Answer:
1. What two chemical content(s) of mast cells enable them to exhibit their unique property on mesentery spread?
Heparin and histamine. Mast cells are commonly found in connective tissue and can be identified under the microscope thanks to their densely-stained granules that contain heparin -a powerful anticoagulant-, and histamine -a substance involved in inflammatory response-.
2. What naturally occurring substance shares the properties of an elastic fiber?
Elastic fibers contain a protein called elastin that allows them to stretch, making them of great importance in tissues such as ligaments.
3. Give one difference between dense and loose connective tissues, which is observable under the microscope.
This classification of the connective tissue relies on <em>how densely packaged are the fibers in it</em>. Loose connective tissue contains small bundles of collagen fibers, separated by the ground substance. Dense connective tissue, on the other hand, is very rich in collagen fibers and has very little ground substance.
4. Give one difference between regular and irregular dense connective tissues which is observable under the microscope.
Irregular dense connective tissue has fibers spreading on multiple orientations, which allows the tissue to lessen the impact of forces coming from multiple directions - this gives this tissue a disorganized appearance under the microscope. Regular connective tissue is the opposite: the fibers are parallel to one another, which makes them capable of resist tension coming from one direction.
