Chapter 4 Tissues: Epithelial and Connective Tissues

Vocabulary flashcards covering the characteristics, classification, and functions of basic tissue types, epithelial tissues, and connective tissues from Chapter 4.

Four Basic Tissue Types

The main functional tissue groupings in the body: nervous tissue (internal communication), muscle tissue (contracts to cause movement), epithelial tissue (forms boundaries, protects, secretes, absorbs, filters), and connective tissue (supports, protects, binds other tissues together).

Nervous Tissue

A basic tissue type responsible for internal communication; found in the brain, spinal cord, and nerves.

Muscle Tissue

A basic tissue type that contracts to cause movement; includes skeletal muscles attached to bones, cardiac muscle of the heart, and smooth muscle in the walls of hollow organs.

Epithelial Tissue Functions

The six main functions of epithelial tissues: protection, absorption, filtration, excretion, secretion, and sensory reception.

Characteristics of Epithelial Tissues

Covers surfaces or forms glands; features cellular polarity (apical vs. basal lamina); consists of many closely packed cells; supported by connective tissue reticular lamina under the basal lamina; avascular but innervated; high rate of regeneration; can be simple (1 layer) or stratified (many layers).

Classification of Epithelia

Epithelial tissues are classified based on the number of cell layers (simple vs. stratified) and the shape of cells (squamous, cuboidal, or columnar).

Stratified Squamous Epithelium

Thick epithelium composed of several cell layers with cuboidal or columnar basal cells active in mitosis and flattened surface cells; protects underlying tissues in areas subjected to abrasion. Nonkeratinized type lines the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin.

Transitional Epithelium

Epithelium that resembles both stratified squamous and stratified cuboidal; features dome-shaped or squamouslike surface cells depending on stretch. Stretches readily to permit stored urine to distend urinary organs; lines ureters, bladder, and part of the urethra.

Dense Irregular Connective Tissue

Connective tissue proper consisting primarily of irregularly arranged collagen fibers, some elastic fibers, and fibroblasts; withstands tension in many directions to provide structural strength. Located in fibrous capsules of organs and joints, skin dermis, and submucosa of the digestive tract.

Elastic Connective Tissue

Dense regular connective tissue containing a high proportion of elastic fibers. Allows tissue to recoil after stretching, maintains pulsatile blood flow through arteries, and aids passive lung recoil; located in arterial walls, vertebral column ligaments, and bronchial tube walls.

Connective Tissue Proper

A tissue class divided into loose (areolar, adipose, reticular) and dense (regular, irregular, elastic) subclasses. Cells include fibroblasts, fibrocytes, defense cells, and adipocytes within a gel-like matrix of collagen, reticular, and elastic fibers. Functions in binding, resisting tension, storing energy, and holding water/salts.

Cartilage

An avascular connective tissue class divided into hyaline, elastic, and fibrocartilage. Contains chondroblasts and chondrocytes in a gel-like ground substance with collagen and elastic fibers; cushions, supports body structures, and resists compression due to large amounts of water in its matrix.

Bone Tissue

A connective tissue class consisting of compact bone and spongy bone. Contains osteoblasts and osteocytes in a collagen-fiber gel-like ground substance calcified with inorganic salts; functions in support as a hard tissue resisting compression and tension.

Blood

A fluid connective tissue consisting of red blood cells (erythrocytes), white blood cells (leukocytes), and platelets suspended in a fiberless plasma matrix; functions to carry $O_2$, $CO_2$, nutrients, wastes, and hormones.

Areolar Connective Tissue

A prototype connective tissue composed of an extracellular matrix (collagen, elastic, and reticular fibers + ground substance) and cells (fat cells, mast cells, neutrophils, fibroblasts, macrophages, and lymphocytes).