Connective Tissue Overview

Connective Tissue

• Connective tissue is derived from mesenchymal cells.
• It has a variety of subclasses, including loose and dense connective tissue, cartilage, and bone (osseous tissue).
• Loose connective tissue has three main types of fibers: collagen, elastic, and reticular.
• Areolar tissue is a type of loose connective tissue located beneath the epithelium and surrounding organs and capillaries. Its function includes strength, elasticity, and support.
• Adipose tissue is another type of loose connective tissue composed of adipocytes. Adipocytes store fat and are crucial in regulating heat loss, energy storage, and structural support.
• Reticular tissue is a loose connective tissue that supports lymphoid organs.
• Dense connective tissue is further categorized into regular, irregular, and elastic types.
• Dense regular connective tissue is packed with parallel collagen fibers, providing strength found in tendons and ligaments.
• Dense irregular connective tissue has irregularly arranged collagen fibers, providing strength to the dermis (skin) and surrounding organs.
• Elastic connective tissue has wavy bands of elastic fibers, providing elasticity and support, found in parts like the vocal cords and the walls of large arteries.
• Cartilage is a supportive connective tissue containing chondrocytes. Hyaline cartilage is a glassy matrix found at the ends of long bones, trachea, and larynx. It supports and allows smooth movement of joints.
• Elastic cartilage supports the external ear (pinna) and epiglottis; it maintains shape and assists in flexible movement.
• Fibrocartilage is a firm matrix found in pubic symphyses and intervertebral discs. It has thick bundles of collagen fibers and high tensile strength for absorbing compression.
• Osseous tissue, or bone, is a hard, calcified matrix containing osteocytes. Osteons, Haversian canals, lacunae, and canaliculi structures are characteristic of bone. Bone protects organs, supports the body, stores minerals, and enables movement.
• Bone has a calcified matrix with osteons, lacunae and canaliculi and osteocytes which provide support, protection, storage of minerals and enable movement.

Muscle Tissue

• Muscle tissue consists of skeletal, cardiac, and smooth muscle.
• Skeletal muscle is voluntary, multinucleated, and striated, providing locomotion and manipulation.
• Cardiac muscle is involuntary, branched, and striated with intercalated discs; it's found in the heart and responsible for blood circulation.
• Smooth muscle is involuntary, spindle-shaped, and non-striated; it enables involuntary movement and substance propulsion throughout the body. It is found in the walls of organs and vessels.

Nervous Tissue

• Nervous tissue is composed of neurons.
• Neurons have a cell body containing the nucleus, axons which transmit signals away from the cell body and dendrites which typically carry signals toward the cell body.
• Nervous tissue transmits electrical signals throughout the body, controlling and communicating information. It is located in the brain, spinal cord, and nerves.