Analyze actions people can take to reduce their risk of developing the disease or disorder

Briefly describe the normal function of these three systems and associated organs. 
Immune System
The immune system plays the role of defending the body against pathogens.
The body has various barriers that seek to ensure that pathogens do not enter the body
(Colbert, Ankney, & Lee, 2013). However, if the pathogens bleach the barriers, an
the immune response is triggered. Microscopic cells attack the pathogens or release
chemicals that break down the invading germ.
The Urinary System
The urinary system plays the role of controlling the electrolyte and fluid
balance in the body. The kidneys play a major role in the urinary system. Kidneys
help in the filtration of the blood, reabsorption, and secretion of ions, and the production
of urine.
Gastrointestinal System
The gastrointestinal system helps in breaking down food particles. Food is
taken in and is broken down both physically and chemically. The breaking down of
food results in the release of usable elements (Colbert, Ankney, & Lee, 2013). The
elements are then absorbed while the waste that is not usable is eliminated.
Choose and briefly describe one chronic disease or disorder for each of the three
systems and explain how the diseases/disorders alter the normal function.
Examine potential causes for the disease or disorder and list signs and symptoms
that indicate the disease has developed.

Analyze actions people can take to reduce their risk of developing the chronic
disease or disorder. 
Immune System
AIDS is a chronic disorder that affects the immune system. AIDS is caused by
the human immunodeficiency virus (HIV). AIDS destroys white blood cells, and this
results in a weak immune system (Colbert, Ankney, & Lee, 2013). The body is unable
to fight the infections, and this makes the body vulnerable. Signs of AIDS include
rapid weight loss, diarrhea, and pneumonia. Having unprotected sex with an infected
person is the primary cause of the disease. The implication is that safe sex can help
prevent one from getting the disease.
Gastrointestinal System
Celiac disease is one of the chronic gastrointestinal conditions. It results in the
destruction of the small intestine when one eats gluten. Symptoms include nausea and
vomiting (Green & Cellier, 2007). Celiac disease is largely passed down through
genes. The implication is that one cannot take measures to protect themselves against
the disease.
The Urinary System
Kidney stones is one of the chronic diseases affecting the urinary system. It
results in the improper functioning of the kidneys (Scales et al., 2012). Foul-smelling
urine, as well as fever and chills, are signs and symptoms of the disease. Drinking
enough water as well as avoiding too much animal proteins can help prevent the
disease.

References

Colbert, B. J., Ankney, J., & Lee. K. T. (2013). Anatomy, physiology, & disease: An
interactive journey for health professionals (2nd ed.). Boston: MA. Pearson
Education.
Green, P. H., & Cellier, C. (2007). Celiac disease. New england journal of
medicine, 357(17), 1731-1743.
Scales Jr, C. D., Smith, A. C., Hanley, J. M., Saigal, C. S., & Urologic Diseases in
America Project. (2012). Prevalence of kidney stones in the United
States. European urology, 62(1), 160-165.