Human Anatomy Block 1 (Ch.4) Terms

Epithelial Tissue

Covers or lines every body surface and all body cavities; it forms both the external and internal lining of many organs and constitutes the majority of glands

Epithelium

composed of one or more layers of closely packed cells between two compartments having different components

Basement membrane

between the epithelium and underlying connective tissue; is a thin extracellular layer

Simple epithelium

one cell layer thick, and all of the epithelial cells are in direct contact with the basement membrane

Stratified epithelium

contains two or more layers of epithelial cells

Psuedostratified epithelium

appears layered because the cells' nuclei are distributed at different levels between the apical and basal surfaces

Squamous cells

Flat, wide, and irregular in shape

Cuboidal cells

About as tall as they are wide; Nucleus spherical and in center of cell

Columnar cells

Slender and taller than they are wide; nucleus oval; oriented lengthwise in basal region

simple squamous epithelium

single layer of flattened cells; diffusion and filtration; air sacs in lungs

simple cuboidal epithelium

single layer of cube shaped cells, secretion and absorption; kidney tubules, lumen

simple columnar epithelium

Single layer of tall, narrow cells, nucleus oriented in the basal region of the cell, apical regions have microvilli, may contain goblet cells; absorption and secretion; lining of GI tract

simple columnar epithelium

Single layer of tall, narrow, ciliated cells, oval shaped nucleus oriented lengthwise in the basal region, may contain goblet cells; secretion of mucus, movement of mucus along apical surface by the cilia; lining of uterine tubes, and larger bronchioles of respiratory tract

psuedostratified columnar epithelium

Single layer of cells of differing heights (apperance of multiple layers), nuclei at different levels, may bear cilia. location trachea, most of upper respiratory. Function is protection.

Serous membrane

Lines internal walls of pericardial, pleural, and peritoneal cavities as well as the external surfaces of the organs within those cavities.

Microvilli

Fingerlike extensions of plasma membrane of apical epithelial cells, increase surface area, aid in secretion and absorption, exist on every moist epithelia, but most dense in small intestine and kidney

Glands

Either individual cells or multicellular organs composed of predominately epithelial tissue; secrete substances for use elsewhere in the body or for elimination from the body; secrete mucin, electolytes, hormones, enzymes, and waste.

Tubular gland

glands with tubular secretory parts

Acinar glands

secretory portion forms expanded sac

merocrine glands

package their secretions into secretory vesicles and release the secretions by exocytosis; cells remain intact; lacrimal (tear) glands, salivary glands, sweat glands.

Apocrine glands

Composed of cells that accumulate their secretory products within the apical portion of their cytoplasm; secretion occurs when the cell's apical portion pinches off; mammary glands.

Holocrine glands

formed from cells that accumulate a product and then the entire cell disintegrates; oil producing glands in skin

Connective tissue

A body tissue that provides support for the body and connects all of its parts

extracellular matrix

made up of ground substance and protein fibers

Connective tissue proper

loose connective tissue and dense connective tissue

loose connective tissue

fewer fibers, more ground substance (areolar, adipose, reticular)

areolar connective tissue

Vascular, cells: fibroblasts, packages and binds materials especially around organs

Adipose (fat) tissue

Cells: adipocytes, nucleus pushed to periphery by fat droplets, energy storage, insulation, protection/support

dense connective tissue

more fibers, less ground substance

Dense irregular connective tissue

Cells: fibroblasts, good vascularity with collagen fibers found in clumps, strength and support, withstands stresses in many directions, dermis layer of skin

Dense regular connective tissue

Cells: fibroblasts, poor vascularity with collagen fibers densely packed, fibers running parallel, strength and support, resists stresses applied in one direction, tendons + ligaments

Cartilage

Supports connective tissue; composed of cartilage and bone

Bone

Osteocytes in spaces called lacunae, mineralized matrix, very vascular, surrounded by a periosteum

Muscle tissue

Moves body or organ walls; contracts

Skeletal muscle tissue

Moves skeleton; voluntary

Cardiac muscle tissue

Only found in the heart, moves blood through the heart, involuntary

smooth (visceral) muscle tissue

Moves material through organs, blood vessels; involuntary

Nervous tissue

Controls activities, processes information