Hormones

Growing up is a normal part of life. Adolescence is the stage of life when the body undergoes changes that lead to reproductive maturity. Around age 11, adolescence begins, and it lasts until 18 or 19. Adolescents are also referred to as ‘teenagers’ because this period encompasses the ‘teens’ (13 to 18 or 19 years of age). Adolescence may begin a year or two earlier in girls than in boys. Furthermore, the adolescent period differs from person to person. The human body goes through a number of changes during adolescence. These changes signal the start of puberty. The most significant change that occurs during puberty is that boys and girls become capable of reproducing. 

Hormones

• Hormones are chemical substances that act as messenger molecules in the bloodstream.
• Hormones transport chemical messages from the glands where they are produced to cells throughout the human body.
• These chemical messages aid in the activation and deactivation of cellular processes that regulate stress, appetite, growth, sleep cycles, blood sugar, sex drive, and sexual function.
• Hormones play a critical role in the proper functioning of the human body. They regulate organ functions and influence their growth, reproduction, and sexual characteristics.
• Furthermore, hormones influence how the human body stores and uses energy, as well as the volume of fluids and the level of sugar and salt in the blood.
• As a result, a small amount of hormone can cause a significant reaction in the human body.
• Your endocrine system is made up of hormones and the majority of the tissues (primarily glands) that produce and release them.

 

Types of Hormones

Different types of hormones are produced in the body to regulate various functions. They are organized as follows:

Hormones Peptide

Peptide hormones are made up of amino acids and are water-soluble. Because the cell membrane contains a phospholipid bilayer that prevents fat-insoluble molecules from diffusing into the cell, peptide hormones are unable to pass through. The pancreas makes the peptide hormone known as insulin.

Hormones Derived from Steroids

Steroid hormones, unlike peptide hormones, are fat-soluble and can cross cell membranes. Steroid hormones include sex hormones such as testosterone, estrogen, and progesterone.

Hormones other than Sex Hormones 

The pituitary gland’s hormones stimulate the testes and ovaries to produce their own hormones. The pituitary gland is an endocrine gland located near the brain. Other endocrine glands in the body include the thyroid, pancreas, and adrenal glands.

Pituitary Glands – Growth Hormones 

The master gland is the pituitary gland. Other glands in the body are controlled and regulated by it. Growth hormone, thyroid-stimulating hormone, LH, FSH, and other hormones are released by this gland.

Located at the base of our brain, the hypophysis, also known as the pituitary gland, is a pea-sized endocrine gland. It is known as the “Master Gland” because it produces many important hormones in the body.

It is located in the Pituitary fossa, a bony structure just below the hypothalamus and close to the optic nerve. The pituitary gland is divided into three sections, known as lobes:

1. Anterior pituitary gland
2. Pituitary intermediate (Absent in adult human beings)
3. Posterior pituitary gland

The anterior pituitary gland produces and secretes the following six hormones:

• Adrenocorticotropic hormone (ACTH or corticotropin).
• FSH (follicle stimulating hormone).
• The hormone of growth (GH).
• Luteinizing hormone (LH).
• Prolactin.
• TSH (thyroid stimulating hormone).

Pancreas – Insulin

• The pancreas can be found in the abdomen. It is located between the stomach and the spine in part. The other part is located in the duodenum, which is the first section of the small intestine.
• The pancreas head is located on the right side of the abdomen and is connected to the duodenum via the pancreatic duct. The pancreas’ tail protrudes to the body’s left side.
• The pancreas is an abdominal organ that is located behind the stomach and is surrounded by the spleen, liver, and small intestine. It is an essential component of the digestive system that regulates blood sugar levels.
• Amylase, proteases, and lipases are a few of the digestive enzymes that the pancreas juices secret into the duodenum.
• These enzymes aid in the digestion of sugar, proteins, and fat. The Langerhans Islets are located in the pancreas and secrete hormones such as insulin and glucagon into the blood.
• Endocrine and exocrine glands together make up the pancreas. As a result, the Pancreas is also referred to as a mixed gland.
• The pancreas secretes hormones such as glucagon and insulin, which balance the body’s blood sugar levels. Somatostatin and pancreatic polypeptide are two other hormones secreted.

