Question

1. describe the difference between pulmonary circulation and coronary circulation. (4 points)
2. describe each of the three types of muscle tissue. (6 points)

Explanation:

Question 11

• Pulmonary Circulation: It is the circulation of blood between the heart and the lungs. Deoxygenated blood from the right ventricle is pumped to the lungs via the pulmonary artery. In the lungs, gas exchange occurs (carbon dioxide is removed, oxygen is picked up), and oxygenated blood returns to the left atrium via the pulmonary veins. Its main function is gas exchange (oxygenation of blood and removal of carbon dioxide).
• Coronary Circulation: This is the circulation of blood that supplies the heart muscle (myocardium) itself. The coronary arteries (branching from the aorta) deliver oxygenated blood to the heart muscle, and coronary veins return deoxygenated blood to the right atrium (usually via the coronary sinus). Its main function is to provide oxygen and nutrients to the heart muscle and remove metabolic wastes from it.

1. Skeletal Muscle: Attached to bones (via tendons). Striated (has alternating light and dark bands), voluntary (under conscious control). Cells are long, cylindrical, multinucleated. Functions in movement of body parts, posture, and heat production (e.g., muscles in arms, legs).
2. Smooth Muscle: Found in walls of internal organs (e.g., stomach, intestines, blood vessels, uterus). Non - striated, involuntary (not under conscious control). Cells are spindle - shaped, uninucleated. Functions in involuntary movements like peristalsis (in digestive tract), regulation of blood vessel diameter, and control of organ size/shape.
3. Cardiac Muscle: Found only in the heart. Striated, involuntary (though it has some inherent rhythmicity). Cells are branched, have intercalated discs (which help in electrical and mechanical connection between cells), and are usually uninucleated (sometimes binucleated). Functions in pumping blood throughout the body; its rhythmic contractions maintain circulation.

Answer:

• Pulmonary Circulation: Circulates blood between heart and lungs. Deoxygenated blood from right ventricle goes to lungs (via pulmonary artery) for gas exchange (loses CO₂, gains O₂), then oxygenated blood returns to left atrium (via pulmonary veins). Function: Gas exchange for blood.
• Coronary Circulation: Circulates blood to/from heart muscle (myocardium). Oxygenated blood from aorta via coronary arteries to heart muscle; deoxygenated blood returns to right atrium (via coronary veins/sinus). Function: Supply heart muscle with O₂, nutrients, and remove wastes.

Question 12