Alvaro Comino
LAB REPORT 5
ANIMAL ORGANS
I. Abstract
In this experiment, identification of different animal organs was performed. Also, the different types of tissues of each organ were to be identified. For this, different already prepared slides were chosen and observed under the microscope to then identify and draw the different parts.
II. Introduction
There are 7 different organs each composed of different types of tissues.
1. Arteries and veins: They have the same layers of tissues in their walls, but the proportions of these layers differ. Lining the core of both is a thin layer called endothelium, and covering each is a sheath of connective tissue. The difference between both comes in the intermediate layers of elastic and muscular fiber, which in the artery are thick and in the veins are less developed. Arteries have to stand big pressure waves that come from the heart. Valves prevent blood flowing in the wrong direction.
2. Integumentary system (skin): It consists on the skin, nails, hair and cutaneous glands. Skin is the largest organ in the body and its made of the superficial layer called epidermis, and a deeper layer called dermis. There is also a third layer which is not part of the skin but serves to anchor the skin to underlying bone and muscle tissue, and its called hypodermis. The skin provides a barrier against water microorganisms, solar radiation and others.
3. Digestive system: Even if very different and specialized processes take place in the digestive track, the wall of the digestive track from the mouth to the anus is composed mainly of 4 basic layers or tunics:
* Mucosa: It varies from stratified squamous (able to resist abrasion) to columnar with a brush border for absorption. The lamina propia is a connective tissue layer that supports the epithelium; blood vessels in it nourish the epithelium. The muscularis mucosa is an incomplete layer of smooth muscle cells that separates the mucosa and...