L1 - Animal Tissues - Tissue, class 9, Science Video Lecture

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animal tissues almost all animals are
made up of tissues tissues are groups of
cells that are similar in structure and
work together to achieve a particular
function animal tissues are grouped into
four basic types epithelial nervous
muscle and connective tissues let's
first look at the epithelial tissue this
tissue covers and protects the internal
and external surfaces of the animal body
epithelial tissue is subdivided into
simple squamous stratified squamous
columnar and cuboidal epithelium based
on the shape and function of yourselves
the simple squamous epithelium is found
in the lining of the alveoli and allows
transport of small molecules across the
membrane it is extremely thin flat and
single layered the stratified squamous
epithelium protects areas subject to
abrasion and is found in the skin it is
multi-layered columnar epithelium acts
as an impermeable barrier against any
bacteria that could be ingested but is
permeable to any necessary ions it is
tall and shaped like a column cuboidal
epithelium aids in absorption and
provides mechanical support it forms the
lining of kidney tubules it is shaped
like a tube
the next issue type is nervous tissue
which consists of a nerve cell or neuron
that has a cell body containing the
nucleus the cell body extends and forms
specialized cell parts called dendrites
and axons these are nerve cells that
help you retract your hand when you
touch a thorn how does this happen
nerve cells carry messages that is the
dendrites bring signals to the cell body
and the axon transmits the information
to the dendrite of another sell these
now impulses allow us to move our
muscles when we want to thus retracting
our hand the brain spinal cord and
nerves are all composed of nervous
tissue
the third tissue type is the muscle
tissues that are responsible for the
movement in our body the three types of
muscle tissues are skeleton smooth and
cardiac the skeletal muscle helps in
locomotion and other voluntary body
movements it is made of long fibers with
alternate light and dark bands or
striations so skeletal muscles are also
called striated muscles smooth muscle
cells provide involuntary movements such
as a contraction of walls they line the
walls of the hollow structures of the
body smooth muscle cells are found in
the intestines and blood vessels they
are spindle shaped flat pointed at both
the ends and broad at the middle the
cardiac or heart muscles are involuntary
muscle cells that contract and relax
throughout life they are cylindrical
branched and uni nucleated
the final tissue we look at is the
connective tissue that binds and
supports body parts and transport
materials connective tissues are
subdivided into blood bone ligament
cartilage areolar and adipose tissue the
blood contains RBC WBC and platelets
that transport gases and other materials
to different parts of the body blood has
a fluid matrix bone cells secrete
calcium that hardens the bone and
supports the main organs of the body
bone cells are solid ligaments function
as a connection between bones they're
fibrous and stretchy cartilage protects
bones by preventing them from rubbing
against each other it is a tough but
flexible tissue areolar fills the space
inside the organs
it is gel-like with both elastic and non
elastic fibers adipose tissues store fat
molecules in conclusion we have seen and
understood the types of animal tissues
they are sub classifications and their
functions
things to remember animal tissues are
grouped into epithelial nervous muscle
and connective tissues epithelial
tissues are subdivided into simple
squamous stratified squamous columnar
and cuboidal epithelium the three types
of muscle tissues are skeletal smooth
and cardiac muscles cells of the nervous
system called nerve cells are
specialized to carry stimulus from one
place to another within the body
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you