tooth above gums tooth below gums center of

� _______ – tooth above gums � _______– tooth below gums � _______ - center of tooth � Blood and nerve supply enter at apex of tooth root � _______- covers crown � Hardest, toughest tissue in body � _______- hard conn. tissue � Covers tooth root � Fasten tooth in bony socket � _______- surrounds and protects tooth pulp � _______ – gums; epithelial tissue around teeth

Dental Prophylaxis �Small animals- scaling away of tartar from the teeth. � Dental “_____” �Horses- teeth are “______”, which reduces points on buccal and lingual edges of teeth.

Functions of the Oral Cavity 1. Prehend food 2. Initiate mastication (mechanical digestion) � Breaks food into smaller particles �Increases surface area for chemical digestion 3. Initiate chemical digestion � Saliva of some animals contains amylase, lipase, and/or buffers to neutralize acidity of rumen � *stress will decrease salivation, while relaxation will increase salivation. *

• Muscular tube that extends from _____to the _____ and is located dorsal to the trachea. Transports swallowed material to the stomach; No significant digestion takes place • Enters stomach at an angle in _____ • As stomach fills, fold of stomach against esophagus closes lower end of esophagus • Reduces risk for reflux • In some species, closure is strong enough to prevent reflux or vomiting (horse, rabbit) Esophagus

Megaesophagus � Loss of muscle tone causing _____ of the esophagus � Causes esophagus to relax � Food accumulates in the esophagus instead of being transported to stomach. � Animal ______ undigested food. � How do we treat? � Feed liquid based diet � Feed on an elevated surface � Holding animal up and allowing gravity to pull food down to stomach. � Can lead to aspiration pneumonia.

Monogastric (Simple) Stomach 1. _____- area immediately surrounding the opening from the esophagus into the stomach; cardiac sphincter helps to prevent reflux 2. _____- distensible blind pouch; expands as more food is swallowed; rich with glands 3. _____ – distensible middle section; rich with glands

Monogastric (Simple) Stomach 4. _____- distal portion that grinds up swallowed food and regulates the HCl produced in the body and fundus 5. _____- sphincter that regulates movement of digested stomach contents (chyme) from stomach to duodenum (first part of intestine). -Prevents backflow of duodenal contents into the stomach. _____ curvature- outer portion of C-shaped stomach _____ curvature- inner portion of C-shaped stomach

Gastric Glands- see chart/picture** �FUNDUS & BODY: Both areas are rich with glands containing the following cells: � _____ cells �Produce hydrochloric acid (HCl) � _____ cells �Produce pepsinogen, an enzyme precursor to pepsin � _____ cells �Produce a protective mucus �PYLORIC ANTRUM � ____ cells �Endocrine cells that secrete the hormone gastrin into the blood when food is present � Gastrin stimulates the parietal cells to release HCl � _____ cells

� Pylorus � Concentration of circular muscle fibers � Maintains constant tone of sphincter � Chyme is forced by contractions into Gastric Motility antrum of stomach. � Remains partially open so contents can move from stomach to duodenum. Empty � _________ reflex- prevents stomach from sending its’ contents into the duodenum before the intestines are ready. Full

Gastric Motility � Stomach contains mucosal layer, submucosa, muscular layer (longitudinal and circular muscle fibers), and outer serosal layer � Smooth muscle in stomach wall responds to actions of the Nervous System. � Relaxed state of mind causes fundus to relax and increases contractions in antrum � Stress can _______ motility

Gastric Ulcers Deep erosions of the stomach’s epithelium Rugae- long folds in the stomach.

Ruminants and Complex Stomachs Only have one true stomach (abomasum), and 3 forestomachs (reticulum, rumen, and omasum). RUMINATION: ______ food ______ it _______ it some more ______it again

Reticulum Smallest and most cranial compartment. _______ arrangement to increase absorption. Wall is continuous with the rumen Rumen and Reticulum work together and produce Reticulorumen contractions. ______ disease is associated with the reticulum.

Rumen Reticuloruminal contractions allow: Regurgitation of partially-digested plant food (cud) to take place _______: expulsion of built up carbon dioxide or methane gas If build up continues, may cause _____. Contains billions of microbes for _________. Microbes contain enzymes (______ and ______) that allow the ruminant to digest cellulose and protein. Cellulose and protein are broken down and converted into VOLATILE FATTY ACIDS, which the animal can use for glucose and fat.

Omasum Muscular with interior full of parallel, longitudinal muscular folds. Breaks down food particles and carry them to the abomasum. ____ VFA’s (that weren’t already absorbed in rumen) and water from ingesta Removes ________ (to preserve the p. H of the abomasum). Abomasum • “_______”; functions very similar to that of mongastric stomach. • Only _______ part of the stomach. • Contains enzymes called _____ that break down microbes “flushed out” from the rumen

Young Ruminant Digestive Tract Newborn’s stomach functions mainly as a monogastric digestive system. _______ is the largest chamber in a newborn Rumen and reticulum are small and non-functional at birth (minimal _____). Development of rumen and reticulum is dependent on rate of diet change to grain. Milk in rumen can disrupt fermentation process so is carried directly to omasum. ______ groove (________ groove)- allows liquids to be carried from esophagus directly to omasum, bypassing rumen and reticulum. As animal ages, groove disappears.

� Where majority of nutrients are _____ into the bloodstream. � Same anatomy for monogastrics and ruminants � Divided into: � _______ �Short, first segment that leaves stomach. Pancreas is nearby. � _______ �Longest portion, makes up majority of small intestines. Large amount of mesentery found here. � _______ �Short section that enters the colon (large intestine). Leads directly to cecum. Small Intestines