I laugh at you!

Chapter 21 Questions
1. Name, in order, all the types of blood vessels, starting at the heart, going into the tissues, and returning to the heart.
The ventricles pump blood from the heart into large, elastic arteries. The elastic arteries gradually turn into muscular arteries, and from there they become arterioles. Blood flows from arterioles into capillaries. From the capillaries, blood flows into the venous system by way of venules. Venules grow larger and become small veins, and from there the small veins grow larger and become medium and or large veins. The large veins eventually bring the blood back to the heart by way of the inferior or superior vena cava.
2. Describe the structure of a capillary.
The capillary wall consists primarily of endothelial cells which rest on a basement membrane. Outside the basement membrane is a delicate layer of loose connective tissue that merges with the connective tissue surrounding the capillary. Pericapillary cells lie between the endothelial cells and the basement membrane.
3. Compare the structure of the three types of capillaries. Explain the ways that materials pass through capillary walls.
Continuous capillaries have walls which have no gaps between the endothelial cells. Continuous capillaries are less permeable to large molecules than other capillary types. Fenestrated capillaries have numerous fenestrates between the endothelial cells. Fenestrate capillaries are in tissues where capillaries are highly permeable. Sinusoidal capillaries have much larger fenestrate than the fenestrate capillaries and gaps may exist between endothelial cells. Substances cross capillary walls by diffusing through the endothelial cells, through fenestrate, or between endothelial cells.
4. Describe the capillary network. Where is the smooth muscle that regulates blood flow into and through the capillary network located? What is the function of a thoroughfare channel?
Arterioles supply blood to each capillary network. Blood then flows through the capillary network and into the venules. Smooth muscle cells called precapillary sphincters are located at the origin of the branches of the metarterioles. Thoroughfare channels connect metarterioles to venules.
5. Contrast the function of capillaries in the skin with the function of capillaries in muscle tissue.
Capillaries in the skin function in thermoregulation, and heat loss results from the flow of a large volume of blood through them. In muscle, however, nutrient and waste product exchange is the major function of the capillaries.


