Tissues

Tissues are the collection of cells with similar structures that can operate as a unit in an organism. They have a shared structure and function to carry out the necessary tasks to ensure overall well-being and functions of a multicellular structure, specifically plant or animal. The word “tissue” came from the French word “tissue”, which means “to weave”. In this article, we will look into the different types and functions of tissues that contribute to specific roles to maintain the integrity of the organism.

What Are Tissues?

Tissues are the building blocks to form the basic structure of a multicellular organism. These are responsible for performing one or more specific functions between cells and organs in an act of coordination. Histology is the field of study related to tissues, and in histopathology, we can learn about the diseases related to tissue.

Types of Animal Tissues

Animal tissues are referred to as a group of specialized cells and can vary in their structure, function, and origin. These cells work together to perform some specific function within the bodies of animals.

Animal tissues are divided into four types:

• Epithelial Tissue
• Connective Tissue
• Muscle Tissue
• Nervous Tissue

Epithelial Tissue or Epithelium	Epithelial tissues are responsible for forming the outer covering of the skin. It is a thin and, protective layer of cells that lines the organs, blood cells, and internal cavities. Epithelium tissue consists of compactly packed cells with minimum intercellular matrix. Examples: Goblet cells, salivary glands, etc.
Connective Tissue	Connective tissues support and connect different types of tissues and organs present in an animal. These are the widely distributed tissues in a body and originate from the middle layer of the embryo (mesoderm). Example: Blood cells, Bone tissue and Adipose tissue.
Muscle or Muscular Tissue	Muscle or Muscular Tissues are one type of specialized tissue that is responsible for applying forces to different parts of the body. These types of cells consist of generally thing and long cells, also known as muscle fibers. The cytoplasm present in this type of fiber is called sarcoplasm. Example: Skeletal Muscle Tissue, Smooth Muscle Tissue, Cardiac Muscle Tissue, etc.
Nervous Tissue	Nervous tissues are found in the brain, spinal cord, and nerves present in the human body. They are the foremost and major tissue of our nervous system.

Functions of Animal Tissues

Animal tissues perform different functions in the body. It also contributes to the overall structure, support, and functionality of the organs and systems. Each type of animal tissue has unique roles as mentioned below:

Epithelial Tissue or Epithelium

The functions of epithelial tissues are:

• Epithelium works as the first line of defense against any kind of injury as it covers the whole body surface from top to bottom.
• These tissues absorb water and nutrients for digestive procedures.
• They also regulate the external exchange of the substances between body and nature.
• As well as they perform internal exchange procedures between the different parts of our body.
• Epithelial tissues also work as the sensory receptors that help to transmit signals from external stimuli to the nervous system.
• Different glands present in our body are also made up of epithelium.

Connective Tissue

The functions of connective tissues are:

• Provides the structural support to the various organs and tissues.
• Protects different organs by forming a supportive framework.
• It connects and binds different tissues together to maintain the overall integrity of our body.
• As a connective tissue, blood transports nutrients, oxygen, and waste materials throughout the body.
• As a connective tissue, adipose stores energy in the form of fat.
• These tissues participate in the immune system and create a barrier against pathogens.
• Also handles the tissue repairing and healing process with a structural framework for cell regeneration.

Muscle or Muscular Tissue

The functions of muscular tissue are:

• Muscular tissues enable the voluntary movements of the body and also contribute to posture and stability.
• They are responsible for involuntary movements in the internal organs (like the digestive tract, blood vessells and respiratory passages, etc.).
• Muscular tissues are present in the heart, which are responsible for pumping blood throughout the body by maintaining the rhythm of the circulatory system.
• These tissues also control the respiration process by automatically driving the movement of air both into and out of our body.

Nervous Tissue

The functions of nervous tissues are:

• Nervous tissues are responsible for response to stimuli and also transmit information within the body.
• These tissues play a major role in emotions, memory, and reasoning.
• Maintains the stability of our body and develops a sense of awareness of the environment.
• Many metabolic activities are controlled by the nervous system.

Types of Plant Tissues

Plant tissue refers to groups of cells. These cells are organized and function together to perform specific tasks in a plant which may be either similar or dissimilar in a structure. Now let’s discuss the major types of plant tissues in detail.

There are two types of plant tissue, categorized based on the types of cells they consist of. These are the major types of the plant tissue.

Meristematic Tissues

Merismatic tissues are a group of young cells that divide continuously to form new cells. These types of tissues are generally found in the growing regions of a plant. There are three main types of merismatic tissues present in a plant body:

• Apical Meristem: These types of meristem tissues are found in the tips of roots and shoots. These are responsible for the primary growth of a plant.
• Lateral Meristem: Lateral meristem is found along the sides of stems and roots which contributes to the secondary growth of a plant in diameter.
• Intercalary Meristem: These tissues are generally found in the nase of leaves and are involved in the growth of a plant structure.

Permanent Tissues

Permanent tissues are a group of cells that have lost their ability to divide and create more tissues. Their origin is also same as their functionality.

There are three major types of permanent tissues:

• Simple Permanent Tissues: Simple permanent tissues are similar in structures and functions. These can be divided into three based on their purpose: Parenchyma, Collenchyma, and Sclerenchyma.
• Complex Permanent Tissues: Complex permanent tissue is composed of different types of cells that collaborate to perform a specific function. They contribute in growth and development of vascular plants to function it correctly.
• Special or Secretory Tissues: The special tissues contribute to the adaptability, defense mechanisms, and overall survival strategies of plants in diverse environmental conditions. These tissues play a major role in the plant’s metabolism.

Functions of Plant Tissues

Plant tissues perform different and specific role in a plant. Each type of plant tissue has unique roles as mentioned below:

Meristematic Tissues

The functions of meristematic tissues are:

• Meristematic tissue plays a key role in the growth and development of plants where cells divide actively through the process of mitosis.
• Vascular tissues, including xylem and phloem, play a crucial role in water and nutrient transport in plants, contributing to both primary and secondary growth.
• Protects the tissues from outer injury.

Permanent Tissues

The functions of permanent tissues are:

• In aquatic plants these tissues help in floating.
• Nutrients, including starch, proteins, oils, and fats, are stored in these tissues.
• These tissues contribute to the rigidity of fruits such as nuts, coconut, and almonds.
• Chloroplasts present in these tissues facilitate the process of photosynthesis.
• Permanent tissues are involved in secretion, transportation, and providing mechanical support to plants.

FAQs on Tissues

1. What are the 4 Types of Tissue?

For animals there are four types of tissues are epithelial, connective, muscle, and nervous tissues.

2. What are Tissues?

Tissues are groups of similar cells working together to perform specific functions in the body. They are the building blocks to form the basic structure of a multicellular organism.

3. What is the Function of Tissue?

Tissues serve various functions, including providing structural support, connecting and binding organs, facilitating movement, and enabling communication between different body parts.

4. What type of tissue is Blood?

Blood is classified as a connective tissue. As a connective tissue, blood transports nutrients, oxygen, and waste materials throughout the body.