOCHLOREMIC alkalosis?)Cant get rid of bicarb bc blocked, keep losing acid, bicarb's negative charge keeps building up, so body dumps Cl-bc only other neg that isnt bicarb that the body can dump easily (to stay electrically neutral)
SELF-LIMITING VOMITING → what does the PTx look like in this situation? How frequent is the vomiting? What kinda database do you wanna collect?This is a stable healthy PTx which has only had a few episodes of vomiting. You will collect a minimum database.
What is inclded in the minimum database when assessing a vomiting case?PCV/TS/ Fecal Float & smear
Therapeutic de-worming
Parvovirus ELISA if puppy
FeLV/FIV if a cat
After collecting a minimum database for a vomiting case, what will you want to DO/recommend? What DON'T you want to do?NPO (nothing per os) for a day
Monitor for worsening signs over next day (this May have to proceed to further diagnostics)
Usually DO NOT give anti-emetics (Hide important CS)
Why must you be careful/aware of using the term NPO?This means "NOTHING PER OS" so technically that would incld water... but you WANT them to have water 99.9% of the time, unless there is an obstruction
What is Dr C's soapbox on antiemetics? Which antiemetic does she HATE HATE?She DOESNT LIKE TO USE THEM! If you give them an antiemetic to suppress the clinical sign, how will you know if your therapy is working or if theyre getting better? (HIDES IMPORTANT CS). This is esp important if you DONT KNOW WHY they are vomiting. If you know why & you treat the problem & you know theyre gonna be ok, then you can give antiemetic. CORRIGAN HATES Sentrene!!!! It’s an anticholinergic which stops gut motility (leaves stuff in there to rot & toxify & gas pains)
****If you see a NON PRODUCTIVE vomiting, what condition are you worried about?GDV!!!
What are some CS associated w/ a SYSTEMIC illness?Pyrexia
Painful abdomen (masses? tympany?)
Oral ulceration
Nonproductive retching (GDV)
LIFE THREATENING VOMITING → how much vomiting? What is the PTx like? What tests do you start w/ & then what?This starts to be dangerous w/ CONTINUOUS VOMITING. This is a non-stable PTx. you will want to do a CBC/Chem/UA (rule in/out many non-gi czs) & then also a fecal flotation & smear. Let those results & your PE guide you to further dx
If you take an abdominal radiograph & you see a mass going from caudal to cranial, what might you think?PYOMETRIA → uterus goes from ca to cr
How might a pyometria & vomiting be related?Pyometria is full of infxn & lots of neutrophils, releasing inflammatory cytokines that can make you super sick
3 major signs that indicate the vomiting is super life threateningUnproductive vomiting, distended abdomen, shock/collapse
Gastric Dilatation & Volvulus → what is going on that is a danger & who is predisposed?There is air trapped, vessels obstructed, progressively gets worse. GIANT breed dogs are predisposed (& bassets... bc theyre big dogs w/ small legs)
Explain optimization (use GDV as an example)A GDV is an emergency so you must take them to Sx. You can't do Sx if theyre unstable, but at the same time, there's no way theyre gonna be STABLE bc they are in an emergency GDV. So what you do is "optimization" which is getting them as stable as possible before Sx
What quick test can you do pre & post stabilization to see how theyre doing?Lactate levels
How would you describe a GDV radiograph?"Smurg hat" or "Popeye arm"
What skin mass might you associate w/ vomiting?MAST CELL TUMOR → has lots of histamine → can trigger vomiting center
BIG LIST of 1° gastrointestinal czs of vomitingDietary indiscretion/Diet change
Motility disorders
Food allergy
Inflammation/ IBD
Intussusception/Hiatal hernia/GDV
Infxn (bacterial, viral, Rickettsial, Fungal/fungal-like)
Foreign body/Outflow obstruction/Hairballs/Obstipation
BIG LIST of non-GI czs of vomitingNeoplasia i.e. MCT
Renal Dz/failure
Hepatobiliary dz
Acid/Base disorders
DKA (Diabetic Ketoacidosis)
What drugs could cz vomiting?NSAIDS
What CNS stuff could cz vomiting?CNS dz/vestibular/abdominal epilepsy
If the dog is vomiting a lot, why might you want to do THORACIC radiographs?Bc if chest full of mets (metastasized) why bother keep going
If there is a CAT that is vomiting a lot, what might this be the 1st clinical sign of?HEARTWORMS (for dogs it'd be coughing, but cats are weird)
What are 3 things she mentioned you'd test for in a GI panel?PLI (pancreatic lipase immunoreactivity)
What 2 toxins did she mention youd really wanna test for w/ vomiting?Lead & Zinc
When should you NOT use barium?If there is a perforation → it will severely irritate the peritoneum
What does an endoscopy allow you to do? What SHOULD YOU ALWAYS DO if you are doing endoscopy?You can VISUALIZE THE MUSCOSA! & also you can & SHOULD TAKE BIOPSIES while youre in there!!!
What are the 2 reasons you can do an Exploratory Laparotomy? What should you do if you're doing this?Can be diagnostic or therapeutic - TAKE BIOPSIES WHILE YOURE IN THERE
If there is a dog w/ chronic vomiting, what is the 1st thing you want to do?Bloodwork & imaging FIRST!!! You can also do Therapeutic de-worming as long as theyre a stable non-life threatening vomit PTx
Chronic vomiter → after doing blood work/imaging/deworming & the PTx is stable, what might you want to try?Therapeutic trials if stable! You can do a dietary change, such as a hypoallergenic food, reduced allergen/ novel protein source food
Chronic vomiter → if bloodwork, imaging, deworming & therapeutic trials (diet changes) aren't fruitful, what can you try next?Proceed to further diagnostics, like endoscopy & Sx

