The Endocrine System’s Link to the Nervous System
A gland selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body. The thymus starts to shrink after puberty. If you don't make any insulin, which is the case for people with type 1 diabetes , your blood sugar levels can get dangerously high. Resources in your library. This condition occurs when the adrenal glands don't produce enough corticosteroids.
They are responsible for secreting endocrine system hormones. Hypothalamus The hypothalamus gland is located above the brain stem in the center of the skull. This important endocrine system gland links the nervous system with the endocrine system via the pituitary gland.
It is responsible for regulating a variety of functions throughout the body, including body temperature, fatigue, circadian rhythms, hunger and thirst. It controls almost all of the internal organs.
You can think of it as the major control center for the autonomic nervous system. Pineal body The pineal gland is a small cone-shaped gland about the size of a pea and found in the brain. It secretes the hormone melatonin, which aids our sleep cycle. Pituitary The pituitary gland is connected to the hypothalamus gland by a short stalk.
It consists of two lobes and each lobe has different functions. This tiny gland plays a major role in many of the functions of the human body. Hormones and neural impulses from the hypothalamus directly influence the hormones secreted by the pituitary gland.
Thyroid The thyroid gland is a butterfly-shaped gland found in front of the trachea on the front of the neck. It has a right and left lobe. When stimulated with the thyroid stimulating hormone TSH from the anterior pituitary gland it releases T3 and T4. In order to operate well the thyroid gland needs to have an adequate supply of iodine and tyrosine as well as other important minerals such as selenium, manganese, magnesium and zinc to name a few. Parathyroids There are usually four parathyroid glands located on the posterior side of the thyroid gland.
These small glands secrete the parathyroid hormone. Thymus The thymus gland is a soft structure located in the mediastinum, just above the heart. This gland plays a big role in the immune system development of infants and children. As we age, the gland begins to shrink and is actually quite small in adults. The major role of this gland is the production of a particular type of lymphocyte called T-cells.
These important immune system cells can attack and destroy foreign antigens. One way to stimulate or boost thymus function is to bang on your chest, Tarzan style. Adrenals There are two adrenal glands in the body. They are located on top of each of the kidneys. Each gland contains two parts that have distinctive endocrine system functions. They are named the inner adrenal medulla and the outer adrenal cortex. Both aspects of the adrenals are responsive to stress.
The following forms of stress can affect the adrenal glands: Adrenal Medulla The adrenal medulla is regulated by the sympathetic nervous system. When the body experiences stress, the sympathetic nervous system stimulates the release of the hormones epinephrine and norepinephrine from the adrenal medulla. They influence the cardiovascular system by increasing heart rate, blood pressure and thereby cardiac output.
The metabolic rate is increased and blood sugar is increased by the conversion of glycogen to glucose. The respiratory passages are dilated for increased respiration.
The result is a hyper vigilant body ready to take flight or fight as necessary. Adrenal Cortex The adrenal cortex releases several different steroid hormones. The pancreas is an organ located just below and behind the stomach. The pancreas is made up of two different kinds of tissues and also has two distinct functions. The major glands of the endocrine system are the hypothalamus, pituitary, thyroid, parathyroids, adrenals, pineal body, and the reproductive organs ovaries and testes.
The pancreas is also a part of this system; it has a role in hormone production as well as in digestion. The endocrine system is regulated by feedback in much the same way that a thermostat regulates the temperature in a room. For the hormones that are regulated by the pituitary gland , a signal is sent from the hypothalamus to the pituitary gland in the form of a "releasing hormone," which stimulates the pituitary to secrete a "stimulating hormone" into the circulation. The stimulating hormone then signals the target gland to secrete its hormone.
As the level of this hormone rises in the circulation, the hypothalamus and the pituitary gland shut down secretion of the releasing hormone and the stimulating hormone, which in turn slows the secretion by the target gland. This system results in stable blood concentrations of the hormones that are regulated by the pituitary gland. The hypothalamus is located in the lower central part of the brain. This part of the brain is important in regulation of satiety, metabolism , and body temperature.
In addition, it secretes hormones that stimulate or suppress the release of hormones in the pituitary gland. Many of these hormones are releasing hormones, which are secreted into an artery the hypophyseal portal system that carries them directly to the pituitary gland. In the pituitary gland, these releasing hormones signal secretion of stimulating hormones. The hypothalamus also secretes a hormone called somatostatin, which causes the pituitary gland to stop the release of growth hormone.
The pituitary gland is located at the base of the brain beneath the hypothalamus and is no larger than a pea. It is often considered the most important part of the endocrine system because it produces hormones that control many functions of other endocrine glands.
When the pituitary gland does not produce one or more of its hormones or not enough of them, it is called hypopituitarism. The pituitary gland is divided into two parts: The anterior lobe produces the following hormones, which are regulated by the hypothalamus:. The posterior lobe produces the following hormones, which are not regulated by the hypothalamus:.
The hormones secreted by the posterior pituitary are actually produced in the brain and carried to the pituitary gland through nerves. They are stored in the pituitary gland. The thyroid gland is located in the lower front part of the neck.
It produces thyroid hormones that regulate the body's metabolism. It also plays a role in bone growth and development of the brain and nervous system in children. The pituitary gland controls the release of thyroid hormones. Thyroid hormones also help maintain normal blood pressure , heart rate, digestion, muscle tone, and reproductive functions.
The parathyroid glands are two pairs of small glands embedded in the surface of the thyroid gland, one pair on each side. They release parathyroid hormone, which plays a role in regulating calcium levels in the blood and bone metabolism. The two adrenal glands are triangular-shaped glands located on top of each kidney.
The adrenal glands are made up of two parts. The outer part is called the adrenal cortex , and the inner part is called the adrenal medulla.