Structure Of The Heart Flashcards
What is the heart?
- The heart is a muscular organ that lies in the thoracic cavity behind the sternum.
- Operates continuously throughout the life an organism
What is the heart split up into?
Two pumps lying side by side
What does the pump on the left side of the heart deal with?
Oxygenated blood from the lungs
What does the pump on the right of the heart deal with?
Deoxygenated blood from the lungs
What are the two chambers of the pumps?
- Atrium
* Ventricle
What is the atrium?
Thin walled and elastic and stretches as it collects blood
Why does the ventricle have thick walls?
• Has a much thicker muscular wall as it has to contract strongly to pump blood some distance, either to the lungs or to the rest of the body
Why does the heart have two pumps?
- Blood has to pass through capillaries in order to present a large surface area for exchange of gasses
- This results in a very large drop in pressure, and the blood flow to the rest of the body without the second pump would be very slow
- The blood is returned to the heart to increase its pressure before it is distributed to the rest of the body
What is the purpose of the right ventricle?
- Pumps blood only to the lungs
* Has a thinner muscular wall than the left ventricle
What is the purpose of the left ventricle?
- Has a thick muscular wall
* This allows it to contract to create enough pressure to pump blood to the reset of the body
When do the pumps pump/
- Both pumps pump in time with each other
- Both atria contract with together
- Then both ventricles contract together pumping the same volume of blood
What is the purpose of valves?
Prevent backflow of blood into the atria when the ventricles contract
What are the two valves?
- Left atrioventricular valve ( bicuspid )
* Right atrioventricular valve ( tricuspid )
What are each of the chambers of the heart connected to?
Each of the four chambers of the heart are connected to large blood vessels that carry blood towards or away from the heart.
• The ventricles pump blood away from the heart and into the arteries
• Atria receives blood from the veins
What are pulmonary vessels?
Vessels connecting to the heart to the lungs are called pulmonary vessels
What are the four vessels connected to the four chambers?
- Aorta
- Vena Cava
- Pulmonary Artery
- Pulmonary Vein
Where is the aorta connected?
Connected to the left ventricle and carries oxygenated blood to all parts of the body except the lungs
Where is the vena cava connected?
Connected to the right atrium and brings de-oxygenated blood back from the tissues of the body ( except the lungs )
Where is the pulmonary artery connected?
- Connected to the right ventricle.
* Carriers deoxygenated blood to the lungs, where its oxygen is replenished and carbon dioxide is removed
Why is a pulmonary artery unusual?
Carries deoxygenated blood
Where is the pulmonary vein connected?
- Connected to the left atrium and brings oxygenated blood back from the lungs
- Carries oxygenated blood
What is the purpose of the right side pump?
• Pumps deoxygenated blood to the lungs
What is the purpose of the left side pump?
• Left side pumps oxygenated blood to the whole body