Biology 172 Exam 2 Types of Animal Tissues

cell layer overlying a non-cellular basement membrane

a. protective coverings for body organs and surfaces
b. control of movement of materials from one side of the epithelium to the other
c. secretion of enzymes and other chemicals

single layer of cells overlying a basement membrane (lamina) covering other tissues (usually connective tissue)

1) cells are very flat
2) oval or circular nucleus situated centrally
3) found where easy, unregulated, transport of materials from one side of the epithelium to the other (e.g., capillary walls and alveolar sacs of the lungs)

1) cells are cube shaped
2) centrally-situated circular nucleus
3) found forming the tubules of glandular tissues involved in producing secretions into ducts

1) cells are columnar
2) oval nucleus situated near the bases of the cells
3) found where high degree of control over the passage of materials from one side to the next is desired (e.g., innermost lining of the digestive tract)
4) involved with secretion and absorption

1) cells occur as multiple tiers of cells
2) basal layer tends to be cuboidal, while distal layer is squamous
3) basal layer generates new cells distally
4) cells get flatter and flatter as they are pushed up
5) uppermost layer often consists of dead or dying cells that are continually replaced from below
6) forms the epidermis of the skin in vertebrates

1) appears stratified because cell nuclei appear at different levels within the epithelium
2) forms the lining of the nasal passageways where olfaction occurs, as well as other respiratory passageways
3) often ciliated on the luminal side and with mucus-producing goblet cells interspersed (mucous membrane)

a. cells surrounded by extracellular matrix
b. matrix composed gelatinous ground substances and web of fibers  
c. macrophages

fibers include:

(white) fibers, which are relatively stiff

(yellow) fibers, which are elastic

thin, branched fibers of collagen continuous with collagenous fibers and assist in binding of tissues

density, relative proportions and orientations of fibers, along with chemical make up of the matrix, determine the properties of this tissue

cells responsible for secreting fibers

1) defensive cells within the matrix of connective tissue
2) engulf foreign particles and cellular debris via phagocytosis

a. binds and supports other tissues
b. blood involved in transport of materials

1) cells packed loosely into a matrix with elastic and collagenous fibers meandering through it
2) primarily involved in binding tissues together  
3) cells consist of fibroblasts (secrete fibers) and macrophages (wandering cells that engulf bacteria and dead cells)

1) more densely packed with parallel-arranged collagenous fibers
2) forms tendons (connect muscle to bone) and ligaments (connect bone to bone)

1) = specialized form of loose connective tissue
2) composed of large oil-containing adipose cells
3) various functions

various functions of adipose tissue

1) matrix is thick and rubbery with small spaces (lacunae) where chondrocytes occur
2) ground substance composed of protein-polysaccharide complex (polysaccharide = chondroitin sulfate)
3) permeated by collagenous fibers
4) important component of skeletal materials that provide flexible, rather than rigid, support

matrix is composed of collagen fibers and mineralized (primarily calcium phosphate) ground substance secreted by osteoblasts

a) osteoblasts become osteocytes found in lacunae arranged in concentric layers around central canal with blood vessels (Haversian system)
b) forms the walls of the long bones of the body

a) tissue laid down in a "spongy" network rather than Haversian systems
b) found in the ends of the long bones of the body
c) spaces filled with red bone marrow which is responsible for the manufacture of blood cells

1. cells with contractile fibers
2. involved in animal locomotion

1) involved in skeletal movements
2) each muscle fiber is a long multinucleated cell
3) exhibits distinct striations
4) requires direct nervous stimulation to initiate contraction
5) often called voluntary muscle
6) provides rapid, powerful contractions, but susceptible to fatigue

1) found in the walls of the hollow organs of the body (e.g., intestines)
2) composed of individual spindle-shaped ells
3) exhibit peristalsis (= rhythmic contractions)
4) contraction response is slow, but exhibits high endurance
5) contraction response is involuntary

1) found only in vertebrate hearts
2) composed of individual striated branched cells that form a network
3) self-contractile (involuntary)
4) exhibits both strength and endurance