Question

(a) Name the three layers of muscle found in the heart wall and briefly describe one function of each.

(b) Briefly describe five differences of cardiac and skeletal muscle.

(c) Briefly describe the three ways in which CO2 is carried in blood. Make sure to comment on any new chemical compounds that are formed as a result of CO2 being carried in blood.

Answer 1

1. ANSWER: The three layers of heart muscle are the epicardium outerlayer, myocardium the middle layer and the endocardium inner layer. Epicardium secretes pericardial fluid which reduces friction between pericardial membranes. Myocardium stimulates the heart muscle to contract to punp blood through the heart. Endocardium protects the valves and heart chambers.

2. ANSWER: Skeletal muscle is voluntary muscle. It is 15% denser fat than adipose tissue. Skeletal muscle is striated in regular parallel bundles of sarcomeres. Gets fatigued easily.

Cardiac muscle is involuntary muscle. Cardiac muscle is also straited but are connected at branching irregular angles. Cardiac muscle does not undergo fatigue.

3. ANSWER: Carbondioxide of about 5% is dissolved in plasma. 10% is combined directly to hemoglobin as carbaminohemoglobin. 85% is transported in the form of hydrogencarbonate ions.