FACT
WATCH: a video
about the different
tissue types in
animals
See video:
SHORTCODEat
http://www.everythingscience.co.zaFACT
Pseudostratified
epithelium refers to
epithelium
consisting of one
layer but looking as
though it consists of
more than one layer.FACT
The skin is the
largest human
organ.2.Connective tissueassists in support and protection of organs and limbs and depending
on the location in the body it may join or separate organs or parts of the body.
3.Muscle tissueenables various forms of movement, both voluntary and involuntary.
4.Nerve tissueis responsible for the carrying of electrical and chemical signals and
impulses from the brain and central nervous system to the periphery, and vice versa.We will now look at each tissue type, examining its structure and function as well as its
specific location in the body. You will be expected to recognise microscope images of each
tissue type and from them produce biological drawings.
Epithelial tissue DUMMY
Epithelial tissues are formed by cells that cover surfaces (e.g. skin) and line tubes and cavities
(e.g. digestive organs, blood vessels, kidney tubules and airways). Epithelial tissue usually
consists of a single cell layer of cells, however in certain cases there may be more than one
layer. All epithelial tissues are free surfaces attached to the underlying layers of a basement
membrane. There are different types of epithelial tissue which are named according to the
number of layers they form and the shape of the individual cells that make up those layers.
Simple epitheliumrefers to asinglelayer of cells. Stratified epitheliumrefers totwo or
morelayers of cells. Squamous epithelium refers to flattened calls, cuboidal epithelium
refers to cells that are cube-shaped and columnar epithelium refers to vertically elongated
cells. Ciliated epithelium refers to epithelial cells that contain many tiny hair-like projections.
Figure 5.20: The different types of epithelial tissue found in mammals.General functions of Epithelial Tissue- Provides a barrier between the external environment and the organ it covers.
- Specialised to function in secretion and absorption.
- Protects organisms from microorganisms, injury, and fluid loss.
- Excretes waste products such as sweat from the skin.
The different types of epithelial tissue are classified according to their shape. The major
categories we are going to examine aresquamous, columnar and cuboidalepithelium. The
table presents each of them in detail.
Chapter 5. Plant and animal tissues 131