IB SEHS Unit 2 - Cardiovascular & Pulmonary Systems

Leukocytes (white blood cells)

Leukocytes (white blood cells)

• protects body from infections

Heart Rate (HR)

• amount of times your heart beats per minute

Erythrocytes (red blood cells)

• delivers and carries oxygen to and around the body

Components of Blood

• plasma (55%)

• erythrocytes (45%)

• leukocytes (less than 1%)

• platelets (less than 1%)

Platelets

• clot, stop, and slow bleeding

Atrioventricular (AV) Node

Location:

• between right atrium and right ventricle

Function:

• slows the electrical signal before it enters the ventricles

• the delay allows the atria to contract before ventricles do

• lub —— dub

Sinoatrial (SA) Node

Location:

• right atrium

Function:

• impulse starts in the right atrium causing the atria to contract, pushing the blood to the ventricles

• heart’s natural pace maker

Plasma

• Liquid part of the blood (55%)

Stroke Volume (SV)

• volume of blood ejected during each ventricular contraction

• the amount of blood your heart pumps per beat

Blood Pressure

• the pressure circulating blood against the walls of arteries

Heart’s Electrical Impulse (Intrinsic Regulation)

1. SA node

2. AV node

3. Bundle of His

4. Purkinje fibers (bundle of branches)

Cardiac Output (CO)

• amount of blood your heart pumps per minute

• CO = HR x SV

Bundle of His

Location:

• inferior to the AV node

Function

• sends impulse to the purkinje fibers

Purkinje Fibers (bundle of branches)

Location:

• throughout the ventricles

Function:

• sends impulse to muscular walls of ventricles so that they can contract

• this contraction forces blood out of the heart and into the lungs THROUGH the right pulmonary arteries or through the aorta

VO2 Max

• maximal oxygen consumption

  • how much oxygen your body can take in to produce

  • higher in males than females

  • higher in trained than untrained individuals

  • as intensity of exercise increases, so does vo2 max

Cardiovascular Drift

• how we maintain cardiac output during prolonged exercise

  • increase HR to compensate for decreased SV

• Thermoregulation - regulating body temp

  • sweating - causes a decrease in blood volume (losing plasma h2o from the blood) and an INCREASE in viscosity - becomes thicker

    • less blood goes back to the heart (lower venous return

• Blood vessels dilalate - get bigger

  • more blood goes to the skin to release heat (feel hot, turn red)

Pathway of Blood Through The Heart

1. right atrium

2. SA node

3. right ventricle

4. AV node

5. right pulmonary arteries to go to the lungs

… after picking up oxygen from the lungs

6. left pulmonary veins

7. left atrium

8. left ventricle

9. out of the body through the aorta

Diastolic Blood Pressure

• 2nd/bottom number of blood pressure reading

• The pressure in the arteries when the heart is resting (ventricles relax)

Systolic Blood Pressure

• 1st/top number of blood pressure reading

• the pressure in the arteries when the heart beats (ventricles contract)

Total Lung Capacity (TLC)

• volume of air in the lungs after a maximum inhalation

• the maximum amount of air your lungs can hold

• approximately 6L

Vital Capacity (VC)

• maximum volume of air that can be exhaled after a maximum inhalation

Tidal Volume (TV)

• volume of air breathed in and out in any one breath

Pulmonary Ventilation

• breathing

Breathing In (Inspiration)

• intercostal muscles and diaphragm contract and flatten

• chest expands upwards and outwards

• volume increases (lungs get bigger)

• pressure decreases (more room for oxygen)

• gas moves from high pressure to lower pressure

  • oxygen rushes into the lungs

Breathing Out (Expiration)

• intercostal muscles and the diaphragm relax

• chest returns to normal size

• volume decreases (lungs get smaller)

• pressure increases (less room for oxygen)

• gas moves from high pressure to lower pressure

  • carbon dioxide leaves the body

Structures of the Ventilatory System

• nose

• mouth

• larynx (voice box)

• pharynx (throat)

• trachea (wind pipe)

• lungs

• bronchi

• bronchioles

• alveoli (where gas exchanges occur)

Residual Volume (RV)

• volume of air still contained in the lungs after a maximal inhalation

Expiratory Reserve Volume (ERV)

• volume of air in excess tidal volume that can be forcibly exhaled

• air leftover after you breathe out

  • breathe in

  • breathe out

  • now push out any extra air after that breath out

    • THAT is your ERV

Inspiratory Reserve Volume (IRV)

• additional inspired air over and above your tidal volume

• amount of air you can forcibly inhale after a normal breath

  • breathe in

  • breathe out

  • breathe in again

    • THIS is your IRV

    • common with heavy exercise

Functions of Conducting Airways

• easier pathway for airflow

• defense against germs and chemicals

• warming and moistening of the air

Gas Exchanges at The Alveoli

• diffusion from high pressure to lower pressure to increase oxygen and decrease carbon dioxide