Tissues 1 Flashcards
What are the four primary tissues?
Epithelia tissue
connective tissue
muscle tissue
nerve tissue
Describe the characteristics of epithelial tissue?
-covers surfaces
-cells connected
-separates compartments
-cells define function
-diversity of secondary functions
-form glands
-good regenerative powers
Describe the characteristics of connective tissue?
-connects and supports
-extracellular matrix and fluid defines the structure and function
-liquid to solid matrix
-fewer cells than epithelial
Give examples of connective tissue?
lose connective tissue for e.g. blood, bone , cartilage and adipose
Describe the characteristics of muscle tissue?
-contractile
-long thin cells so can pull
-cytoplasm of cells packed with apparatus to contract
-can shorten length and therefore close down spaces
names of diff kinds of muscle cells?
skeletal
cardiac
smooth
Describe skeletal muscle cells?
striated(visible bands), highly ordered arrangement of contractile proteins
Describe cardiac muscle cells?
striated, branched , less highly ordered arrangement
Describe smooth muscle cells?
non striated , random ordered arrangement
Describe the characteristics of nervous tissue?
-for communication
-features neurons and support cells
-receive, generate and transmit electrical signals
-integrates information
Describe a neuron cell?
axon=conducts electrical impulses away from cell body
axon terminal=end of axon and release neurotransmitters to communicate with other neurons
dendrites=receive incoming signals and transmit towards cell body
soma=cell body
How does epithelial tissue maintain coverage of surfaces?
-no contact inhibition
-cell - cell junctions
-cell- ECM (extra cellular matrix) junctions
Characteristics of epithelial tissues junctions?
-have to allow things in and out
-look alike
-close together
-connected by cell - cell junctional complexes
tight/occluding cell junctions?
-seals intercellular spaces
Desmosomes?
Adhering junctions, function of having firm anchorage.
Have fibrals sticking out ( tono fibrals)
-hold together two cell membranes
What junctions are in epithelial cells?
tight and desmosomes
Describe gap junctions?
-must allow things to go through
-for communicating
What is the basement membrane?
The basement membrane is composed of Reticular Lamina on the bottom and Basal Lamina on the top. All epithelia lie on the basement membrane.
How does epithelia connect to basement membrane?
By half desmosomes (hemidesmosomes)
What are the secondary roles of epithelia?
-Are thick-to be protective
-Are thin- for diffusion for blood cells into tissues
-Have structures- for movement of substances from lumen, for e.g. cilia
-Absorption-to increase S.A of of apical surface have projections into lumen (villus and microvillous)
for e.g. gastrointestinal system
What is cilia?
Finger like projections from apical surface
Epithelia cells that line trachea have cilia to waft dust towards throat
What are the classifications of simple epithelia? (one layer)
Squamous=flat
cuboidal=cubical
columnar=columnal
What is stratified epithelia?
Many layered epithelia and top layer defines name
What is epithelia is only in urinary system?
Transitional epithelia - uroepithelia
Top layer can expand when bladder is full
