The mechanisms which control the blood pressure within normal limits and how drugs can be used to correct abnormalities of these mechanisms.

The mechanisms which control the blood pressure within normal limits and how drugs can be used to correct abnormalities of these mechanisms. Blood pressure is a measure of how hard the blood presses against the artery walls. When blood pressure is recorded, it is recorded as two numbers. The high number provides the systolic pressure and the low number provides the diastolic pressure. The systolic pressure correspond to the pressure of the arteries when the ventricles contracts. The diastolic pressure corresponds to the pressures when the arteries are at rest (after the left ventricular contraction and while the heart chambers are being refilled with blood). The Blood pressure is measured using a sphygmomanometer. There is no such thing as average (or normal) blood pressure as blood pressure differs between individuals depending on many factors. Some of the factors are: 1) age 2) Ethnicity 3) sex 4) Family history etc. There are a number of physiological mechanisms which help regulate the blood pressure within normal limits. These include Autonomic nervous system responses (Baroreceptors and chemoreceptors), Capillary shift mechanisms, vascular stress relaxation, Hormonal responses and kidney and fluid balance mechanisms. Baroreceptors (pressure sensitive nerve endings) found in the arch of the aorta and the carotid bodies detect a drop in blood pressure. The

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Cardiovascular system and health promotion

This assignment is going to be based on the structure and function of the cardiovascular system and how homeostatic mechanisms work with the system to regulate it. The many functions of the heart will be recognised, but the main focus will be on the regulation of heart beat. Various Health Promotion initiatives will then be looked at in context to how they help people maintain a healthy heart and how successful these initiatives are in doing this. At some point, a definition of homeostasis and a definition of health promotion will also be given. Throughout the assignment, my own personal thoughts and accounts will be given to demonstrate the workings of the cardiovascular system and how effective health promotion is in reality. The cardiovascular system consists of two components. Firstly there is the heart and secondly the blood vessels. The heart is a muscular organ which is about the size of a fist and is cone shaped, according to Mader (2006). It is situated in-between the lungs directly behind the sternum. There are three layers of tissue that make up the heart according to Waugh and Grant (2006); the myocardium, which makes up the largest proportion of the heart and consists largely of cardiac muscle; the endocardium which consists of connective tissue and the pericardium, which consists of two sacs and secretes a small amount of lubricating liquid to ensure

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Sports injuries outcome 2 Muscular systemWhen a muscle tissue is damaged it undergoes a repair process, which

Unit 17: sports injuries outcome 2 Muscular system When a muscle tissue is damaged it undergoes a repair process, which begins on the third day after injury once the swelling has started to go down and reduce. By this stage the damaged blood vessels will have been restored, enabling them to deliver oxygen and also nutrients to the specific tissue, which has been damaged. Muscle cannot produce new tissue so it therefore produces scar tissue. This is mainly collagen, which is fibrous and inelastic, it is not as strong or as flexible as muscle tissue and therefore as a result the muscles function is reduced. Ligaments and tendons Ligaments and tendons are soft tissues that are primarily made out of collagen. Ligaments connect bone to bone and tendons connect muscle to bone. Ligaments and tendons can adapt to changes within their mechanical environment due to cause such as injury, disease or exercise. A ligament or tendon is made up of fascicles. Each fascicle contains the basic fibril of the ligament or tendon, and the fibroblasts, which are the cells that make the ligament or tendon. Unlike normal ligaments, healed ligaments are partly made up of a different type of collagen, which has fibrils with a smaller diameter and is therefore a mechanically inferior structure. As a result the healed ligament is often fails to provide adequate joint stability, which can therefore

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Identification of traces left on skeleton by trauma. Due to the ability of the human body to redevelop new bones, trauma left on the skeleton can be identified as bones generally do not heal back to the exact same way they were.

