Avian and Reptilian GI & Urogenital tracts Flashcards
What reflects the distinctive anatomy and physiology of avian GIT?
Constraints of flight, such as hollow bones
The adaptations in avian anatomy facilitate flight efficiency.
What is the continuous tube structure of the avian GIT from beak to vent?
- Mouth
- Oesophagus
- Crop
- Proventriculus
- Ventriculus (gizzard)
- Intestine
- Caeca
- Rectum
- Cloaca
- Vent
Each part plays a specific role in digestion and food processing.
What is the role of the oesophagus in avian GIT?
Extends down the neck into the thoracic cavity and is expandable due to longitudinal folds
This allows for the accommodation of large food items.
What occurs if there is a buildup of grains in the avian crop?
Sour crop due to fermentation
This condition can affect the bird’s health and digestion.
What is the function of the proventriculus in birds?
Glandular stomach that secretes mucous, HCl, and pepsinogen
It prepares food for further digestion in the gizzard.
What distinguishes the ventriculus (gizzard) in birds?
Muscular stomach with 2 pairs of smooth muscles arranged in bands
It mechanically breaks down food.
What is the significance of the caeca in avian GIT?
- Present as 2 distinct caeca
- Vestigial in psittacine and passerines
- Very well developed in domestic birds
The caeca play a role in digestion and absorption.
What is the cloaca in avian GIT?
Terminal chamber into which digestive tract and urogenital ducts empty
It serves multiple functions, including excretion and reproduction.
What type of teeth do snakes and lizards have?
Acrodont teeth
This type of tooth is fused to the jawbone.
What is unique about the glottis in reptiles?
Always closed unless taking a breath
This adaptation helps in respiration while eating.
What allows snakes to ingest prey significantly larger than themselves?
Loosely connected jaw bones and elasticated skin
These adaptations provide flexibility in feeding.
What is the function of the ciliated epithelium in the oesophagus of reptiles?
Facilitates movement of food and secretes mucus
The cilia help in the propulsion of food.
Where is the stomach located in reptiles?
On the left side of the body, attached to the left lung
Its position is crucial for mechanical and chemical digestion.
What are the functions of the liver in reptiles?
- Largest visceral organ
- Consists of two lobes
- Caudal to the heart and cranial to the stomach
The liver plays an essential role in metabolism and detoxification.
What is the role of the pancreas in reptiles?
Located along the duodenum, secretes bicarbonate and digestive enzymes
It aids in digestion and neutralization of stomach acid.
What is the caecum’s role in reptiles?
Present in most lizards and chelonians but absent in most snakes
It varies in size depending on diet.
What does the large intestine do in reptiles?
Reclaims water, ions, and degrades complex carbohydrates
It plays a key role in hydration and nutrient absorption.
What is the cloaca in reptiles?
Common opening of the digestive and urogenital tracts
It serves multiple biological functions.
