Lecture 53- Avian Digestive Physiology Flashcards
Trace the avian GI tract
Beak and oropharynx
Pre-crop esophagus
Crop
Post-crop esophagus
Proventriculus (glandular stomach)
Gizzard (muscular stomach)
Duodenal loop
Small intestine (Jejunum and ileum)
Ceca
Large intestine (very short)
Cloaca
Vent
What is the oropharynx?
Combined cavity of mouth and pharynx extending from beak to esophagus
What is the laryngeal mound?
Caudal to base of the tongue with medial slit = glottis
No epiglottis guarding the glottis
Where is the pre-crop esophagus?
Cervical region
Where is the crop?
Near the thoracic inlet
What is throughout the esophagus?
Mucus glands
Ability to stretch and accommodate large food items
Where is the post-crop esophagus?
Thoracic region
What are the two aspects of the avian stomach?
Proventriculus—gastric chamber
Gizzard (ventricular)—mechanical grinding
Describe the gizzard
Very strong muscle
Small stones and grit accumulation
Lined with cuticle called koilin
*solid secretion to protect from acid and pepsin
*secretions solidly after exposure to acid
What is the distinction between Jejunum and ileum?
Meckel’s diverticulum
(TRUE/FALSE) intestines are much shorter in birds compared to mammals
TRUE
Important for birds that fly
Describe the gastroduodenal motility?
-contraction of thin ventricular muscles
-2 to 3 peristaltic waves through duodenum
-contraction of thick ventricular muscles
-peristaltic wave through ventricles
*about 4x/hr digesta from duodenum and upper Jejunum refluxes into ventriculus
What is the paired ceca separated from?
Ileum by ileocecal folds
Where is water reabsorbed from reflux urine?
Paired ceca
What is the cloaca?
Common opening for digestive, reproductive, urinary systems
Excrete feces and urine together
Urine is in form Urin acid
What does antiperistalisis in colon move urine from?
Cloaca to ceca and colon
How many antiperistaltic contractions/minute occur?
10-14
Antiperistalsis in the colon ceases before ________.
Defecation
Major and minor cecal contractions
Series of major contractions- _____ ________
One major contraction- ________
Minor contractions- _________
Series of major contractions- cecal evacuation
One major contraction- defecation
Minor contractions- mixing
Describe the avian liver
-bi lobed
-gallbladder in chickens, turkeys, ducks, geese, not pigeons
-each lobe has a bile duct draining into duodenum near pancreatic ducts
Describe cecal v. Intestinal droppings
Cecal droppings: chocolate brown color, 1-2 cecal droppings per day, series of major contractions to evacuate cecum
Intestinal droppings: greenish, granular-texture, 25-50 intestinal droppings per day
What are the most efficient diets for commercial poultry?
Highly digestible starch and protein
What is impacted crop?
Consuming too much grass/fibrous material
Can happen if one goes too long of a time without eating and then eating too fast
What is sour crop?
Overgrowth of yeast-> disrupts normal bacteria
Digestion of crop, thickening crop wall, bad breath
