Interrelations between the hypothalamic-pituitary-adrenal system ( HPA ) and the immune system represent a well-documented biological phenomenon .
interrelations between the hypothalamic-pituitary-adrenal system ( hpa ) and the immune system represent a well-documented biological phenomenon .
O O O B-body_part I-body_part O B-body_part O O O B-body_part I-body_part O O O B-other_name I-other_name O