question

Parasympathetic Nervous System

answer

Includes nerves that emerge from the CNS as cranial nerves and nerves in the caudal portion of the spinal cord Includes the vagus nerve Effects are associated with the neurotransmitter acetylcholine Cholinergic Drugs

question

Stimulation of PNS

answer

Decreases the heart rate Constricts the pupils Increases digestive secretions Improves blood flow to the GI tract Increases GI smooth muscle tone and motility Net Effect = Increased digestion and absorption The Rest and Restore System

question

Sympathetic Nervous System

answer

Antagonizes or opposes the effects of the parasympathetic nervous system Neurotransmitter - Norepinephrine Nerves emerge from the spinal cord at the thoracic and lumbar segments of the spinal column Anticholinergic Drugs

question

Stimulation of the SNS

answer

Increases heart rate Elevates blood pressure Redirects blood flow from nonessential to essential organs and skeletal muscle Fight or Flight System

question

Ruminant

answer

has mixing and fermentation compartments called a forestomach which consists of the rumen, reticulum, and omasum and also has a true stomach called the abomasum

question

Gastric

answer

refers to the stomach

question

Enteric

answer

refers to the small intestine

question

Colonic

answer

refers to the colon

question

Prehension

answer

grasping food with the lips or teeth

question

Mastication (Mechanical digestion)

answer

the mechanical grinding and breaking down of food (chewing)

question

Layers of the wall of the GI tract

answer

Mucosa, Submucosa, Muscle, Serosa, Mesentery

question

Mucosa

answer

the lining layer; consists of the lining epithelium and some loose connective tissue

question

Submucosa

answer

between the mucosa and the thick muscle layer; contains glands (if present) and dense connective tissue

question

Serosa

answer

outermost layer of thin, tough layer of connective tissue

question

Mesentery

answer

sheets of connective tissue that suspend the GI tract from the dorsal body wall; contains blood and lymph vessels, and nerves

question

Stratified squamous epithelium

answer

thick and tough; lines the mouth, pharynx, esophagus, and anus

question

Simple columnar epithelium

answer

thin (allows for nutrient absorption); lines the stomach, small intestine, large intestine

question

Skeletal muscle

answer

under voluntary control; present in the mouth, pharynx, cranial part of the esophagus, and the external anal sphincter

question

Smooth muscle

answer

under involuntary control; present in the rest of the esophagus, stomach, small intestine, large intestine, and internal anal sphincter

question

Circular muscle fibers

answer

narrow a section of the tube when they contract

question

Longitudinal muscle fibers

answer

shortens a section of the tube when they contract

question

Peristaltic Contractions

answer

Propel contents along the GI tract; consist of circular muscle contractions that move along the tract like waves, propelling contents along the tube ahead of them

question

Segmental Contractions

answer

Back-and-forth mixing movements of intestinal contents; periodic, circular muscle contractions that occur in different adjacent sites; aid in digestion and absorption

question

Soft palate

answer

soft mucosal flap that extends caudally from the hard palate on the roof of the mouth; divides the pharynx into the oropharynx and nasopharynx

question

Oropharynx

answer

the opening at the back of the throat through which food and air both pass

question

Hard palate

answer

bony roof of the mouth

question

Parotid salivary glands

answer

located just ventral to the ear canals

question

Mandibular salivary glands

answer

located ventral to the parotid glands at the caudal angle of the mandible

question

Sublingual salivary glands

answer

located medial to the shafts of the mandible just under the base of the tongue

question

Occlusal surface

answer

the surface on which the teeth come together

question

Lingual surface

answer

"inner" surface of the teeth of the lower arcade

question

Palatal surface

answer

surface of the teeth "facing" the hard palate

question

Labial surface

answer

"outer-facing" surface of the teeth on the upper and lower arcade at the rostral end of the mouth

question

Buccal surface

answer

"outer-facing" surface of the teeth more caudal in the mouth

question

Dental Pad

answer

A flat, thick, connective-tissue structure on the maxilla opposite the lower incisors and canine teeth that ruminants have; in other words, ruminants do not have any upper incisors or canine teeth

question

Dental Formula

answer

First number after the letter is the number of teeth in half of the upper arcade. This number is followed by a slash. The second number is the number of teeth in half of the lower arcade

