III. MIcroanatomy of Avian and Ruminant GI system Flashcards
The avian stomach consists of….
Two organs that function together:
- Proventriculus which contins glands with Oxynticopeptic cells that secrete both HCL and digestive enzymes
- Ventriculus which is extremely motile and serves to mash and grind the ingesta
What do oxyticopeptic cells secrete and what avian organ are they found in?
Oxynticopptic cells secrete HCl nd digestive enzymes and are located within glands of the proventriculus.
T. Mucosa of avian proventriculus
- Epithelium - simple columnar extensive folds (plicae, separated by sulci)
- L. propria - lymphatic tissue
- L. muscularis - split in some species by glands
How is a single papilla formed?
From several plicae, gives star-shaped appearance to lumen.
T. Submucosa of Avian proventriculus
- Compound tubuloalveolar submucosal glands
- Located between layers of the lamina muscularis
- Glandular cells (oxynticopeptic cells) are cuboidal and secrete BOTH Hcl and digestive enzmes
- A central duct drains the secretory product onto the papillae
How many ayers is the T. Muscularis of the avian proventriculus?
Three layers - difficult to discern the individual layers
What is the last tunica of the avian proventiruclus?
Tunica serosa - as in common body cavity
T. Mucosa of avian ventriculus
- Epithelium - columnar
- Mucosal glands - branched tubular with simple cuboidal epithelium (the lining eptiehlial cells are secretory)
- Serete cornified product, cuticle (pellicle) that along with grit, aides in mashing the food, as birds do not have teeth to break down ingested food.
T. Submucosa of avian ventriculus
Nonglandular - unlike proventriculus
T. muscularis of avian ventriculus
- Smooth muscle
- Dense white fibrous c.t.
- thicker than T. muscularis of proventriculus
What is the last tunica of the avian ventriculus?
Tunica serosa - as in common body cavity
What is a common name for avian ventriculus?
Gizzard
Avian small intestine has what kind of nodules?
Lymphatic
The large intestine in avians has…., and function to?
Paired ceca, functions for water resporption and cellulose digestion.
Avian Cloaca
- Excretory (digestive and urinry
- Reproductive
- Immunological function (cloacal bursa)
What do you call the normal glandular ruminant stomach?
Abomasum