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Hormones of puberty

This flow chart shows the different hormones and the organs they act on at the onset of puberty. The hypothalamus is shown on top. The right half of the flowchart shows the hormones in females and the left half shows the hormones in males.
During puberty, the release of LH and FSH from the anterior pituitary stimulates the gonads to produce sex hormones in both male and female adolescents.

Signs of puberty

Different sex steroid hormone concentrations between the sexes also contribute to the development and function of secondary sexual characteristics. Examples of secondary sexual characteristics are listed in [link] .

Development of the Secondary Sexual Characteristics
Male Female
Increased larynx size and deepening of the voice Deposition of fat, predominantly in breasts and hips
Increased muscular development Breast development
Growth of facial, axillary, and pubic hair, and increased growth of body hair Broadening of the pelvis and growth of axillary and pubic hair

As a girl reaches puberty, typically the first change that is visible is the development of the breast tissue. This is followed by the growth of axillary and pubic hair. A growth spurt normally starts at approximately age 9 to 11, and may last two years or more. During this time, a girl’s height can increase 3 inches a year. The next step in puberty is menarche, the start of menstruation.

In boys, the growth of the testes is typically the first physical sign of the beginning of puberty, which is followed by growth and pigmentation of the scrotum and growth of the penis. The next step is the growth of hair, including armpit, pubic, chest, and facial hair. Testosterone stimulates the growth of the larynx and thickening and lengthening of the vocal folds, which causes the voice to drop in pitch. The first fertile ejaculations typically appear at approximately 15 years of age, but this age can vary widely across individual boys. Unlike the early growth spurt observed in females, the male growth spurt occurs toward the end of puberty, at approximately age 11 to 13, and a boy’s height can increase as much as 4 inches a year. In some males, pubertal development can continue through the early 20s.

Chapter review

The reproductive systems of males and females begin to develop soon after conception. A gene on the male’s Y chromosome called SRY is critical in stimulating a cascade of events that simultaneously stimulate testis development and repress the development of female structures. Testosterone produced by Leydig cells in the embryonic testis stimulates the development of male sexual organs. If testosterone is not present, female sexual organs will develop.

Whereas the gonads and some other reproductive tissues are considered bipotential, the tissue that forms the internal reproductive structures stems from ducts that will develop into only male (Wolffian) or female (Müllerian) structures. To be able to reproduce as an adult, one of these systems must develop properly and the other must degrade.

Further development of the reproductive systems occurs at puberty. The initiation of the changes that occur in puberty is the result of a decrease in sensitivity to negative feedback in the hypothalamus and pituitary gland, and an increase in sensitivity of the gonads to FSH and LH stimulation. These changes lead to increases in either estrogen or testosterone, in female and male adolescents, respectively. The increase in sex steroid hormones leads to maturation of the gonads and other reproductive organs. The initiation of spermatogenesis begins in boys, and girls begin ovulating and menstruating. Increases in sex steroid hormones also lead to the development of secondary sex characteristics such as breast development in girls and facial hair and larynx growth in boys.

A baby’s gender is determined at conception, and the different genitalia of male and female fetuses develop from the same tissues in the embryo. View this animation that compares the development of structures of the female and male reproductive systems in a growing fetus. Where are the testes located for most of gestational time?

The testes are located in the abdomen.

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Questions & Answers

ഫസ്റ്റ് ചാപ്റ്റർ ഇംപോർട്ടൻസ് പോസ്റ്റ്
Reshma Reply
Yes....
Loving
nhi samjh aya
Anshika
Nhi wt is this
Loving
I don't know
Anshika
Okk wre frm u r
Loving
what is mean of? reshma
Asad
D bone in d ankle joint re what ?
Ifunanya Reply
can one define a cell as a basic unit of a living organism
Michael Reply
Which of the following hormones are responsible for the adolescent growth spurt? estrogen and testosterone, even in women?
Kepa Reply
estrogen
Farhana
Estrogen!
Jazil
estrogen hormone
Michael
yes estrogen hormone
Anshika
yes
Sale
What is sling give d characteristics of sling uses of sling
adamu Reply
a sling a rope used in hunting ie throwing of rocks
Michael
I went to learn anatomy of joints
Arman Reply
me 2
adamu
joint have 3 cartilaginous joint fibrous joint synovial joint U can reserch in Google can explain U well
sopheaktra
define sling
adamu
To throw with a circular or arcing motion
real
what is respiration
Osele Reply
what is respiration
Paul
Respiration is the process by which oxygen is taken in and carbon dioxide is given out.
Md
Respiration is the combination of inhalation and exhalation.
Khim
inhalation is the taking in air from environment to lung and exhalation is taking out sir from the lung to environment ..
Khim
is the process by wich gases(oxygen and carbon(IV)oxide go through the nose, trachea and the lungs to the blood stream
Michael
what is holistic
Kibrom Reply
Holistic means encompassing the whole of a thing, and not just the part. Holistic medicine looks at the whole person for answers, not just at physical symptoms. You might have heard of holistic medicine, which tries to treat someone as mind and body, instead of treating only the part of the patient
I want to learn one by one system like skeleton system... muscular system
Mary Reply
i want to learn this
Kibrom
what is the difference between regional anatomy and system anatomy
David
system anatomy is when we study the system like digestive, circulatory, reproductive, but regional anatomy is studying the anatomy by regions of body like anatomy of neck, thorax, head etc. Regional anatomy may include system anatomy...
Biplav
yes
Anshika
explain in details factors that affects bone development
Precious Reply
describe the process of bone healing
Precious
out line factors that delays bone healing
Precious
actually,for the bone formation they must be sufficient level of calcium,phosphorus and vitamin D in the body for it to happen smoothly.
lucky
the above mentioned substances are the ones able for the formation and repairing of bones.
lucky
explain in details factors that affects bone development
Precious
what are tissue
muki Reply
a lots of cells make tissue and a cell body is tissue
Rabab
cells come together to form a tissue and tissues come together to form an organ
Adoma
what is appendicular skeleton
OSE Reply
appendicular skeleton is upper limbs and lower limbs
sopheaktra
what is decompression sickness?
Japhar Reply
It occurs in Scuba divers when they rise too quicky to the sea surface , their oxygen tanks have oxygen mixed with N2 gas which has a high solubility at sea level , when the diver rises the N2 gas bubbles out of plasma and this causes Air Ebolism
Siphiwesihle
if a single part if Nervous system doesn't function like synapse? what will occur
Lilian Reply
no transmission of impulses no respond cause mechanical damage
Komolika
what happens when calcium ion channel is blocked
Jachike
a MORAH /MORAH
Kechi
meaning?
Jachike
transmission of impure
sopheaktra
when calcium ion channels block . lightheadedness Low blood pressure. Slower heart rate. Drowsiness. Constipation. Swelling of feet ankles and legs. Increased appetite. Gastroesophageal reflux disease (GERD
sopheaktra
I'm not sure about it
sopheaktra
low blood pressure
Anshika
what is this substance
Peng Reply
In the human body, there are no atoms as separate entities. Instead, they constantly interact with other atoms to form and break down more complex materials. To fully understand anatomy and physiology, you must understand how atoms are involved in such interactions. The key is to understand the beha
Warid
what are functions of muscle cell
Veronicah
please can someone help with ten functions of the following hormones 1.Gastrin 2. Adrenal sex hormone 3. Secretin 4. Follicle Stimulating Hormone 5. Glucagon 6. Progesterone
Har
4.produces the oetrogen and bursts open to release egg cells.
Komolika
5.regulates the level of glucose in the blood and it is secreted when glucose low in the blood.
Komolika

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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