tissues Flashcards
describe what is meant by tissues
a collection of cells containing a predominant cell type that work together and perform the same function
4 basic tissue types
connective
epithelial
muscle
nervous
characteristics of epithelial tissue
cell rich
cells bound tightly together
junctional complexes
where are epithelial cells found
on the surface of skin, blood vessels, glands etc.
(lie on a basement membrane)
functions of epithelial cells
protection
absorption
diffusion
secretion
characteristics connective tissue
few cells
cells are far apart
spaces filled with fibres + ground substance +fluid (ECM)
where is connective tissue found
in bone and blood
function of connective tissue
connects and supports
ECM provides structural and functional properties
characteristics of muscle tissue
elongated thin cells
cytoplasm packed with contractile apparatus
function of muscle tissue
shortens lengths, closes down spaces
types of muscle tissue
skeletal
smooth
cardiac muscle
characteristics of nerve tissue
angular-shaped neurons with prominent nucleoli and communication processes
where is nerve tissue found
cerebellum
function of nerve tissue
receives, generates and transmits electrical signals
integrates information
shape of surface layer of cells classification
squamous, cuboidal, collumnar
number of layers classification
simple (one layer), stratified (multiple layers)
cell surface specialisation classifications
cilia, villi, microvilli, keratin
describe junctional complexes
junctions between epithelial cells which help keep them close together
the function and origin of cilia
movement of particles in the respiratory system
the function and origin of microvilli
increase area for absorption (brush border) found in the GI tract
types of connective tissue
loose CT
dense CT
specialised CT
types of loose CT
areolar
adipose
describe areolar CT
an aggregation of loosely arranged fibres and many cells of differing types
location of areolar CT
beneath epithelia that cover surfaces or line tubes/cavities
function of areolar CT
site of defence against bacteria
describe adipose tissue
specialised loose CT with abundant fat storing adipocytes
characteristics of adipose tissue
single large droplet of lipid pushes nucleus to one side and flattens cytoplasm to a thin rim
rich blood supply
location of adipose tissue
in connective tissue under skin
function of adipose tissue
insulation around organs for protection
describe dense irregular connective tissue
thick collagen fibres that run in all directions
include fibroblasts
function of dense irregular CT
able to withstand tension exerted in many directions
provides structural strength
location of dense irregular CT
dermis of the skin
submucosa of digestive tract
fibrous capsules of organs and joints
describe dense regular connective tissue
closely packed collagen fibres all running in the same direction
poorly vascularized
function of dense regular CT
attaches muscles to bones to muscles, bones to bones
withstands great tensile stress when pulling force is applied in one direction
location of dense regular CT
tendons and ligaments
muscle types
skeletal muscle
cardiac muscle
smooth muscle
characteristics of skeletal muscle
striated
attaches to skeleton
voluntary
characteristics of cardiac muscle
striated branched
found in heart
involuntary
smooth muscle
non striated
found in organs
involuntary
4 regions of neurons
cell body
dendrites
axon
terminals
what are glands
derivatives of epithelium
describe exocrine
remain in contact with epithelium by ducts
where do exocrine glands secrete
into lumen of tubes
describe endocrine
loose contact with epithelium
where does endocrine glands secrete
into blood vessels
unicellular gland
goblet cells
multicellular gland
acini
shapes of exocrine glands
tubular
acinar
tubuloacinar
mucous secreting exocrine glands
pale staining
e.g mucous glands of trachea
serous secreting glands
dark staining
exocrine part of pancreas
mechanisms of exocrine secretion
merocrine secretion e.g sweat
apocrine secretion e.g mammary
holocrine secretion e.g sebaceous
function of myoepithelial cells
contractile function - they help in expelling secretions from the lumen of gland secretory units (acini)
