Essay Examples on MCPHS University

Malaria is a fatal infectious disease that harms people all around the World

Malaria is fatal infectious disease that harms people all around the world mainly in tropical Saharan locations The risk of malaria increase with the climate change and changes in land such as through logging road-building mining and agricultural irrigation project The disease can be contracted from the bite of a female anopheles mosquito infected with the plasmodium parasite Out of plethora of plasmodium parasites only 5 cause the disease in humans falciparum vivax malaria ovale and knowlesi After being bite by the plasmodium infected mosquito tiny worm-like sporozoites leave the insects saliva and enter the humans bloodstream to infect red blood cells Minutes is all it takes for the sporozoites to reach the liver where they begin to mature by asexual reproduction and attack hepatic parenchymal cells In 1 2 weeks falciparum malaria and knowlesi change from sporozoites to merozoites as the host cells die while vivax and ovale take another route Taking a longer amount of time from months to years these diseases become hypnozoites and go dormant 

This means instead of dividing right away they cause a delay from the time initially infected to experiencing the symptoms These diseases are generally not inside the red blood cells or asymptomatic Ovale invade red blood cells of all age and vivax invade young immature red blood cells Vivax also uses an erythrocyte surface receptor known as the Duffy antigen and those with sickle cell anemia protect against this disease as they don t the Duffy Other diseases like thalassemia and G6PD make the parasite more likely to die from oxidative stress Merozoites that have been released into the blood each bind to a surface receptor and invade a red blood cell Malariae prefers older red blood cells as does knowlesi and falciparum has no preference Once the merozoite is inside a red blood cell it asexually reproduces which is an ongoing process for 2 3 days The disease then goes into a series of transformation known as the erythrocytic phase

2 pages | 651 words

The Circulatory System

The complexity of the human body is never more evident than within the circulatory system The circulatory system has many structures performs vital functions and also has diseases and disorders that are specific to it The circulatory system works with other systems to deliver oxygen and nutrients to organs and tissues throughout the body This functions as the transportation system of the body The system partners with the digestive respiratory and urinary systems to ensure that the body functions properly and maintains homeostasis There are two types of circulation systemic and cardiopulmonary that the system is responsible for While systemic circulation ensures that blood and the nutrients it carries reaches the entire body cardiopulmonary circulation allows blood to travel to the lungs to gain oxygen Circulation is driven by the heart which acts as a double pump This is possible due to the heart's electrical activity WebMD explains that an electrical message travels through two types of cells in the heart conducting cells that transport the message and muscle cells that cause contractions of the heart muscle The electrical system begins work with the sinoatrial node that causes the atria to contract The signal is then sent to the ventricles by the atrioventricular bundle Following this the Bundle of His carries the signal through the septum and then the Purkinje fibers cause the ventricles to contract The circulatory system is made of blood vessels of which are three different types arteries veins and capillaries The vessels have characteristics that distinguish them from each other Arteries carry blood from the heart under high pressure Because arterial blood is oxygen rich it is bright red Blood leaving the heart travels through the aorta before going to arteries and then arterioles throughout the rest of the body Veins are the opposite of arteries they carry oxygen poor blood to the heart causing the blood to be a darker shade of red

2 pages | 635 words