Cardio and Resp Systems Flashcards
Functions of the cardiovascular system
The cardiovascular system, also known as the circulatory system, is responsible for the transportation of blood, nutrients, oxygen, hormones, and waste products throughout the body.
Two types of circulation
Pulmonary circulation - Deoxygenated blood from heart to lungs (right side of heart)
Systemic circulation - Oxygenated blood which has just returned from lungs to heart then to rest of body
Describe pathway of deoxygenated blood
Blood is delivered to the right atrium from the superior and inferior vena cava. The buildup of deoxygenated blood in the right atrium allows the tricuspid valve to open.
The blood then flows into the right ventricle. From the right ventricle, it’s pumped through the pulmonary semilunar valve then and out the pulmonary arteries to the lungs.
Vena cava –> right atrium —-> tricuspid valve —> right ventricle —-> semilunar valve —-> pulmonary arteries —–> lungs
Describe pathway of oxygenated blood
Blood returns from the lungs through the pulmonary veins to the left atrium.
The build up of oxygenated blood causes the bicuspid valve to open.
The blood then flows into the left ventricle.
Blood is pumped out through the aortic semilunar valve, into the aorta.
Pulmonary veins –> left atrium —-> bicuspid valve —> left ventricle —-> semilunar valve —-> aorta —–> organs
Syncytium
The ability for these cells to transmit electrical signals allows the myocardium to contract as a single unit.
Electrical excitation of the heart
Pathway
1. SA Node: pace maker starts signal
2. Internodal Pathways : signal travels to both atria via these pathways causing next step
3. Atria Contracts
4. AV Node: AV node transmits the electrical signal from the atria into the ventricles. It also transmits the signal along bunde of his
5. Bundle of HIS
6. Right & Left Bundle Branches
7. Purkinje Fibres: which in turn pass the electrical signal to the myocardium that
8. Ventricle Contracts
movements from top to bottom help push blood out of heart
Arteries
Arteries are vessels with a very thick muscular wall, which carry blood away from the heart to the different tissues and organs in the body.
Can recoil
Arterioles
Arterioles are smaller than the arteries and are important in the regulation of blood distribution to the various tissues of the body.
Arterioles are surrounded by rings of smooth muscle and these rings can contract, constricting the arteriole and reducing the amount of blood flow, or relax, opening the arteriole and increasing the amount of blood flow.
Capillaries
Capillaries are the smallest vessels within the body and they have the most important function of all the vessels.
Gas and nutrient exchange happens here
Venules & Veins
Once blood travels through the capillaries, it enters the venules. Venules lead into veins, which return blood to the heart.
Cardiac Output
The volume of blood pumped out of the left ventricle in one minute. Its measure is litres per minute (L/min).
Q = SV (mL) x HR (beats per minute)
Stroke Volume (amount of blood ejected from left ventricle in a single beat)
Ventilation
volume of air moved by the lungs in 1 minute. Combination of inspiration and expiration.
Ventilation = Tidal Volume x Respiratory Frequency
TV: Volume of air each breath
RF: Number of breaths taken per minute
VO₂ max
VO₂ max describes the maximum rate of oxygen consumption during exercise.
VO₂ max depends on:
Oxygen delivery (air exchange in the lungs, pumping power of the heart, blood flow to the muscles)
Oxygen demand of the tissues (especially the mitochondria).
Oxygen Deficit
the amount of oxygen taken in during stressful exercise minus the amount of oxygen that would otherwise have been required for steady-state aerobic exercise.
Lactate Threshold
a point is reached where blood lactate concentrations begin to increase faster than your body can absorb it.
