Part 2: Heart and Lungs

factors affecting O2 uptake

1. O2 extraction

2. Capillarization

What is O2 extraction?

• Ability of tissues to extract O2

• Affected by mitochondria number and

enzyme efficiency

What is capillarization?

• Number of capillaries in tissue

• Affects the ability of cardiovascular

system to place RBCs close to the

working tissues

the respiratory system does…

• Delivers oxygenated air to blood

• Removes CO2 from blood

• Regulates acid-base balance

What is the conduction zone of the respiratory system?

filters, humidifies and adjusts air to body’s temperature

what is the respiratory zone in the respiratory system?

gas exchange

Respiration includes…

1. ventilation

2. gas exchange

3. oxygen utilization

ventilation is…

Inspiration and Expiration, movement of air gases in and out of lungs (O2, CO2, Nitrogen)

gas exchange is…

• Between air and blood

• Between blood and other tissue

Oxygen utilization is…

• At the tissues

• Cellular respiration

During inspiration…

• Muscles contract

• Cavity and lungs expands

• Lung pressure decreases

• Air flows in

during expiration…

• Muscles relax

• Cavity and lungs shrinks

• Lung pressure increases

• Air flows out

Alveoli are surrounded by…

pulmonary capillaries

alveoli receive…

• O2 rich air from outside air

• CO2 rich blood from capillaries

How is gas diffusion possible in alveoli?

• Alveoli structure

• Gas concentration difference

• O2 to capillaries and left ventricle

• CO2 to alveoli and outside air

Exercise benefits/adaptations for the heart

• increased heart size

• increased stroke volume

• increased maximal cardiac output

• lower resting heart rate

Exercise benefits/adaptations for the capillaries

• increased # of caps in muscles

• increased total blood volume

• increased volume of red blood cells

• increased hemoglobin levels

Exercise benefits/adaptations for muscles

• increased number and size of mitochondria

• increased oxygen consumption

• increased oxygen extraction

• increased muscular endurance

Exercise benefits/adaptations for lungs

• increased lung capacity

• increased gas exchange in lungs

• increased endurance of respiratory muscles

• faster recovery time after exercise

higher atria and ventricle size=

higher amount of blood pumped per heart

higher wall thickness=

higher rate of contraction, higher rate of ventricles emptying

Result of large atria and ventricles and thick heart walls…

maximal cardiac output, higher pumpin efficiency

Higher surface area and lower distance between blood and tissues means…

high O2 and CO2 diffusion, more transport of nutrients, higher O2 extraction

Higher # of RBCs =

higher erythropoiesis (RBC formation) in bone marrow

higher total blood volume=

higher O2 amount extracted, higher O2 carrying capacity, lower blood thickness

Higher O2 amount extracted=

higher O2 carrying capacity, and lower blood thickness

Exercise

more breath depth, higher breathing rate, more gas exchange, more efficient gas exchange

what are the two common enviromental changes

altitude and temperature

altitude environment effects

low gas density, lower oxygen for each breath

Bodily effects of altitude

hyperventilation, acute mountain sickness, higher heart rate, higher O2 capacity over long term (more RBCs, more Hb per RBC)

during exercise body heat must…

be released by additional means, 80% of energy is released as heat

bodily effects of exercise in the heat…

sweating (hyperthermia/heat stroke), higher heart rate (higher peripheral vasodilation and heat dissipation), lower muscle flow, lower stroke volume (high fluid loss and low blood volume)

Bodily effects on exercise in the cold

body is less capable to adapt to prolonged exposure, hypothermia, shivering (bodys way to move body and create heat), lower peripheral vasoconstriction, low skin blood flow and heat dissipation