Tissues Flashcards
Tissues?
groups of cells in similar structure and function
What the four kinds of tissues?
1) Epithelial-covering
2) Connective-support
3) Muscle-movement
4) Nerve-Control
Function of Epithelial Tissue
Protection Absorption Filtration Excretion Secretion Sensory Reception
Cellularity
composed almost entirely of cells
Special Contacts
Form continuous sheets held together by tight junctions and demosomes
Polarity
Apical (microvilli) (top)
Basal (glucoproteins) (bottom) surfaces
Basal acts as a what?
filter
Supported by connective tissue
rest upon and supported by connective tissues/ Deep to basal lamina is reticular lamina
Avascular
receive nerve impulses
regenerative
rapidly replaces lost cells by cell division
How’s each epithelia named?
2 names first is layers (simple or stratified); second is shape
Simple
one layer
Stratified
2 or more layers
example of stratified
high abrasion areas
Three shape kinds
Squamus, cuboidal, columnar
Squamus
flat
cuboidal
sperical
columnar
elongated
Shape in nucleus determines what for cell?
shape
If part of body needs fast absorption what shape cell do you not want?
columnar
Epithealia: Simple Squamous Defintion
Single layer of flattened cells with disc-shaped nuclei and sparse cytoplasm
Function of Simple Squamous
Diffusion and Filtration
Provide a slick, friction-reducing lining in lymphatic and cardiovascular systems
Where are simple squamous located?
Present in the kidney, glomeruli, lining of heart, blood vessels, lymphatic vessels, and sersae
Definition of Simple Cuboidal
Single layer of cube like cells with large, spherical central nuclei
Functions of Simple Cuboidal
Secretion
Absorbtion (thick operations)
Location of Simple Cuboidal
kidney tubules
ducts and secretory portions of small glands and ovary surface
Simple Columnar
single layer of tall cells with oval nuclei; many contain cilia
What cells are found in simple columnar?
goblet cells
Function of Simple Columnar
Absorption and Secretion
What do nonciliated type of simple columnar line in the human body?
digestive tract and gallbladder
What do ciliated type of simple columnar line in human body?
small bronchi, uterine tubes, and some regions of the uterus
What does Cilia help do?
move through internal passageways
Pseudostratified Columnar
single layer of cells with different heights; some do not reach the free surface
What are seen at different layers in Pseudostratified columnar ?
Nuclei
Pseudostratified Columnar functions
secretion and propulsion of mucus
Where is pseudo stratified columnar located?
Present in the male sperm-carrying ducts (conciliated) and trachea (cilated)
Stratified Squamous
Thick membrane composed of several layers of cells
Function of Stratified Squamous
protection of underlying areas subjected to abrasion
Stratified Squamous forms
the external part of skin’s epidermis (keratinized cells)
Stratified Squamous lines?
esophagus, mouth, and vagina (nonkeratinized cells)
Stratified Cuboidal
rare in body, typically two cell layers
Where are stratified cuboidal found?
some sweat and mammary glands
Stratified Columnar
limited distribution in the body
Where are stratified columnar located?
pharnyx, male uretha
Where does stratified columnar line?
some glandular ducts
Transitional Definition
Several cell layers, basal cells are cuboidal or columnar, surface cells are dome shaped
Transitional stretches to?
permit the dissension of the urinary bladder
Transitional lines?
the urinary bladder, ureters, and part of the urethra
Gland
one or more cells that makes and secretes an aqueous fluid, releases proteins, steroids or lipids
Glandular are classified by?
site of product release
relative numbers of cells forming the gland
site of product release
endocrine (internal) or exocrine (external)
Relative number of cells forming the gland
unicellular (w/in epithelial) or multicellular (invagination, evagination)
Endocrine Gland
Ductless gland that produces hormones (regulatory chemicals), hormones will enter blood or lymp to target organ
EXAMPLE OF ENDOCRINE GLAND
hormones produced by intestinal cells causes the pancreas to release enzymes
Secretions include amino acids, proteins, glycoproteins, and steroids
Exocrine Glands is more?
numerous than endocrine glands
Exocrine gland secretes what?
their products onto body surfaces (skin) or into body cavities
Example of exocrine glands
mucous, sweat, oil and salivary glands
The only vital unicellular exocrine gland is?
goblet cell forms mucin
Multicellular exocrine glands are composed of …?
a duct and secretory unit
Multicellular exocrine are more complex than?
unicellular glands
Multicellular exocrine glands are classified according to …?
structure of their secretory units Simple (unbranched duct) Compound duct (branched duct)
Multicellular exocrine glands shapes
tubular (if secretory cells forms tubes), alveolar (flask like sacs), tub alveolar (have both types of secretory units