Identification of the traces left on the skeleton by trauma In the human skeleton, bones break and repair by themselves. Bones are solid matters that contain minerals, produce red blood cells and store fat. The bones in our bodies are constantly changing-undergoing bone remodeling: cells called osteoclasts break down the old bone and osteaoblasts replace it with new tissues. These two types of cells along with chondroblasts (cartilage formation) are responsible for the growth of bones throughout life. Due to the ability of the human body to redevelop new bones, trauma left on the skeleton can be identified as bones generally do not heal back to the exact same way they were. When fractures occur, a clot (called fracture hematoma) is formed as a result of blood leaking from veins near the bone. The clot helps the broken bone to stabilize and keeps the two broken parts together for mending. Inflammation then follows and tiny blood vessels grow into the fracture hematoma to stimulate the healing process. A few days later, a soft callus will form from the fracture hematoma and fibers of collagen start to appear. A type of cartilage called fibro cartilage will be created and it causes the callus to be tougher which bridge the gap between the two pieces of bone. Lastly, osteoblasts play a role in turning the callus into bone callus which provides necessary protection to the

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Differentiate between blood vessels relating the structure of each to its function.

Amanda Alderson Access to Healthcare (day) 8th November 2003 Differentiate between blood vessels relating the structure of each to its function. Basic Introduction to the human circulatory system The human body has two blood circulatory systems, the first being that blood leaves the heart through the pulmonary artery and travels to the lungs where the body gives up carbon dioxide and takes on oxygen. The blood then returns to the heart through the Pulmonary vein. This blood flow is called the pulmonary circuit.The other circuit is called the systematic circuit, the blood leaves the heart through the aorta carrying oxygen rich blood and travels to organs throughout the body and returns back to the heart through veins. The right half of the heart circulates blood from the body to the lungs, the left side of the heart circulates blood from lungs around the body. The heart has its own set of blood vessels to keep it in healthy working condition. These vessels are called the coronary artery and vein. The structure of arteries and veins are very similar and the structure of each is very much related to its function. Tunica Adventitia- this is the strong outer covering of arteries and veins. It consists of connective tissue, collagen and elastic fibres. Tunica Media-This is the milled layer of walls in veins and arteries. This consists of smooth muscle and elastic fibre.

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  • Subject: Medicine and Dentistry
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Calcium transport study of SF-9 lepidopteran cells and bull frog sympathetic ganglion cells

Calcium transport study of SF-9 lepidopteran cells and bull frog sympathetic ganglion cells ABSTRACT The intracellular calcium level and the calcium efflux of the bull-frog sympathetic ganglion cells (BSG) and the SF-9 lepidopteran ovarian cells were investigated using a calcium-sensitive fluorescence probe fura-2. It was found that the intracellular calcium levels were 58.2 and 44.7 nM for the BSG cells and SF-9 cells respectively. The calcium effluxes following zero calcium solution were 2.02 and 1.33 fmole·cm-2·s-1 for the BSG cells and SF-9 cells. The calcium effluxes following sodium orthovanadate (Na2VO4) in zero calcium solution were 6.00 and 0.80 fmole·cm-2·s-1 for the BSG cells and the SF-9 cells. The SF-9 cells also lost the ability to extrude intracellular calcium after 2-3 applications of Na2VO4 while the BSG cells showed no apparent lost of calcium extruding abilities for up to 4 applications of Na2VO4. INTRODUCTION Spodoptera frugiperda clone 9 (SF-9) cells are a cultured insect cell line derived from the butterfly ovarian tissue. SF-9 cells are used by molecular biologists for the studies of gene expression and protein processing (Luckow and Summers, 1988). However, there is not much known about these cells' basic biophysiology. Since calcium is involved in many cells' activities such as acting as a secondary messenger, it is important for cells to

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Describe the Mechanism of Action of Diuretics. How does this Help us to Understand the Mechanism of Water and Salt Movements in the Kidney.

Describe the Mechanism of Action of Diuretics. How does this Help us to Understand the Mechanism of Water and Salt Movements in the Kidney Diuretics cause an effect on the kidneys, to increase the excretion of salt and water. They are used in the treatment of heart failure and oedema (the accumulation of extracellular fluid), but also are used to treat hypertension. General Mechanism of Action Diuretics cause a net loss of water from the body by an action on the kidney, normally associated with a loss of sodium. The effect of causing increased water loss is achieved by decreasing the reabsorption of sodium and chloride from the filtrate. There are two methods of achieving this i. A direct action on the cells of the nephron ii. Indirectly modifying the content of the filtrate As the glomerulus filters such a large volume of water per day, a small decrease in reabsorption can result in a large increase in excretion of water. Diuretics Acting on the Cells of the Nephron To cause a net loss of salt by acting on cells, the diuretics must affect the parts of the nephron where the majority of the active and selective solute reabsorption occurs. These are i. The ascending loop of Henle ii. The early distal tubule iii. The collecting tubules and ducts Loop Diuretics These drugs include * Frusemide * Bumetanide * Piretanide and are the most powerful of the

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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The structure and functions of body tissues.