6. Name the three layers of a blood vessel. What kinds of tissue are in each layer?
The tunica intima consists of endothelium, a delicate connective tissue basement membrane, a thin layer of connective tissue called the lamina propria, and a fenestrated layer of elastic fibers called the internal elastic membrane.
The tunica media consists of smooth muscle cells arranged circularly around the blood vessel. The tunica media also contains variable amounts of elastic and collagen fibers, depending on the size of the vessel.
The tunica adventitia is composed of connective tissue, which varies from dense connective tissue near the tunica media to loose connective tissue that merges with the connective tissue surrounding the blood vessel.
7. Compare the amount of elastic fibers and smooth muscle found in each type of artery and vein.
Large elastic arteries have a large amount of elastic tissue and a smaller amount of smooth muscle occurring in their walls. Muscular arteries have relatively thick walls because the tunica media contains 25-40 layers of smooth muscle. Arterioles have no observable elastic membrane and the tunica media consists of one or two layers of circular smooth muscle cells. Venules and small veins have a few smooth muscle cells. Medium and large veins have a few scattered elastic fibers and the tunica media is thin and composed of a thin layer of circularly arranged smooth muscle cells.
8. What is the function of valves in the blood vessels? In which blood vessels are they found?
Valves allow blood to flow toward the heart but not in the opposite direction. Many valves are present in the medium veins, and the number is greater in veins of the lower extremities than in veins of the upper extremities.
9. Define vasa vasorum and arteriovenous anastamosis, and give their function. Define portal veins and name two examples.
Vasa vasorum are blood vessels which penetrate from the exterior of the blood vessel to form a capillary network in the tunica adventitia and the tunica media. These networks provide nutrients to blood vessels. Arteriovenous anastamosis allow blood to flow from arterioles to small veins without passing through capillaries. Portal veins are veins that begin in a primary capillary network, extend some distance, and end in a secondary capillary network. There is no pumping mechanism like the heart between the two capillary networks. There are two systems of portal veins in humans: the hepatic portal system and the hypothalamohypophysial portal system.
10. Describe the innervation of the walls of blood vessels. Which types of vessels have the greatest innervation?
Nerve fibers branch to form plexuses in the tunica adventitia, and nerve terminals containing neurotransmitter vesicles project among smooth muscle cells of the tunica media. Small arteries and arterioles are innervated to a greater extent than other blood vessel types.
11. Describe the changes that occur in the arteries due to aging. In which vessels do the most significant changes occur?
Arteriosclerosis is the hardening of the arteries. It consists of degenerative changes in arteries that make them less elastic. Arteriosclerosis greatly increases resistance to blood flow. Atherosclerosis is the deposition of material in the walls of the arteries to form distinct plaques. It is a common type of arteriosclerosis. The plaques narrow the lumens of blood vessels and make their walls less elastic. The most significant changes occur in the large elastic arteries, such as the aorta, the large arteries that carry blood to the brain, and the coronary arteries.
12. Name the factors associated with premature arteriosclerosis.
There are many risk factors associated with the development of arteriosclerosis. These factors include being at an advanced age, being a male, being a postmenopausal woman, having a family history of arteriosclerosis, smoking cigarettes, having hypertension, having diabetes mellitus, having increased blood LDL and cholesterol levels, being overweight, leading a sedentary lifestyle, and having high blood triglyceride levels.
13. For the vessels of the pulmonary circulation, give their starting point, ending point, and function.
The heart pumps blood from the right ventricle into the pulmonary trunk. This short vessel branches into the right and left pulmonary arteries, one transporting blood to each lung. Within the lungs, gas exchange occurs between air in the lungs and the blood. Two pulmonary veins exit each lung and enter the left atrium.
14. Name the parts of the aorta.
The aorta is usually divided into three parts: the ascending aorta, the aortic arch, and the descending aorta.
15. Name the arteries that branch from the aorta to supply the heart.
The coronary arteries are the only branches of the aorta which supply the heart.
16. Name the arteries that branch from the aorta to supply the head neck.
The brachiocephalic artery branches off to form the right common carotid artery which transports blood to the right side of the head and neck. The left common carotid artery supplies blood to the left side of the head and neck. The common carotid arteries continue superiorly and branch to form the internal and external carotid arteries. The external carotid arteries have several branches that supply the structures of the neck and face. The internal carotid arteries, together with the vertebral arteries, which are branches of the subclavian arteries, supply the brain with blood.

Homework

Chapter 20 Questions Josh Buchanan 1

16. Name the two valves that separate the right atrium from the right ventricle and the left atrium from the left ventricle. What are the functions of the papillary muscles and the chordae tendinea?

The tricuspid AV valve separates the right atrium from the right ventricle and the Mitral-Bicuspid AV valve separates the left atrium from the left ventricle. The papillary muscle contract when the ventricles contract and prevent the valves from opening into the atria by pulling on the chordae tendinea attached to the valve cusps.


22. What substances do cardiac muscle cells use as an energy source? Do cardiac muscle cells develop an oxygen debt?

Cardiac muscle cells use adenosine triphosphate as a source for energy. Cardiac muscle cells cannot and do not develop an oxygen debt.

30. What does and ECG measure? Name the waves produced by an ECG, and state what events occur during each wave.

An ECG measures the electrical activity occurring in the heart. An ECG records P waves, QRS complex, and a T wave. The P wave is a result of the depolarization of the atria. The QRS complex occurs as a result of the depolarization of the ventricles. The T wave occurs as a result of the repolarization of the ventricles.

32. List the five periods of the cardiac cycle, and state whether the AV and semilunar valves are open or closed during each period.

1. Systole: period of isovolumic contraction. Semilunar and AV valves are both closed.
2. Systole: period of ejection. Semilunar valves are opened, AV valves are closed.
3. Diastole: period of isovolumic relaxation. Semilunar and AV valves are closed.
4. Diastole: passive ventricular filling. Semilunar valves are closed, AV valves are opened.
5. Diastole: active ventricular filling. Semilunar valves are closed, AV valves are opened.

