Adolescence Flashcards
Age of adolescence
Begins at puberty and ends at adulthood; no consensus in age definition
* Early adolescents: 10 to 14 years
* Late adolescents: 15 to 19 years
* Early adulthood: 20 to 24 years
WHO life course model
- Fetal life
- Infancy and childhood
- Adolescence
- Adulthood
Physiological Development of adolescents
Puberty: physical transformation from child to adult and includes
* sexual maturation
* increased rate of gains in height and weight
* completion of skeletal growth
* changes in body composition
Classifications WHO Growth Charts
When does sexual maturation for females begin?
Starts 8 to 12 years of age and process is ~5 years in length
* big height spurt happens first
* menarche usually develops in the middle
* breast usually develops before pubic hair
primary driver of sexual maturation in females
Estrogen
* reproductive organ maturation
* secondary sex characteristics
* menarche (close to middle of puberty)
What are the female tanner stages
sexual maturation rating (SMR)
* breast development
* pubic hair growth
When does sexual maturation for males begin?
Starts 9.5 to 13.5 years of age and process is ~4 years in length
primary driver of sexual maturation in males
Testosterone
* increases testicular volume
* changes to external genitalia
* sperm production
* secondary sex characteristics
Tanner stages for males
Sexual Maturation Rating (SMR)
* genital development
* pubic hair growth
How do the stages of development occur?
Stages of development are consistent,
but duration and timing varies
* nutritional needs based on stage
What mediates increases in weight and height?
Sex hormones and growth hormones mediate increases in weight and height
* gains in bone mass, muscle, organs, blood volume, fat mass (females)
Normal Body Composition Changes in females
peak weight gain after peak height velocity and before menarche of both FM and LM but proportionatly more FM
* gain in fat mass (120%) > lean mass (44%)
* Increased proportion FM and decreased proportion LM
Normal Body Composition Changes in Males
peak weight gain coincides with peak
height velocity (occur together) with increased LM and decreased FM
* decreased proportion FM and increased proportion LM
Why has the age of menarche decreased?
Trend in age of menarche has gone down where it used to be ~13 year but now it is 9-10 year most significantly due to increased BMI associated with earlier puberty in girls
* Leptin is made in adipose tissue and play a role in regulating hormones driving female reproductive cycle which signals that energy stores are adequate for puberty to start
* Permissive signal: removes suppression of GnRH (hypothalamic-pituitary gonadal
axis) iniating menarche`
Role of Leptin in females
related to glutofemoral fat
* increase in leptin precede menarche by about 6 months and remains elevated
leptin in males
increases in leptin precede initiation of puberty, but leptin concentrations then decline
Consequences of very early age of first menses
- social and behavioral impact
- increased risk of: metabolic syndrome/PCOS & breast cancer
Cognitive Development
Switch from concrete to abstract thinking
* Early adolescence: concrete, egocentrism, impulsive behavior
* Middle adolescence: still concrete but starting abstract thinking
* Late adolescence: abstract thinking
Social Development
Starts ~12 years of age and continues until ~24 years of age with development of:
* independence (Getting a vehicle)
* self-identity
* body image
* relationships
* individual beliefs and behaviours related to lifestyle choices
Stages of social development
Early adolescence
* body image and awareness of sexuality
* peer influence strong
Middle Adolescence
* emotional and social independence from family; making decisions for self
* peer influence strongest
Later Adolescence
* personal identity and beliefs
* social confidence, less influence of peers
Early Adulthood
* completion of independence
* adult roles and responsibilities