NOTES: CONDUCTION AND BLOOD VESSELS

1. What is the location and function of the SA node?

Cardiac conduction system = special cells that create its own nerve impulse

Location: wall of the right atrium

Function: “pacemaker” that causes the atria to contract = heart beat

2. What is the location and function of the AV node?

Location: junction between the atria and ventricles

Function: receives electrical impulse from SA node and causes the ventricle to contract

The heart in action:

3. What is the location and function of the AV bundle?

Location: between the ventricles

Function: the electrical connection between the atria and ventricles

4. What is the location and function of the Perkinje fibers?

Location: bottom of the ventricles

Function: conduction of signals to the ventricular muscles

5. What is a EKG/ECG? What is its function?

Electro-cardiogram

A graphical tracing of the hearts electrical activity

6. EKG Explanation

There are 5 major deflections on an EKG: P, Q, R, S, and T

6. EKG Explanation

P Wave: atria contract

6. EKG Explanation

QRS Complex: ventricles contract and the atria relax during this time

6. EKG Explanation

T wave: ventricles relax and aortic and pulmonary valves close.

7. 5 general classes of blood vessles

Arteries: carry blood away from heart

Arterioles: smallest branches

Capillaries: connect arteries and veins, site of gas exchange

Venules: smallest branches

Veins: carry blood towards the heart

8. Arteries!

Carry blood away from the heart.

Main artery called the aorta

Tough on the outside Smooth on the

inside Elastic walls of

smooth muscle to withstand blood pressure

9. Capillaries

Connect arterioles and venules Very thin Only one cell thick Site of gas exchange O2 and nutrients from capillaries

diffuses across the membrane into the tissues

CO2 and other wastes diffuses into the capillaries

10. Veins!

Carry blood back to heart

Transport waste and un-O2 blood back to heart and lungs

Valves located inside to allow blood to move in one directions

11. Pulmonary circulation

Circulation from heart to the lungs and back to heart

12. Systemic circulation

Circulation from heart to the rest of the body