Biology Questions and Answers
- What are the specialized
structures that help the
adhesion between cells?
The structures resof the epithelial cells arponsible called ce for the unionell
junctions. Tinterdigitations,he main cell j desmosomes, zunctions aronulae
adherens (adherens junction), tight
junctions (zjunctions. onula occludens) and gap
- Is the epithelium
vascularized? How do
nutrients and oxygen reach
the epithelium? Why is this
feature an important
evolutionary acquisition?
Epithelia are not vascularized
(capillaries dcells). The epithelium eo not directly reach thxchanges eir
substances by diffusion with the
connective tissue situated under it.
Since the epithelia are not vascularized
minuscule skin ihappen all the time donjuries or scratches that not trigger
bleeding and do not expose the blood to
contaminationThis is an important pr from external agents.otective strategy (^)
discovered by evolution.
- How are the epithelial
tissues classified?
The epithelial tissuesaccording to the shape of the cells that are classified (^)
form it (epithelial cells may be cuboidal,
columnar, or to the number of layers in which thossquamous) and accordinge
cells are placed in the tissue (into
simple or stratified).
The main types of epithelial tissues are
simple cuboidal, simple simple squamous, stratified scolumnar,quamo (^) us
and pseudostratified columnar
(resembling mactually having only one). There areore than one layer but
also stratified cuboidal and stratified
columnar epithelia (rare).
- How different is the simple
cuboidal epithelium from the
columnar epithelium? Where
can these epithelia be found in
the human body?
The simple cuboidal epithelium is made
of a single laycells. The simple columer of cuboidal enar epithelium ispithelial (^)
made of a single layer of prismatic cells.
The simple cufound, for example, in the renal tubulesboidal epithelium can be (^)
and in the wallsThe simple columnar is th of the thyroid follicles.e epithelium
that covers internally the intestines, the
stomach anexample. d the gallbladder, for
- How different is the simple
squamous epithelium from the
stratified squamous
epithelium? Where can these
epithelia be found in the
human body?
The simple squamous epithelium is
made of a single (squamous) cells. The stratifiedlayer of flat (^)
http://www.biology-questions-and-answers.com