Puberty
derived from the latin word pubescene which means "to grow hairy". At this stage the body undergoes a biological reveloution that dramatically changes the adolescents anatomy, physiology, and physical appearance.
Endocrine System
consist of glands in various parts of the body, the glands release chemicals called hormones into the bloodstream and the hormones affect the development and functioning of the body,
Hypothalamus
puberty begins in this gland, through hormonal changes. This is a bean-sized structure located in the lower part of the brain beneath the cortex. it stimulates and regulates the production of hormones by other glands.
How is puberty initiated in the hypothalamus?
the hypothalamus begins to increase its production of Gonadotropin-releasing hormone (GnRH). it releases (GnRH) in pulses at intervals of about 2hrs. This increase in production occurs in middle childhood. puberty begins once a threshold level of body fat
Leptin
fat cells produce this protein to initiate puberty and alert the hypothalamus
Gonadotropin-releasing hormone (GnRH)
Hormone released by the hypothalamus that causes gonadotropins to be released by the pituitary
Pituitary Gland
A f=gland about half an inch long located at the base of the brain that releases gonadotropins as part of the body's preparation for reproduction
What happens once there is increased production in GnRH?
it affects the pituitary gland, GnRH causes hormones called gonadotropins to be released. FSH and LH
Gonadotropins
Hormones (FSH and LH) that stimulate the development of gametes. they also influence the production of sex hormones by the ovaries and testes
Follicle-Stimulating Hormone (FSH)
Along with LH. stimulates the development of gametes and sex hormones in the ovaries and testicles
Luteinizing hormone (LH)
Along with FSH, stimulates the development of gametes and sex chromosomes in the ovaries and testicles
Gametes
Cells, distinct to each sex, that are involved in reproduction (egg cells in the ovaries of the female and sperm in the testes of the male)
gonads
The ovaries and testicles. Also known as the sex glands
Sex hormones
Androgens and estrogens that cause the development of primary and secondary sex characteristics.
Estrogens
The sex hormones that have especially high levels in females from puberty onward and are mostly responsible for female primary and secondary sex characteristics.
androgens
The sex chromosomes that have especially high levels in males from puberty onward are are mostly responsible for male primary and secondary sex characteristics.
estradiol
The estrogen most important i pubertal development among girls
testosterone
The androgen most important in pubertal development among boys
adrenocorticotropic hormone (ACTH)
The hormone that causes the adrenal glands to increase androgen production (occurs in the pituitary gland)
feedback loop
system of hormones involving the hypothalamus, the pituitary gland, and the gonads, which monitors and adjusts the levels of the sex hormones
set point
optimal level of sex hormones in the body. When this point is reached, responses in the glands of the feedback loop cause the production of sex hormones to be reduced (reduces production of GnRH by reducing FSH and LH and ACT, the gonads and adrenal gland
adolescent growth spurt
The rapid increase in height that takes place at the beginning of puberty
Peak height velocity
The point at which the adolescent growth spurt is at its maximum rate. Girls grow about 3.5 inches per year and boys 4.1 inches per year. Girls reach their point 2 year earlier than boys.
asynchronicity
Uneven growth of different parts of the body during puberty. (explains gangly look)
extremities
The feet, hands, and head are the first to grow, torso, chest and shoulders are the last to grow
What happens to girls during puberty
Their body fat increase more than boys
Both boys and girls hearts become larger during puberty
Vital capacity
The amount of air that can be exhaled after a deep breath, which increases rapidly during puberty, especially for boys
Maxium oxygen uptake (VO2 max)
A measure of the ability of the body to take in oxygen and transport it to various organs; peaks in the early 20s