Sept%2025th%20disease

Sept%2025th%20disease - Disease Disease: Any impairment of...

Info iconThis preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
Disease
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Disease: Any impairment of normal physiological functioning Environmental disease : lung cancer Genetic disease : sickle cell disease Infectious disease : capable of being transmitted by an infectious agent (a vector) ex. malaria is spread by mosquitoes
Background image of page 2
The relationships between humans, disease and the environment are complex Environment, biological history, social- cultural factors including politics and economics are important Examples today: Sickle cell disease, Polio, Malaria and HIV/AIDS
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Sickle Cell Disease Red blood cells do not circulate properly Victims suffer damage to the spleen, anemia, joint pain Average life expectancy: 42 yrs for males, 48 for females
Background image of page 4
Sickled cell mutation low oxygen in blood stream or dehydration can cause cells to sickle (change from donuts to to sickle or half moon-type shapes) Heterozygous carriers have some sickling Homozygous carriers have lots of sickling Sickles -are tools used by farmers to cut grain crops Normal red blood cell Sickled cell
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Quick genetics lesson: Homozygous : inherited the trait from both parents (ex people with blue eyes are homozygous for blue eyes) Heterozygous : inherited the trait from one parent and it is often not fully expressed Sickle cell mutation is incompletely recessive and is partially expressed in heterozygous carriers, and fully expressed in homozygous carriers
Background image of page 6
Geography of Sickle Cell Mutation Malaria range Sickle cell mutation
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Genetic mutation Conferred advantage against an infectious disease (malaria) Allowed sickle cell trait to spread in the population Heterozygous carriers are protected from malaria Homozygous carriers develop sickle cell disease
Background image of page 8
Lessons from Sickle Cell Trait We have responded over evolutionary time to our environment Some populations have genetic defenses against certain diseases Genetics can also cause diseases Often there is a trade-off in terms of survival Disease is not just a battle between us and the disease - there is a larger environmental and historical context
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Classic ‘Us vs the disease’: Polio Poliomyelitis -a human virus Highly infectious, passed through feces, contaminates food, water etc. and enters the nervous system Mainly infects young children Causes fever, pain, short term paralysis, may cause permanent paralysis
Background image of page 10
Polio and History Outbreaks throughout history Early 20th C. there was a high increase in cases Pre-20th C. poor sanitation =constant exposure to disease, only children from 6 m to 4 yrs suffered infections, paralysis is rare in such young patients Sanitation = lack of exposure to the virus at an early age which led to more older patients Possible Polio victim Ancient Egypt 1403-1365 BCE
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Polio epidemics appeared in Europe and N.A. around 1900
Background image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/22/2008 for the course GEOG 200 taught by Professor Dowsley during the Fall '08 term at McGill.

Page1 / 44

Sept%2025th%20disease - Disease Disease: Any impairment of...

This preview shows document pages 1 - 13. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online