list the various types of tissue present in animals and explain them.
Answers
Answer:
there are four types of tissue in animal that is epithelium tissues, muscular tissues, connective tissues, nervous tissue.
Animal Tissues
There are four types of tissues found in animals: epithelial tissue, connective tissue, muscle tissue, and
nervous tissue. In this lab you will learn the major characteristics of each tissue and examine various
types of each tissue under the microscope.
I. Epithelial Tissue
Epithelial tissues line body surfaces and cavities, as well as form glands. The cells of the tissue are
closely connected to each other via cellular junctions and because epithelium is found on the edges of
organs, it has two distinct surfaces. The apical surface is exposed to the body cavity or exterior, while
the basal surface is adjacent to the underlying tissue (see the figure below). Epithelia contain no blood
vessels (they are non-vascular) and are dependent upon the underlying connective tissue for nutrients
II. Connective Tissue
Connective tissues vary widely in their form and function, but they are all characterized by the presence
of extracellular matrix. The extracellular matrix is nonliving material composed of protein fibers and
ground substance. The protein fibers are composed of collagen (which gives strength) or elastin (whichgives flexibility). The number and type of fibers differs between the various types of connective tissue.
The ground substance fills the spaces between the cells and the fibers. It contains interstitial fluid
(tissue fluid) and large polysaccharide molecules. The consistency of the ground substance can vary
from liquid to gel-like to a solid.
**Hint: Because connective tissue consists largely of extracellular matrix, the cells that are present will
be scattered among the matrix components. For most of these slides (adipose tissue is an exception),
you will not see cells directly adjacent to other cells as they are in epithelial tissue.
III. Muscle Tissue
Muscle tissue is specialized for contraction. The cells are elongated, and are also known as muscle
fibers. They contain the contractile proteins actin and myosin, which interact to shorten and elongate
the cells. There are three different types of muscle tissue: skeletal, cardiac, and smooth. Examine
each type of tissue using the muscle composite slide. (*The skeletal and smooth muscle are shown as
part of organs, so they are not the only tissue present)
IV. Nervous Tissue
Nervous tissue is specialized for communication and composes the brain, spinal cord, and peripheral
nerves. The tissue consists of two major cell types: neurons and glial cells. Neurons communicate with
each other via electrical and chemical signals. They have nucleated cell bodies and two types of
elongated cellular processes: dendrites – which receive signals, and axons – which send signals.
Glial cells are the support cells of nervous tissue. There are several different types with various
functions, including maintaining proper ion concentrations in the fluid surrounding neurons, generating
myelin (an insulating material that surrounds some axons), and cleaning up debris.
Examine the slide of nervous tissue (giant multipolar neuron slide). Note the large neurons with theirelongated cellular processes and the smaller, more numerous glial cells.