Download Digestive Tract Musculature

 _____________ – 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 pH 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