UNIT 2 - Human Physiology Assignment 1 - THE STRUCTURE AND FUNCTIONS OF BODY TISSUES Histology is the name for the study of tissues. A tissue is a group of cells which forms a specialised function. There are many different types of tissue and one type of tissue may be found in many parts of the body. In the body we have four main types of tissue which are: * Epithelial * Connective * Muscle * Nervous All these different types of tissue are needed in order for the body to function. All of these tissues have different characteristics and functions. The first type of tissue to look at is: Epithelial Tissue There are 6 main types of epithelial tissue: * Squamous epithelium * Cubodial epithelium * Columnar epithelium * Ciliated epithelium * Compound transitional epithelium * Glandular epithelium Squamous Epithelium Simple squamous These are usually made up of thin flat scale like cells, which rest on the basement of the membrane. This type of tissue can be found in renal capsules of the kidneys, alveoli of the lungs and blood capillary walls. They are usually found in these areas as the thinness of the cells allows diffusion of materials through them. Therefore the main functions are to reduce friction, and to perform absorption and secretion. Stratified squamous Stratified squamous are made up of several layers of cells. They are like simple sqarmous cells

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Scleroderma and Society

IB Biology Essay Scleroderma and Society Mimi You 42883 December 16, 2004 Gabbott You wake up in the morning and your body feels heavy and fatigued as if you've just run a marathon, and your joints feel like their burning, but all you've done is sit up on the bed. You find it hard to breathe and there is a painful, swollen sensation in your feet and hands that makes you feel as if they were about to burst and when you touch your face it feels stiff and unnatural. When you stand up off the bed and try to make it to the bathroom, within seconds you need to sit down again, the only way you can get around is by wheelchair. Today's a school day so you have to be efficient, put on your shoes which are a size too big because your feet get too swollen, brush your hair into a ponytail to try and hide thinnest areas, and get to class and listen as carefully as you can because your hands are so stiff and swollen you can't manage writing notes (Senécal, 1990), (Seibold, 1999), (Blau and Dodi, 1984). This is what a day in Ashley Looper's life is like, a teenage girl who was diagnosed with several forms of autoimmune disorders, including mixed connective tissue disease, lupus erythematosus, juvenile arthritis and scleroderma. Autoimmune responses occur when the body is not able to recognize it's own cells, which prompts the body to reject it's cells by producing antibodies for the

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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Serum Leptin Levels and Adiposity in Chinese.

Serum Leptin Levels and Adiposity in Chinese* *This work was financially supported by the Rockefeller Foundation of the United States and Natural Science Fund of Shanghai Secondary Medical University 98-11-25 SUMMARY Objective: To establish normal serum leptin levels in Chinese and to investigate the relationships between serum leptin levels and body fat, gender, age and androgen. Methods: Serum leptin levels were measured in 77 lean (BMI<25) and 28 overweight or obese(BMI?25) subjects by a RIA method. Results: The serum leptin levels in lean Chinese were 2.15?1.46ng/ml in male and 7.85?3.60ng/ml in female, which are similar to those of Caucasians, while in overweight or obese ones, the levels were 4.87?3.47ng/ml and 16.59?6.92ng/ml respectively, lower than those in Caucasians. A 2-3 times higher leptin concentrations were found in women than in men in both conditions. Even when the number of lean males were expanded to 79 subjects aged from 17-80, no significant leptin-age relationship was found. Despite 25% of obese subjects manifested a relative deficiency of leptin, as a whole, leptin levels in both men and women were significantly correlated with BMI (r=0.69, P<0.001 in male and r=0.63, P<0.001 in female). Conclusion: Serum leptin levels in Chinese lean people are similar to those in Caucasians and in both lean and obese groups, the leptin levels are correlated with

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  • Level: University Degree
  • Subject: Medicine and Dentistry
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