-
Daphne Sumodlayon posted an update in the group
MT30-Histology Art AB 4 years ago The digestive system includes the mouth, pharynx (throat), esophagus, stomach, small intestine, large intestine, rectum, and anus. It also includes the salivary glands, liver, gallbladder, and pancreas, which make digestive juices and enzymes that help the body digest food and liquids.
Recently Active Members
4 layers of the GI tract
Mucosa – a mucous membrane composed of a layer of epithelium in direct contact with GI tract contents, lamina propria, and muscularis mucosae. It lines the inside of the stomach as surface cells and forms numerous tiny invaginations called gastric pits.
Submucosa – a thick layer of connective tissue that is flexible and mobile. Aside from rich vasculature and lymphatics, this layer also holds the submucosal plexus which carries parasympathetic intervention to the blood vessels and smooth muscle of the stomach walls
Muscularis – smooth muscle located deep in the submucosa which consists of 3 layers – oblique, middle circular, and outer longitudinal. It produces movements required for mechanical digestion
Serosa – consists of a simple squamous layer called mesothelium and underlying connective tissue. This lubricates the outer wall of the stomach and ensures its movement in the abdominal cavity.
Wall of the stomach with rugae
Rugae is the lining of the stomach at rest which forms into thick, velvety folds. These contain microscopic invaginations called gastric pits, that each open into gastric glands. It allows for expansion of the stomach after the consumption of food and liquid.
A tooth is composed of four dental tissues. Three of them – enamel, dentine, and cementum – are hard tissues. The 4th tissue is called the pulp, which contains nerves, blood vessels, and connective tissue. Besides being essential for chewing, the teeth play an important role in speech. A normal adult has 32 teeth.