Hormones are chemical messengers in the body that regulate the body’s physiology. They act due to the
- The feedback mechanisms and
- By the action on the specific cell surface receptors
These hormones in the human body are secreted by endocrine glands.
How do the Hormones Work
Feedback mechanisms
The method aims to control the levels of hormones in blood circulation.
The synthesis, storage, and release of hormones are regulated by a mechanism involving feedback signals between the hypothalamus, pituitary, and endocrine glands synchronously.
The second method relates to hormonal action on the nucleus to bring out the effect.
Hormonal secretion and inhibition:
This happens in the following steps.
- Signal by the simulator for Synthesis from the pituitary.
- Positive feedback to the pituitary for more secretion.
- Negative feedback inhibits the simulator’s secretion.
Most hormones are secreted under the influence of pituitary hormones.
These hormones are synthesized and then secreted into the blood. When the blood levels reach a specific point, they are inhibited by a feedback signal.
The signal for synthesis: Hormonal synthesis is done by endocrine glands in the body. However, hormonal synthesis is initiated by a signaling pathway. This stimulated the glands to synthesize the hormone.
For example, the thyroid-stimulating hormone (TSH) regulates the secretion of thyroid hormones. TSH is secreted by the anterior pituitary gland. This TSH stimulates the thyroid gland to synthesize thyroid hormones.
As a result, thyroid hormones like thyroxine (T4) and triiodothyronine (T3) are formed. These two hormones are then carried by the blood to all the tissues of the body.
Inhibition of stimulation/secretion:
This is the inhibition of TSH secretion.
A feedback mechanism is initiated when the blood levels of T3 and T4 are high.
This negative feedback inhibition signal stops the secretion of TSH. This hinders the further formation of thyroid hormones.
So, the secretion of TSH directly controls the formation and release of T3 and T4 hormones.
Hormonal action on the cells.
This step is the actual mechanism by which the hormone’s action is seen at the cellular level.
Hormones enter the cell membrane and the nucleus. There, they act on the nuclear receptor.
This leads to conformational changes in the genes and specific transcription and translation.
This brings the desired protein synthesis and, thereby, the hormonal effect.
The deficiency or the hypersecretion of these hormones can lead to severe hormonal disorders like diabetes mellitus, infertility, dwarfism, etc.
Frequently asked questions and answers.
What controls most hormone concentrations
The hypothalamus, a part of the brain through the pituitary gland, controls the hormone concentrations in the blood.
It directs release under the emotional influence, but the concentration is maintained through feedback mechanisms.
Does blood transport hormones
Yes, blood transports most hormones from the point of synthesis to the site of action.
What makes a cell a target of a particular hormone
Hormones can act only on the cells with specific hormone receptors.
Of all the types of cells, hormones act only on secretory cells.