7: 1st Line Of Defence Flashcards
1
Q
phys barriers - 1st LOD
A
- skin
- mucous membrane + cilia + peristalsis
- urine flow
2
Q
chem barriers - 1st LOD
A
- stomach acid + enzymes
- alkali of sml intestine
- tears + lysosomes
- earwax
3
Q
phys barrier - skin
A
- cells of epidermis contain keratin = impenetrable to pathogens (kinda)
- dead cells upper epidermis constant shed = removes any microbes present
- sweat glands in dermis = creates salty, acidic environment which inhibit pathogen growth
4
Q
phys barrier - mucous mem
+ cilia
+ peristalsis
A
- mm secretes mucus = traps pathogens
- movement of respiratory cilia = directs mucus + trapped microbes out and away from the body’s organs (coughing/sneezing)
- peristalsis moves mucus + trapped microbes towards anus, secreted in faeces
5
Q
phys barrier - urine flow
A
creates enough pressure and force to hopefully remove pathogens within the urinary tract
6
Q
chem barrier - stomach acids and enzymes
A
- Before entering stomach, lysosomes (digestive enzymes) within saliva attack + perforate the cell walls of many bacteria
- Stomach contains hydrochloric acid (produced by parietal cells) with pH between 1-2; acid kills most microbes, preventing them from entering body via food/water
