Castoreum Castoreum Castoreum is a yellowish exudate from the castor sacs of the mature North American beaver ("Castor canadensis") and the European beaver ("Castor fiber"). Beavers use castoreum in combination with urine to scent mark their territory. Both beaver sexes have a pair of castor sacs and a pair of anal glands, located in two cavities under the skin between the pelvis and the base of the tail. The castor sacs are not true glands (endocrine or exocrine) on a cellular level, hence references to these structures as preputial glands, castor glands, or scent glands are misnomers. It is used as
Nobel Prize in Physiology or Medicine this year's prize 'for Physiology or Medicine' to three men who had until recently been regarded as 'mere animal watchers'". Laureates have been awarded the Nobel Prize in a wide range of fields that relate to physiology or medicine. , eight Prizes have been awarded for contributions in the field of signal transduction through G proteins and second messengers. 13 have been awarded for contributions in the field of neurobiology and 13 have been awarded for contributions in Intermediary metabolism. The 100 Nobel Prizes in Physiology or Medicine have been awarded to 195 individuals through 2009. Twelve women have received