Which white blood cell type is primarily involved in allergic reactions?

A. The adrenal gland's hormones are primarily steroid-based:Many adrenal cortex hormones (glucocorticoids, mineralocorticoids, and androgens) are steroid hormones derived from cholesterol, distinguishing them chemically from many pituitary peptides.
B. The adrenal gland's hormone release is regulated by thyroid hormones:While thyroid hormones affect metabolism broadly, they are not the main regulators of adrenal hormone release; ACTH and the HPA axis primarily regulate adrenal cortisol production.
C. The pituitary gland's hormone release is directly controlled by the hypothalamus:The hypothalamus controls anterior pituitary hormone secretion via releasing and inhibiting hormones delivered through the hypophyseal portal system.
D. The pituitary gland produces hormones in response to blood glucose levels:Some pituitary functions can be influenced indirectly by metabolic state, but direct regulation of pituitary hormone release by blood glucose is not a primary mechanism.

A. The HPA axis directly controls the release of growth hormone.:Growth hormone release is regulated mainly by GHRH and somatostatin from the hypothalamus and feedback from IGF-1, not primarily by the HPA axis.
B. The HPA axis is responsible for regulating blood sugar levels through insulin secretion.:Insulin secretion is controlled by the pancreas in response to blood glucose; the HPA axis influences glucose metabolism indirectly via cortisol but does not control insulin release.
C. The HPA axis responds to stress by stimulating cortisol release from the adrenal glands.:The HPA axis (CRH → ACTH → cortisol) is activated by stress and results in increased cortisol production by the adrenal cortex.
D. The HPA axis regulates the secretion of thyroid hormones.:Thyroid hormone secretion is primarily regulated by the hypothalamic–pituitary–thyroid axis (TRH → TSH → T3/T4), not the HPA axis.