what is an aggregation of cells of similar structure and function?
what is the study of tissues?
how many principal tissue types are there?
list the four primary tissue types:
epithelial, connective, muscle, nervous
what primary tissue type acts as a covering or lining?
list the functions of epithelial tissue:
cellular, polar, attached, avascular, innervated, high regeneration capacity
what are the two major categories of epithelial tissue?
one side of membranous epithelium is always exposed to what?
a body surface, lumen, cavity
one side of epithelium is attached to what?
a basement membrane
what two factors are used to classify membranous epithelia?
layering or stratification
what are the three classifications of epithelium based on cell layers?
simple, stratified, pseudostratified
what are the classifications of epithelium based on shape?
squamous, cuboidal, columnar, transitional
what type of epithelium consists of a single layer of flattened cells?
simple squamous epithelium
In general, where is simple squamous epithelium found?
only in protected regions such as alveoli or lining the lumen of blood vessel walls
what are the functions of simple squamous epithelium?
it allows for rapid exchange of nutrients and waste between blood and the interstitial fluid surrounding the blood vessels.
what type of epithelium consists of a single layer of cells that are as tall as they are wide?
simple cuboidal epithelium
where is simple cuboidal epithelium found?
kidney tubules, exocrine glands, ovaries, thyroid gland
what is the function of simple cuboidal epithelium?
absorbs fluids and other substances across its apical membrane and to secrete specific molecules.
what type of epithelium is composed of a single layer of tall narrow cells?
simple columnar epithelium
what are the general functions of simple columnar epithelium?
absorption and secretion of mucin. oocyte movement through uterine tube.
what are the two general types of epithelium composed of a single layer of cells that are taller than wide?
where in the body does the simple ciliated columnar epithelium occur?
lining of uterine tubes and larger bronchioles of respiratory tract.
simple nonciliated columnar epithelium often has what finger-like projections?
what is the function of microvilli?
to increase surface area for secretion and absorption
what unicellular glands occur within simple columnar epithelium?
what do goblet cells secrete?
what type of epithelium is composed of multiple layers with the apical layer being flat?
stratified squamous epithelium
what is the function of stratified squamous epithelium?
to protect underlying tissues from damage due to activities that are abrasive and cause friction
what two general types of stratified squamous epithelium occur?
nonkeratinized stratified squamous epithelium, keratinized stratified squamous epithelium
where does nonkeratinized stratified squamous epithelium occur?
oral cavity, pharynx, esophagus, vagina, anus
where does keratinized stratified squamous epithelium occur?
what type of epithelium is typically composed of two layers with the apical layer being cube-shaped cells?
stratified cuboidal epithelium
what is the main function of stratified cuboidal epithelium?
where is stratified cuboidal epithelium found?
what type of epithelium is composed of two or more layers of cells with the apical layer being made of cells taller than they are wide?
stratified columnar epithelium
what is the function of stratified columnar epithelium?
protection and secretion
where is stratified columnar epithelium found?
the large ducts of salivary glands, the membranous segments of the male urethra
what type of epithelium appears to be layered but is not?
pseudostratified columnar epithelium
what two types of pseudostratified columnar epithelium occur?
pseudostratified ciliated columnar epithelium, pseudostratified nonciliated columnar epithelium
where is pseudostratified ciliated columnar epithelium found?
respiratory tract, nasal cavity, pharynx, larynx, trachea, bronchi
where is nonciliated pseudostratified columnar epithelium found?
male urethra, epididymis
what is the function of pseudostratified columnar epithelium?
protection, secretion, movement of mucus
what type of epithelium may be stretched?
where does transitional epithelium occur?
urinary bladder, ureters, proximal part of the urethra
what is the function of transitional epithelium?
distention and relaxation to accommodate urine volume changes in bladder, ureters and urethra
glands arise from epithelial tissue invaginating into what type of underlying tissue?
what is the function of a gland?
they perform secretory functions by producing substances either for use elsewhere in the body or for elimination from the body.
what are the two general types of glands?
what type of gland releases its product directly into the bloodstream?
what type of gland releases its product onto an epithelial surface?
what type of tissue supports other tissues both physically and physiologically and also protects and binds other tissues?
what are the three basic components of connective tissue?
cells, protein fibers, ground substance
what is the extracellular matrix of connective tissue?
a combination of ground substance and protein fibers
list the main functions of connective tissue:
physical protection, support and structural framework, binding of structures, storage, transport, immune protection
from which of the primary germ layers does connective tissue arise?
connective tissue may be classified into what three broad categories?
connective tissue proper, supporting connective tissue, fluid connective tissue
what are the two broad categories of connective tissue proper?
loose connective tissue, dense connective tissue