Ch.4 Bio20

Epithelial Tissue — Description

Sheets of tightly packed cells with minimal extracellular matrix; main cell type: epithelial cells.

Epithelial Tissue — Special Characteristics

Highly cellular, specialized junctions, polarity, supported by connective tissue, avascular but innervated, and regenerative.

Simple Squamous Epithelium — Description

Single layer of flat epithelial cells with disc-shaped nuclei; main cell type: squamous epithelial cells.

Simple Squamous Epithelium — Function

Allows passive diffusion and filtration; secretes lubricating substances in serosae.

Simple Squamous Epithelium — Location

Kidney glomeruli, air sacs of lungs, lining of heart, blood and lymphatic vessels, and ventral body cavity.

Simple Cuboidal Epithelium — Description

Single layer of cube-shaped epithelial cells with large spherical nuclei; main cell type: cuboidal epithelial cells.

Simple Cuboidal Epithelium — Function

Secretion and absorption.

Simple Cuboidal Epithelium — Location

Kidney tubules, secretory portions of small glands, and ovary surface.

Simple Columnar Epithelium — Description

Single layer of tall epithelial cells; may include goblet cells and cilia; main cell type: columnar epithelial cells.

Simple Columnar Epithelium — Function

Absorption and secretion of mucus, enzymes, and other substances; ciliated type propels mucus or reproductive cells.

Simple Columnar Epithelium — Location (Nonciliated)

Digestive tract, gallbladder, and ducts of some glands.

Simple Columnar Epithelium — Location (Ciliated)

Small bronchi, uterine tubes, and uterus.

Pseudostratified Columnar Epithelium — Description

Single layer of epithelial cells of varying heights; all contact basement membrane; main cell type: columnar epithelial cells.

Pseudostratified Columnar Epithelium — Function

Secretion of mucus and propulsion of mucus by cilia.

Pseudostratified Columnar Epithelium — Location (Nonciliated)

Ducts of male reproductive organs and large glands.

Pseudostratified Columnar Epithelium — Location (Ciliated)

Trachea and most of the upper respiratory tract.

Stratified Squamous Epithelium — Description

Multiple layers of epithelial cells with squamous surface cells and cuboidal or columnar basal cells; main cell type: squamous epithelial cells.

Stratified Squamous Epithelium — Function

Protects underlying tissues from abrasion.

Keratinized Stratified Squamous Epithelium — Description

Surface epithelial cells are dead and filled with keratin; main cell type: keratinized squamous epithelial cells.

Keratinized Stratified Squamous Epithelium — Special Qualities

Waterproof and contains the protective protein keratin.

Keratinized Stratified Squamous Epithelium — Location

Epidermis of the skin.

Nonkeratinized Stratified Squamous Epithelium — Description

Surface epithelial cells remain alive and moist; main cell type: squamous epithelial cells.

Nonkeratinized Stratified Squamous Epithelium — Location

Esophagus, mouth, anus, vagina, and urethra.

Stratified Cuboidal Epithelium — Description

Two or more layers of cube-shaped epithelial cells; main cell type: cuboidal epithelial cells.

Stratified Cuboidal Epithelium — Function

Protection.

Stratified Cuboidal Epithelium — Location

Ducts of mammary glands, salivary glands, and largest sweat glands.

Stratified Columnar Epithelium — Description

Multiple layers with cuboidal basal cells and elongated surface cells; main cell type: columnar epithelial cells.

Stratified Columnar Epithelium — Function

Protection and secretion.

Stratified Columnar Epithelium — Location

Male urethra and large ducts of some glands.

Transitional Epithelium — Description

Stratified epithelium with dome-shaped epithelial cells that flatten when stretched; main cell type: transitional epithelial cells.

Transitional Epithelium — Function

Allows distension of urinary organs.

Transitional Epithelium — Location

Urinary bladder, ureters, and proximal urethra.

Areolar Connective Tissue — Description

Loose connective tissue with gel-like matrix containing collagen, elastic, and reticular fibers; main cell type: fibroblasts.

Areolar Connective Tissue — Function

Wraps and cushions organs, holds tissue fluid, and plays a role in inflammation.

Areolar Connective Tissue — Location

Underlies epithelia, surrounds blood vessels and nerves, and borders all tissues.

