tissues Flashcards
what is tissue
group of similar cells that perform the same function:
- act as coverings,
- shorten or lengthen to create movement
- act as building material
- coordinate with other cells
specify how tissues act as coverings
- can create boundaries between environments tgat prevent dessication
- can interat with the outside environment
- have many layers for wear and tear
- smooth surfaces to reduce friction
what is the function of epithelial tissues
- to cover
- protect, absorb, secret, filtrate, excrete or sense
epithelial tissue protect from:
- dehydration
- mechanical irritation
- toxic substances
- trauma
epithelial tissues absorb:
- substances that are transported into cells
epithelial tissues secret:
- cell products that are transported out of the cell or body
epithelial tissues transport:
- substances across the cell membrane into or out of the cells
epithelial tissues excrete by:
- removing waste like urine
epithelial tissues sense:
- with receptors in skin, ear, nose, or mouth
what are common characteristics of epithelial tissues?
- tightly packed cells with no spaces
- polarity in structures
- avascular (no blood vessels)
- regenerates (active cell devision)
- can be organized into glands
how is epithelial tissues polar?
- different polarities at difference poles/end of cells
- apical and base are the top and bottom
- polar end is facing outwards
how are epithelial tissues classified
by cell shape and number of layers
what’s the difference between simple and stratified
- simple: one layer
- stratified: multiple layers
where is simple squamous found
lungs and blood capillaries for diffusion
whats the function of simple squamous epithelial
- diffusion
- provides slick and friction reduced surface
where is stratified squamous found
- found where protection from where and tear is required
- mouth, esophagus, skin
what is the function of stratified squamous
protects from wear and tear
where is pseudostratified found
trachea
what is the function for pseudostratied squamous
absorption and secretion
what is the function of simple columnar
absorption and secretion
where is simple columnar found
digestive and respiratory tracts
what is the function of simple cuboidal
absorption and secretion
where is simple cuboidal found
kidney tubules and glands
what are transitional cells and where are they found
- cells that vary in shape and that can stretch
- urinary bladder
what is the function of a gland
secrete cells products
what’s the difference between and endocrine and exocrine gland
endo:
- cells products are secreted into IF and distrubuted by blood
- lack ducts
- secrets into body
exo:
- cell products are secreted onto a cell surface
- uses ducts
what do tight junctions and desmosomes do?
form connection between cells
what are micovili? what’s their function? where are they found?
- projections of the cell membranes
- inc surface area for absorption
- digestive tract
what are cilia? what’s their function? where are they found?
- short skeletal appendages that beat in unison
- move fluids across cell surfaces
- respiratory tract
what’s a basement membrane? what’s the function?
- layer formed from glycoproteins
- glues epithelial to connective
what’s the difference between avascular and vascular
avascular: no blood vessels
vascular: contains blood vessels
what does innvervated mean
supplied by nerves
what is the general function of connective tissue
connect, support, protect body parts, transports, insulates
what are the common characteristics of connective tissues
- origin in the embryo
- extracellular matrix (matrix dominates)
- properties of tissue is determined by the nature of the matrix
- vascularization varies
what are the structural elements that are common to connective tissue
- few cells
- ground substance
- extracellular fibers
what is ground substance
- material between cells
- composed of IF and secreted cell products (determines that the ECF us fluid, gel or solid)
what are extracellular fibers
- fibers that provide support and make matrix less pliable
what are the 3 types of extracellular fibers
- collagen: provides strength
- elastic: allows for stretch and recoil
- reticular: form a net
how are CT classified
- based on nature of the ground substance (liquid, gel, solid)
- proper, fluid, support
what is a matrix
ground substance and extracellular fibers secreted by cells
what is the function of loose/areolar CT
- soft wrapping for organs
- fluid media for cells
- reservoir for water and fat
where is areolar/loose CT found
around organs and under skin
what is the function of adipose CT
- reservoir for energy supply
- insulates
- cushions organs
where is adipose found
surrounding organs and under skin
what is the function of dense regular CT
used to handle tensions in one direction
where is dense regular CT found
tendons and ligaments
what is the function of dense irregular (fibrous connective)
handle stresses in many directions
where is dense irregular found
under skin and in membranes
what is the function of cartilage
shock absorption
where is cartilage found
ends of bone, ear, nose
what is the function of bone
support
where is bone located
osteocytes in lacunae and connected to blood vessels
how is blood a connective tissue?
it’s a fluid that acts as a transport medium
what does -blast mean
young cells that are actively synthesizing and secreting matrix
what does -cyte mean
mature cells involved in maintenance and repair of matrix
what does fibro- mean
refers to cells of CT
what does chondro- meant
cartilage
what does osteo- mean
bone
what does adip- mean
fat
what does proper mean in term of CT
lumpy fluid matrix
what are the cells of the areolar CT
- fibroblasts
- macrophages
- mast cells
- lymphocytes
- adipocytes
what are fibroblasts
cells that synthesize matrix of areolar CT
what are macrophages
phagocytic cells of the immune system
what are lymphocytes
cells of the immune system
what are mast cells
- cells that release histamine and heparin
- part of the inflammation reaction
whats histamine and heparin
hista: increases permeability of blood vessels
hep: anticoagulant
what are adipocytes
cells that store fat
what chondroblasts/chondrocytes
cartilage cells
they dont divide
what is lacunae
pools or spaces in matrix that house cells of cartilage and bone
what are osteoblast/osteocytes
bone cells
what is the function of muscle tissue
to contract
what is the function of skeletal muscle
attaches and moves bones
what are some characteristics of skeletal muscles
- not a true cell but is a megacell (many fused cells)
- multinucleated
- striated
- innervated
what is the function of cardiac muscle
pumps blood
what are some characteristics of cardiac muscles
- mononucleate cells with some branching
- striated
- involuntary control
- contains intercalated discs and gap junctions between cells
what is the function of smooth muscles
squeezes fluid through tubes
what are some characteristics of smooth muscle
- not striated
- mononucleate
- involuntary control
what is the basic role of neural tissue
communicated and regulates
what are structural features of Nervous tissue
- cell body
- processes (axons and dendrites)
what are the 2 types of nervoud tissue cells and what are their functions
- neuron: conduct electrical signals
- neuroglia: helps and supports neuron
what is a membrane
- coverings made up of epithelial and connective tissue
what is cancer
loss of a cell’s ability to be a tissue
name some characteristics between normal tissue and cancerous tissue
- uncontrolled division
- loss of specialization
- loss of attachment
- loss of growth and regulatory factors