question

Crown

answer

the enamel covered, exposed part of a tooth

question

Root

answer

the unexposed part of a tooth

question

Gingiva

answer

the epithelial tissue that composes the "gums"

question

Enamel

answer

outer coating of the crown of a tooth; the hardest tissue of the body

question

Infundibulum

answer

a folding in the equine tooth that is a deep invagination of enamel

question

Apex

answer

the tip of the tooth root where the blood and nerve supply enters the tooth

question

Pulp

answer

the lattice-like material in the center of the tooth, which contains the nerve and blood supply

question

Dentin

answer

the layer surrounding the tooth pulp; more dense than bone, but not as dense as the overlying enamel; makes up most of the tooth

question

Cementum

answer

the hard connective tissue that covers the root of a tooth and helps secure it in its bony socket

question

Digestive enzymes

answer

Proteins that promote the chemical reactions that split complex food molecules into simpler compounds; usually end in the suffix -ase

question

Amylase

answer

an enzyme found in the saliva of omnivores but absent in carnivores; breaks down amylose, a sugar component of starch

question

Lipase

answer

an enzyme found in the saliva of some young animals while they are nursing or are on a high-milk diet; breaks down lipids (fats)

question

Salivary glands

answer

Under autonomic nervous system control Parasympathetic nervous system stimulation results in increased salivation Sympathetic nervous system stimulation results in "dry mouth"

question

Esophagus

answer

A muscular tube that extends from the pharynx (throat to the stomach) that transfers swallowed material to the stomach (no digestion or absorption takes place here)

question

Esophagus makeup

answer

Enters the stomach at the cardia which is surrounded by a weak sphincter (cardiac sphincter) which is capable of closing off the opening, enters the stomach at an angle, when the stomach becomes full, the stomach folds against the esophagus acting as a natural valve closing the end of the esophagus to prevent reflux This closure is so strong in the horse and the rabbit that they are incapable of vomiting

question

Monogastric Stomach

answer

Cardia, Fundus, Body, Pyloric antrum, Pylorus

question

Cardia

answer

area immediately surrounding the opening from the esophagus into the stomach

question

Fundus

answer

forms a distensible, blind pouch that expands as more food is swallowed

question

Body

answer

distensible section in the middle of the stomach

question

Pyloric antrum

answer

distal part of the stomach that grinds up swallowed food

question

Pylorus

answer

muscular sphincter that regulates the movement of chyme (digested stomach contents) from the stomach into the duodenum; prevents backflow of duodenal contents into the stomach

question

Rugae

answer

multiple, long folds in the stomach

question

Gastric Motility

answer

Food is ingested then fundus and body relax due to stimulation of the parasympathetic nervous system through the vagus nerve, body contracts to mix food antrum increases contractions (grinding), food moves towards pylorus chyme (liquified food) moves into the duodenum

question

Parietal cells

answer

produce hydrochloric acid

question

Chief cells

answer

produce pepsinogen (a precursor for the proteolytic (protein-digesting) enzyme pepsin)

question

Mucous cells

answer

produce mucus, which contains mucins produced by goblet cells, that coats and protects the stomach (bicarbonate ions are also secreted which neutralize hydrochloric acid)

question

G cells

answer

secrete gastrin

question

Gastrin

answer

Release is stimulated by the presence of proteins (food) in the stomachStimulates parietal cells to produce hydrochloric acid Inhibits muscular activity by the fundus causing it to relax so that more food can be stored

question

Histamine

answer

normally released by basophils and mast cells during inflammation or allergic reactions

question

Enterogastric reflex

answer

prevents the stomach from pushing its contents into the duodenum before the small intestine is able to handle more chyme

question

Secretin

answer

a hormone released from the duodenum in response to excess stomach acid being present in the small intestine - causes the stomach to relax - inhibits peristalsis of the body and antrum to slow gastric emptying

question

Cholecystokinin (CCK)

answer

a hormone that decreases contractions of the antrum, body, and fundus and slows gastric emptying; released when large amounts of fat or protein are in the duodenum

question

Reticulum

answer

Smallest forestomachSeparated from the rumen by the ruminoreticular fold - food moves freely between the reticulum and the rumen Lining is honeycomb shaped