43. What effect do parasympathetic stimulation and sympathetic stimulation have on heart rate, force of contraction, and stroke volume?
Parasympathetic stimulations have an inhibitory influence on the heart, primarily by decreasing heart rate. There is little effect on stroke volume, it may even increase. Sympathetic stimulation increases both the heart rate and the force of muscular contraction. Stronger contractions can also increase stroke volume.

My Stance Essay

Debate 4 - Reparations for African Americans: Overdue Justice?

The era of slavery was not a particularly grand time in American history. In all actuality, the atrocities and heinous acts committed will never be accurately depicted nor justified. During the Reconstruction period, American congressmen and politicians struggled with concepts on how to successfully take strides forward in creating an equal America which best upholds the values and decrees stated within the Constitution. After the passage and acceptance of the 13^th, 14^th, and 15^th Amendments, along with the abolishment of Jim Crow laws, and the establishment of Equal Opportunity Acts and countless organizations concerned foremost with the advancement of African Americans, many citizens declare adequate reparations have not yet been made. Kibibi Tyehimba, Co-Chair for the National Coalition of Blacks for Reparations in America, agrees with these sympathies. Debating that such actions are illogical and unconstitutional is Roger Clegg, President and General Counsel for the Center for Equal Opportunity. Both men plead their case before the U.S. House of Representatives Committee on the Judiciary, Subcommittee on the Constitution, Civil Rights and Civil Liberties. Both these men requested their stance be heard concerning H.R. 40, a House of Representatives resolution sponsored by Representative John Conyers. The ambitions of the resolution are discover the extent of injustices slavery caused and then to create an apology for those actions.

Kibibi Tyehimba begins his statement by depicting the grotesque accounts of slavery and the infinite disadvantages African Americans have been burdened with as a result. Tyehimba presents five areas in which he believes the African American people suffer greatest. These areas include the loss of African nationhood, significant disadvantages in education, unfair criminal punishment for convicted African Americans, the extreme gap between wealthy White Americans and African Americans, and the staggering difference in African American health in comparison to that of White Americans. Tyehimba continues by stating the moral and legal justification for the reparations which the African American community deserves is long overdue. In conclusion Tyehimba declares acts of reparation will only bridge the gap between white supremacy and the devastation unleashed upon the African American community due to slavery and racial acts afterward. Tyehimba feels the only way to move forward is for America to face the past and deal with it.

Roger Clegg presents a stance in stark contrast to that of Tyehimba’s. Clegg begins his discussion by proclaiming H.R. 40 is “an unnecessary and hopeless task for such a government commission.” Citing that there already has been an enormous amount of research focused upon unearthing the direct results of slavery within the African American community and that it would be absurd for any congressional committee to deem otherwise. An additional point in Clegg’s argument is that a “race-based compensation would be both illogical and unconstitutional” for African Americans are not the sole ethnic group facing trials and tribulations and to present compensations would directly go against the basis of the foundation which forms American and the American dream. Furthermore, Clegg believes “an apology would make no sense either,” as there are no longer any slave owners nor slaves alive, thereby creating an apology that would be given to no one for whom it was intended. Clegg concludes that H.R. 40 would “accomplish nothing and would cost much.”

Upon reading both statements and allowing significant time for pondering, I believe each man has valid points but one argument outweighs the other. The points which Tyehimba presents are at best ludicrous and outlandish. African Americans are allowed to freely express their heritage and nationhood and even have a month designated for such events to transpire. With the abolishment of segregation, African Americans receive the exact same educational opportunities as White Americans and African Americans even have scholarships set aside strictly for advancing their educational opportunities. The accusation concerning African Americans receive harsher penalties and even being arrested more frequently than White Americans is ridiculous and a farce. America has strict laws and the consequences for breaking these laws are the same for whoever commits the crimes. The fact that African Americans are arrested at higher rates is exactly that, a fact, and the only action which can be done to combat these facts is to eliminate the breaking of the laws; point blank and simple. Tyehimba failed to accurately depict the validity of his points; thereby one can only conclude his statement was one based on favoritism and false logic.

