Friday, May 16, 2008

Anatomy Sr. Assessment

Matt LaMalfa
Anatomy Final Assessment

One of the most important and complex organ systems in your body is the cardiovascular system, which includes the heart as well as all the veins and arteries of the body. The main function of the cardiovascular system is to transport blood, hormones, and cell waste. By far, the most important part of the cardiovascular system is the heart. The heart is a muscle, which weighs about one pound and is about the size of your fist. It is located around the fifth intercostal space, on the left side of your sternum. To insure the heart is protected, it is covered by a special covering called the pericardium, which looks like plastic wrap made into a sack. Inside the pericardium is serous fluid, which keeps the heart lubricated and maintains a frictionless environment for heart processes to take place. The heart is divided into three layers, the epicardium, which is the outermost layer, the myocardium, the layer in the middle, and the endocardium, which is the innermost layer. The epicardium is made up mostly of connective tissue, and its main function is protecting the heart. The myocardium has special muscle cells you can’t find anywhere else in the body. As the inner layer, the endocardium lines the chambers of the heart. All these layers are combinations of skeletal muscle, which helps to pump blood, and smooth muscle, which aids in involuntary processes.
The heart is made up of four chambers, two atria and two ventricles. The atria, which are located above the ventricles, serve as receiving chambers for blood and play no role in the pumping of blood. The ventricles serve as the pumping chambers, and are made have thick, muscular walls, unlike the atria, which have walls made up of smooth muscle. Because of these multiple parts, the heart is sometimes referred to as a double pump. One of the major jobs of the cardiovascular system is pulmonary circulation, the process when blood without oxygen is transported to the lungs, oxygenated, and then returned to the heart. Pulmonary circulation begins on the right side of the heart, when the blood returns to the right atrium after all the oxygen has been used. The heart moves from there into the right ventricle, from where the blood leaves the heart for the lungs via the left and right pulmonary arteries. After the blood picks up the needed oxygen in the lungs, it returns to the heart at the left atria. From the left atria, blood flows into the left ventricle, where it departs for the rest of the body via the aorta.
Opposite pulmonary circulation is systemic circulation, which includes carrying oxygenated blood away from the heart, to the body, and returning deoxygenated blood back to the heart. The first organ supplied with blood is, obviously, the heart, through the coronary arteries. Then we go to the aortic arch, where the first branch, the brachiocephalic, supplies the right common carotid and the right subclavian. The left common carotid branches into the internal carotid, which supplies the brain, and the external carotid, which supplies skin and muscles. The third branch of the aortic arch, the left subclavian, supplies the vertebral artery. Moving away from the aortic arch, you hit the axillary artery, which goes into the brachial artery and supplies the upper arm and then goes into the radial and ulner arteries, which take care of the lower arm. The thoracic aorta in the chest goes into the intercostal arteries, which provides blood to the muscles of the thoracic wall. In the abdomen, the abdominal aorta leads to the celiac trunk which has three major branches, the left gastric artery, splenic artery, and common hepatic artery. These arteries supply the stomach, the spleen and the liver. The superior mesenteric supplies half of the entire small intestine and half of the large intestine, the renal artery supplies the kidneys, the lumbar artery supplies the lower back, and the inferior mesenteric takes care of the remaining portion of the large intestine. The left and right common iliac arteries both split into internal iliac arteries that are responsible for supplying the pelvic region. The anterior and posterior tibial lead to the dorsalis pedis which supplies the foot.
For all this movement to happen, there has to be something in the heart regulating the flow of blood, and that is the valves. There are four sets of valves in the heart, the atria ventricular valves and the semilunar valves. The atrioventricular valves separate the atria from the ventricles and makes sure blood only flows in one direction. Semilunar valves are located in the pulmonary artery and the aorta. Valves make sure there is no backflow of blood to areas where it should not be going. If there is some backflow, leaky valves is probably the culprit, a condition that isn’t fatal, but needs to be corrected if recognized.
The heart is always working; it pumps about six quarts of blood one thousand times a day, meaning the heart pumps around six thousand quarts of blood a day. To keep the heart going, it has an internal conduction system that is split up into two parts, the autonomic nervous system and the intrinsic conduction system. The autonomic nervous system is responsible for speeding up or slowing down the heart; while the intrinsic conduction system forces the heart to beat it’s seventy plus times a minute. For the heart to beat, a nerve impulse starts in the sinoatrial node, in the upper right part of the heart. It then travels to the AV node at the bottom of the right atria, which causes the right atria to contract. After a short pause, the impulse travels to the Purkinjey fibers, which causes the ventricles to contract, and atria relax. If something happens to the SA node, a person’s heartbeat and pulse can slow down, which may cause the need to have an artificial pacemaker installed.
Since circulation is incredibly important to your survival, you probably want to monitor it, which you can do by keeping track of your vital signs: arterial pressure, the expansion and recoil of the arteries, blood pressure, the pressure against the vessels walls, respiratory rate, and finally body temperature. There are two things to consider when measuring blood pressure: the systolic pressure which measures pressure in the arteries when the ventricles are fully contracted, and the diastolic pressure, which is measured when the ventricles are relaxing. Normal systolic pressure is between 110 and 140; normal diastolic pressure is between 70 and 80. A myriad of different factors can cause blood pressure to fall outside of that range. A person is considered hypertensive if blood pressure is above 140/90, and considered hypotensive if the systolic pressure is below 100. The two things blood pressure relies on are cardiac output, the amount of blood pumped out of the left ventricle in one minute and peripheral resistance, the amount of friction encountered as blood flows. It’s also important to keep track of the pressure points on your body located at your temporal artery, facial artery, carotid artery, brachial artery, radial artery, femoral artery, popliteal artery, posterior-tibial artery, and the dorsalis-pedis artery.
Since the heart works as a double pump, it is able to complete a cardiac cycle, which is one full heartbeat and usually takes about .8 seconds to complete. This takes place in three phases with the first being mid-to-late diastole. During this part, blood flows passively into the heart, deoxygenated blood into the right atrium, and oxygenated blood into the left atrium. At the end of this phase, the blood travels to the ventricles. The second phase to begin is called ventricular systole, when the ventricles contract, the AV valve shuts, and blood flows into the relaxing atria. In the third phase, early diastole, the ventricles relax, semilunar valves close, the AV valves open, and blood flows to the atria.
A case of special circulation takes place in the Circle of Willis. Located in the brain, the Cirlce of Willis is made up as a combination of veins and arteries. Its biggest function is another pathway to the brain in case the primary one gets blocked. Another case of special circulation is in a fetus. The lungs and digestive system of a fetus are inactive, so all nutrient and gas exchanges take place through the placenta. In the umbilical cord are three blood vessels, the very large umbilical vein, which brings nutrient rich blood and two smaller umbilical arteries that get rid of waste. The ductus venosus bypasses the liver bringing the blood right into the fetuses’ placenta and the foramen ovale allows blood to bypass the lungs and enter directly into the heart.

