(a)(i) Draw and label.the mammalian heart.
(ii) Explain briefly pulmonary circulation in mammals.
(b) State five processes by which the mammalian body reduces its temperature.
Explanation
a(i) Diagram of the mammalian heart
(a)(ii) Pulmonary circulation in mammals takes the following process: The heart muscles contract, allowing de-oxygenated blood from the right ventricle to pass through the pulmonary valve into the pulmonary artery to the lung capillaries for exchange of oxygen and carbon dioxide. Oxygenated blood from the lungs then return by the pulmonary vein to the left auricle.
(b) The processes by which mammalian body reduces its temperature are:
(i) relaxation of hair erector muscles
(ii) increased sweat production
(iii) vasodilation
(iv) reduction in heat generated by muscles
(v) reduction of metabolic activities by the body
(vi) conversion of energy into ATP instead of heat
(vii) panting/yawning also reduces temperatures.