Puberty and adolescene Flashcards
Define the following terms
Adrenarche Gonadarche Pubarche Thelarche Menarche Spermarche
- Adrenarche: activation of the adrenal cortex
- Gonadarche: activation of gonads by the pituitary hormones FSH and LH
- Pubarche: appearance of pubic hair
- Thelarche: appearance of breast tissue
- Menarche: first menstrual period
- Spermarche: age at first ejaculation
First phase: Explain the role of the adrenal gland in puberty (adrenarche)
- Precedes Gonadarche around 2 years
- Independent of HPG
- Increased secretion of adrenal steroids which helps prepare the body for a more dramatic change that will happen in 2 years
- Effects: pubic/ axillary hair, body hair, acne
Second phase: Explain the role of Gonadarche in puberty
- HPG axis: hypothalamus- pituitary- gonads
- Normally, the hypothalamus secretes hormones to the pituitary which impacts the endocrine cells of the pituitary. Here, the pituitary releases the secondary wave of hormone release
- The hypothalamus releases the Gonadotropin Releasing Hormone which stimulates the anterior pituitary to release FSH/ LH which stimulates gonads to release sex hormones
- Hormones released from gonads (testosterones, oestrogen) actually negatively impacts the hypothalamus to stop the release of GnRH
Be able to explain the reasons behind growth velocity
- When the baby is born, there is a decrease in placental sex hormones which leads to a rise of release in GnRH = growth spurt for baby
- Gradually GnRH decreases during childhood because low levels of sex exert a powerful negative effect on the hypothalamus and the CNS exerts an inhibitory effect on hypothalamus secretion of GnRH as the brain grows = decreased growth spurt
- During puberty, the CNS no longer exerts an inhibitory effect on the release of GnRH and the hypothalamus becomes less sensitive to gonadal steroids = increased growth spurt
Discuss the roles of LH and FSH in males
LH
• Increases testosterone production
FSH
• Sperm production
Discuss the roles of LH and FSH in females
LH
• Increases androgen and progesterone production
• Stimulates ovulation
FSH
• Ovarian follicle development
• Estrogen production
State the effects of testosterone in males and females
Male • Growth of genitals • Growth of pubic/facial hair • Increased libido • Increased muscle mass • Deepening voice • Thickened cortical bone
Female
• Growth of pubic hair
• Thickened cortical bone
State the effects of oestrogen in males and females
Male
• Low levels of pubertal growth spurt
• High levels: closure of epiphyses in bones: no more growth
Female • Same bone effects as in males • Growth of breasts and genitals • Increased vaginal pH and length • Proliferation of endometrium • Triggers LH surge
Understand the impacts of sex hormones on the oral cavity
- High levels of progesterone and oestrogen during puberty can make patients susceptible to gingivitis and periodontitis
- During puberty there are high levels of glucose in the bloodstream and gingiva = gingivitis and periodontitis
- Thus follow up sessions should be relatively close to each other and close monitoring
Explain how the growth hormone works
- Once secreted, the GH travels to the liver
- The liver produces insulin- like growth factor (IGF-1)
- IGF 1 stimulates chondrocytes to multiply in the cartilage at the end of the long bones = taller
- IGF-1 impacts immature cells to increase muscle mass
- In adults, IGF-1 helps repair and regeneration
List the additional roles of GH
- GH breaks down fats to generate amino acids to eventually make proteins (lipolysis) and increases protein synthesis
- Reduces liver uptake of glucose
- GH increases calcium retention
- GH helps maintain blood glucose levels to ensure that there is a constant source of energy for growth
List the four factors that impact the level of growth hormone produced
- Stress
- Exercise
- Nutrition
- Sleep
