Tongue
The tongue is a muscular organ in the mouth that assists in chewing and swallowing food. A specialized mucosa situated in the dorsal region of the tongue structures a variety of papillae and taste buds. It is lined with non-keratinized stratified squamous epithelium. It has dermal papillae, which are connective tissue ridges that protrude into the epithelium, and foliate papillae, which are parallel ridges on the sides of the tongue separated by deep mucosal furrows. It also contains taste buds, which are elliptical projections located in the furrow epithelium that contains taste receptor cells.
Small intestine
The small intestine is the longest part of the digestive system and is where nutrition absorption occurs. Food is chemically broken down by acidic chyme from the stomach, which flows down into the duodenum via the pyloric sphincter. The stomach acid aid in the digestion of proteins. To neutralize the acid, it requires a neutral pH which is achieved through secretions from the Brunner’s glands and the exocrine pancreas.
The small intestine is made up of three parts:
Duodenum – proximal portion adjacent to the stomach
Jejunum- upper portion
Ileum – distal portion adjacent to the large intestine
All these three have villi which are tiny, finger-like projections that extend from the mucosal epithelial layer. Jejunum and ileum lack Brunner’s gland, which secretes a mucus-rich alkaline secretion to neutralize the acidic chyme. Only the ileum has Peyer’s patches, which are lymphoid cell aggregations in the lamina propria.
Large intestine
The large intestine is the largest and final organ of the digestive system. Colon is another name for it. The primary functions of the LI are reabsorption of water and maintaining the fluid balance in the body and removal of undigested food. The colon is a divided into four layers: mucosa, submucosa, muscularis, and serosa.
The innermost layer is the mucosa and it is composed of simple columnar epithelium. Next to the mucosa is a layer of dense irregular connective tissue known as submucosa, which contains multiple layers of visceral muscle cells that aid waste products in peristaltic movement. And the outermost layer is the serosa which consists of a thin layer of simple squamous epithelial tissue.
Tongue
The tongue is a muscular organ in the mouth that assists in chewing and swallowing food. A specialized mucosa situated in the dorsal region of the tongue structures a variety of papillae and taste buds. It is lined with non-keratinized stratified squamous epithelium. It has dermal papillae, which are connective tissue ridges that protrude into the epithelium, and foliate papillae, which are parallel ridges on the sides of the tongue separated by deep mucosal furrows. It also contains taste buds, which are elliptical projections located in the furrow epithelium that contains taste receptor cells.
Small intestine
The small intestine is the longest part of the digestive system and is where nutrition absorption occurs. Food is chemically broken down by acidic chyme from the stomach, which flows down into the duodenum via the pyloric sphincter. The stomach acid aid in the digestion of proteins. To neutralize the acid, it requires a neutral pH which is achieved through secretions from the Brunner’s glands and the exocrine pancreas.
The small intestine is made up of three parts:
Duodenum – proximal portion adjacent to the stomach
Jejunum- upper portion
Ileum – distal portion adjacent to the large intestine
All these three have villi which are tiny, finger-like projections that extend from the mucosal epithelial layer. Jejunum and ileum lack Brunner’s gland, which secretes a mucus-rich alkaline secretion to neutralize the acidic chyme. Only the ileum has Peyer’s patches, which are lymphoid cell aggregations in the lamina propria.
Large intestine
The large intestine is the largest and final organ of the digestive system. Colon is another name for it. The primary functions of the LI are reabsorption of water and maintaining the fluid balance in the body and removal of undigested food. The colon is a divided into four layers: mucosa, submucosa, muscularis, and serosa.
The innermost layer is the mucosa and it is composed of simple columnar epithelium. Next to the mucosa is a layer of dense irregular connective tissue known as submucosa, which contains multiple layers of visceral muscle cells that aid waste products in peristaltic movement. And the outermost layer is the serosa which consists of a thin layer of simple squamous epithelial tissue.
Sources:
https://histologyguide.com//slidebox/14-gastrointestinal-tract.html
https://www.verywellhealth.com/large-intestine-797216
https://courses.lumenlearning.com/boundless-ap/chapter/the-small-intestine/
https://askinglot.com/what-neutralizes-the-acid-in-the-small-intestine