Human Sexual Development and Puberty

Study Notes

Physical growth is summarized as a key aspect of adolescence
Puberty is described as a period of rapid growth and sexual maturation, starting between ages 8 and 13 for girls and 9 and 14 for boys.
Sex steroids are identified as the hormones causing puberty.
The growth process, according to the data, starts from the extremities towards the torso (distal-proximal development).
Sex differences (sexual dimorphism) exist, with males typically being taller and heavier than females by age 18.
The average American boy is 84% of adult height by age 12, while the average girl is 93% of adult height.
Average height and weight of American adolescents is tracked for comparative analysis.

Brain maturation involves pruning of synaptic connections and strengthening of neural pathways.
Cognitive efficiency increases throughout adolescence.
Energy use by the adolescent brain is lower compared to childhood brains.
Glucose is the primary energy source for adult brains, whereas adolescent brains also use ketones.
Grey matter (clusters of cell bodies) and white matter (myelinated nerve fibers) play a role in this maturation process.
Parts of the brain like parietal, frontal, and temporal lobes mature at different rates.
Adolescent brain regions for reward and emotion develop earlier than rational thought regions.
Development results in an imbalance between reason and emotion.
Variations in brain size by sex exist, with male brains typically slightly larger (controlling for body size).

Increased brain efficiency leads to reduced need for deep sleep.
Adenosine accumulation is partly responsible for the changes in sleep patterns.
Sleep homeostasis and diurnal rhythms of hormones (like melatonin) affect sleep patterns in adolescents.
Melatonin secretion is diminished in the evening, promoting later sleep onset.

Increased nutritional needs coincide with the rapid growth of adolescence.
Iron and calcium requirements are crucial during this stage, especially for girls considering menstruation.
Obesity and weight issues are prevalent during adolescence.

Chronic conditions, such as asthma and musculoskeletal issues, are common.
Mental health concerns, including anxiety, depression, and suicidal thoughts, are also prevalent.
Acne is a frequent issue and can impact mental health.
Death rates among adolescents are substantially higher compared to pre-puberty.