Adipose Tissue — Description

Loose connective tissue composed of closely packed adipocytes; main cell type: adipocytes.

Adipose Tissue — Function

Stores energy, insulates against heat loss, and protects organs.

Adipose Tissue — Location

Under skin, around kidneys, behind eyeballs, abdomen, breasts, and hypodermis.

Reticular Connective Tissue — Description

Loose connective tissue with a network of reticular fibers; main cell type: fibroblasts (reticular cells).

Reticular Connective Tissue — Function

Forms supportive framework (stroma) for other cells.

Reticular Connective Tissue — Location

Lymph nodes, spleen, and bone marrow.

Dense Irregular Connective Tissue — Description

Dense connective tissue with irregularly arranged collagen fibers; main cell type: fibroblasts.

Dense Irregular Connective Tissue — Function

Withstands tension in many directions.

Dense Irregular Connective Tissue — Location

Dermis of skin, submucosa of digestive tract, fibrous capsules of joints and organs.

Dense Regular Connective Tissue — Description

Dense connective tissue with parallel collagen fibers; main cell type: fibroblasts.

Dense Regular Connective Tissue — Function

Attaches muscle to bone and bone to bone; resists stress in one direction.

Dense Regular Connective Tissue — Location

Tendons, ligaments, aponeuroses, and fascia.

Elastic Connective Tissue — Description

Dense connective tissue rich in elastic fibers; main cell type: fibroblasts.

Elastic Connective Tissue — Function

Allows recoil after stretching.

Elastic Connective Tissue — Location

Walls of arteries, certain ligaments, and bronchial tubes.

Hyaline Cartilage — Description

Specialized connective tissue with glassy matrix and fine collagen fibers; main cell type: chondrocytes.

Hyaline Cartilage — Function

Supports, cushions, and resists compressive stress.

Hyaline Cartilage — Location

Fetal skeleton, ends of long bones, ribs, nose, trachea, and larynx.

Elastic Cartilage — Description

Specialized connective tissue similar to hyaline but with elastic fibers; main cell type: chondrocytes.

Elastic Cartilage — Function

Maintains shape while allowing flexibility.

Elastic Cartilage — Location

External ear and epiglottis.

Fibrocartilage — Description

Specialized connective tissue with thick collagen fibers; main cell type: chondrocytes.

Fibrocartilage — Function

Absorbs compressive shock and provides tensile strength.

Fibrocartilage — Location

Intervertebral discs, pubic symphysis, and knee joint discs.

Bone Tissue — Description

Hard connective tissue with mineralized matrix of collagen and calcium salts; main cell types: osteocytes and osteoblasts.

Bone Tissue — Function

Supports and protects organs, stores minerals and fat, and produces blood cells.

Bone Tissue — Location

Bones of the skeleton.

Blood Tissue — Description

Fluid connective tissue with cells suspended in plasma; main cell types: red blood cells, white blood cells, and platelets.

Blood Tissue — Function

Transports gases, nutrients, and wastes.

Blood Tissue — Location

Within blood vessels.

Skeletal Muscle Tissue — Description

Long, striated, multinucleate cells; main cell type: skeletal muscle fibers.

Skeletal Muscle Tissue — Function

Voluntary movement, manipulation of environment, and facial expression.

Skeletal Muscle Tissue — Location

Attached to bones (occasionally skin).

Cardiac Muscle Tissue — Description

Branching, striated cells with intercalated discs; main cell type: cardiac muscle cells.

Cardiac Muscle Tissue — Function

Pumps blood through the circulatory system.

Cardiac Muscle Tissue — Location

Walls of the heart.

Smooth Muscle Tissue — Description

Spindle-shaped, nonstriated cells arranged in sheets; main cell type: smooth muscle cells.

Smooth Muscle Tissue — Function

Moves substances through internal passageways involuntarily.

Smooth Muscle Tissue — Location

Walls of hollow organs.

Nervous Tissue — Description

Tissue composed of neurons and neuroglia; main cell types: neurons and neuroglial cells.

Nervous Tissue — Function

Transmits electrical signals for communication and control.

Nervous Tissue — Location

Brain, spinal cord, and nerves.