chapter 4 book Flashcards
what are tissues
collection of specialized cells and the extracellular substances surrounding them.
how are body tissues classified into groups
structure of cells, composition of non-cellular substances, function of cells.
what are the four primary tissues
epithelial, connective, muscle, nervous.
how are epithelial and connective tissues classified
structure, cell shape, relationship of cell to another, composition of extracellular matrix.
how is muscle and nervous tissue classified
structure and functioning characteristics and location.
what is histology
microscopic study of tissues
what is biopsy
process of removing tissue samples from patients surgically or with a needle for diagnostic purposes.
what is an autopsy
examination of organs to determine the cause of death or to study the changes caused by disease.
what are the two layers of the embryonic stem cells
epiblast and hypoblast
what are the three embryonic germ layers
endoderm, mesoderm, ectoderm
what is the endoderm
inner layer, forms lining of digestive tract and derivaties.
what is the mesoderm
middle layer, forms tissies such as muscle, bone, and blood vessels
What is the ectoderm
outer layer, forms the skin
what is the neuroectoderm
portion of ectoderm that becomes nervous system.
what is neural crest cells
groups of cells that break away from neuroectoderm during development, give rise to parts of periphal nerves, skin pigment, the medulla o adrenal gland and many tissues of face.
what is epithelial tissue
covers and protects surfaces, both outside and inside body
What are some common characteristics of epithelial tissue
composed of cells covers body surfaces tissue surfaces cell and matrix connections nonvascular-diffusing across basement membrane regeneration
what body surfaces does epithelial tissues cover
exterior, lining digestive and respitory tracts, heart and blood vessels, body cavities.
what tissue surfaces does epithelial tissue cover
apicol surface, lateral, basal
what is the apicol surface
cells are exposed and not attached to other cells
what is the lateral surface
cells attached to other epithelial cells
what is the basal surface
base of tissue, attached to basement membrane
what is the basement membrane
specialized type of extracellular material secreted by epithelial and connective tissue cells.
what is basement membranes important role
supporting and guiding cell migration during tissue repair.
what are major functions of epithelial tissues
protecting underlying structures acting as barrier permitting passage of substnaces secreting substances absorbing substances
how do epithelial tissues act as barriers
reduce water loss and prevent toxic molecules and microorganisms
what are the 4 types of epithelial tissues
simple epithelium
stratified epithelium
pseudo-stratified
transitional
what is simple epithelium
single layer cells, extending basement to free surface
what is stratified epithelium
more layer cells, basal layer attach to basement membrane
what is pseudostratified
special type of simple, one layer cell attached to basement membrane
what is transitional
special type stratified, cell changes from cubical and columnar to squamous when stretched.
what are the three types of epithelium
squamous, cubidoil, columnar.
what are two types of stratified squamous epithelium
nonkeratinized- consists of living cells in both deepest and superficial layers
keratinized- living cells in deepest layer, dead containing keratin protein in superficial.
Where is keratinized found
skin, gums, hard palate of mouth.
where is nonkeratinized found
mouth, esophagus, rectum, vagina.
what is transitional epithelium
lines urinary bladder, ureters, kidney and urethra. surface cells cuboid or columnar when not stretched, and squamous when stretched.
what is purpose of simple epithelium
covers internal organs, facilitates diffusion of gases on lungs, filters blood in kidneys, cellular products in glands, absorbs nutrients in intestines.
what is function of stratified epithelium
protection
where is stratified squamous found
in areas of body where abrasion can occur, such as skin, mouth, pharynx, esophagus, anus, vagina.
what is the shape of cells that filter
flat and thin
what is the shape of cells that secrete
cubiodal or columnar.
what are goblet cells
specialized columnar epithelial cells. responsible for synthesizing and secreting mucus.
what are free surfaces
not in contact with other cells
what are the types of free surfaces
smooth, microvilli, folded, cilia.
what is microvilli
nonmotile, contain microfilaments, extensions of clll that increase surface area, occur in cells that absorb or secrete, such as serous membrane and lining of small intestine.
what is a ground substance
gel mile mixture of nonfiberous molecules
what are the two major components of ground substance
hyaluronic and proteoglycans
what is hyaluronic acid
long, unbranched polysaccharide chain composed of repeating disaccharide units.
what is a proteoglycan
large molecule consist of protien core attached to many long polysaccharides called glycosaminoglycans.
what are adhesive molecules
ground substance hold proteoglycans aggregates together.
what is chondronectin
ground substance of cartilege
what is fibronectin
ground substance of fiberous connective tissue
what are two major connective tissue
embryonic connective
mucous connective
what is embryonic connective tissue
composed of fibrofblasts surronded by semifluid extracellular matrix containing delicate reticular fibers.
what is mucous connective tissue
umbilical cord, sim to that of mesenchyme, rich source of stem cells.
what are the three types of adult connective tissue
connective tissue, fluid connective, supporting connective.
what is loose connective tissue
consist of relatively few protein fibers that form lacy netweork with numerous spaces filled with ground substance and fluid.
what are 3 subdivisions of connective tissue
areoler, adipose, reticular.
what is areoler tissue
loose packing material of most organs and tissues. attaches skin to underlying tissues. contains collegen, reticular, and elastic fibers.
what is adipose tissue
connective tissue with special properties- composed of large cells and small amount of extracellular matrix.
what does adipose tissue function as
insulator and site of energy storage.
what are two types of adipose tissue
yellow
brown
what is yellow adipose tissue
appears white at birth, turns yellow with age becuas accumulation of pigments, carotene, plant pigment
what is brown adipose tissue
found in armpits, neck, kidneys.
what is reticular tissue
form framework of lymphatic tissue. spleen. lymphocytes, bone marrow.