EXAM 4 P3

Question 1

consequences of disrupting gut flora

Answer 1

poor nutritional absorption and pathogen invasion

improper immune function, causing autoimmune disorders (asthma)

Question 2

microflora of the skin

Answer 2

first line of defense
its dry, acidic, and salty conditions are not good for microbial growth
associated with anaerobes that grow in hair follicles and sebaceous fluids

Question 3

what can cause flora to change

Answer 3

the weather, age, and hygiene

Question 4

what is the predominant class of skin flora

Answer 4

gram positive cocci

Question 5

residents of the upper respiratory tract/oral cavities

Answer 5

transient organisms get trapped in the mucus membrane (breathing) and are expelled (snot, sneeze)
common micro flora are gram positive cocci

Question 6

lower respiratory tract

Answer 6

relatively sterile area
airborne and inhaled organisms are trapped in the upper tract and removed by ciliated epithelium
cough reflex and alveolar macrophages

Question 7

microflora of the gastrointestinal tract

Answer 7

majority of microbes are located here

change with age

Question 8

in what direction does pH increase

Answer 8

from the esophagus to the colon
inverse relationship to O2
stomach is extremely acidic (pH 2)

Question 9

helicobacter

Answer 9

rare organism that grows in the stomach
survives pH2 environment
is a spirochete, good at moving through viscous fluid
can burrow into the mucous membrane lining of the stomach and modifies the environment to increase pH

Question 10

damage due to helicobacter

Answer 10

damages human tissue, causing ulcers

can lead to gastric cancer if left untreated

Question 11

Bacteroides

Answer 11

most abundant in the colon
positive, good at degrading complex polysaccharides found in fiber and grains
if they get into the peritoneal space, it can cause abscess and infection

Question 12

Escherichia

Answer 12

aka E. coli

commonly used to track contamination (fecal in water)

Question 13

methanobrevibacter

Answer 13

rare archaea

thano makes it a methanogen, producing methane (an odorless gas)

Question 14

C difficile

Answer 14

number 1 hospital infection in the U.S.
normal gut inhabitant for most people
antibiotics can disrupt normal flora and allow it to spread. it becomes more resistant and can disrupt the colon

Question 15

colitis

Answer 15

caused by an abundance of C difficile
aka mega colon
serious infection that can be fatal
to cure it, add more antibiotics to decrease the C diff population. is now a race to see is the normal flora will grow back first or the diff
most often C diff since it produces spores

Question 16

probiotics

Answer 16

can repopulate the gut and prevent C diff from taking over and allowing normal flora to recover

Question 17

fecal transplant therapy

Answer 17

first treated with antibiotics
fecal matter is collected by a donor, but in a blender with saline, and delivered to the colon.
cures 95% of C. diff infections
the other person may have viruses or bacteria that don’t both them, but may bother you unknowingly

Question 18

beneficial functions of GI microflora

Answer 18

vitamin synthesis (thiamine, K, B12)
gas production (CO2, CH4, H2)
odor production (H2S, NH#)
organic acid production (acetic, butyric)
glycosidase reactions
steroid metabolism (bile acids)

Question 19

what do bile acids do

Answer 19

break up fats and oils into a more soluble state

Question 20

genitourinary flora

Answer 20

upper urethra and bladder are generally sterile. flushing action of urine keep the bladder clear
UTI or bladder infections

Question 21

anterior urethra

Answer 21

closest to the exit of the body (anus). can be colonized with gram negative organisms like E. coli. most don’t move up very far, but ones that do cause UTIs and kidney infections.

Question 22

women’s urethra

Answer 22

shorter than men’s

more susceptible to UTI

Question 23

vagina

Answer 23

flora of the vagina is one region that changes with age and physiological state
pre puberty and after menopause has streptococci and enterobacteria
during fertile years, pH is lowered and you find lactobacilli

Question 24

capsules

Answer 24

extracellular polysaccharides

some bacteria produce specific proteins that will bind to the surface of a human cell.

Question 25

fimbriae

Answer 25

short, highly abundant filaments on the surface of the cell

fixed and produce a lot of sticky surface area

Question 26

pili

Answer 26

retractable

bind to something and retract to pull the other surface closer

Question 27

puncture wounds

Answer 27

can disrupt O2 flow and allow things to grow (infection)