23.1 Structure and Function of the Cardiovascular and Lymphatic Systems

• The center of the cardiovascular system is the heart

• At times the lymph nodes themselves get infected and become visibly swollen and tender; swollen lymph nodes are called buboes

• Lymph nodes are also an important component of the body’s immune system.

23.2 Bacterial Diseases of the Cardiovascular and Lymphatic Systems

• An acute illness that is associated with the presence and persistence of pathogenic microorganisms or their toxins in the blood is termed septicemia

• When sepsis results in a drop in blood pressure (shock) and dysfunction of at least one organ, it is considered to be severe sepsis

• There is an emerging awareness of group B streptococci (GBS). S. agalactiae is the only GBS and is the most common cause of life-threatening neonatal sepsis

• An inflammation of the endocardium is called endocarditis.

  • A more rapidly progressive type of bacterial endocarditis is acute bacterial endocarditis, which is usually caused by Staphylococcus aureus.

• Streptococci can also cause pericarditis, inflammation of the sac around the heart

  • Streptococcal infections, such as those caused by Streptococcus pyogenes, sometimes lead to rheumatic fever, which is generally considered an autoimmune complication.

• Tularemia is an example of a zoonotic disease, that is, a disease transmitted by contact with infected animals, in this case most commonly rabbits and rodents.

• Cutaneous anthrax results from contact with material containing anthrax endospores.

• A relatively rare form of anthrax is gastrointestinal anthrax caused by ingestion of undercooked food containing anthrax endospores.

  • The most dangerous form of anthrax in humans is inhalational (pulmonary) anthrax.

23.3 Viral Diseases of the Cardiovascular and Lymphatic Systems

• The identification of EB virus as the cause of infectious mononucleosis, or mono, resulted from one of the accidental discoveries that often advance science.

• This disease of the newborns was given the name of cytomegalic inclusion disease (CID).

  • Patients who recover without major incident are classified as having dengue.

• If the patient suffers from severe bleeding and organ impairment, the case is classified as severe dengue.

• Ebola virus disease (EVD) or Ebola, for a regional river, this is now a well-publicized disease, with mortality approaching 90%.

• Argentine and Bolivian hemorrhagic fevers are transmitted in rural areas by contact with rodent excretions.

• Hantavirus pulmonary syndrome, caused by the Sin Nombre virus,* a bunyavirus, has become well known in the United States because of several outbreaks, mostly in the western states.

23.4 Protozoan Diseases of the Cardiovascular and Lymphatic Systems

• Toxoplasmosis, a disease of blood and lymphatic vessels, is caused by the protozoan Toxoplasma gondii.

• Malaria is characterized by chills and fever and often by vomiting and severe headache.

• Leishmaniasis is a widespread and complex disease that exhibits several clinical forms

23.5 Helminthic Disease of the Cardiovascular and Lymphatic Systems

• Schistosomiasis is a debilitating disease caused by a small fluke

  • Schistomiasis is treated with praziquantel.

• Sanitation and elimination of the host snail are also useful forms of control.

23.6 Disease of Unknown Etiology

• Probably the most common cause of acquired heart disease in the United States (replacing rheumatic fever) is an acute febrile illness of unknown etiology, Kawasaki syndrome (KS).