Monday, November 26, 2007

11/26 - @ Flyers

Whatever happened at Claude Julien's practice yesterday was super-effective. For the first period, the Bruins outplayed the Flyers in every facet of the game. Maybe there were a few lucky bounces, but this wasn't the same team from Saturday night. Glen Murray has finally hit his stride, Glen Metropolit is filling in admirably for Patrice Bergeron, and Matt Hunwick is doing a nice job back on the point. Tuukka Rask was good enough in his second NHL start though its obvious he isn't ready to carry the load yet. The main downer was the PK, which was horrendous allowing all three goals. This is an area that desperately needs improvement.

*The Flyers continue to be the dirtiest team in the league as Scott Hartnell put an awful hit on Andrew Alberts who left the game. Hartnell was ejected and hopefully suspension will follow. I think it should be steeper than Jones on Bergy since this hit was far more deliberate. The Broad Street Bullies are defiantly back.

* Jack Edwards could have used a deer tranquilizer or three in the booth tonight. He completely overreacted to a stat inaccuracy about hits, and continues to act like he knows everything about everything.

10/24 - @ Islanders

After a solid first game of the home and home against the Isles, the Bruins just looked Saturday night on Long Island. There was no jump in any ones step and and the boys with the spoked B's on their chests were thoroughly beaten down. A few bright spots were the continuing solid play of Tim Thomas in net and the emergence of Mark Stuart as a legitimate top-4 defenseman. The Bs are going to need to find some offense soon, as Rick DiPietro was never really rattled in this one. Claude Julien has his work cut out with these guys.

