The Endocrine System

*Endocrine glands produce – hormones, they work with other hormones to perform many functions including: control water & electrolyte balance, regulating carbohydrate metabolism, working as neurotransmitters, maintaining stress & inflammation, regulate reproductive functions

The endocrine system is the system of the body in which releases hormones into the bloodstream. The hormones then cause different reactions within the body, and these reactions shape

This system enables specific signals to be sent and received by cells and tissues that are distant from one another. The endocrine system controls activities that take place in the body by releasing mediators, which are known as hormones. A mediator molecule can also be known as a hormone and it is released into one specific part of the body and normalizes the activity of cells in other parts of the body. Once a hormone is released it is transported to the target cells through the circulating blood in our bodies. Hormones in the body are significant in the processes of regulating growth, development, metabolism and

The hypothalamus produces hormones that travel in blood vessels to the anterior pituitary, stimulating it to produce other hormones.

The case is about the same with thyroid hormones. The hypothalamus is apart of the brain that produces thyroid-releasing hormones. This hormone pairs with what is known as our pituitary gland to begin the production of a thyroid-stimulating hormone. This pairing up acts on the thyroid in order to produce thyroid hormones, which travel through our bodies.

According to Shier, Butler & Lewis (2009) “other glands that produce hormones and thus are parts of the endocrine system include the pineal gland and the thymus gland”. Shier et al., 2009 argued the pineal gland, located deep between the cerebral hemispheres, secretes hormone melatonin that acts on certain brain regions that function as a biological clock. The changing levels of melatonin across 24 hours enable the body to know when day is and when is night.

The Adrenal glands secretes compounds including cortisone and adrenaline which helps you react to emergencies. This gland regulates your metabolic process in the cells and blood pressure. The Pineal gland produces melatonin, which helps regulate reproductive hormones. The Reproductive glands which includes the ovaries and testes, these glands influence blood circulation and determines mental vigor and sex drives. These glands all play major roles which work hand in hand with other body systems constantly.

The Pituitary Gland - The pituitary gland is a pea-sized structure located at the base of the brain, just below the hypothalamus, to which it is attached via nerve fibers. It is part of the endocrine system and produces critical hormones, which are chemical substances that control various bodily

The adrenal gland is an organ involved in endocrine functions in the body. It is divided into adrenal cortex and adrenal medulla. The adrenal medulla is part of the sympathetic nervous system. The adrenal cortex is part of the hypothalamic pituitary adrenal endocrine system. It consists of three layers which are:

A: The hypothalamus controls hormone release mainly through the pituitary gland by sending signals in the form of releasing hormones to prompt the anterior lobe to secrete them as the main function of the pituitary gland is hormone secretion into the body. The anterior lobe is responsible for the release of crucial hormones including; growth hormone, follicle stimulating hormone, luteinizing hormone, adrenocorticotrophic hormone, thyroid stimulating hormone and finally prolactin.

It connects with these glands through two distinct pathways. Neurosecretory cells in the hypothalamus produce chemicals that communicate with the anterior pituitary via the blood vessels in the infundibulum. After the inhibiting and releasing hormones travel through the primary plexus and hypophyseal portal veins, they exit the infundibulum and enter the secondary plexus, another capillary network that is instead located in the anterior pituitary. There they diffuse out into the cells and initiate the production of specific hormones – either tropins (which incite other endocrine glands to release their hormones) or not tropic. Neurosecretory cells in the hypothalamus produce chemicals that communicate with the posterior pituitary via, again, the infundibulum. The hormones travel the short distance through the axon in vesicles, to be stored in the axon terminals of the posterior pituitary. Action potential produced upon stimulation of the neurosecretory cells initiate release of the stored hormones into a capillary network

The adrenal glands produce and secret important hormones that help control heart rate, blood pressure, blood sugar, and the way the body reacts to stress or danger. (National Cancer Institute, 2014)

In the posterior pituitary hormones released are ADH and Oxytocin. Antidiuretic hormone (ADH) targets the kidneys to raise water retention to reduce urine for stable blood pressure. Oxytocin is the release of labor contractions, lactation of milk from mothers when they feel their baby close to them and emotional bonding.

It is located just under the hypothalamus in the skull, in the bottom half of the brain. The pituitary gland produces crucial hormones which control the functions of the rest of the endocrine system. The posterior lobe is an extension of the hypothalamus, and releases hormones made by it. For example, it secretes the antidiuretic and oxytocin hormones which control functions of the kidneys and uterus respectively. The anterior lobe, composed of glandular tissue, synthesizes its own hormones separate from the hypothalamus. It produces growth hormone, prolactin, follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone and adrenocorticotropic hormone, all of which regulate other functions throughout the endocrine

Adrenal glands, located near the kidneys, secrete several hormones that are activated by the nervous system. These hormones dictate the body’s reaction to stressful situations. Each person secretes a different amount of hormones, therefore affecting behavior in stressful situations differently (Morris & Maisto, 2005).