Difference Between Tissue and Organ

Main Difference – Tissue vs Organ

Tissue and organ are higher organizational levels of the body of multicellular animals. The main difference between tissue and organ is that tissue is composed of similar types of cells, specialized to perform a unique function whereas an organ is made up of several types of tissues, performing several related functions in the body. Tissues and organs can be found in both animals and plants. The four types of tissues present in animals are epithelial tissue, connective tissue, muscular tissue, and nerve tissue. The epidermis, vascular tissue, and ground tissue are the three types of plant tissues. Heart, brain, lungs, kidney, and liver are the major organs in animals. The stem, roots, and leaves are the major organs in plants.

Key Areas Covered

1. What is a Tissue
      – Definition, Types, Function
2. What is an Organ
      – Definition, Types, Function
3. What are the Similarities Between Tissue and Organ
     – Outline of Common Features
4. What is the Difference Between Tissue and Organ
      – Comparison of Key Differences

Key Terms: Animal Tissues, Brain, Connective Tissue, Epidermis, Epithelial Tissue, Ground Tissue, Heart, Kidney, Liver, Lungs, Muscular Tissue, Nerve Tissue, Organ, Organ Systems, Plant Organs, Plant Tissues, Tissue, Vascular Tissue

What is a Tissue

A tissue is a structure with similar types of specialized cells that perform unique functions in the body of multicellular organisms. Animals have four types of tissues; epithelial tissue, connective tissue, muscular tissue, and nerve tissue. Epithelial tissues line the surfaces and cavities of the body, protecting the body from dehydration and mechanical damage. Connective tissue connects and binds separate tissues and organs together. The connective tissue is composed of few cells, embedded in a matrix, which is secreted by the cells in the connective tissue. Muscular tissue is involved in controlling internal body functions such as digestion, respiration, urination as well as external body functions such as movement of body parts. Nerve tissue coordinate both internal and external functions of the body with the different stimuli. The four types of animal tissues are shown in figure 1.

Figure 1: Four Tissue Types

Plants also consist of three tissue types known as epidermis, vascular tissues, and ground tissues. Epidermis lines all the body parts of the plant such as stem, leaves, and roots. Vascular tissue is involved in transporting water and nutrients throughout the plant body. Ground tissue is involved in photosynthesis and storage of food.

What is an Organ

An organ is a part of an organism, which performs a set of unique functions in the body. An organ is an incorporation of several types of tissue.

There are five main organs in the animal body, which performs vital functions for the survival of an animal. They are brain, heart, lungs, liver, and kidney. The brain is a component of the central nervous system of an animal, which coordinate body functions depending on the internal and external stimuli. Heart is the pump of the circulatory system of an animal, which transports both oxygen and nutrients to the cells in the body. Lungs serve as an interface that allows the exchange of respiratory gases between the blood and external environment. Within the lungs, the blood is saturated with oxygen while carbon dioxide is removed from the blood. Liver serves as the main storage organ in the animal body. It stores glucose as glycogen. Kidney is the main excretory organ in the body, allowing the removal of metabolic wastes and the excess fluid from the circulation. Organs in the animal body are organized into organ systems.

Figure 2: Flower

The primary organs in plants are stem, root, and leaves. Flowers, seeds, and spores are considered as reproductive organs in plants. The structures in a flower are shown in figure 2.

Similarities Between Tissue and Organ

Tissue and organ represent two higher organizational levels in the body of multicellular organisms.
Both tissue and organ perform a unique function in the body.
Both tissue and organ are made up of cells.
Both animals and plants comprise tissues and organs.

Definition

Tissue: Tissue is any of the distinct types of material of which animals or plants are made, consisting of specialized cells and their products.

Organ: An organ is a part of an organism, typically self-contained and has a specific vital function in the body.

Components

Tissue: A tissue is composed of similar types of cells.

Organ: An organ is composed of several types of tissues.

Complexity

Tissue: Tissue is involved in performing a single function in the body.

Organ: An organ is capable of performing several functions in the body.

Structure

Tissue: Tissues are evenly distributed structures.

Organ: An organ is a hollow structure.

Importance

Tissue: Tissue is the major structural component of an organ.

Organ: Organs are the structural components of the organ system.

Examples

Tissue: Epithelial tissue, connective tissue, muscular tissue, nerve tissue, and ground tissue are the examples of tissues.

Organ: Heart, stomach, intestine, lungs, and kidney are the examples of organs.

Repair

Tissue: Tissues can be repaired by regeneration and fibrosis.

Organ: The repair in tissues causes the repair in organs.

Functions

Tissue: A tissue may have a unique function in the body, and it forms organs.

Organ: An organ has vital physiological functions in the body.

Significance

Tissue: Tissues form organs in the body.

Organ: Organs form organ systems in the body.

Conclusion

Tissue and organ are two higher organizational levels in the body of multicellular organisms. Tissues are made up of similar types of cells, which are specialized to perform a unique function. In contrast, organs are composed of several types of tissues. Therefore, organs are capable of performing several related functions. Both tissues and organs of the body are vital to the survival of that particular organism. The main difference between tissue and organ is the structure and function of each component in the organism’s body.

Reference:

1.”What Are Tissues? – Types & Explanation.” Study.com. N.p., n.d. Web. Available here. 04 July 2017.
2. “Organ.” Encyclopædia Britannica. Encyclopædia Britannica, inc., n.d. Web. Available here. 04 July 2017.

Image Courtesy:

1. “Four types of tissue” By Medline Plus – (Public Domain) via Commons Wikimedia
2. “Mature flower diagram” By Mariana Ruiz LadyofHats – Own work (Public Domain) via Commons Wikimedia