Pg 17-31 Cardiovascular system Flashcards
Systemic Circulation
The left ventricle pumps oxygenated blood through the aorta to the body, while deoxygenated blood returns via the vena cava to the right atrium.
Pulmonary circuit
The right ventricle pumps deoxygenated blood to the lungs via the pulmonary artery, and oxygenated blood returns to the left atrium via the pulmonary vein.
circulation of blood
Thermoregulation
Maintenance of body temperature and the heat exchange that occurs between the body and the environment.
Core temp:
Core temperature 36.5 – 37.5 degrees
Factors that influence the body’s core temperature during exercise:
muscle use and energy production, increased blood flow around the body, changes in environmental conditions such as heat and humidity.
Vasodilation
The body increases blood flow to skin to release heat through sweating. Blood vessels dilate to aid cooling.
Vasoconstriction
Blood flow to the skin decreases, redirecting it to organs to reduce heat loss as blood vessels contract.
Blood flow + performace
During exercise, vasodilation (to skin) and vasoconstriction (to organs) can reduce blood flow to muscles, limiting energy production and performance.
Sweat Production During Exercise
Body generates heat -> Hypothalamus triggers cooling -> Blood vessels dilate -> Blood flows to skin -> Heat transfer to environment -> Sweating.
Hyperthermia:
A rise in core temperature above 37.5–38.3°C, placing stress on the body’s thermoregulation and cardiovascular system.
Hyperthermia in the Cardiovascular System
To cool the body, the cardiovascular system increases blood flow to the skin (vasodilation) and boosts sweat production for heat loss.
How Hyperthermia Impairs Performance
Less blood flow reaches working muscles, reducing oxygen delivery. Sweating causes fluid loss, lowering blood plasma and leading to fatigue and decreased performance.
Hypothermia:
A drop in core temperature below 35°C, causing the body to struggle with heat loss and maintain function.
Hypothermia in the Cardiovascular System
To conserve heat, the cardiovascular system redirects blood flow to major organs and vasoconstricts blood vessels near the skin to minimize heat loss.
How Hypothermia Impairs Performance
Less blood flow reaches working muscles, reducing oxygen delivery and muscle function, leading to stiffness, slower reactions, and fatigue.
Increased Heart Rate (HR) & Exercise
HR increases as exercise intensity rises to meet the muscles’ oxygen demands and remove waste.
Max & Resting HR
Resting HR ~72 BPM, can exceed 200 BPM at max effort.
HR Response to Exercise
HR rapidly increases at the start of exercise and returns to resting levels after stopping.
What is Stroke Volume (SV)?
Stroke Volume (SV) is the amount of blood ejected from the left ventricle with each heartbeat. Measured in mL/beat.
How does exercise affect Stroke Volume?
SV increases during exercise to deliver more oxygen to muscles.
What limits Stroke Volume during high-intensity exercise?
High heart rates reduce filling time, limiting SV increase.
What is the average stroke volume at rest for females and males?
60 mL/beat for females and 80 mL/beat for males.
What happens to Stroke Volume in trained athletes?
Trained athletes have a higher stroke volume at rest and during exercise.
