The fossil record tells us what types, kinds, and numbers of organisms may have lived in the past, as well as what they ate, what age they lived in,.
Handwashing is one of the most important (and easiest) practices used to prevent transmission of bloodborne pathogens. Hands or other exposed skin should be thoroughly washed as soon as possible following an exposure incident. Use soft, antibacterial soap, if possible.
Presentation Transcript. blood-testis barrier: blood-testis barrier The blood-testis barrier (BTB) is a physical barrier between the blood or lymph vessels and the lumen of seminiferous tubules of the animal testes.lood-testis barrier: HOW IT FORM Myoid layer Sertoli cell junction Sertoli cell junction formed by tight connections between the Sertoli cells, which are sustentacular cells (nurse cells) of the seminiferous tubules, and nourish the spermatogonia.