7.1 Physiology of Adolescence Flashcards
What are the physical changes in Tanner Stage I (Males)?
- Pre pubertal, testicular volume < 2mls
- no pubic hair
What are the physical changes in Tanner Stage II (Males)?
- Enlarged scrotal skin
- Some pigmentation scrotum
- small amount long downy pubic hair
What are the physical changes in Tanner Stage III (Males)?
- increase in length of penis
- scrotum and testes enlarged further
- pubic hair coarse and curly, extending laterally
What are the physical changes in Tanner Stage IV (Males)?
- increase in length and thickness of penis
- development of glans penis
- scrotum and testes enlarge further
- adult pubic hair, no spread to medial thighs
What are the physical changes in Tanner Stage V (Males)?
- genitalia of adult size and shape
- testicular volume > 20mls
- adult pubic hair spread to medial thighs
The first sign of secondary sexual development in males is the attainment of _________ and this occurs at a mean age of _________ The pre-pubertal testis is around 2ml. This sexual development is followed by
- ____________ (1 year)
- Pubic hair development
- Increasing ___________
- Increased ___________
- Continued testicular enlargement to an adult volume __________
- Growth of ____________ (voice breaks)
4ml testes;
12 years.;
Penile and scrotal enlargement ;
body hair;
muscle mass;
> 20ml;
larynx
The first sign of puberty in females is ___________ at a mean age of 10.5 years. This sexual development is followed by
1. Pubic and axillary hair growth
2. Fat redistribution (______________)
3. Menstruation (menarche) usually ____________ after breast development
4. _____________ occurs before menarche
The Tanner stages for female puberty are shown below.
breast development (thelarche) ;
hips and breasts;
2-3 years;
Growth spurt
What are the physical changes in Tanner Stage I (Females)?
- no glandular tissue
- no pubic hair
What are the physical changes in Tanner Stage II (Females)?
- breast bud forms, small area of surrounding glandular tissue
- small amount low downy pubic hair
What are the physical changes in Tanner Stage III (Females)?
- breast most elevated
- areola widen
- pubic hair coarse and curly, extending laterally
What are the physical changes in Tanner Stage IV (Females)?
- increased breast size and elevation
- areola and papilla project from contour of breast
- adult pubic hair, no spread to medial thighs
What are the physical changes in Tanner Stage V (Females)?
- adult sized breast
- adult pubic hair spread to medial thighs
what is adrenarche?
Adrenarche is an endocrine developmental process that is separate from puberty.
Prepubertal children mostly develop small amounts of axillary and pubic hair growth. It is associated with a progressive increase in the secretion of androgen hormones (DHEA and DHEAS) from the adrenals.
Adrenarche occurs at 6-8 years old, before puberty occurs. Besides the hair growth and acne, there are no other signs of sexual development. There is no known triggering mechanism for adrenarche.
how is delayed puberty defined in boys?
Absence of testicular development (or testicular volume < 4ml) in boys > 14 years old
how is delayed puberty defined in girls?
Absence of breast development in girls > 13 years old
How does the growth chart of an individual with constitutional delay of growth and puberty look like?
The individual with constitutional delay of growth and puberty will not have reached his/her pubertal growth spurt and so may begin to drop down the centiles on a growth chart. However, once the individual enters puberty, the rapid acceleration will cause a climb back up to the appropriate centile on the growth chart.
How to manage a child with constitutional delay of growth and puberty?
In most children, all that is required is reassurance about the acceptable final height. Some adolescents can exhibit psychological problems associated with delayed puberty and short stature. While the onset of puberty can be induced with exogenous androgens or oestrogens, therapy does not influence the final height.
What are the pathological causes of delayed puberty?
The activation of pulsatile GnRH secretion can be delayed by
- Chronic illnesses (e.g. renal disease, cystic fibrosis)
- Malnutrition (e.g. anorexia, coeliac disease)
- Excessive physical exercise
- Steroid therapy
- Hypothyroidism
What are central causes of pubertal failure?
- Tumours adjacent to the hypothalamus-pituitary axis
• Pituitary adenoma
• Optic glioma - Irradiation treatment to the brain
- Trauma
• Head injury
• Surgery - GnRH deficiency
• Kallmann’s syndrome
• Prader-Willi syndrome - Suppression secondary to
• Hyperthyroidism
• Hyperprolactinaemia
• Cushing Syndrome
What are peripheral causes of female pubertal failure?
- Gonadal dysgenesis (under-developed ovaries)
• Turner’s syndrome (45 XO) - Steroid hormone enzyme deficiencies
- Ovarian damage
• Post-irradiation
• Post-chemotherapy
• Surgery - Toxic damage in the ovaries
• Galactosaemia – unable to metabolise galactose properly
• Thalassaemia – resulting in iron overload
What are the peripheral causes of male pubertal failure?
- Gonadal dysgenesis (under-developed testes)
• Klinefelter syndrome (47 XXY) - Cryptorchidism (undescended testes)
• Idiopathic
• Noonan’s syndrome
• Prader-Willi syndrome
3. Testicular damage • Post-irradiation • Post-chemotherapy • Surgery • Testicular torsion
- Toxic damage
• Galactosaemia
• Thalassaemia
What is precocious puberty defined as ?
- Boys: Onset of testicular development (or a testicular volume > 4ml) in boys < 9 years old
- Girl: Onset of breast development in girls < 8 years old
What are indications of pathological causes of precocious puberty?
- Abnormal sequence of puberty
• Isolated pubic hair and virilisation of genitalia (implies excess androgens) - Rapid onset
- Neurological signs or symptoms
What are pathological causes of Gonadotrophin dependent precocious puberty?
Pathological causes include
1. CNS anomalies
• Hydrocephalus (build-up of fluid on the brain can stimulate the hypothalamus)
• Tumours
- Acquired
• Post-irradiation
• Post-chemotherapy
• Surgery
What are pathological causes of Gonadotrophin independent precocious puberty?
This is always pathological and causes include
1. Adrenal disorders
• Congenital adrenal hyperplasia
• Adrenal tumours
2. Ovarian or testicular tumours producing sex steroids