Exocrine Pancreas

Question Answer
What are zymogens? How do these work?The pancreas makes zymogens, which are pro-enzymes. They are secreted into the intestines, where they are cleaved from inactive to active forms by enterokinases
What are some protective mechanisms that keep the pancreas from eating itself & the stuff around it? (3)(1) Physical separation of zymogens w/in acinar cells
(2) Distance btwn the site of enterokinaserelease & zymogens
(3) Presence of enzyme inhibitors w/in the pancreas & w/in the circulation
What are the digestive enzymes the pancreas makes called (general term) what other super important thing does the pancreas make?ZYMOGENS (pro-enzymes)....also makes BICARBONATE to neutralize the gastric acid which just was dumped into the duodenum
The pancreas also makes bicarbonate. What are some things bicarb facilitates? What are some things bicarb inhibits?Facilitates:
Nutrient absorption
Mucosal cell turnover
Enzyme activation
Inhibits: Autodigestion via enzyme inhibitors
Bacterial proliferation
What kinda dz is pancreatitis? What is happening in it (describe).It is an inflammatory dz which can range from mild to SEVERE! There is Activation of digestive enzymes w/in pancreas, which is Maintained & exacerbated by inflammatory cytokines & free radical production. You will see Vasculitis & edema, as well as multisystem involvement (even just by how close it is to other stuff)
What is the most TYPICAL PTx (PTx characteristics) & what is the most typical situation which can trigger it in these PTxs?MIDDLE AGED, FEMALES & YORKIES, ESP if they are OBESE!! The main trigger is a Hx of a ↑ fat meal or garbage invasion!! ("Holiday dz")
If a dog gets into the garbage & starts vomiting, what will you think?Pancreatitis! bc even if it isnt pancreatitis, the worst thing it could be is pancreatitis, so just think that 1st
What are the main CS you MIGHT see (DOGS) (it could be all, some or none that show if there is pancreatitis)Depression, anorexia
**Vomiting (like almost intractable vomiting)
*Abdominal pain
"Prayer positioning"
What are CS for pancreatitis like in cats & what are they?In cats the signs are generally LESS specific
The major 1 is Triaditis which is Pancreatitis, Cholangiohepatitis, IBD all at once (Inflamed pancreas, liver & duodenum)
Additionally, in cats you might see Hepatic Lipidosis, Diabetes mellitus, Thromboembolism & Toxoplasmosis
What is the pose which might indicate a dog has pancreatitis?Prayer position
Bloodwork → how does acute pancreatitis affect blood sugar? How does it affect blood Calcium?It can present w/ hyper OR hypoglycemia! There will also be hypocalcemia.
How does the blood look like (like in the tube) when the animal has acute pancreatitis? & why is this?It looks like a "strawberry milk shake" bc acute pancreatitis will cz hypercholesteremia, hypertriglyceridemia & hyperlipidemia.
What kind of enzymes will be elevated in acute pancreatitis? Explain why & what other related problems you might seeThere will be elevated liver enzymes, especially ALP. This is bc acute pancreatitis can cz chloangioheptatitis, which is why there might ALSO be bile duct obstruction, bilirubinemia & possibly icterus
Can an acute pancreatitis PTx have azotemia?Yes! Can have renal OR prerenal azotemia.
What should you know about amylase & lipase level in acute pancreatitis PTx?These are not sensitive OR specific for pancreatitis-they aren't really good measures at all
What will a CBC look like for an animal w/ acute pancreatitis?There will be hemoconcentration, anemia, thrombocytopenia & Neutrophilia w/ left shift
What will a USG look like for an animal w/ acute pancreatitis?Bilirubinuria
Concentrated USG
What is a DPL & how does it relate to pancreatitis?DPL = Diagnostic peritoneal lavage! This where you inject some fluid into the peritoneum, then pull it out again & you can look at the cells (do cytology) in the peritoneum to try to diagnose pancreatitis
***********What is the TEST OF CHOICE FOR PANCREATITIS (for dx & checking success of Tx)PANCREATIC LIPASE IMMUNOREACTIVITY test!!
What are 2 advanced tests you can use to test for pancreatitis & which is the better/more preferred one?There is TLI (Trypsin-like immunoreactivity) & PLI (pancreatic lipase immunoreactivity). PLI is the preferred choice
How is TLI a useful test for pancreatitis?This test May elevate prior to amylase & lipase
Explain the PLI test a little bit-how sensitive/specific? What forms does the test come in?There are species differences btwn dogs & cats, but BOTH are good-in Dogs it is 82% sensitive. In cats it is 100% sensitive & specific! This test is also available as a snap test!!!
How would a radiograph look if there was an acute pancreatitis?There would be a loss of cranial abdominal detail - The "ground glass" appearance
What are the characteristics of pancreatitis on an ultrasound?↓ peristalsis
Mixed pancreatic echogenicity
Peripancreatic hyperechogenicity
Cranial abdominal mass
Free abdominal fluid

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