SPLs Flashcards
What are the main functions of the respiratory and cardiovascular systems?
The respiratory system is designed to allow gas exchange to occur easily and efficiently. In particular, uptake of oxygen and exhalation of carbon dioxide are the prime goals. The cardiovascular system is designed to efficiently deliver the oxygen to the tissues and transport the waste products of metabolism away from the tissues. It is controlled in such a way that the blood flow and delivery of oxygen matches the metabolic needs at any particular time.
What is meant by the statement that the pulmonary and systemic cardiovascular systems are arranged in series?
The pulmonary and systemic systems are arranged in series thus blood flowing through one system then flows through the other. Each is pumped by the heart, the right in the case of the
pulmonary system, the left in the case of the systemic system. Although the pressures in the two circulations are different, the flows must be the same otherwise blood would pool in one or other circulation. A consequence of this is that the output of the two sides of the heart must change in parallel.
The vascular supplies to the organ systems of the body are arranged in parallel. What is the functional significance of this arrangement?
The fact that the vascular supplies are arranged in parallel is important since it allows the flow to one vascular bed (e.g., supplying the kidney) to be altered independently of the others (e.g., skin). Thus, the vascular needs of a particular organ can be matched to its requirements without compromising the flow to other organs; i.e., the blood flow to different organs/tissues can be DIFFERENTIALLY regulated.
What is the functional significance of the valves in a. the heart b. the veins?
Valves are important in that they allow blood flow to occur in one direction only.
a) Within the heart they direct blood through the heart and into the pulmonary artery and the aorta.
b) Within the veins, they direct blood towards the heart and stop backflow of blood; particularly important in the lower limbs where blood is flowing against gravity.
What is the autonomic nervous system? What are its two principle components?
The autonomic nervous system is a set of motor nerves that innervate cardiac muscle, smooth muscle and secretory glands. It is composed of the SYMPATHETIC and PARASYMPATHETIC components.