Not a single soul can deny the horrible events which ensued upon African Americans during the era of slavery and even up to the late 1960s; however, Americans realized their wrongs and have gone vast lengths to assure African Americans have an equal place in society. It is only natural for African Americans to harbor feelings of ill will, malice and spite, even to feel as if they are entitled to sufficient reparations; nonetheless, America has abolish slavery, granted freedoms and rights to all ethnic groups through the passage of the 13^th, 14^th and 15^th Amendments. When a white man and a minority have identical credentials and apply for the same position, the job must go to the minority as a result of Affirmative Action. Through countless strides and legislation, American congressmen and politicians have ensured the tragedy of slavery and Jim Crow laws will never again resurface. The era of slavery is a black eye for American history, but the remarkable aspect of a black eye is that a black eye will heal. No one will ever be able to sweep the accounts of slavery under the rug, and the actions which incurred with never be forgotten. African Americans have been given and continue to receive every opportunity for advancement in society, and many African Americans take advantage of these opportunities and accomplish indescribable feats which shape and mold the day to day lives of us all. Sadly it is those who refuse to accept the open hand of America and continue to dwell on the past which causes America to remain stuck between gears. White Americans should never forget slavery and the direct effects it had on those who were enslaved. African Americans should continue to take advantage of the immense opportunities supplied to them. American is a nation of unity, with work from both sides and an infinite sense of equality, citizens, regardless of ethnic makeup, will continue to prosper while pursuing happiness. The wounds of America’s past have only provided an opportunity for America to grow stronger and continue to be the great nation it is.

WhiteBerry

This shall be a quick post, for class is about to come to an end. I had to spend the majority of class time to finish my paper. Yes I know I had the entire weekend to accomplish this; however, I just had other things to do. Better things one might ask? My answer would be yes. I was busy enduring PT drill after drill with fellow Marine recruits. Honestly I never imagine I would play in the mud with such intenseness. I could not think of anything else I would rather of been doing. Rain or no rain, it was an amazing experience. Atlanta is not as bad a place as I have thought it to be. True certain places are rather bad, but with the correct friends any situation become a great one. I had such friends this past weekend. I could not thank them enough for their friendship and everything they did for me. I do look forward to seeing and spending time with them all again. next weekend sounds good yes? Also I discovered a new phone. A blackberry. I am still getting the hang of it, but it seems pretty cool. Time to run to my next class.

Cerebral Cortex

Today shall be an exciting day. After four hours of classes in the morning I report down in Perry for another day of work. While some might complain at the thought or even the action, I an complacent. This feeling does not arise because I dread or detest my job, rather I will be inquiring as to whether or not I am suited for a higher position. Without a doubt I have the experience and support from the nurses for the position I desire, I am required to have certification. If my superiors decide my experience is not acceptable then I will always be able to transfer to Warner Robins and work; the odd thing is Warner Robins does not demand certification for the position I seek. While the drive down to Perry is not particularly a delightful one, my fellow coworkers are people who make my days and experiences great. Each new day brings about new, and even sometimes disturbing experiences. With each experience I receive critical on the job training, for free. Any question I may have regarding procedures or protocol results in an easy to understand response always with a smile and a genuine sense of caring. Now I know nurses such as these do not only reside at Perry, I just favor them more highly. Another reason I seek this position is this position is unique in the aspect of it being the only one in the ICU. I will work directly with the nurses and doctors. Valuable experience which will only aid in my future class and occupations. Granted if my request is politely declined, I will still continue to work hard and happy. I wholly enjoy what I do several days out of the week.

Sitting in class. Mulling over decisions. In the back of my mind I know everything shall occur as it should, the wait is what runs one ragged. While I claim to be content with life, I find I am more busy, which leaves less time to ponder, that is unless I am in English class. I need to take advantage of this nice weather and job tonight after work. Also, I need to inquire into my gym. We have out first Lab exam this week, Tuesday for my class. By far the most difficult and in depth examination I have ever endured. Confidence shall prevail providing an acceptable grade. I do believe this is, and will contiune to be, the most intesne semester yet. Things remain to stay in balance, to my joy; however, joy has never proved to have a high half-life. The end of this week brings the arrival of a potentially major stepping stone in my future. The outcome of my work-shift today shall weigh heavily on the maturation of these potential events. While these thoughts consume the majority of my free thoughts, I have not forgotten the hatred which is the fire that consumes my inner emotions. Masked, but only for the moment. There is but one thought which has no course of action nor an answer: what I am going to have for lunch?

