Gi system flashcards q/a

Flashcards about the the gastrointestinal system of animals.

What are the three main functions of the gastrointestinal system?

Takes food and fluid into the body, absorbs nutrients and fluid, and excretes waste products.

How do monogastric animals digest food?

Food enters the mouth, travels down the esophagus to the stomach, mixes with bile and pancreatic enzymes in the intestines for absorption, and waste is excreted through the rectum.

How does the digestion of ruminants differ from that of monogastric animals?

Ruminants have a four-chamber stomach (reticulum, rumen, omasum, abomasum) to help digest plant material.

What is the function of the crop in birds?

The crop is a pouch on the esophagus where food is stored.

What is chyme?

Chyme is the term for food once it enters an animal’s small intestine.

What type of contractions move chyme through the intestines?

Peristaltic waves (contractions).

What are villi and what is their function?

Small fingerlike projections that cover the surface of the intestines to increase the surface area for absorption.

What is the function of the colon?

Removes water from material, forms certain vitamins (in hind-gut fermenters), and stores waste products.

What is the defecation reflex?

Mass-action contraction that moves waste matter out of the body.

How does parasympathetic stimulation affect the gastrointestinal system?

Increases motility, increases secretions, and opens sphincters.

How does sympathetic stimulation affect the gastrointestinal system?

Decreases motility and secretions, and closes sphincters.

What part of the brain controls vomiting?

Medulla.

Name three triggers for vomiting.

Pain, excitement, fear. Disturbances of the inner ear. Drugs—apomorphine, digoxin. Metabolic conditions (uremia and ketonemia [blood abnormalities], endotoxemia [sickness caused by internal toxins]). Irritation of peripheral receptors.

What is the function of emetics?

Drugs used to cause vomiting, to expel toxic substances before absorption.

When should emetics NOT be given?

To animals who are comatose or are actively having seizures, have depressed pharyngeal reflexes, are in shock or are dyspneic, or have ingested strong acids, alkali agents, or other caustic agents.

What is the function of antiemetics?

Drugs used to help control vomiting.

How do phenothiazines work as antiemetics?

By inhibiting the CRTZ and possibly by directly inhibiting the emetic center.

How do procainamides work as antiemetics?

Centrally blocks the CRTZ and peripherally increases stomach contractions and emptying, and strengthens cardiac sphincter tone.

How do antihistamines work as antiemetics?

By blocking the CRTZ impulses to the emetic center.

What are common NK-1 receptor antagonists used to treat vomiting?

Maropitant (injectable Cerenia) and maropitant citrate (Cerenia tablets).

What are common side effects of anticholinergics?

Dry mucous membranes and urinary retention.

Name three classes of antiulcer medications.

H2 receptor antagonists, proton-pump inhibitors, antacids, gastromucosal protectants or coating agents, and prostaglandin E-1 analogs.

How do H2 receptor antagonists work?

Blocking the stimulation of this H2 receptor will slow or stop acid production.

How do proton-pump inhibitors work?

Bind irreversibly to the proton pump, so that the parietal cell can’t release acid until new proton pumps are made.

How do prostaglandin E-1 analogs work?

By inhibiting secretion of acid from the parietal cell and are also protective of the stomach lining.

What is a common side effect of antacids with aluminum and calcium salts?

Constipation

What are the five broad causes of diarrhea?

Parasites, Hypersecretion, Increased Permeability, Osmotic Overload, Altered Intestinal Emptying.

Name the electrolyte that could be loss due to serve dirrahea.

Sodium, chloride, potassium, and bicarbonate

What is the role of protectants in the treatment of diarrhea?

Protectants, such as bismuth subsalicylate (Pepto-Bismol) or activated charcoal (treated with oxygen to make the charcoal highly absorbent), coat the intestines and relieve inflammation.

What agent causes the stool to turn black, and should not be used in cats?

Pepto-Bismol

Name the categories of laxatives.

Saline or hyperosmotic agents, Bulk-producing agents, Lubricants, Surfactants or stool softeners, Irritants, Miscellaneous agents.

What drug is a GI prokinetic/Stimulant?

Dopaminergic antagonists, such as metoclopramide

What are examples of Serotonergic drugs.

cisapride

What does SLUD stand for?

Salivation, lacrimation [excessive tears], urination, defecation.

What are two miscellaneous gastrointestinal drugs.

Antibiotics and anti-inflammatory

Name a commonly used oral appetite stimulants.

Mirtazapine, capromorelin (dogs only), and cyproheptadine