6a A&P: Introduction to the Human Body - Tissues

Tissue

Group of similar cells that act together to perform a specific function.

Epithelial tissue

Tissue that lines or covers the body's external surface (skin), internal organs, blood vessels, body cavities, and the digestive, respiratory, urinary, and reproductive tracts.

Example: skin, endothelium that lines blood vessels and the heart.

Connective tissue

Tissue that is the most abundant and diverse. Connects, supports, transports, and defends.

Fibrous connective tissue

The packing material of the body. It attaches the skin to underlying structures in a basement membrane, serves to wrap and support the body cells, fills the gaps between structures such as organs and muscles, and helps keep them in their proper places.

Loose fibrous connective tissue, AKA: areolar

One of the most widely distributed connective tissue and has little tensile strength.

Adipose fibrous connective tissue

Tissue that specializes in storage of fat that insulates the body against heat loss, provides fuel reserves for energy, and provides a cushion around certain structures such as the heart, kidney, and some joints.

Examples: yellow bone marrow

Reticular fibrous connective tissue

The supportive framework of bones, and of certain organs such as the liver and spleen.

Dense connective tissue

Compact, strong, inelastic bundles of parallel collagenous fibers that have a glistening white color.

Dense irregular connective tissue

Resists pulling forces in several directions.

Examples: deep fascia, dermis of the skin, periosteum, and capsules of organs.

Dense regular connective tissue

Resists pulling forces in two directions.

Examples: ligament, tendon, retinacula, and aponeuroses

Bone connective tissue

The hardest and most dense connective tissue type.

Cartilage connective tissue

Avascular, tough, protective tissue capable of withstanding repeated stress and is found chiefly in the thorax, joints, and certain rigid structures of the body such as the trachea, larynx, nose, or ears.

Hyaline cartilage, AKA: gristle

Elastic, rubbery, and smooth cartilage that covers articulating ends of bones. Connects ribs to the sternum. Supports the nose, trachea, and part of the larynx.

Fibrocartilage

Cartilage with a dense matrix of white collagenous fibers. Has the greatest tensile strength of all cartilage types.

Examples: intervertebral disks and knee joint.

Elastic cartilage, AKA: yellow cartilage

The softest and most pliable cartilage type. Consists of elastic fibers in a flexible fibrous matrix.

Examples: external nose and ears, epiglottis, part of the larynx, and auditory tubes.

Liquid connective tissue

Contains a distinct collection of cells floating in a liquid matrix.

Muscle tissue

Tissue that produces movement of the body. Has the ability to contract, elongate, respond to stimulus, and return to its original shape after movement.

Smooth muscle tissue

Involuntary, non-striated muscle tissue that forms the walls of hollow organs and tubes. Controls the transport of materials, moving them along or restricting their flow.

Examples: stomach, bladder, and blood vessels.

Skeletal muscle tissue

Voluntary, striated muscle tissue that is attached to bones or related structures and is stimulated by a nerve impulse to contract.

Cardiac muscle tissue

Involuntary, striated muscle tissue located in the heart wall. Intercalcated disks between each muscle cell synchronize the contraction to pump blood from the heart.

Nervous tissue

Tissue that has the ability to detect and transmit electrical signals by converting stimuli into nerve impulses.

Examples: brain and spinal cord.