Coffee

I expected to see a thin white frost covering everything as far as the eye to see; however, to my amazement, when I poked my head outdoors after waking up I notice everything to appear as if it were a spring day. Everything that is except the sheer magnitude of the bitter cold. If one were to only look outside from a window instead of walking outside, they would be lead to believe the weather was sunny, warm and comfortable. Upon closing the door, I was over come with a sense of confusion and dismay; how could the temperature be in the low twenties but yet there was no frost clinging to my car's window? Overrun with befuddlement, I preceded to open the door and once more and venture out into this bizarre world. Instantly the frigid air washed over and consumed my entire being. Each neuron within me was synapsing with my thalamus and clearly demanding the retreat back into the alleviating and thermal blankets which comprised my bed. A welcoming as this suggestion sounded I was able to devise a course of action far superior: a warm, steamy shower.

That was how my morning began. I could of sworn it was the start of a warm sunny day. Sunny it is, but warm is anything but. The weather reports have the winds picking up throughout the day making the wind chill remain low, dangerously low if you ask me. While one will easily make it through the day without fail, I still complain about the harsh cold. While nothing can be done to reverse these conditions, I will have to bundle up and sip on a hot cup of coffee. Sounds like an acceptable course of action to me.

Back To CLass

Back in the classroom for it is Monday morning.
We are receiving back our rough draft essay papers, and the tension is palpable. Not.
I believe I have done a decent job for a rough draft, considering the fact how worked up I get concerning writing. I really do enjoy my Lit teacher. I will do everything in my ability to have her next semester, that is if I take summer courses. I do believe I shall; however, I do long to make something happen this up coming summer. I still remain torn over decision making. Why? I cannot fathom. I just want to decide and go with it, just do it. 6 years is not a large amount of time, I will be in school for at least the next 6 years. He is my best friend, I know I will lose him if I do not follow. There en lies the problem. I believe everyone loses something and friends seem to be the first to go. Another one of my dear friends is back in town, and shall remain for he no longer is going to school. At the onset, we both were elated for the circumstance, however we do not hang out any more than we did while he was off at school. It truly saddens me. I shall have a final decision within the weeks end. I do not want to miss softball season, lol. Such an unimportant item, to many and probably all, is dear to me. There shall always be time for softball, heck, we even have a co-ed team for the fall. It's not so bad playing with the women. Softball will be there, a dear friend might not always. I enjoy how you make a whore out of yourself by the way. Party late, sleep in missing class. Nice, attractive as well, did not take long for that to present. I hope the sarcasm is blatant. Yes even though I do believe friends will come and go, I do not want to see this one depart into the memories and remain in such a state. A shock will await me, one in which I shall take in stride. I look to the future, my future that is. I enjoy weekend nights like the ones I had this past weekend. I look forward to new people, no matter how many times I tell myself I despise new. It shall be at least two more weeks until an experience such as that will repeat itself. hmmm, I know what I want, what I desirem what I long for. Perhaps it shall come to pass. Who needs a week to decide. My decision is made. The ball has begun its motion. Things are looking well, extremely well.

Today

Was a good day, maybe even a great day
A great night yes.
I must say it was relieving to have a night such as this
I am thankful for my friend
Hopefully made a new friend in the process
I am really seriously beginning to consider my future
More so my summer
I value you my space
My space makes me happy
I do not want my space encroached upon
And the during the summer time that shall occur
It is about time I do something I want to do, something for myself
Tonight was a great night
Relaxing more so than anything
My eye might have been caught
Random hookups no longer captivate thine self
I also cannot state how great it feels to have someone agree with me, who's not a male
Who knows what my future has in store
Nights like these are good
And I desire and shall enjoy them again
Live and learn, well perhaps I do not
I still am Josh Buchanan, a great guy
Those who do not want it shall not receive it
Life is good
as it should always be