What is the Difference Between Liver and Gallbladder

The main difference between liver and gallbladder is that the liver is the largest organ of the body, producing bile whereas the gallbladder is the pear-shaped sac which stores bile between meals. Furthermore, the liver is responsible for the metabolism of proteins, carbohydrates, and lipids and the detoxification of various metabolites while gallbladder is responsible for concentrating and acidifying bile upon storage. 

Liver and gallbladder are two anatomical structures in the body, involving in the digestion. Both are located in the right, upper quadrant of the abdomen.  

Key Areas Covered 

1. What is Liver
     – Definition, Location, Structure, Role
2. What is Gallbladder
     – Definition, Location, Structure, Role
3. What are the Similarities Between Liver and Gallbladder
     – Outline of Common features
4. What is the Difference Between Liver and Gallbladder
     – Comparison of Key Differences

Key Terms 

Bile, Gallbladder, Hepatic Lobules, Liver, Metabolism 

What is Liver 

The liver is the largest organ of the human body. It is located in the upper right-hand portion of the abdominal cavity. Also, it occurs beneath the diaphragm and on top of the stomach, right kidney, and the intestine. Moreover, the liver is dark reddish brown in color and cone-shaped. It weighs about 3 pounds. Two different sources supply blood to the liver. First one is the hepatic artery, which supplies oxygenated blood and the second one is the hepatic portal vein, which supplies nutrient-rich blood. Moreover, the liver holds 13% of the total blood volume of the body at any given moment.  

Figure 1: Liver Location

From the above view, the liver consists of two lobes: the right and the left lobe. When viewed from the below, it consists of four lobes: the left, right, caudate, and quadrate lobes. Moreover, each of these lobes contains small lobes called hepatic lobules. Each hepatic lobule is roughly hexagonal. They contain plates of hepatocytes radiating from a central vein. The central vein connects to the hepatic vein, which carries blood out of the liver. Furthermore, the distal compartment of the hepatic lobule is the portal triad, which consists of five structures. They are a branch of a hepatic artery, hepatic portal vein, bile duct, lymphatic vessel, and a vagus nerve. Liver sinusoids occur in between the hepatic plates.  

Figure 2: Liver – Microscopic Anatomy

Furthermore, the liver plays a key role in the metabolism of carbohydrates, proteins, amino acids, and lipids. It undergoes glycogenesis to synthesize glycogen and stores it. It also releases glucose into the blood when needed for glycogenolysis. Moreover, the liver undergoes both synthesis and the breakdown of proteins. Also, a large part of the amino acid synthesis occurs in the liver. Liver undergoes cholesterol synthesis, lipogenesis, and the production of triglycerides. Further, it breaks down hormones, bilirubin, ammonia, drugs, ethanol, etc. Significantly, the liver produces bile, which aids in the digestion of lipids. 

What is Gallbladder 

The gallbladder is the pear-shaped hollow sac located beneath the liver. Its main function is to store bile between meals. The liver continuously produces bile, which is a dark brown to yellowish brown color liquid. This bile flows out from the liver through the left and the right hepatic ducts to the common bile duct. When food is not available in the digestive system, bile flows to the gallbladder.  

Figure 3: Gallbladder – Anatomy

In addition, the gallbladder concentrates and acidifies bile while storing it. The lining of the gallbladder absorbs water from the bile. Hence, this causes acidification. However, a hormone called cholecystokinin is released when food enters the small intestine. This hormone signals to the gallbladder to contract and secrete bile through the common bile duct. Additionally, cholesterol, bilirubin, or bile salts in the bile may develop gallstones.  

Similarities Between Liver and Gallbladder 

• Liver and gallbladder are two anatomical structures located in the right, upper quadrant of the abdomen. 
• Also, their main function is to their role in digestion. 

Difference Between Liver and Gallbladder 

Definition 

Liver refers to a large lobed glandular organ in the abdomen of vertebrates, involved in many metabolic processes while gallbladder refers to a small sac-shaped organ beneath the liver, in which bile is stored after secretion by the liver and before release into the intestine. Thus, this is the main difference between liver and gallbladder.

Structure 

Another difference between liver and gallbladder is their structure. Liver is a wedge-shaped organ with four lobes while gallbladder is a pear-shaped sac.  

Location 

Location is another difference between liver and gallbladder. The liver is located in the right, upper quadrant of the abdomen while gallbladder is located beneath the liver. 

Functional Significance 

The functional significance is also a major difference between liver and gallbladder. Liver produces bile while gallbladder stores bile between meals. 

Other Functions 

Liver is involved in the metabolism of proteins, lipids, and carbohydrates, breakdown, and excretion of hormones and many waste products, storage of glucose, vitamins, and minerals, etc. while gallbladder is responsible for concentrating and acidifying bile. 

Conclusion 

The liver is the largest organ and the largest gland of the body. It produces bile. On the other hand, the gallbladder is the sac which occurs beneath the liver. It stores bile between meals, concentrating and acidifying it. Therefore, the main difference between liver and gallbladder is their functional relationship with bile.

References:

1. “Liver: Anatomy and Functions.” JOHNS HOPKINS MEDICINE, Available Here 
2. “Gallbladder Function, Location & Anatomy | Body Maps.” Healthline, Healthline Media, Available Here 

Image Courtesy:

1. “Anatomy Abdomen Tiesworks” By Tvanbr – Own work (Public Domain) via Commons Wikimedia  
2. “2423 Microscopic Anatomy of Liver” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (Public Domain) via Commons Wikimedia  
3. “Gallbladder (organ)” By BruceBlaus – Own work (CC BY-SA 4.0) via Common Wikimedia