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Puberty Defining - Anatomy & Physiology (view source)
Revision as of 18:31, 8 December 2010
, 18:31, 8 December 2010no edit summary
== Introduction ==
Generally, puberty can be defined in both sexes as the ability to accomplish reproduction. The fundamental requirement for the onset of puberty is the secretion of GnRH at the appropriate frequency and quantity to stimulate gonatotrophin release by the [[Pituitary_Gland_- Anatomy & Physiology#Anterior_Pituitary_Gland|anterior pituitary gland]]. Gonadotrophins promote:
Generally, puberty can be defined in both sexes as the ability to accomplish reproduction. The fundamental requirement for the onset of puberty is the secretion of GnRH at the appropriate frequency and quantity to stimulate gonatotrophin release by the [[Pituitary_Gland_- Anatomy & Physiology#Anterior_Pituitary_Gland|anterior pituitary gland]]. Gonadotrophins promote:
* Genetics
* Genetics
= Male=
== Male==
== Age when Behavioural Traits are Expressed ==
=== Age when Behavioural Traits are Expressed ===
* Generally acquire reproductive behavioural traits such as [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mounting]] and [[Pre-copulatory Behaviour - Anatomy & Physiology#Erection|erection]] a long time before they acquire the ability to [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] and produce spermatozoa.
* Generally acquire reproductive behavioural traits such as [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mounting]] and [[Pre-copulatory Behaviour - Anatomy & Physiology#Erection|erection]] a long time before they acquire the ability to [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] and produce spermatozoa.
* Behavioural traits are easy to determine, as [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mounting behaviour]] and [[Pre-copulatory Behaviour - Anatomy & Physiology#Erection|erection]] can be easily observed.
* Behavioural traits are easy to determine, as [[Copulatory Behaviour - Anatomy & Physiology#Mounting|mounting behaviour]] and [[Pre-copulatory Behaviour - Anatomy & Physiology#Erection|erection]] can be easily observed.
== Age at First Ejaculation ==
=== Age at First Ejaculation ===
* [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|Ejaculation]] is a complex process,requiring coordinated development of nerves, specific muscles and secretion of seminal fluids from the accessory sex glands.
* [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|Ejaculation]] is a complex process,requiring coordinated development of nerves, specific muscles and secretion of seminal fluids from the accessory sex glands.
* Generally the ability to [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] preceeds the ability to produce sufficient spermatozoa to achieve [[Fertilisation - Anatomy & Physiology|fertilization]].
* Generally the ability to [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] preceeds the ability to produce sufficient spermatozoa to achieve [[Fertilisation - Anatomy & Physiology|fertilization]].
== Age when Spermatozoa First Appear in the Ejaculate ==
=== Age when Spermatozoa First Appear in the Ejaculate ===
* Males acquire the ability to produce seminal fluid and [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] before spermatozoa are available to be [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculated]].
* Males acquire the ability to produce seminal fluid and [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculate]] before spermatozoa are available to be [[Copulatory Behaviour - Anatomy & Physiology#Ejaculation|ejaculated]].
** Enables determination of the age at which spermatozoa first appear in the ejaculate.
** Enables determination of the age at which spermatozoa first appear in the ejaculate.
== Age when Spermatozoa First Appear in the Urine ==
=== Age when Spermatozoa First Appear in the Urine ===
* Most spermatozoa produced are lost in the urine during periods of sexual abstinence.
* Most spermatozoa produced are lost in the urine during periods of sexual abstinence.
* Frequent urine collection is difficult in large domestic species and requires special equipment, so this method of determining pubertal onset has limitations.
* Frequent urine collection is difficult in large domestic species and requires special equipment, so this method of determining pubertal onset has limitations.
== Age when the Ejaculate Contains a Threshold Number of Spermatozoa ==
=== Age when the Ejaculate Contains a Threshold Number of Spermatozoa ===
* Even if the ejaculate contains spermatozoa, there may be insufficient numbers for optimum [[Fertilisation - Anatomy & Physiology|fertilization]].
* Even if the ejaculate contains spermatozoa, there may be insufficient numbers for optimum [[Fertilisation - Anatomy & Physiology|fertilization]].
* Practically, this is the most valid criterion for puberty in the male.
* Practically, this is the most valid criterion for puberty in the male.
= Female =
== Female ==
== Age at First Oestrus ==
=== Age at First Oestrus ===
* The age that the female becomes sexually receptive and displays the first [[Oestrus Behaviour - Anatomy & Physiology|oestrus]].
* The age that the female becomes sexually receptive and displays the first [[Oestrus Behaviour - Anatomy & Physiology|oestrus]].
* The first [[Ovulation - Anatomy & Physiology|ovulation]] is usually not accompanied by behavioural [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] in heifers and ewes and is hence termed 'silent ovulation'. Thus, the age at first [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] may not accurately reflect acquisition of puberty.
* The first [[Ovulation - Anatomy & Physiology|ovulation]] is usually not accompanied by behavioural [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] in heifers and ewes and is hence termed 'silent ovulation'. Thus, the age at first [[Oestrus Behaviour - Anatomy & Physiology|oestrus]] may not accurately reflect acquisition of puberty.
== Age at First Ovulation ==
=== Age at First Ovulation ===
* The age at which [[Ovulation - Anatomy & Physiology|ovulation]] first occurs.
* The age at which [[Ovulation - Anatomy & Physiology|ovulation]] first occurs.
* All techniques require frequent observation of the [[Ovary - Anatomy & Physiology|ovary]], so although age at [[Ovulation - Anatomy & Physiology|ovulation]] is a good criterion for puberty, it is difficult to determine.
* All techniques require frequent observation of the [[Ovary - Anatomy & Physiology|ovary]], so although age at [[Ovulation - Anatomy & Physiology|ovulation]] is a good criterion for puberty, it is difficult to determine.
== Age at which the Female can Support Pregnancy without Deleterious Effects ==
=== Age at which the Female can Support Pregnancy without Deleterious Effects ===
* Most practical definition in all domestic animals.
* Most practical definition in all domestic animals.
[[Category:Reproductive System]]
[[Category:Puberty]]