Endocrine System: Hormones, Function, and Disorders
The Endocrine System
The endocrine system is distinct from the nervous system. It consists of a series of glands located throughout the body, called endocrine glands or glands of internal secretion. These glands secrete substances directly into the bloodstream. Endocrine glands are composed of specialized secretory cells that synthesize chemicals called hormones. Once produced, hormones are discharged into the blood and transported throughout the body via blood vessels. However, they only exert their action on specific organs or cells, called target cells or target organs.
Hormones are chemical messengers with the following characteristics:
- They function at a distance from where they were synthesized.
- Responses are slower than those produced by the nervous system but are more durable.
- They operate in very small amounts and degrade quickly once their function is executed.
Hormonal System Function
Hormones act in small amounts and are eliminated once their function is performed. An excess or deficiency of a hormone can cause certain diseases. Therefore, endocrine glands do not secrete hormones continuously; there is a mechanism that interrupts production. Normally, it is the amount of hormone in the blood or the hormone’s action that interrupts its own release. This regulatory mechanism is called negative feedback. In this manner, when a gland receives a chemical or nerve stimulation, it usually starts producing hormones. As the amount of this hormone in the blood increases, its secretion is inhibited.
Mental Health
Physical or Organic Disorders
These may be caused by various factors: infectious diseases, cerebral artery rupture or obstruction, trauma, and neurodegenerative diseases such as Alzheimer’s or Parkinson’s disease. These nervous system diseases have a significant impact on our society.
Alzheimer’s Disease
Alzheimer’s occurs due to the degeneration of neurons in the cerebral cortex. It is an irreversible illness that begins with mild memory and orientation losses, which gradually worsen. The disease generally affects older people, although it may appear at younger ages.
Parkinson’s Disease
Parkinson’s is caused by the death or deterioration of neurons in brain areas responsible for controlling and coordinating movement and posture. The most common symptoms are muscle stiffness, tremors, difficulty walking, and alterations in the coordination of movements, especially in the hands and arms.
Mental Disorders
- Anxiety: An unpleasant emotional state often accompanied by physiological and behavioral changes similar to those caused by fear.
- Attention Deficit Hyperactivity Disorder (ADHD): Characterized by a lack of attention, hyperactivity, and impulsivity. It is generally diagnosed in childhood.
- Depression: A disorder that affects the whole body and mood, interfering with an individual’s daily activities.
- Schizophrenia: A very serious brain disorder that affects a person’s ability to think clearly, control emotions, make decisions, or interact with others.
- Obsessive-Compulsive Disorder (OCD): A disease characterized by the presence of obsessions, compulsions, or both simultaneously.
Diseases of the Endocrine System
Diabetes
Diabetes is a chronic and, for now, incurable disease. It is due to a scarcity or lack of insulin, which prevents the body from absorbing sugar from the blood and using it as a source of energy. This causes blood sugar to remain at higher levels than normal.
- Type I Diabetes: Usually affects young people and is due to a lack of insulin-producing cells in the pancreas. It is treated with daily insulin injections.
- Type II Diabetes: Affects people over 40. It occurs because the body’s cells do not use insulin properly, resulting in less glucose consumption and an increase in blood sugar levels.
Thyroid Diseases
These are due to an excess or defective production of thyroid hormones, conditions called hyperthyroidism and hypothyroidism, respectively. Hyperthyroidism causes increased metabolism, nervousness, insomnia, irritability, hyperactivity, and weight loss, often accompanied by an increase in the size of the thyroid, which manifests as a prominent goiter.