Tissues Test - 74

The Haversian canals, a characteristic feature of the mammalian bones, are present in the matrix. Haversian canals are a series of tubes around narrow channels formed by lamellae. They contain the bone’s blood vessels and nerve fibres. So, the correct answer is option C. 

A. The epicardium is the outermost layer of our heart

B. The endocardium is the innermost layer of our heart. It lines the inner surfaces of the heart chambers which also includes the heart valves.

C. The cardiac muscle layer of the heart is known as the myocardium. These are made up of cardiomyocytes. The myocardium is found in the walls of all four chambers of the human heart.

So the correct answer is Myocardium. Thus the correct option is C.

Basophils: 0.5–1.0 percent. Eosinophils: 1–4 percent. Lymphocytes: 20–40 percent. Monocytes: 2–8 percent, Neutrophils: 40% to 60% Lymphocytes: 20% to 40%.

The haemocytometer is a counting-chamber device originally designed and usually used for counting blood cells. The hemocytometer was invented by Louis-Charles Malassez and consists of a thick glass microscope slide with a rectangular indentation that creates a chamber. Hemocytometer remains the most common method used for cell counting around the world. The most frequently used haemocytometer is the Neubauer (or ‘Improved Neubauer’) chamber. Other haemocytometers include the Burker, Thoma and Fuchs-Rosenthal. Using these, the particles (e.g., leucocytes, erythrocytes, thrombocytes, bacteria, fungus spores, pollen) are visually counted under a microscope.

1. Gap junctions facilitate the cells to communicate with each other. So, this is a wrong statement.

2. Areolar tissue contains various cells like fibroblasts, macrophages, adipocytes, mast cells, and plasma cells. This statement is true.

3. Tight junctions help to stop substances from leaking across tissues. So, it is a wrong statement.

4. Adhering junctions cement the adjacent cells together. Hence, it is a wrong statement.

5. Cells of connective tissue except blood secrete fibers of structural proteins called elastin. It is a true statement.

Hence, the correct option is B. Because I, III, and IV only are wrong answers.

Muscle fibres of smooth muscle do not show striations which means they do not have alternate light and dark bands, like in skeletal muscles. 

A root hair, or absorbent hair, the rhizoid of a vascular plant, is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. In plants with secondary growth, the epidermis of root and stem is usually replaced by a periderm through the action of a cork cambium. 

The given diagram is of areolar tissue (loose connective tissue). It is found between the skin and muscles, around blood vessels and nerves, and in the bone marrow. It fills the space inside the organs, supports internal organs, and helps in the repair of tissues.