Human Digestive System Overview

What is the main function of the small intestine?

Which of the following accessory glands is associated with the duodenum of the small intestine?

What structure increases the surface area for absorption in the small intestine?

Which part of the digestive system is responsible for absorbing water from indigestible food matter?

What is the approximate length of the large intestine?

How many functions does the liver perform?

Which part of the digestive system is responsible for the expulsion of feces?

What is a unique feature of the liver?

What is the main type of cell found in the liver responsible for its essential functions?

What structure serves as the 'gate' for various vessels, ducts, and nerves entering and exiting the liver?

What is the shape of the hepatic lobules found in the liver?

What type of blood vessels are liver sinusoids, and what is their main function?

Which structure collects bile produced by hepatocytes before it is transported to larger bile ducts?

What role do Kupffer cells play in the liver?

What happens to the liver when part of it is surgically removed?

Which ligament separates the two major lobes of the liver?

Small Intestine

About 22 feet long, tube-like organ connecting the stomach to the large intestine
Digests food, absorbs nutrients and water, moves food through the gastrointestinal tract
Consists of the duodenum, jejunum, and ileum
The liver and pancreas are major accessory glands associated with the duodenum
Has finger-like projections called villi, covered with microvilli, which increase surface area for absorption

Large Intestine

About 1.5 meters long, the final stage of the alimentary canal
Absorbs water from indigestible food matter
Consists of the cecum and colon
The large intestine is connected to the anus, the external opening of the rectum
Sphincter muscles control the closure of the anus
Feces are expelled from the body through the anus during defecation

Liver

Largest gland in the body, weighing between 1 and 2.3 kg
Located in the upper part of the abdominal cavity
Performs over 500 functions, including breaking down food, producing bile, storing vitamins and minerals, and regulating blood clotting
Can regenerate itself

Anatomy of the Liver

Two major lobes: right and left, separated by the falciform ligament
Two minor lobes: caudate and quadrate, visible from an inferior view
The porta (gate) is on the inferior surface, where vessels, ducts, and nerves enter and exit
Enclosed in a thin capsule and partially covered by peritoneum
Peritoneum folds form ligaments attaching the liver to the diaphragm

Microscopic Anatomy of the Liver

The interior consists of hepatic lobules
A lobule has a central vein surrounded by radiating sheets of hepatocytes
Lobules are formed by hepatocytes arranged in pairs of columns
The lobes contain:
- Hepatocytes: Main cell, responsible for majority of the liver's functions
- Sinusoids: Enlarged capillaries where blood exchanges with the perisinusoidal space
- Bile canaliculus: Microscopic spaces collecting bile and carrying it to larger ducts
- Kupffer cells: Macrophages found in the liver, protecting it from inflammation

Dive into the human digestive system with this quiz that covers the small intestine, large intestine, and liver. Explore key functions such as digestion, nutrient absorption, and the anatomy involved. Test your knowledge about this complex and essential system of the body.