10
secretion of ADH. ADH promotes kidney retention of water by enhancing the permeation of collecting ducts to water and following the absorption from the tubular fluid.
Oxytocin
Paraventricular nuclei is primarily involved in production of oxytocin hormone.
During labor, oxytocin secretion is increased. As the fetus travel through the birth
canal it stimulates the afferent nerves which is transmitted to the hypothalamus,
causing oxytocin release ultimately promoting labor. When baby sucks, touch
receptors located at nipple of breast communicate signals to hypothalamus that
leads to secretion of oxytocin to excrete milk.
Oxytocin is mainly produced in the paraventricular nucleus. The secretion of
oxytocin is enhanced during childbirth. After the fetus descends along the birth
canal, it transmits impulses to the afferent nerves of the hypothalamus, causing the
release of oxytocin, which increases the labor force. During breastfeeding, the tactile receptors in the breast nipple transmit a signal that terminates in hypothalamus,
triggering the oxytocin secretion which is ultimately responsible for excretion of
milk [6]. In a nutshell, oxytocin causes uterine contraction and stimulates lactating
mammary epithelial cells to contract, causing milk to eject from the alveoli, into the
mammary duct, and then from the nipple.
Thyroid Gland
Thyroid gland consists of two lobes; each is located laterally to the trachea and it is
situated on neck below throat. It is said to be body’s largest gland, possessing an
efficient mechanism of active transport that involves absorption of iodide ions circulating in blood.
T3 and T4
The thyroid gland is accountable for the secretion of iodothyronines, three of which.
The main secretory product is inactive thyroxine or T4, which is a pro-hormone of
triiodothyronine or T3. T4 is converted to T3 by the periphery of type 1 deiodinase
in high blood flow tissues such as liver and kidney. In the brain, type 2 deiodinase
produced by glial cells converts T4 to active T3. The third iodothyronines is called
reverse T3 or rT3. rT3 is inactive and is formed by type 3 deiodinase activity
on T4 [8].
These iodothyronines consist of iodine and thyroglobulin. Thyroglobulin is
formed from amino acids in the form of thyroid cells themselves to the apex.
A. Ahsan et al.
secretion of ADH. ADH promotes kidney retention of water by enhancing the permeation of collecting ducts to water and following the absorption from the tubular fluid.
Oxytocin
Paraventricular nuclei is primarily involved in production of oxytocin hormone.
During labor, oxytocin secretion is increased. As the fetus travel through the birth
canal it stimulates the afferent nerves which is transmitted to the hypothalamus,
causing oxytocin release ultimately promoting labor. When baby sucks, touch
receptors located at nipple of breast communicate signals to hypothalamus that
leads to secretion of oxytocin to excrete milk.
Oxytocin is mainly produced in the paraventricular nucleus. The secretion of
oxytocin is enhanced during childbirth. After the fetus descends along the birth
canal, it transmits impulses to the afferent nerves of the hypothalamus, causing the
release of oxytocin, which increases the labor force. During breastfeeding, the tactile receptors in the breast nipple transmit a signal that terminates in hypothalamus,
triggering the oxytocin secretion which is ultimately responsible for excretion of
milk [6]. In a nutshell, oxytocin causes uterine contraction and stimulates lactating
mammary epithelial cells to contract, causing milk to eject from the alveoli, into the
mammary duct, and then from the nipple.
Thyroid Gland
Thyroid gland consists of two lobes; each is located laterally to the trachea and it is
situated on neck below throat. It is said to be body’s largest gland, possessing an
efficient mechanism of active transport that involves absorption of iodide ions circulating in blood.
T3 and T4
The thyroid gland is accountable for the secretion of iodothyronines, three of which.
The main secretory product is inactive thyroxine or T4, which is a pro-hormone of
triiodothyronine or T3. T4 is converted to T3 by the periphery of type 1 deiodinase
in high blood flow tissues such as liver and kidney. In the brain, type 2 deiodinase
produced by glial cells converts T4 to active T3. The third iodothyronines is called
reverse T3 or rT3. rT3 is inactive and is formed by type 3 deiodinase activity
on T4 [8].
These iodothyronines consist of iodine and thyroglobulin. Thyroglobulin is
formed from amino acids in the form of thyroid cells themselves to the apex.
A. Ahsan et al.