**1. Introduction**

544 A Bird's-Eye View of Veterinary Medicine

Zahorsky-Reeves JL, Gregory CR, Cramer DV, et al.Similarities in the immunog-lobulin

Zhou XP, Du M, Li JY, et al. Steady livability after orthotopic liver transplantation in rats [J].

hepatocytes[J].BMC Immunol,2006,7:3

Shanghai Jiaotong Daxuebao, 2006, 26(6):603-606

response and VH gene usage in rhesus monkeys and humans exposed to porcine

Almost all the body functions of vertebrate animals including swine are regulated by the nervous system and endocrine system. Especially the hormones released from the endocrine system have effective biological amplifying effects. Minor changes in the hormone level could cause huge alternations in physiology.

Hypothalamus, extensively connected with other brain regions, is the vital bridge between nervous system and endocrine system. It exerts its regulating function on endocrine system mainly via the pituitary, which is the central endocrine organ in vertebrate animals. Except the growth hormone, most of the hormones secreted by pituitary have their specific target organs. For example, thyrotropin target thyroid. The hypothalamus, pituitary and target organs are always described together as "axis", e.g. hypothalamo-pituitary-gonadal axis, hypothalamo-pituitary-adrenal gland axis, and hypothalamo-pituitary-thyroid (HPT) axis.
