Blood Flow Is Preferentially Directed to Working Skeletal Muscle During Exercise

Local control of blood flow ensures that only working muscles with increased metabolic demands receive increased blood and oxygen delivery. If the legs alone are active, leg muscle blood flow should increase while arm muscle blood flow remains unchanged or is reduced. At rest, skeletal muscle receives only a small fraction of the cardiac output. In dynamic exercise, both total cardiac output and relative and absolute output directed to working skeletal muscle increase dramatically (Table 30.2).

Cardiovascular control during exercise involves systemic regulation (cardiovascular centers in the brain, with their autonomic nervous output to the heart and systemic resistance vessels) in tandem with local control. For millennia our ancestors successfully used exercise both to escape being eaten and to catch food; therefore, it is no surprise that cardiovascular control in exercise is complex and unique. It's as if a brain software program entitled "Exercise"

Absolute and Relative Costs of Daily Activities

% Maximal Oxygen Uptake

Activity

Energy Cost (kcal/min)

Sedentary 22-Year-Old

Sedentary 70

Sleeping

Was this article helpful?

0 0
Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

Get My Free Ebook


Responses

  • iggi
    How is blood flow directed to muscles during exercise?
    8 years ago
  • calliope longo
    How blood is directed to working muscles?
    8 years ago

Post a comment