Describe the structure of the Pericardium
- Composed of Fibrous Connective Tissue
- Fluid filled sack surrounding the heart.
What are the 3 protective functions of the pericardium?
3 Protective/ Mechanical functions:
- Prevents the Heart from overfilling.
- Reduces friction allowing the heart to beat smoothly
- Protect the heart from infection.
What are the 2 main reasons why a circulatory system is needed in most animals.
1) To exchange material and energy with the environment.
2) To facilitates exchanges that occur throughout the body.
What is coronary circulation?
Circulation of blood to the heart muscles.
What blood vessels are involved in coronary circulation and state their function
- Coronary Arteries: Provide and transport oxygen-rich blood.
-Coronary Veins: Remove waste products away from the heart.
What is an MI? Explain how they occur.
- MI: Myocardial Infarction aka Heart Attack
- Occurs when coronary arteries become blocked. Once blocked cardiac muscle tissue begins to die.
True or False: The Cardiac Cycle has 2 phases.
TRUE! (The 2 phases are called diastole and systole!)
What occurs during diastole?
-Stage where heart is relaxed
- Blood is flowing in all 4 chambers
-AV Valves (Mitral and Tricuspid Valves Open)
During Diastole, 2 valves open. What are their names, and specify which side of the heart they belong to?
- Mitral Valve: Right AV Valve
- Tricuspid Valve : Left AV Valve
Describe the 2 stages of systole.
-Stage 1: Atria briefly contract to fill Ventricles
-Stage 2: Ventricles contract and pump blood out (Semilunar Valves open)
True or False: The Mitral and Aortic Valve are opened during stage 2 during systole.
FALSE! During Systole the Semilunar valves (Pulmonary Valve and Aortic Valve are opened)
What 2 nodes create the hearts rhythm?
- Atrioventricular Node (AV Node) –> Internal septum closer with the R atrium
- Sinoatrial Node (SA Node)–> Located on the top right portion above R Atrium
Explain how the SA Node and AV Node contribute to our heart rhythm.
-SA Node generates electrical signals which are sent to atria leading to contraction
-AV Node receives electrical activity from R Atrium and sends that same signal in a coordinated manner to the ventricles to contract.
Both the SA Node and AV Node create coordinated electrical signals, which allow the heart. beat in a coordinated manner.
List the 4 functions of the Mammalian Heart!
1) Generate BP–> Blood pressure from the contractions allows blood to move through the vessels.
2) Routing blood –> Separation of the different circulations allows blood to travel in a more efficient manner
3) Ensuring unidirectional blood flow–> Valves ensure that blood flow through the heart and vessels in one direction and prevent backflow.
4) Regulating blood supply. Changes to the rate and force of contraction match the blood delivery to the changing metabolic needs of the tissue.
What are 3 components all blood vessels contains
- Layer of endothelial tissue
- Layer of smooth muscle tissue
- Contains connective tissue –> allows it to be elastic.
What are the main differences between veins and arteries?
- Arteries: Thicker smooth muscle component to withstand higher pressure from blood flow.
- Ventricles: Thinner smooth muscle component and contains valves.
What type of tissue makes the capillaries?
- Simple Squamous Epithelial Tissue
True or False: Capillaries are composed of simple squamous epithelial cells because of its main function for gas exchange.
TRUE! Capillaries have thinner walls for the specialized function of gas exchange throughout the body.
Explain why the L ventricle has a slightly thicker wall than the R Ventricle.
- L ventricle is thicker because it requires more force to pump the blood to the extremities and to other parts of the body.
- R ventricle is thinner because it only pumps blood towards the lungs. Travels a shorter distance.
True or False: Arteries have an inverse relationship between velocity and blood pressure.
FALSE! Arteries and veins have a proportional relationship (High Velocity and High BP)
