The shape of the stomach is related to the body shape of the animal, which is divided into the following types:

1. Fish;

2. Tailed amphibians; < /p>

3. Snakes have a slender body and a spindle-shaped stomach;

4. Mammals have a short and thick body and a bag-shaped stomach that lies horizontally in the abdominal cavity. Inside.

Extended information:

The stomach wall of mammals is generally composed of three layers of tissue. The relevant introduction is as follows:

1. The inner layer is the mucosal layer;

2. The outer layer is the serosa layer;

3. The middle layer is the muscular layer composed of smooth muscle. The muscle layer is divided into three layers: oblique, circular and longitudinal due to different directions of muscle fibers.

The structure of the gastric mucosa is relatively complex. Most gastric mucosa has gastric glands, but some do not. For example, the stomach of mice is divided into two parts, the front and back. The front part is called the forestomach and does not contain gastric glands. , the posterior part is called the glandular stomach, containing gastric glands.

Among the multiple stomachs of ruminants, only the abomasum has gastric glands, and the other three stomachs do not contain gastric glands. The gastric mucosa without gastric glands is covered by stratified squamous epithelium, while the mucosa containing gastric glands is covered by single-layer columnar epithelium.

Reference: Baidu Encyclopedia - Stomach