question

Rumen

answer

Large, fermentative vat Largest forestomach A series of muscular sacs partially separated by pillars (muscular folds)

question

Ruminoreticular contractions

answer

occur 2 times per minutes and mix the contents of the stomach (Rumen)

question

Fermentative digestion

answer

Bacteria and protozoa produce enzymes that break down feed Proteases break down protein into peptides Peptides are incorporated into the protein structure of microbes or ammonia and volatile fatty acids (VFAs) (provide energy) Cellulase breaks down cellulose and pectin in the cell walls in plants into monosaccharides (e.g. glucose) and polysaccharides

question

Omasum

answer

Feed enters here from the rumen contains parallel, longitudinal muscular folds (leaves) further breaks down feed particles, dehydrates them, and moves them into the abomasum

question

Abomasum

answer

true stomach

question

Duodenum

answer

first section; leaves the stomach

question

Jejunum

answer

middle section; where most absorption of nutrients occurs; longest part

question

Ileum

answer

last section; enters the colon

question

Ileocecal sphincter

answer

regulates movement of material into the colon or cecum

question

Crypts

answer

are invaginations between the villi that produce new villus cells (old cells are shed)

question

Secretory Diarrhea

answer

Secretion of intestinal fluids into the lumen occurs at a rate that cannot be compensated by absorption of the fluid from the bowel (e.g., Transmissible gastroenteritis in swine, parvovirus in dogs)

question

Exudative Diarrhea

answer

Increased permeability of the intestinal mucosa from inflammation or infection results in protein, fluid, serum, and even blood lost in the intestinal lumen

question

Maldigestion or malabsorption

answer

More fluid remains in the intestinal lumen because of the osmotic force the undigested food material has to hold fluid in the gut

question

Decreased transit time

answer

Intestinal contents move through too quickly for the fluid to be absorbed

question

Carbohydrate Digestion

answer

Amylase converts starch into small sugar segments called disaccharides which are further broken down into monosaccharides by other enzymes

question

Protein Digestion

answer

Proteins are broken down by proteases into amino acids or dipeptides (two amino acids linked together)

question

Emulsification

answer

the process by which fat globules are broken down

question

Cecum, colon, and rectum

answer

Recovers fluids and electrolytes and stores feces until they can be eliminated

question

Cecum

answer

(a blind sac that consists of a base, body, and apex; comma shaped; occupies the right side of the abdomen) - has longitudinal bands that separate the structure into haustra (sacculations of the colon and cecum)

question

Ventral colon

answer

has longitudinal bands

question

Sternal flexure

answer

between the left and right halves

question

Dorsal colon

answer

has longitudinal bands, Diaphragmatic flexure - between the left and right halves

question

hindgut fermenters

answer

Guinea pig, rabbits, rats, swine, horse

question

Rectum

answer

Terminal portion of the large intestine, Contains stretch receptors that signal the defecation response when full

question

Anus

answer

Internal (involuntary control) and external sphincters (voluntary control) control passage of fecal material

question

Tenesmus

answer

straining to defecate from colonic or rectal inflammation and irritation

question

Liver

answer

Largest gland in the body, Divided into hepatic lobes which are further, divided into hepatic lobules, filters materials absorbed from the gut, Receives its blood supply from the hepatic artery and the portal vein, Blood leaves the liver from the hepatic vein

question

Bile

answer

Produced by the liver and contains bile acids, cholesterol, and bilirubin, Secreted into small canaliculi that merge to form bile ducts, which form the hepatic duct which combines with the cystic duct that leads to the gallbladder where bile is stored Horses do not have a gallbladder

question

Albumin

answer

a protein made by the liver that plays an important role in maintaining the osmotic fluid balance between capillaries (blood) and tissues; a lack of albumin results in movement of fluid from the capillaries into the tissues, producing edema and fluid accumulation in body cavities (ascites)

question

Glycogenolysis

answer

is the process by which glycogen is broken down into glucose for energy

question

Gluconeogenesis

answer

a process in which glucose is made in the liver from amino acids

Gastrointestinal System Vet. Anatomy and Physiology – Flashcards

Unlock all answers in this set

Haven't found what you were looking for?

Search for samples, answers to your questions and flashcards