Adrenal Glands – Adrenaline 

• The adrenal cortex and adrenal medulla are two regions of the adrenal gland.
• Cortisol, aldosterone, and androgens are secreted by the cortex region of the adrenal gland, while adrenaline and noradrenaline are secreted by the medulla region. Adrenaline is the hormone that causes the body’s fight or flight response in times of emergency.
• The inferior vena cava and the right lobe of the liver are located on the anterior side of the right adrenal gland.
• The posterior side is flanked by the right diaphragm crus. The stomach, pancreas, and spleen are located on the left adrenal gland’s anterior side. The posterior side is flanked by the left diaphragm crus.
• The adrenal glands produce the following hormones:
  • Cortisol.
  • Aldosterone.
  • Androgens and DHEA
  • Adrenaline (epinephrine).
  • Noradrenaline (norepinephrine).

Thyroid Glands – Thyroxine 

• An endocrine gland without ducts, the thyroid is situated at the front of the neck. It roughly resembles a butterfly in shape.
• It is also one of the largest endocrine glands, weighing between 25 and 30 g on average. This gland has two lobes, one on each side of the trachea, each measuring 4 – 6 cm long and 1.3 – 1.8 cm wide.
• The thyroid gland is located between the C5 and T1 vertebrae in the anterior neck. It is made up of two lobes with parathyroid glands on their posterior surfaces.
• The thyroid gland’s primary function is to secrete two hormones: triiodothyronine (T3) hormone and thyroxine hormone (T4). T3 and T4 hormones both play critical roles in the body, affecting nearly every tissue.

Properties of Hormones

• Because of their low molecular weight, they can easily pass through capillaries.
• Because they are water-soluble, they can be transported through the blood.
• Hormones always have a low concentration of action. Hormones are important because they are non-antigenic.
• They function as organic catalysts. In the human body, hormones serve as coenzymes for other enzymes.
• Hormones are notable for their ability to be destroyed, excreted, or inactivated after their function has been completed.
• Hormones cause a limited number of reactions in their initial action and do not directly influence any metabolic activities of a cell.
• Hormonal activity is not inherited.

Functions of Hormones

The bloodstream is where hormones are released to perform their role as messengers. Blood transports them to the human body’s various organs and tissues. Hormones bind to receptors once they reach their target site. Once this process is complete, hormones send a message to an organ or tissue, causing it to perform a specific action.

Hormones perform the following important functions:

• Mood and cognitive function regulation.
• Development and growth.
• Food metabolism and body temperature regulation.
• Controlling hunger and thirst.
• Starting and maintaining sexual development and reproduction.

Question 1: Why are hormones referred to as Chemical Messengers?

Answer:

Hormones plays an important role as messengers. The hypothalamus is a forebrain region that contains a large number of neurosecretory cells. These neurosecretory cells are trained to secrete a hormone known as neurohormones. They stimulate the anterior pituitary lobe to produce a variety of other hormones.

Question 2: Write two hormones other than sex hormones.

Answer:

Growth hormone and insulin.

Question 3: What are the characteristics of hormones?

Answer:

• Hormones communicate chemically.
• They are produced by living cells/tissues or organs known as glands.
• They are secreted in minute amounts by glands.

Question 4: What exactly are lipid-derived hormones?

Answer:

Lipid-derived hormones are primarily derived from cholesterol, and their structures are similar. The most significant lipid hormones in the human body are steroid hormones, which are chemically either alcohols or ketones. 

Question 5: What exactly is a thyroid gland disorder?

Answer:

Many disorders and diseases can affect the thyroid gland. These issues could be caused by excessive hormone secretion, abnormal gland growth, malignant lumps, and so on. 

GeeksforGeeks

Improve

Article Tags :

• Class 8
• School Biology
• School Learning