A&P Lab 6: Tissues & Membranes Flashcards
4 Types of Tissues
epithelial, connective, muscle, & nervous
Histology
study of tissues
Cellularity
condition of many cells with little material between
Covering/Lining Epithelium
sheet-like epithelial tissue that covers body and organ surfaces and lines all hollow structures
Glandular Epithelium
clump-like epithelial tissue; forms glands and secretes various products
Exocrine glands
secrete products into body cavities and surfaces by way of tubular ducts
Endocrine glands
secretions diffuse into the bloodstream for their transport throughout the body; product = hormones
Free/apical surface
side of the cells exposed to a body space
Basal surface
side of the cells exposed to the connective tissue layer
Basement membrane
a thin layer of protein fibers beneath the basal surface connects the epithelial sheet to the underlying connective tissue
Simple epithelium
a single layer of cells; barrier for diffusion, secretion, absorption, and filtration of selected substances
Stratified epithelium
a multiple layered arrangement of cells; provides a thicker barrier with a protective function
Squamous
flat with a thin nucleus
Cuboidal
cube-shaped with a round nucleus near the center of the cell
Columnar
tall with an oval nucleus near the basal surface of the cell
Transitional
shape-changing from round when the tissue is relaxed to flat when the tissue is stretched
Mesenchyme
early connective tissue
Types of Connective Tissue
loose, dense, cartilage, bone, and blood
Common Bond of Connective Tissue
arrangement of living cells dominated by extracellular material containing a matrix of protein fibers and ground substance
Protein Fibers
collagen, elastin, and reticular fibers
Ground Substance
fluid, semifluid, gelatinous, or hard mixture of molecules that serve as a medium of transport and support
3 Types of Muscle Tissue
Skeletal, smooth, cardiac
Skeletal Muscle Tissue
type of muscle tissue that is attached to bones; primary tissue of the muscular system; AKA muscle fibers; long and cylindrical, each containing many nuclei and filaments that run perpendicular to the fiber length producing a striped appearance (striations); contraction is voluntary
Smooth Muscle Tissue
forms sheets that contribute to the walls of hollow organs, such as blood vessels, stomach, and small intestine; spindle-shaped cells with a single nucleus, lack striations; contraction is involuntary
Cardiac Muscle Tissue
forms the wall of the heart; cells are branched, contain striations, and also contain specialized junctions between adjacent cells (intercalated discs); involuntary
Conductivity
specialization of nervous tissue
Neurons
nervous tissue cells; populate the brain, spinal cord, and nerves; many different shapes, most of which contain a long process called an axon, which conducts the signal to another cell, and smaller processes called dendrites, which receive signals from other cells
Neuroglia
non-conductive cells that support neurons; outnumber neurons 10 to 1
Mesothelium
simple squamous epithelium forming part of the peritoneum
Endothelium
simple squamous epithelium lining the inside wall of a large artery
Goblet cells
produce and secrete mucus
Nonciliated simple columnar epithelium
forms an inner lining of the digestive, reproductive, and urinary tracts, and the ducts of many glands; often contains microvilli at the apical surface of cells, which aids in secretion/absorption
Ciliated simple columnar epithelium
lines portions of the respiratory tract, the uterine tubes, the uterus, the paranasal sinuses, and the central canal of the spinal cord; its cilia propel mucus and other substances
Brush border
thin red line of microvilli
Pseudostratified
columnar epithelium that appears to have many layers, but in fact has only one
PSCC epithelium
Pseudostratified columnar ciliated epithelium; found lining the trachea and bronchi
Fibroblast
large cell capable of movement throughout the semifluid ground substance; productive cells, secreting the protein fibers of the loose matrix and many of the ground substance molecules
3 Types of Loose Connective Tissue
areolar, adipose, and reticular
Adipose cells (adipocytes)
dominant cells of adipose tissue, capable of housing a very large volume of lipid molecules (efficient means of storing energy); efficient insulating blanket, cushion that protects from injury; mainly found associated with areolar tissue between the skin/muscles, forming the subcutaneous fat of the superficial fascia; also found around certain visceral organs (kidneys, heart, spleen)
Reticular cells
specialized type of fibroblast; forms an internal scaffolding for certain organs, such as lymph nodes and the spleen
Dense connective tissue
characterized by a high concentration of collagen fibers, allowing relatively little ground substance and few cells; AKA fibrous connective tissue; cells = fibroblasts, which produce the collagen fibers and ground substance
3 Types of Dense Connective Tissue
dense regular, dense irregular, elastic
Dense Regular Connective Tissue
roughly parallel arrangement of collagen fibers; forms tendons & ligaments
Dense Irregular Connective Tissue
random arrangement of fibers; found in the deep layer of the skin (dermis), the sclera of the eyes, in the fascia in and around the muscles, in capsules surrounding many organs, and in the valves and pericardium of the heart
Elastic Connective Tissue
has a dense arrangement of collagen fibers, but it is dominated by a large number of branching elastic fibers; found in the walls of large arteries, where it provides a firm but flexible structure
Chondroblasts
ground substance & fibers of cartilage are produced by these active cells, which become isolated in lacunae
Lacunae (cartilage)
spaces in cartilage; “little lakes”
Chrondrocytes
mature cartilage cells
Perichondrium
cartilage surrounded by a region of these protein fibers and blood vessels, which serve as the source of nourishing interstitial fluid for the embedded chondrocytes
3 Types of Cartilage
hyaline, fibro-, and elastic
Lamellae
matrix of bone tissue organized in onion-like layers
Osteoblasts
bone tissue is produced by these mobile bone cells; “bone-developing”
Lacunae (bones)
as new bone is produced, the osteoblasts cement themselves into these spaces
Osteocytes
immobile, mature bone cells; receive nourishing interstitial fluid by way of diffusion through tiny canals that penetrate the lamellae (canaliculi)
Canaliculi
tiny canals that penetrate the lamellae, allowing the entombed cells to communicate to one another
Osteonic (central) canal
central canal in bones that transmits blood vessels
Compact bone
very dense tissue that is composed of repeating cylindrical units
Osteon
each unit of compact bone is called this
Spongy bone
consists of thin plates of bone; spaces between the plates are filled with red marrow (site of blood formation)
Plasma
ground substance of blood; slightly thicker than water; proteins present in very small quantities
Formed elements
cells of blood; include red blood cells, white blood cells, and fragments of cells (platelets)
2 Membrane Categories
Epithelial, synovial
Epithelial membranes
cutaneous, mucous, serous; composed of 1 or more layers of epithelial cells bound to an underlying layer of connective tissue
Cutaneous membrane
skin (integument); only epithelial membrane that does not secrete a lubricating fluid, since the epithelium is the keratinizing stratified squamous epithelium of the epidermis
Mucous membranes
line the openings into the body, the digestive tract, and the respiratory tract; composed of epithelium that secrete mucous
Mucosae
AKA mucous membranes
Serous membranes
line body cavities and cover the surfaces of many internal organs; usually a single layer of squamous cells (simple squamous epithelium) which is associated with a small amount of areolar tissue; the epithelial cells produce a watery lubricating fluid (serous fluid)
Serosae
AKA serous membranes
Synovial membranes
composed entirely of connective tissue; line the cavities surrounding the joints, forming a smooth surface and a lubricating fluid (synovial fluid)
