The arrows indicate the flow of air in of the human body through the respiratory system organs. In the above diagram, the air at first enters through the nose, then flows through the nasal cavity, pharynx, larynx, trachea, and then into the lungs through the Bronchi.
The endocrine system gets some help from organs such as the kidney, liver, heart and gonads, which have secondary endocrine functions. The kidney, for example, secretes hormones such as erythropoietin and renin.
Most hormone secretions are regulated by negative feedbacks. The 3 main feed backs are: 1)(Blood level of certain chemicals controls hormone secretion) Blood composition; Exâ¦: blood glucose levels control the insulin secretion. 2)(Hormones controlled by nervous system) Neural control; Ex: Epinephrine is release from adrenal medulla as result of nervous system stimulation. 3)(Hormone secretion controlled by other hormones) Hormonal control; Ex: hormones from pituitary gland act on the ovaries and testes causing release of sex hormones.