This website uses cookies to ensure you have the best experience. Learn more

The Heart And Circulatory System Essay

743 words - 3 pages

The Heart and Circulatory System

The regular heart beat and pulse is produced by contractions of the
heart muscle during the cardiac cycle. These contractions are caused
by an electrical stimulus called the cardiac impulse. This natural
pacemaker of the heart, called the Sinoatrial node, is located in the
Right Atrium.

The electrical impulse leaves the Sinoatrial node and travels to the
right and left Atria, causing them to contract together. After
contraction, there is a period of insensitivity to stimulation which
allows the Ventricles to fill with blood. The impulse now at the
Atrioventricular node moves to the Bundle of His then divides into ...view middle of the document...

When blood
pressure is high, the rate of heart beat is lowered by impulses which
slow heart rate, from the cardiovascular centre via the vagus nerve.
When blood pressure is low, the rate of heart beat is increased. The
rate of heart beat is also influenced by impulses from the higher
centres of the brain.


Another factor that affects heart rate is Adrenaline. Adrenaline is a
hormone produced by the adrenal gland and secreted in tiny amounts
when you are afraid. It raises your heart rate immediately, preparing
you to run or fight. Adrenaline also improves the strength of the
contractions of the heart. Caffeine, sugar and other substances can
also affect heart rate.

Mechanisms of control of heart rate - nervous etc

Regulatory impulses come from the cardiovascular centre in the medulla
of the hind brain via two nerves:

The Sympathetic Nerve - part of the Sympathetic nervous system, helps
prepare the body for "fight or flight" and create conditions in the
tissues for physical activity. It is stimulated by strong emotions
such as anger and excitement and will therefore speed up heart rate,
increase the activity of sweat glands, adrenal glands, and decrease

Other Essays Like The Heart And Circulatory System

Racial Discrimination and the Judicial System

1939 words - 8 pages “The Ethical Issues of Racial Discrimination and the Judicial System. Does it Exist?” By Captain Jerry K. Craig Marion County Sheriff’s Office This commentary is designed to examine whether or not racial profiling exists in our judicial system. The affects that it may have and if it does exist, where are its origins. Watch the news or read the newspaper and you will find people killing people based on their ethnicity or religious

The Chargeback System, Its Problems, and Solutions

541 words - 3 pages Case Study: The Charge-back system, its problems, and solutions. By Adam Smith This case study asks three questions: First how this person named Oluwatosin’s pretexting attempt at Checkpoint so effective? My reasoning is that checkpoint did not screen this man, yet instead they were intrigued by this person con and simply made the classic mistake of trusting a person because he seemed like he fit in. What they should have made him wait

The System Of Governance And Americans' Rights And Liberties

3369 words - 14 pages Overall, the United States system of government is effective in protecting the rights and liberties of its citizens. The systems of checks and balances as well as concurrent powers exist to protect Americans’ liberties and represent their interests. The use of public opinion and the media also play a large role in the functioning of the system of governance and at the same time act to safeguard the liberties and rights of the American people

Symbols And Symbolism In Heart Of Darkness - The Symbol Of Ivory

596 words - 3 pages ." The almost god-like power that Kurtz wields is unchecked, save for disease.         In Heart of Darkness ivory plays a dual role in significance. On one hand it is representative of evil and greed, and on the other, it is representative of the measures taken to acquire it in the first place (i.e. mistreatment of blacks). Conrad's use of ivory in order to symbolize darkness is also in keeping with his occasional reversal of the colors normally associated with good and evil, white and black. Ivory as a material is one of the purest and whitest found in nature, while Kurtz's soul is purely black.  

