Alimentary Canal
Alimentary canal is a muscular canal which extends from mouth to anus through stomach, oesophagus, small intestine and large intestine. All are consisted in alimentary canal. Basically, alimentary canal forms a long tube with a bag shaped structure which is stomach. It is a canal which forms our gastrointestinal track which includes oesophagus, stomach and intestine.
Do you know that our food does not need gravity or it does not get just get fall down into stomach when you eat. What happens in the space with astronaut when they eat food cuz there is no gravity? The reason is that muscles in our oesophagus contract and relax because of movement of the muscles of alimentary canal it prevent the backflow of food.
There is a lot to know about alimentary canal , so lets get started with histology of alimentary canal which is anatomy of alimentary canal
There are four different types of layer in alimentary canal:
1. SEROSA
2. MUSCULARIS
3. SUB MUCOSA
These 4 layers are all present in stomach, small intestine and large intestine .
SEROSA
It is the outer most layer of alimentary canal. It is made up of mesothelium which is epithelium of visceral organ . It has some connective tissues.
MUSCULARIS
It is made up of smooth muscles. It has two different section, outer longitudinal and inner circular. On the basis of their structure they are named as longitudinal and circular. Muscularis layer has collection of neuron called plexus. In our body muscle are controlled by our nervous system. Muscles in alimentary canal are controlled by autonomic nervous system.
So, above we were studying about movement of alimentary canal , here is the reason how does it happen. The plexus controls the movement of digestive system and thus, movement happens in alimentary canal. It's name is myenteric plexus. Mye means muscle and Enteric means alimentary canal.
SUB MUCOSA
It is made up of loose connective tissue containing nerves, blood and lymph. This layer also contain plexus called Meissner's plexus, it controls the secretion of HCL in stomach and is controlled by ans(AUTONOMIC NERVOUS SYSTEM). In the duodenum part of small intestine submucosa contain glands one of them is Brunner's gland.
MUCOSA
It is the inner most layer of alimentary gland. Basically, it has mucus that why it's mucosa. It performs different function in different parts of the body. In stomach it gets folded and forms rugae, made of mucus. It protects the stomach from HCL. In small intestine it forms villi and microvilli which increases the surface area for absorption of food.
In this picture you can see these 4 layers as well as Rugae in the stomach.
Hope you like this blog and informative, thanks for reading.
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