• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The cause and consequences of atherosclerosis and hypertension and the use and action of Beta blockers.

Extracts from this document...

Introduction

Rohit Gumber The cause and consequences of atherosclerosis and hypertension and the use and action of Beta blockers. As animals grew in size and complexity, the need arose for a system to transport materials, especially food, oxygen, carbon dioxide and wastes. This system must service every cell in the body. In humans, this is achieved by having capillaries within diffusing distance of them. The fluid is circulated by a specialised pump - the heart. The blood is circulated around the body in vessels called arteries and returned to the blood by veins. Arteriosclerosis is a chronic disease caused by the abnormal thickening and hardening of the arteries, with a resulting loss of elasticity. The major form of arteriosclerosis is atherosclerosis. Atherosclerosis is a disease of both large and medium sized arteries, in which plaques of fatty deposits, or atheromas, form on the inner walls of the arteries. In atherosclerosis, cholesterol-carrying lipoproteins in the circulating blood are gradually deposited on the inner linings of arteries over a period of years. As more cholesterol is deposited on the lining, initially tiny lesions enlarge and thicken to form plaques, narrowing the vessel channel and interfering with the flow of blood through it. ...read more.

Middle

Over time, this higher pressure, or hypertension, can damage the arterioles (the small terminal twigs of an artery that end in capillaries) in such organs as the liver, kidney, or brain and can also weaken the overworked heart. The increased risk of death from congestive heart failure, kidney failure, or stroke is the chief danger of hypertension. (Microsoft, 1996, Encarta 97 Encyclopedia) From Heartpoint: High Blood Pressure Information I found that 90 percent of people who have high blood pressure have something called essential hypertension. This type of high blood pressure has no known cause. However, studies have pointed out several contributing factors. Included among these are family history, obesity, high salt intake, smoking, high alcohol consumption, and emotional and physical stress. Another type of high blood pressure that occurs is called secondary hypertension. This may result from a wide range of uncommon causes * A number of kidney diseases cause high blood pressure. * Disorders of the adrenal glands: * Pheochromocytoma, This tumour produces adrenaline and/or similar substances. Patients with this disorder typically have spells of high blood pressure which are accompanied by strong and rapid heart beats, sweating and headaches. ...read more.

Conclusion

Therefore, blocking the beta 1 receptor (and all beta blockers block the beta 1 receptor) results in the heart rate slowing down and the heart beating less forcefully. This causes the heart to require less oxygen, less blood is ejected from the heart, and blood pressure is lowered. Beta blockers are a fundamental treatment in myocardial infarctions ("Heart Attacks"). The main beta 1 selective drugs used are metoprolol (Lopressor) and atenolol (Tenormin). These drugs do not allow the hormones that cause the blood vessels to constrict (norepinepherine and epinephrine) bind to their site on the blood vessel. Because these hormones cannot bind, the blood vessels do not contract and the blood pressure is lowered. Stimulating the beta 2 receptor causes smooth muscle (muscles that control body functions which you do not have control over) to relax. This means that lungs relax (bronchodilation), uterus relaxes, and arterioles (a type of blood vessel) relax. They also cause skeletal muscles (as in biceps, triceps, etc.) to become activated and large. Therefore, drugs which block the beta 2 receptor have adverse effects and uses in addition to the effects mentioned for beta 1 blockade. The classic non-selective beta blocker is propranolol (Inderal). Other examples include: Nadolol Acebutolol Labetolol (About Beta Blockers - Marshall U. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Humans as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Humans as Organisms essays

  1. Marked by a teacher

    Myocardial infarction

    5 star(s)

    In response to injury, platelets begin to stick to each other and to the sides of the injured tissue to form a plug, blocking further blood loss. Aspirin has also been shown to inhibit the development of arthrosclerosis. Because of its benefits, aspirin is recommended for many heart and stroke patients (Hamby, R D'Agostino, R, 2005 ).

  2. Should people with diabetes 2 receive medical treatment?

    Transcription is the first stage in protein synthesis. It occurs in the nucleus of the cells in the islets of Langerhans. The DNA uncoils to expose the relevant bases (see below) mRNA (messenger Ribonucleic Acid) which is in the cytoplasm enters the nucleus through nucleic pores. The mRNA aligns with the exposed bases of DNA.

  1. The Biological and Psychological Impact of Smoking Cigarettes

    Finally concentration is expected to be affected by smoking. Research has shown that people who smoke have lower levels of concentration than non-smokers, research has also proved that smoking lowers the mental performance of the smoker.

  2. Panic Disorder

    Sarah, also experienced severe anxiety in social situations. She had a terrible fear of having another attack, fear of losing consciousness, and a fear of embarrassment in social situations. Sarah had suffered in her sleep as well. Constant nightmares persisted, causing lack of sufficient sleep. Sarah felt she was going crazy, because of the fact that she didn't know what was wrong with her.

  1. HSC Module-Blueprint of Life

    genotype is expressed - A lack of sufficient resources can stunt the growth of a person, eg. - Examples: * Phenylketonuria (PKU): Babies born with PKU can not make the important enzyme phe-hydroxylase, and as a result, can not metabolise the amino acid phenylalanine (phe)

  2. The effect of beta blockers on golfer's performance.

    Less common side effects include impotence, dizziness, wheezing, digestive tract problems, skin rashes and dry eyes. Beta-blockers are only available on prescription. Many are available as oral preparations (e.g. tablets, capsules), some as injections, and some in eye drops (for glaucoma).

  1. Exercise has certain benefits on a person's health, and physical condition.

    of people worldwide who are overweight now rivals the number who are underweight, according to the World Health Organisation - obesity is a growing problem. In the UK, 15% of men and 18% of women are clinically obese, while the figures in the US are closer to 25%.

  2. Factors Affecting the Development of Coronary Heart Disease.

    So it is established that the development of coronary heart disease can start early on in life and grows progressively until the problems mentioned above occur. However there are factors that affect the rate at which development occurs, and explain why age, wealth, family history, lifestyle and the country you live in affect your chance of developing the disease.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work