Question

1. What is the main function of the accessory organs in the digestive system?

2. Which part of the digestive system is the longest?

3. Why does the small intestine have both longitudinal and circular muscles?

4. What are villi, what is their function and in which layer can we find them and in which tissue?

5. What substance cannot be easily absorbed by the blood stream and through which systems does this then enter the body?

6. What is the name of the cells which make up the cords in a liver lobule?

7. What is the function of the sinusoids and what do they contain?

8. Where can we find Kupffer cells and what is their main function?

9. What type of tissue separates the liver lobules and in which structure can these be found?

Answer 1

1. The accessory gland in digestive system are-

a). Liver- secretes biles through gall bladder which helps in emulsification of fats.

b). Pancreas- secretes pancreatic juice which helps in digestion of the food in small intestine.

c). Salivary gland- secretes saliva which contains mucus, salivary amylase and lysozyme. Salivary amylase helps in partial digestion of carbohydrate. Mucus lubricates the food while lysozyme has antibiotic activity.

d). Tongue- helps in mastication of food.

2. Small intestine is the longest part. It even could be of 6 metres.

3. Complete absorption takes place in small intestine so absorption of more and nutrients from the food these muscles helps as well contraction of both the muscle helps in peristalsis of food.

4. Villi are the finger like projection present in the lumen of the small intestine. Villi increase the surface area of the internal wall of the small intestine so that maximum absorption of nutrients could take place. It is present in the inner linning of the small intestine.

5. Lipids are not absorbed by the blood easily. So, they are first emulsified by bile juice and are converted into small micelles and then absorbed in the lymph first and from lymph and extra cellular fluid it comes to blood.

6. Hepatocytes.

7. Sinusoids are the vascular channels in liver which receives blood from hepatic artery and portal vein and transfer it to the central vein. They contain blood, some phagocytic cells Kupffer's cells.

8. Kupffer's cells are present in liver sinusoids which are macrophages and help in immunity of the body. Macrophages are phagocytic cells which engulf pathogens.

9. Connective tissues separate hepatic lobules.