Class Notes (835,300)
Canada (509,079)
Biology (2,253)
BIOL 101 (73)


2 Pages
Unlock Document

BIOL 101
Christine Dupont

Pathogenesis: How Microorganisms Cause Disease  Damage or destroy host cells - e.g. HIV, Salmonella o Organism is taken up by epithelial cells in the intestine  HOST SPECIFIC: ligand on pathogen must fit onto receptor proteins on host  Some hosts are more susceptible than others because proteins depend on gene coding o Destroy brush border of microvilli o Host creates a ruffled surface / Invaded cells detach from intestinal wall, creating inflamed lesions / Secretion of large amounts of watery fluid into the lumen of the gut → diarrhoea  Produce toxic waste - e.g. Vibrio cholerae o Are harmless but produce harmful "exotoxins" - toxins released from the cell o Causes loss of chloride and hydrogencarbonate ions from the intestinal cells o Osmotic loss of up to 10 litres of water per day o Impaired absorption of water and salt from the gut o This explains severe watery diarrhoea and death from dehydration  Body's own immune response to the presence of microorganisms which produce the symptom o e.g. Mycobacterium tuberculosis o Body tries do destroy the invading bacteria o This causes inflammation and damage to the surrounding cells occur o Lesions may become hard or spongy, leaving "holes" in the lungs, sometimes damaging blood vessels  Some bacteria will cause all of the 3 ways above; Some require a large number of bacteria for a disease; Some will only a few number of
More Less

Related notes for BIOL 101

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.