"From My Heart to Your Heart"

WOW!!! Students this past week completed their first big lab exam. Talk about intensity!!! The open lab was in operation every hour on the hour and was filled to capacity. Now that it is done and over with, students must kick themselves back into the gear and finish off strong their last few weeks. It is half way over now!!! Yet there is still much to learn and much more of the human body to explore. How exciting!!!

The focus of this weeks lab is the heart and arteries. These structures combined, compose of the machinery that carry oxygen rich blood to supply nourishment to many parts of the body. Your heart beats about 100,000 times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times. Also, your body has about 5.6 liters (6 quarts) of blood. This 5.6 liters of blood circulates through the body three times every minute. In one day, the blood travels a total of 19,000 km (12,000 miles)-- that's four times the distance across the US from coast to coast. There is no machine like the heart!!! If one were to try and compose a machine that performed like the heart, it would break down in a manner of days due to overload and stress. It truly is amazing that with each day that passes by, our heart is working off the clock, 24/7.

The neat thing about this week is that some of the structures taught, you already know. Some were presented the very first week of class in lecture. Now it is a matter of digging out that old information and applying it now. Here are just a few things to remember to help you in your studies this week:

1. Know the pathway of blood well. It may sound unimportant, but those who know the pathway of blood, find it easier to master the heart structures. You have to know it for lecture too.
2. Know the body regions. When working with the arteries, they are all named by body region. Even though it looks like one continuous artery, different areas of the body change its name. They are like some streets; even though you don't turn off, their names still change. Here are a few examples:

• Axillary region: Axillary artery
• Brachial region: Brachial artery
• Femoral Region: Femoral artery
• Running under the clavicle: Subclavian artery

**Now for a few mnemonics and study tips...

Protective Layers of the Heart: think of the "fist in the balloon model."

• Outside of the balloon: Parietal Pericardium
• Space in between the balloon and hand: Pericardial Cavity
• Covering the fist: Visceral Pericardium (Epicardium)

**Think of the heart protective layers this way: from superficial to deep, their names go alphabetically.

Layers of the Heart

Epicardium: Outermost layer; interchanges its name with the visceral pericardium

Myocardium: muscular layer

Endocardium: fills the heart wall; contains several other structures

• Trabeculae Carne (Cross Bars of Flesh): look for the mesh networks of crossing tissue
• Chordae Tendinae: Chord-like
• Papillary muscle: anchors the Chordae Tendinae to the heart wall.

Heart Valves

Right atrioventricular (tricuspid) valve: (RAT) try to choose the right

Left atrioventricular (mitral or bicuspid) valve: (LAB or LAMB)

Pulmonary valve: valve directing blood from the right ventricle to the pulmonary trunk.

Aortic valve: valve directing blood from the left ventricle to the ascending aorta.

**Metal probe test: when studying the heart, take some time to place a metal probe through a valve and lay it down on a tray. You will observe that a metal probe in the tricuspid or bicuspid valve will lay straight up and down. A metal probe in the pulmonary or aortic valve will lay at an angle, either to the left or right.

Arteries in the Body

Arteries from the Aortic Arch

Ascending Aorta -> Brachiocephalic artery -> Left Common Carotid Artery -> Left Subclavian Artery

A B C 's

Intercostal Artery: "in" between the ribs (in the costal groove)

Internal Thoracic Artery: "inside" - internal side of the thoracic cage

**You can find this artery coming off the right subclavian artery and on the detached rib cage.

Celiac Trunk: the branches coming off the trunk fit to the saying of Salt Lake City.

1. Splenic Artery: Salt
   
2. Left Gastric Artery: Lake
   
3. Commom Hepatic Artery: City
   

Latin Origins of Structures

1. Gastric - Stomach
2. Pulmonary - Lungs
3. Coronary - Heart
4. Hepatic - Liver
5. Mesentery - Intestines
6. Renal - Kidney
7. Suprarenal - Adrenal Gland
8. Celiac - Abdominal
9. Axillary - Arm Pit
10. Popliteal - Knee Cap
11. Gonadal - Gonads
12. Femoral - Femur
13. Iliac - Ilium
14. Brachial - Upper Arm

**Well there you have it for this week!!! Remember that we start learning the veins next week. Lucky for you, most of the arteries we have just learned share the same name with the veins. So start now getting used to ending each term with artery, vein, nerve or vessels. This will become very important when it comes time for the final. These endings are a matter of whether or not you receive full credit, even if you technically got the answer right. Good luck in all your studies!!! Keep going, you are nearly half way done!!!