Frog Heart Lab, Animal Physiology Essay Example
Chemical and Environmental Effects on the Heart
Introduction
The heart is the centerpiece of the circulatory system, its muscular contractions allow for the timely delivery of essential gases and nutrients to virtually all cells of the body. The pressure created by the heart also plays a vital role in eliminating wastes through organs such as the kidney, thus the heart delivers and helps maintain nutrient and waste composition throughout the body. The heart, like all muscle cells, releases ionic calcium when stimulated which binds to troponin which in turn causes tropomyosin to uncover the myosin-actin binding sites on the muscle. Temperature has effects on the metabolism and activity of all cells. Warmer temperatures increase the kinetic energy of molecules in cells, providing more energy which allows metabolic processes to proceed more quickly. Cooler temperatures, on the other hand, decrease molecular kinetic energy and cause slower metabolic rates in cells and tissues, hence when a bear hibernates, its body temperature is some degree lower than it is during the bear’s active periods.
The heart is also susceptible to certain molecules for which are able to bind to its receptors or diffuse across its membrane and affect intracellular activity and consequently have effects on the overall homeostatic condition of the organism. The Sinoatrial Node (SA Node) acts as the pacemaker of the heart by providing a small, autorhythmic electrical pulses that travel to the atrioventriclar node (AV node) and through the Bundle of His and Purkinje Fibers through gap junctions at the intercalated disks which stimulate the cells of the heart to contract via calcium release. This contraction is similar to a neuron in the sense that a threshold stimulus is needed to cause a contraction, a refractory period follows contraction at which time a new contraction cannot occur. Drugs that have an effect on the tissues of the heart, especially those where the SA Node resides
Introduction
The heart is the centerpiece of the circulatory system, its muscular contractions allow for the timely delivery of essential gases and nutrients to virtually all cells of the body. The pressure created by the heart also plays a vital role in eliminating wastes through organs such as the kidney, thus the heart delivers and helps maintain nutrient and waste composition throughout the body. The heart, like all muscle cells, releases ionic calcium when stimulated which binds to troponin which in turn causes tropomyosin to uncover the myosin-actin binding sites on the muscle. Temperature has effects on the metabolism and activity of all cells. Warmer temperatures increase the kinetic energy of molecules in cells, providing more energy which allows metabolic processes to proceed more quickly. Cooler temperatures, on the other hand, decrease molecular kinetic energy and cause slower metabolic rates in cells and tissues, hence when a bear hibernates, its body temperature is some degree lower than it is during the bear’s active periods.
The heart is also susceptible to certain molecules for which are able to bind to its receptors or diffuse across its membrane and affect intracellular activity and consequently have effects on the overall homeostatic condition of the organism. The Sinoatrial Node (SA Node) acts as the pacemaker of the heart by providing a small, autorhythmic electrical pulses that travel to the atrioventriclar node (AV node) and through the Bundle of His and Purkinje Fibers through gap junctions at the intercalated disks which stimulate the cells of the heart to contract via calcium release. This contraction is similar to a neuron in the sense that a threshold stimulus is needed to cause a contraction, a refractory period follows contraction at which time a new contraction cannot occur. Drugs that have an effect on the tissues of the heart, especially those where the SA Node resides