Final answer:
Blood pressure and flow are influenced by the heart rate, stroke volume, cardiac output, peripheral resistance, and blood volume in the arterial system, and factors like muscle and respiratory activity in the venous system.
Step-by-step explanation:
The factors influencing blood pressure (BP) and blood flow are complex and multifactorial. In the arterial system, five main variables play a crucial role:
In the venous system, the factors affecting blood flow include venous return, which is influenced by skeletal muscle activity, respiratory activity, and venous valves.
Cardiac output is a key variable and is determined by the product of heart rate and stroke volume. Essential determinants of stroke volume include preload, contractility, and afterload. Contractility can be affected by both positive and negative inotropic agents, including various ions like calcium.
Other factors influencing heart rate and cardiac performance include autonomic innervation, endocrine control, body temperature, oxygen levels (hypoxia), and pH balance. Environmental factors such as electrolytes, metabolic products, and temperature also play a role, emphasizing the importance of maintaining homeostasis.