Question

Match each pituitary hormone with its target. $$ \text {antidiuretic hormone} \quad \quad \text {a. gonads (ovaries, testes)} $$ $$ \text {oxytocin} \quad \quad \text {b. mammary glands, uterus} $$ $$ \text {luteinizing hormone} \quad \quad \text {c. kidneys} $$ $$ \text {growth hormone} \quad \quad \text {d. most body cells} $$

Short answer

ADH: kidneys, Oxytocin: mammary glands/uterus, LH: gonads, GH: most body cells.

Step-by-step solution

Identify the Hormones

We have four hormones to match with their targets: antidiuretic hormone (ADH), oxytocin, luteinizing hormone (LH), and growth hormone (GH).

Identify the Target Organs

The targets provided are the gonads (a), mammary glands and uterus (b), kidneys (c), and most body cells (d).

Analyze the Function of Antidiuretic Hormone (ADH)

Antidiuretic hormone primarily acts on the kidneys to regulate water balance by increasing water reabsorption. Therefore, its target is (c) kidneys.

Analyze the Function of Oxytocin

Oxytocin stimulates contractions of the uterus during childbirth and the ejection of milk from the mammary glands; hence, its targets are (b) mammary glands and uterus.

Analyze the Function of Luteinizing Hormone (LH)

Luteinizing hormone acts on the gonads, stimulating ovulation in females and testosterone production in males. Thus, its target is (a) gonads (ovaries, testes).

Analyze the Function of Growth Hormone (GH)

Growth hormone stimulates growth and cell reproduction in many tissues throughout the body; its target is (d) most body cells.

Match Hormones to Their Targets

Based on the analysis, the matches are: antidiuretic hormone with kidneys (c), oxytocin with mammary glands and uterus (b), luteinizing hormone with gonads (a), and growth hormone with most body cells (d).

Key concepts

Antidiuretic Hormone

The antidiuretic hormone (ADH), also known as vasopressin, plays a significant role in regulating water balance in the body. It is secreted by the posterior pituitary gland and primarily targets the kidneys. ADH signals the kidneys to increase water reabsorption, which helps the body maintain adequate hydration levels.
When ADH is released, it causes the kidneys to retain more water, reducing the amount of urine produced. This is crucial in preventing dehydration, especially when the body has lost fluids due to sweating, illness, or insufficient water intake. Interesting enough, ADH also influences blood pressure by constricting blood vessels, which contributes to its alternative name, vasopressin.
ADH levels can be affected by factors like salt intake, exercise, and alcohol consumption. Drinking alcohol, for example, inhibits ADH release, leading to increased urine production and potential dehydration.

• Regulates water balance
• Targets kidneys
• Prevents dehydration
• Influences blood pressure

Oxytocin

Oxytocin is often termed the "love hormone" due to its role in social bonding, but it has important physiological functions as well. Secreted by the posterior pituitary gland, oxytocin's primary targets are the uterus and mammary glands. In women, it plays a vital role during childbirth by stimulating contractions of the uterus, which aid in delivering the baby. After childbirth, oxytocin continues to be crucial by promoting the release of milk from mammary glands, facilitating breastfeeding.
Besides its physical functions, oxytocin is involved in emotional and social interactions. It enhances feelings of trust and bonding between individuals, shaping behaviors that are important for relationship building and social cohesion. This hormone is a prime example of how intricate and multi-functional endocrine signals can be, influencing both our physical and emotional states.
The release of oxytocin can be induced by various stimuli, such as physical touch, warmth, and even the act of breastfeeding itself, which creates a positive feedback loop.

• Stimulates uterine contractions
• Promotes milk ejection
• Fosters emotional bonding
• Involved in social interactions

Luteinizing Hormone

Luteinizing hormone (LH) is an essential component of the reproductive system, secreted by the anterior pituitary gland. This hormone primarily targets the gonads—ovaries in females and testes in males. In women, LH plays a critical role in triggering ovulation, which is the release of an egg from the ovary. This event is a key process in the reproductive cycle, making pregnancy possible. In men, LH stimulates the production of testosterone, an important hormone for male reproductive health and secondary sexual characteristics.
The regulation of LH involves a delicate balance with other hormones, such as follicle-stimulating hormone (FSH) and gonadotropin-releasing hormone (GnRH), illustrating the complex network of hormonal interactions.

• Induces ovulation in females
• Supports testosterone production in males
• Targets the ovaries and testes
• Works alongside FSH and GnRH

Growth Hormone

Growth hormone (GH) is a vital hormone produced by the anterior pituitary gland, influencing growth and metabolism. It primarily targets most body cells, promoting growth and cellular reproduction. GH stimulates the growth of bones and muscles, which is particularly important during childhood and adolescence, contributing to height increase and physical development.
Additionally, growth hormone affects metabolism by promoting protein synthesis and increasing the use of fats for energy. This contributes to tissue repair and muscle mass maintenance, especially important throughout adulthood. GH release follows a diurnal rhythm, with higher levels secreted during sleep, which is why adequate sleep is essential for growth and recovery.
Disorders related to GH can lead to growth issues. For instance, insufficient production can cause growth hormone deficiency, leading to dwarfism, while excessive production may result in gigantism or acromegaly. These conditions highlight the significant role GH plays throughout the human lifespan.

• Stimulates growth and cell reproduction
• Targets most body cells
• Affects metabolism and protein synthesis
• Linked to sleep cycles