What are the structures formed from hindgut?

The hindgut is the last portion of the digestive tract. It is derived from the embryonic cloaca and includes the rectum, anal canal, and associated structures.

The structures formed from the hindgut are:

1. Rectum: It is the straight, terminal portion of the large intestine that extends from the sigmoid colon to the anal canal. It serves as a temporary storage site for feces before defecation.

2. Anal canal: It is the short, terminal portion of the digestive tract that extends from the rectum to the anus. It is lined with stratified squamous epithelium and contains the internal and external anal sphincter muscles, which control the passage of feces.

3. Anus: It is the external opening of the digestive tract through which feces are expelled. It is surrounded by the anal sphincter muscles and the perianal skin.

4. Perianal skin: It is the skin that surrounds the anus. It is rich in nerve endings and contains specialized glands that produce mucus to lubricate the area during defecation.

5. Anal glands: These are small, sac-like structures located on both sides of the anus. They produce a strong-smelling fluid that helps mark territory in animals.

6. Rectal ampulla: It is the dilated portion of the rectum just above the anal canal. It serves as a temporary storage site for feces and helps facilitate defecation.

7. Anal valves: These are folds of tissue that project into the anal canal from above. They help control the passage of feces and prevent fecal incontinence.

8. Anal columns: These are vertical folds of tissue that line the anal canal. They contain a network of blood vessels and help support the anal canal during defecation.

9. Anal papillae: These are small, finger-like projections that line the anal canal. They help sense the presence of feces and contribute to the continence mechanism.