When people talk about glands, what do they mean? The answer is many different things. Glands are important organs, you have a variety of them all over your body, and though many of them are small, each produces something important.
Some glands make something that is released from the body — like saliva, sweat, or tears. And if you're a girl, the mammary glands in your breasts could someday make breast milk to feed a baby.
Other glands release hormones (say: hor-mones), which are substances inside your body that tell it how to work and how to grow. Glands that do this are part of the endocrine (say: en-doh-krin) system. Puberty — body changes that turn a kid into an adult — depend on the endocrine system.
Still other things that we call "glands" are part of your immune (say: ih-myoon) system. They release substances that help you fight off illnesses and, if you are sick, help you get better. When you have a bad cold and your neck glands are swollen, that is your immune system in action.

Exocrine glands are a type of ductal glands that secrete their products (including digestive enzymes, and some hormone chemical messengers) into ducts that lead directly into the external environment. They are the counterparts to endocrine glands, which secrete their products (hormones) directly into the bloodstream (ductless glands) or release hormones (paracrines) that affect only target cells nearby the release site.

The hypothalamus (from Greek ὑπό = under and θάλαμος = room, chamber) is a portion of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions of the hypothalamus is to link the nervous system to the endocrine system via the pituitary gland (hypophysis).

The hypothalamus is located under the thalamus, one of the most evolutionarily ancient parts of the human brain, which is located directly at its center. Being as old as it is, the hypothalamus is a brain region possessed by birds, reptiles, and mammals alike, though the structure of the hypothalamus in mammals is more complex than hypothalamuses in reptiles and birds.
The hypothalamus controls the nervous system by synthesizing and releasing neurohormones at regular intervals. Different neurohormones represent distinct signals to the rest of the nervous system. The hypothalamus serves as an interface between the limbic system, endocrine system, and the autonomous nervous system. One well-known hormone released by the hypothalamus is oxytocin, known to play a role in both romantic love and female lactation.
Communicating with the autonomous nervous system via neural signals and the endocrine system via endocrine signals (chemical signals which travel through the bloodstream), the hypothalamus is an axis around which a variety of complex systems within mammals evolve

The main function of endocrine glands is to secrete hormones. These endocrine glands secrete hormones by receiving hormones from the Pituitary gland telling them to either release or inhibit hormones. I am going to tell you how the Hypothalamus in the brain helps control release of these hormones.

The hypothalamus is connected to the Pituitary gland via the infundibulum. The Pituitary gland is seperated into anterior and posterior parts. Each of these parts gives off different hormones in different ways. The hormones that are stored and secreted by the posterior pituitary gland are produced in the neuron bodies of the supraoptic nuclei and paraventricular neuclei of the hypothalamus. Hormones are produced in the hypothalamus and then sent to the posterior pituitary gland by axons via the hypothalamo-hypophyseal tract. It is then stored here and released later. This gland is more of a storage organ. Secretion by the posterior pituitary is done by stimulation of osmoreceptor neurons in the hypothalamus. A hormone that is secreted by the posterior pituitary gland is the antidiuretic hormone (ADH). The action of this hormone is to stimulate water retention by the kidneys so less water is excreted in the urine.

Control by the hypothalamus in the anterior pituitary gland is done through hormones instead of neural regulation. Releasing and inhibiting hormones are produced in the hypothalamus by neurons and sent to the axon endings in the basal potion. These neurons then send hormones to the hypothalamo-hypophyseal portal system which is a vascular link between the hypothalamus and anterior pituitary gland. The hormones are then sent out to endocrine glands that will secrete or inhibit homrones to send throughout the body. A hormone that is stimulated by the anterior pituitary gland is the thyrotropin-stimulating hormone (TSH). This hormone is sent to the thyroid gland to produce and secrete thyroxine and triidothyronine into the blood. Below is a video that shows and explains more indepth on how the hypothalamus and anterior pituitary gland secrete the hormone TSH.

hypothalamus is the small cone-shaped structure within the brain that plays a central role in controlling our autonomous nervous system (ANS), responsible for regulating homeostatic metabolic processes in the body. Examples of homeostatic processes include sleeping, eating, thirst, blood pressure, body temperature, and electrolyte balance.

Exocrine vs Endocrine
Exocrine glands are glands that secrete their products through the ducts, and discharge it into the external environment, to organs or the outside the body. Exocrine glands differ from endocrine glands, because they have ducts that deliver the products in the superficial part of the body, such as the skin, or in the inner part where they are necessary, such as the pancreatic juice that is carried into the intestine to aid digestion. The glands that are found in the body are mostly exocrine glands. Examples of exocrine glands are sweat, saliva and mammary glands, as well as oil and enzymes. There are glands which function as both endocrine and exocrine glands.
Exocrine glands manufacture and release hormones. These hormones are transported to the surround area, and to the blood. A specific receptor is then needed for that hormone to do its specified job. The ducts may be simple or compound. Simple ducts are ducts that are single, while compound ducts accommodate more areas, because they branch out. These ducts can coil and turn in different ways giving rise to sub-classifications, depending on the shape of the ducts. Classifications of exocrine ducts are merocrine glands, holocrine glands and apocrine glands. Secretions in merocrine glands are generated by intact cells. In holocrine glands, cells are permitted to break up to produce compounds, and discharge desired secretions. Apocrine glands dispense the cells with their secretion. Cells are sprouting, and are replaced when needed. These glands secrete proteins or mucus depending on where they are located.
The endocrine system is one of the body’s most important systems, especially with the control of the body’s functions. This is how the body communicates and coordinates with the nervous system, reproductive system, pancreas, liver, kidneys and fat to maintain balance, or homeostasis, with reproduction, growth and development, and energy levels and responses to external stress and injury. Endocrine glands produce hormones that can be used inside the body. The endocrine transmits the hormonal messages to cells by secreting them into the blood and extracellular fluid. A receptor is needed in order to receive the message transmitted. The target points may be cells, tissues or organs.
Endocrine glands are ductless, therefore the secreted hormones are released into the interstitial spaces that surround the cells. The hormones are delivered to the nearest capillaries, and spread throughout the body. The responses are delayed because hormones must first travel through the blood to reach the target organs. The duration is longer because the kidneys filter the blood. The functions of the endocrine are interrelated. Many of the hormones generated serve to alter the work of other endocrine hormones.