science

Neohormone

Neohormone is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Neohormone rather than just read about it. In short: Neohormones are a group of recently evolved hormones primarily associated to the success of mammalian development. These hormones are specific to mammals and are not found in other vertebrates—this is because neohormones are evolved to enhance specific mammalian functions.

Key takeaways

Neohormone belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Neohormone to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Neohormone from memory before moving on to harder problems.

Reference excerpt

Neohormones are a group of recently evolved hormones primarily associated to the success of mammalian development. These hormones are specific to mammals and are not found in other vertebrates—this is because neohormones are evolved to enhance specific mammalian functions. In males, neohormones play important roles in regulating testicular descent (the testes descend into the scrotum during foetal development) and preparing the sperm for internal fertilisation (the sperm fertilizes the egg within the female). In females, neohormones are essential for regulating early pregnancy, mammary gland development lactation (secretion of milk from the mammary gland), and viviparity (allowing the fertilized egg to grow inside the female until they can exist independently). Neohormones superimpose their actions on the hypothalamic-pituitary-gonadal axis (a hormone system which regulates key reproductive functions in animals) and are not associated with other core bodily functions.

Pre-natal functions of neohormones Prenatally, neohormones play a role in the development of the embryo as well as supporting early pregnancy.

H2 Relaxin In the human ovary, H2 relaxin is produced by the corpus luteum and by Granulosa cells from large antral follicles. Research has shown that the relaxin gene is expressed once the Granulosa cells have reached a certain luteinised status, by which Granulosa cells differentiate into Luteal cells. Therefore, it can act as a good biomarker in relation to Granulosa cell differentiation status. Relaxin is produced to support early pregnancy until the placenta can take over. Relaxin plays a key role in implantation and placenta formation. The relaxin receptor RXFP1 is found on myometrial cells. In rats, it has been linked playing a role in the spacing between embryos in the uterus. RXFP1 is also located on endometrial stromal cells where it can induce cyclic adenosine monophosphate (cAMP). cAMP is a molecule which is necessary for the functional changes in the endometrium to form the decidual lining, where the blastocyst can implant. This results in neo-angiogenesis and endometrial thickening, both linked to early pregnancy development.

Human chorionic gonadotropin Human chorionic gonadotropin (hCG) is a hormone produced by the placenta during pregnancy. This hormone stimulates the Corpus Luteum to produce progesterone to maintain pregnancy. Therefore, hCG plays a role in human maternal recognition of pregnancy.

Insulin-like peptide 3 Insulin-Like Peptide 3 (INSL3) is produced by the interstitial Leydig cells located in the adult testes. Leydig cells are responsible for steroidogenesis, the fetal Leydig cells differentiate during the development of the embryo. They produce necessary androgens for the masculinisation of organs. They also produce INSL3, which is required for the first transabdominal phase of testicular descent. INSL3 acts on RXFP2 receptors which link the testis to the inguinal abdominal wall. As a result, the testes move from the inguinal canal into the scrotum. Only mammals have a scrotum and descended testes. INSL3 measured in amniotic fluid can therefore be a biomarker for testis development, although this period differs between species.

Post-natal functions of neohormones After birth, neohormones play a major role in development of mammary glands and their function. Alongside, neohormones have also been measured to be a significant component of breast milk. The so-called lactocrine hypothesis dictates that breast milk does not simply fulfil nutritional requirements but also plays an important role in signaling and development in the neonate. Neohormones are theorised to have specific effects on target organs in the neonate, but more research is needed in this area, and effects have been observed to different extents in different species.

Oxytocin Oxytocin is responsible for the milk let-down reflex as a response to neonate suckling. It is released from the posterior pituitary gland in a pulsatile manner, via stimulation of the vagus nerve. This causes myoepithelial cells, which surround the mammary alveoli, to contract. Oxytocin injections have been found to increase milk yield in cows. The role of oxytocin in the neonate is yet quite unclear, however we know that oxytocin has an important role in empathy and bonding between pairs.

Relaxin There are three relaxin genes in humans. One type, H2, is made and secreted in the ovaries, as well as in the mammary glands. Relaxin acts via locally expressed specific receptors located on parenchyma and myoepithelial cells. It reaches peak concentrations 24-48 hours after birth and then declines.

Human Chorionic Gonadotropin Like relaxin, hCG may be measured, although the effects on the neonate are not well understood. It is posited that it may act as an LH paralogue to affect the development of neonatal gonads, although further research is required.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Neohormone

Start with the simplest possible case. Write down what Neohormone claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Neohormone before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Neohormone ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Neohormone

In research: Neohormone appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Neohormone in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Neohormone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Endocrine system, Hormones, Mammalian hormones, so understanding it makes those chapters shorter.
In everyday life: Look for Neohormone outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Neohormone in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Neohormone means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Neohormone out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Neohormone in simple terms?

Why does Neohormone matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Neohormone?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Neohormone.