Compare Themes of Heart of Darkness and Tess of the D'Urbervilles

1472 words - 6 pages Throughout the two novels, Thomas Hardy’s “Tess of the d’Urbervilles” and Joseph Conrad’s “Heart of Darkness,” the common theme of oppression by using psychological methods prevails. Tess’ parents and Alec can control her by leveraging guilt as a way of victimization which ultimately seals her fate. Mr. Kurtz in” Heart of Darkness” takes control over the weaker African natives to force them into submission. Both stories have this underlying

Majoritian System and the Impacts on the African Political Power

1785 words - 8 pages Politics play vital role in the state’s affair and for people to take positions of running the state’s affair. The political system of the world has device mechanisms on how those persons can take a role in the state’s issues, through electoral systems. For instance in Africa, the southern part of it. Each country that was once a colony of the British Empire has adopted a colonialist system even after gaining their independence. This essay will

Compare and Contrast a Toxin That Affects the Nervous System

669 words - 3 pages Research Paper: Toxicant MOS 5425 – Advanced Toxicology 2/3/2015 Background This paper will compare and contrast a toxin that affects the nervous system, one that affects the endocrine system and another that affects the cardiovascular system. Identify the characteristics that are shared by these toxins and characteristics of these toxins make these toxins vulnerable to toxicity of these specific systems? Central Nervous System

Victimology and Alternatives to the Criminal Justice System

1298 words - 6 pages Victimology and alternatives to the traditional criminal justice system Jennifer Pavalinski University Of Phoenix Victimology and alternatives to the traditional criminal justice system The fathers of victimology were two German criminologists, Hans Von Hentig and Benjamin Mendelsohn (Encyclopedia Britannica, n.d., p. 1). “They studied behaviors, characteristics, and vulnerabilities of crime victims. In 1937, Mendolsohn proposed a

Vulnerable Populations and the United States Health Care System

1455 words - 6 pages Vulnerable Populations Part 1 Christine HCS/531 Vulnerable Populations Part 1 Vulnerable populations are groups not well integrated into the health care system for various reasons. Some of these reasons can include cultural, economic, geographic, and ethics sources of vulnerability. In the United States vulnerable populations can even consist of underinsured or uninsured Americans considered middle class. For many the impact that the

Health Care System in the U.S. and Changes by Obama

3386 words - 14 pages | Health care system in the U.S. and changes by Obama | | Semir Golic30.11.2010 | Table of Contents: 1. Introduction 3 2. The History of health care in the USA 4 3. The Health Care System 5 4.1 How health insurance works 4.2 Different insurance programs 4.3 Problems 3.3.1 Financial & bureaucratic problems 3.3.2 Conflict with the American Dream 4. Changes

The Criminal Justice System, and It's Effects in Victoria, Bc

2045 words - 9 pages . If you were to examine the rate of youth charged as opposed to the rate of youth given rehabilitative measures, you will see, in fact, that the number of offences is climbing. (Taylor-Butts, A., Bressan, A.). With this problem in mind, consider the YCJA and what it stands for. “Every legal system recognizes that children and adolescents are different from adults and should not be held accountable for their violations of the criminal law in

Related Papers

Conduction System Of The Heart Essay

741 words - 3 pages The Normal Conduction system of the heart A Labelled P QRS and T wave seen on a single Lead ECG complex. | What is the heart rate in sinus rhythm? Normal sinus rhythm is the rate of around 60 – 100 beats per minute (bpm) What is the definition of sinus tachycardia? Sinus tachycardia is the rhythm with an elevated amount of impulse which is greater than 100bpm. What is the definition of sinus bradycardia? This is a rate

The Westminster System And Corruption Essay

846 words - 4 pages Evaluate Whether the Westminster Model System of Government Adopted by English Speaking Caribbean Countries Accommodates Corruption as a Way of Governance. The Westminster System is a democratic system of government modelled after that of the United Kingdom, as used in the Palace of Westminster, the location of the UK parliament. The system is a series of conventions and procedures for operating a legislature. Between 1962 and 1983, the

Contrasting The Differences And Similarities Between Heart Attacks And Strokes

269 words - 2 pages In this essay I will compare and contrast the differences and similarities between a heart attack and a stroke. A heart is damage and loss of function of an area of the heart muscle. Strokes are sudden episodes of weakness or paralysis that occur when blood flow to the brain is interrupted.Heart attacks and strokes are two different conditions, but they both have some common elements. In both cases, the restriction of blood flow is the crucial

Race And The Zone System Controversy

2001 words - 9 pages Race and the Zone System Controversy You get in the cab; you are white and well dressed showing your social status. The cab driver is friendly and takes you directly to your destination. The little map in the backseat of the cab tells you the cost of your trip; however since you, like most people, never even read it, the cabbie tells you the price, and you go ahead and pay without question. You are a resident of the District and have gone