Tissues in Multicellular Organisms

Tissues are groups of similar cells.

Main Tissues for Animals

• nervous tissue^[1]

• epithelial tissue^[2]

• muscle tissue^[3]

• connective tissue^[4]

Main Tissues for Plants

• dermal^[a]

• ground tissue^[b]

• vascular tissue^[c]

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Nervous Tissue
This tissue is specialized for communication through the body. It is composed of the brain, spinal cord and peripheral nerves. The major cell groups in the tissue are neurons and glial cells. ↵

Nervous tissue

Epithelial Tissue
This tissue is the lining of gastrointestinal (GI) tract organs and other hollow organs. It can also be the epidermis of the skin (outside of the skin.) ↵

Types of epithelial tissue

Muscle Tissue
This is a tissue specialized for contraction. The cells are elongated, and termed muscle fibers. There are three types: skeletal, smooth and cardiac. Skeletal tissues are attached to the bones and generate body movements. Smooth muscle tissues are found in hollow organs to propel materials through those organs. Cardiac muscles line the heart and coordinate with the beating of the heart. ↵

Simple illustrations of each type of muscle

Connective Tissue
These tissues cover a variety of tasks, but all of them are characterized by the presence of extracellular matrix. This means that there is nonliving material composed of protein fibers and ground substance. They include skin and bone tissues. ↵

An example of connective tissue

Dermal Tissue
This tissue is mostly epidermis cells, because the dermal tissue is a layer that protects the plant from invaders. ↵

Dermal tissue

Ground Tissue
This type of tissue support the plant at its base. It is mainly composed of parenchyma cells, but may also contain collenchyma and sclerenchyma cells. ↵

Ground tissue

Vascular Tissue
This tissue is made from xylem and phloem. They are arranged in distinct strands, called vascular bundles which run along the stem of the plant. They carry materials up and down the stem. ↵

Vascular tissues