Blood and Heart

Here's a breakdown of the answers to your questions about blood vessels, heart anatomy, circulation, and the conduction system:

Blood Vessels

1. Layers of blood vessel walls: The three layers are the tunica intima (inner layer), tunica media (middle layer), and tunica adventitia (outer layer).

2. Carries blood to heart: Veins.

3. Carries blood away from heart: Arteries.

4. Vessels where gas exchange occurs: Capillaries.

5. Path of blood flow through vascular system: Heart → Arteries → Arterioles → Capillaries → Venules → Veins → Heart.

6. Larger veins have ____ to prevent the backflow of blood: Valves.

7. Smallest blood vessels that connect arterioles and venules: Capillaries. 

Heart Anatomy

1. Be able to label all structures of the heart: You'll need a diagram for this. Key structures include: atria (right and left), ventricles (right and left), valves (tricuspid, mitral, aortic, pulmonary), aorta, pulmonary artery, vena cava (superior and inferior), and coronary arteries.

2. 3 layers of heart:

   • Sac around the heart: Pericardium.

   • Muscular layer: Myocardium.

   • Lines chambers: Endocardium.

3. Divides heart into right and left side: Septum.

4. Brings blood from lungs to heart: Pulmonary veins.

5. Carries blood from heart to lungs: Pulmonary artery.

6. Brings blood from body to heart: Vena cava (superior and inferior).

7. Carries blood from heart to all systems in body: Aorta.

8. Supplies nutrients and oxygen to the myocardium: Coronary arteries.

9. Chamber with the thickest wall: Left ventricle.

10. Role of chordae tendinae: Prevent the atrioventricular valves from inverting back into the atria during ventricular contraction.

11. Pointed tip of the heart: Apex.

12. Two superior receiving chambers: Atria.

13. Two inferior discharging chambers: Ventricles. 

Circulation

1. Where does pulmonary circulation take blood? To the lungs.

2. Where does systemic circulation take blood? To the rest of the body.

3. Be able to trace a drop of blood through the heart: Vena cava (superior and inferior) → Right atrium → Tricuspid valve → Right ventricle → Pulmonary valve → Pulmonary artery → Lungs → Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aortic valve → Aorta → Body.

4. Which vessels bring oxygenated blood? Pulmonary veins.

5. Which vessels bring deoxygenated blood? Pulmonary artery.

6. When atria contract which valves close? No valves close during atrial contraction; the atrioventricular valves (tricuspid and mitral) are open to allow blood flow into the ventricles.

7. When ventricles contract which valves close? Atrioventricular valves (tricuspid and mitral) close, and the semilunar valves (aortic and pulmonary) open.

8. Blood from the upper and lower vena cavas enters the heart via this structure: Right atrium.

9. Blood passes to the lungs from this structure: Right ventricle.

10. Deoxygenated blood exits the heart from this structure: Pulmonary artery.

11. Oxygenated blood enters the heart via this structure: Pulmonary veins.

12. Blood is pumped to the majority of the body by this structure: Left ventricle.

13. Heart chamber that receives oxygenated blood: Left atrium. 

Conduction System

1. Normal pattern of conduction: SA node → AV node → Bundle of His → Right and left bundle branches → Purkinje fibers.

2. Acts as the pacemaker of the heart: SA node.

3. Instrument used to record the electrical currents generated by the heart: Electrocardiogram (ECG or EKG).

4. Uncoordinated contractions of the heart: Fibrillation.

5. Atrial fibrillation vs. ventricle fibrillation – which is more life threatening? Ventricular fibrillation.

6. Scientific name for a heart attack: Myocardial infarction.

7. Systole means: Contraction.

8. Diastole means: Relaxation.

9. What occurs during systole? The heart muscle contracts, pumping blood out of the heart.

10. Heart sounds LUB: Closing of the atrioventricular valves (tricuspid and mitral) and contraction of the ventricles.