4 - Physical Development

Vocabulary practice flashcards covering physical, endocrine, neurological, and health development concepts across infancy, childhood, and adolescence.

Cephalocaudal pattern

Growth sequence that works gradually from top to bottom of the body

Proximodistal pattern

Growth sequence, development starts at center of body and moves outward toward the extremities

Which part of the body is disproptionately large at first?

Head

____ and ____ increase rapidly in infancy

height & weight

By what age does growrth slow?

2 years

By 4 months, infants have ____ their weight and ____ their weight by 12 months

doubled
tripled

How many inches do infants grow per month in their first year?

1 inch

From age 6-11, growth is

slow & consistent

As baby fat decreases, what gradually increases?

muscle mass & strength

Puberty

transition to adulthood & sexual maturation

Endocrine System

Body system responsible for the production, circulation, and regulation of hormones.

Gonadotropin Releasing Hormone (GnRH) Neurons

Neurons implicated in pubertal development that are activated by pubertal hormones.

HPG Axis

A hormonal feedback loop composed of the Hypothalamus, Pituitary Gland, and Gonads that regulates sex hormone levels.

Hypothalamus

Brain structure that monitors sex hormone levels, maintains set points, and controls the pituitary gland and GnRH neurons.

Pituitary Gland

The master gland in the endocrine system that regulates hormone levels and signals the gonads to release sex hormones.

Gonads

The sex glands (testes in males, ovaries in females) that secrete sex hormones such as androgens and estrogens.

Testosterone

An androgen hormone associated in boys with genital growth, increased height, and vocal changes during puberty.

Estradiol

An estrogen hormone associated in girls with breast, uterine, and skeletal development during puberty.

Kisspeptin

A brain chemical thought to trigger the onset of puberty, with production regulated by melatonin and leptin.

Leptin

A protein hormone produced by fat cells that regulates hunger and appetite, signaling sufficient body fat for pubertal onset.

Melatonin

A hormone produced in response to darkness that regulates the sleep cycle and influences pubertal timing.

Epiphysis

The end portion of long bones whose growth and eventual closing marks the end of pubertal physical growth.

Tanner Stages

Also known as Sexual Maturity Rating (SMR), a standardized classification system used by healthcare providers to evaluate physical sexual maturation.

Neuroconstructivist View

Theory stating that brain development is influenced by biological processes and environmental conditions, exhibits plasticity, and is closely tied to cognitive development.

Cerebral Cortex

The outer layer of forebrain cells that accounts for approximately $80\%$ of brain volume and handles higher-order cognitive functions.

Lateralization

The specialization of function in one hemisphere of the cerebral cortex over the other.

Myelination

The process of encasing nerve axons with a fatty myelin sheath, which increases the speed of electrical impulse transmission.

Corpus Callosum

A thick band of nerve fibers connecting the left and right cerebral hemispheres that thickens in adolescence to enhance information processing.

Prefrontal Cortex

The highest region of the frontal lobes responsible for reasoning, decision-making, judgment, and self-control, maturing into emerging adulthood.

Dual-Systems Model

Also known as the maturational imbalance model, proposing that adolescent risk-taking occurs because the reward/emotional limbic system matures earlier than the self-regulatory prefrontal cortex.

Sudden Infant Death Syndrome (SIDS)

A condition in which an infant unexpectedly stops breathing and dies suddenly during sleep without an apparent cause.

REM Sleep Development

A stage of sleep characterized by rapid eye movement; infants spend roughly $50\%$ of their total sleep time in REM compared to $20\%$ in adults.

Marasmus

A severe malnutrition condition caused by a total deficiency in protein-calorie intake, leading to extreme muscle loss and an aged appearance.

Kwashiorkor

A life-threatening form of malnutrition caused by severe protein deficiency, resulting in swelling of the abdomen and feet due to fluid retention.