*Tonight marked the NHL debut for Vladimir Sobotka

Saturday, November 24, 2007

11/23 - vs. NY Islanders

The Bruins notched an important win in an important contest against the Islanders yesterday afternoon at the Garden. After a very slow start for both team, the late second and third periods were pretty good. Glen Murray showed signs of life, getting his name on the score sheet and looking more mobile than usual in the process. Tim Thomas was very solid again, allowing only one goal late, but the Tank hung in for the win. This guy has to be in the All-Star Game, no questions asked. As Glen Metropolit scored the game winner Andy Brickley said Metropolit was the best tryout invitee in NHL history, take it easy Brick. Home and homes are always fun, so tonight should be another good one on the Island.

*Vladimir Sobotka will probably see his first NHL action in place of the dinged up Milan Lucic.

* Spectors Trade Site is reporting the Bruins are shopping for an experienced back-up goalie. I'm not sure that should be on the top of Peter Chiarelli's wish list. Even though Rask is young, he certainly can stay up, though after Toivonen and Raycroft, I understand his reluctance to rush young netminders.

Sunday, November 11, 2007

11/11 - vs. CT Selects

Due to the fast approaching Xavier season, I changed the site over, and put the last game write-up on here. This is the end for game summaries and three stars.

*Not the way anyone wanted to end the season this afternoon, as the Red Devils fell 5-3 at the hands of the CT Selects in Cromwell. Ryan Lee kept the score out of the double digits, making over 40 saves, and stopping everything he could. After an awful start, the Devils picked it up a bit, but with Piscottano touring the Rockies and Malz battling a fever, it just wasnt meant to be. Captain Vino did what he could notching two goals, but it wasnt enough in the end, even with Will doing what he could to fire up the bench. Coach Ken stayed suprisingly calm throughout the game. After the banquet on Thursday its go time!

*The Last Three Stars: 1)Lee 2) O'Hara 3) Even

*If anyone knows a junior who wants to help me out this year, let me know.

Sunday, September 16, 2007

Summer(s over) Camp

Wow, I havent written anything in a long time. I've been really busy, and as a result the site has been neglected...sorry. Camp has opened since the last time I wrote. Today, the Bruins rookie team played a game in Shelton, CT. Being a CT resident I caught the beginning of the game, and I was very impressed, especially with Tuukka Rask and Milan Lucic. Rask looked solid during his time in net, though he wasnt tested that often. Lucic looked like a really dominant big man. He dominated a fight towards the end of the game (so I heard from a friend who was there to the end)

* One interesting note: the Bruins have invited Glen Metropolit to camp on a tryout basis. Glen is much better than candidates from the last couple years (ie. Billy Tibbetts) and unlike many non-roster guys, with a strong camp, Metropolit just might make the roster.

* If you havent checked out NHL 08 yet, you need to. It is a great game, especially for PS3. One issue I had with the game is Tim Thomas has a skill rating of only 78, give Boston's real number one goalie a littlw love, but really check this game out.

Thursday, September 6, 2007

Camp Coming Fast

You know we are nearing the start of the season when all the veterans have arrived at camp in Wilmington. Oh wait, almost all the veterens! "Big-time" offseason pickup Manny Fernandez is yet to strap on the pads at Ristuccia Arena. As far as I'm concerned, this is a positive since it may allow Tim Thomas to get a leg up on the number one goalie job. Bergeron, Murray, and enforcer Jeremy Reich are some of the most recent arrivals, rounding out the veteran core. The Globe put out a full list of the attendees: Andrew Alberts, P.J. Axelsson, Patrice Bergeron, Brandon Bochenski, Zdeno Chara, Chris Collins, Jeff Hoggan, Matt Hunwick, Martins Karsums, Phil Kessel, David Krejci, Matt Lashoff, Mark Mowers, Glen Murray, Jeremy Reich, Marc Savard, Jonathan Sigalet, Jordan Sigalet, Marco Sturm, Nate Thompson, Dennis Wideman.

* Among the veterans who have yet to arrive and skate: Peter Schaefer, Shawn Thornton, Manny Fernandez, Aaron Ward, and Chuck Kobasew.

* While attending the Redsox game last Friday, I was walking around before the game and saw the towering figure of Captain Zdeno Chara nearby. He was on his way to the pregame show on Yawkey Way and let me tell you, Chara is even bigger in person!