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Ch18 summary notes...

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cardiovascular system is the pipeline of the body The cardiovascular system provides tissues with oxygen and nutrients and carries away carbon dioxide and waste products, delivering them to the appropriate organs for removal away from the heart under relatively high pressure. They branch into smaller vessels called arterioles. Veins actually begin as smaller venules in the periphery of the body and coalesce into veins. The smallest blood vessels, the capillaries, connect arterioles to venules. Both arteries and veins have walls made of three layers of tissue. The innermost layer is composed of a smooth epithelium called endothelium. Its smooth surface encourages the smooth flow of cells and platelets through the system. The various types of white blood cells include the lymphocytes, responsible for specific immunity, and the phagocytes, which are so critical to nonspecific as well as specific immune responses. Very few microbes can survive in the blood with so many defensive elements. Bacteria frequently are introduced into the bloodstream during the course of daily living. Brushing your teeth or tearing a hangnail can introduce bacteria from the mouth or skin into the bloodstream; this situation is usually temporary. But when bacteria flourish and grow in the bloodstream, the condition is termed septicemia There is evidence that the blood cells do contain bacteria of various types. HIV is a retrovirus in the genus Lentivirus. Many retroviruses have the potential to cause cancer and produce dire, often fatal diseases and are capable of altering the host’s DNA in profound ways. They are named “retroviruses” because they reverse the usual order of transcription. They contain an unusual enzyme called reverse transcriptase (RT) that catalyzes the replication of double-stranded DNA from single-stranded RNA. Not only can this retroviral DNA be incorporated into the host genome as a provirus that can be passed on to progeny cells, but some retroviruses also transform cells (make them malignant) and regulate certain Semen and vaginal secretions also harbor free virus and infected white blood cell A person is diagnosed as having HIV infection, as opposed to having AIDS, if he or she has tested positive for the human immunodeficiency virus. Preexposure prophylaxis, called PrEP, is currently recommended for people who are high risk for becoming infected; The signs and symptoms are similar for both types of endocarditis, except that in the subacute condition they develop more slowly Acute endocarditis is most often the result of an overwhelming bloodstream challenge with bacteria. Subacute forms of this condition are almost always preceded by some form of damage to the heart valves or by congenital malformation The cause of this dreadful disease is a tiny gram-negative rod, Yersinia pestis, a member of the family Enterobacteriaceae Empiric therapy should be started immediately before culture and susceptibility results are available. These cases often progress to massive bacterial growth in the blood termed septicemic plague

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The plague bacterium resides in over 200 species of mammalian host. After an incubation period ranging from a few days to 3 weeks, acute symptoms of headache, backache, fever, chills, coughing, and weakness appear. Individuals exposed to the outdoors should routinely inspect their bodies for ticks). This is a condition lasting weeks or months characterized by fatigue and muscle and joint pain A number of agents that infect the blood and lymphatics cause extreme fevers, some of which are accompanied by internal hemorrhaging. The diseases yellow fever, chikungunya, and dengue fever are all notable for the fact that they are spread by the Aedes genus of mosquito aegypti mosquitoes infected with the bacterium Wolbachia are being released in areas with heavy dengue burden. When these males mate with females The Brucella bacteria responsible for this disease live in phagocytic cells. These cells carry the bacteria into the bloodstream, The bacterial genus Brucella contains tiny, aerobic, gram-negative coccobacilli. Several species can cause this disease in humans: Brucella enters through damaged skin or via mucous membranes of the digestive tract, conjunctiva, The name of this disease arose from the frustration created by not being able to identify its cause. The Q stands for “query C. burnetii is a very small pleomorphic (variously shaped) gram-negative bacterium, and for a time it was considered a rickettsia Anaplasma is another small intracellular bacterium. It shares lifestyle characteristics with Ehrlichia and causes nearly identical clinical manifestations. Babesia is a protozoan that infects red blood cells. It produces similar symptoms to Ehrlichia and Anaplasma Rapid diagnosis is done through PCR tests and indirect fluorescent antibody tests. It can be critical to differentiate or detect coinfection Ehrlichia is a small intracellular bacterium with a strict parasitic existence and association with ticks (Ixodes species). B. henselae is the agent of cat-scratch disease (CSD), an infection connected with being clawed or bitten by a cat. This disease is one of a group of diseases caused by different species of the small gram-negative rod Bartonella. Anaplasma is another small intracellular bacterium. It shares lifestyle characteristics with Ehrlichia Babesia is a protozoan that infects red blood cells. It produces similar symptoms to Ehrlichia and Anaplasma. Since it is a protozoan, treatment is different than for Ehrlichia and Anaplasma. Anthrax causes disease in the lungs and in the skin, and is addressed elsewhere in this book. Bleeding in the intestine and from mucous membranes and orifices may occur in late stages of septicemia Bacillus anthracis is a gram-positive endospore-forming rod that is among the largest of all bacterial pathogens. The main virulence factors of B. anthracis are its polypeptide capsule and what is referred to as a “tripartite” toxin—a protein complex composed of three separate exotoxins....