directionality

The principle that describes growth as having intrinsic direction

cephalocaudal

Directional growth that begins with the head and moves towards the toes

Proximodistal

Directionality that begins near the center of the body and proceeds towards the extremities

Independance of Systems

The principle that different body systems grow on different schedules

Canalization

The tendency for growth,if disturbed or deflected, to return to an expected path

Epiphyses

Skeletal Age

An assessment of physical maturity that depends on examination of the size and appearance of the epiphyses

Primary Teeth

The first teeth to appear, usually in the latter half of the 1st year; often called baby teeth.

Neurotransmitters

Chemicals that move across synapses, allowing communication between neurons

Apoptosis

The programmes process of cell death undergone by some neurons in response to a relative lack of environmental input

Synaptic Pruning

The death over time of many synapses that are not stimulated by input from the environment

Glial Cells

Fatty cells responsible for mylenating the neruons in the brain and providing other support functions to neurons

Cerebral Cortex

The 2 large, outer hemospheres that make up the layer of the brain; responsible for much of perception, thought, and planning

Lateralization

Separation of functions in the two hemisperes of the cerebral cortex

Plasticity

The ability of the brain to be changed by experience

Experience-expectant plasticity

The brain's ability to creat circuits based on typical human experiences, such as hearing voices or seeing faces.

Experience-dependant plasticity

The brain's ability to create circuits based on atypical or idiosyncratic forms of experience, such as extensive training in music or sports

Tripod position

Visual Cliff

Cruising

Moving around on two feet while holding onto furniture forsupport; a mode of movement used by infants before thy learn to wal independently

Haptic Discrimination

Ability to tell objects apart using touch

Visual Acuity

Clarity of vision; the ability to distinguish details

Object Segregation

The ability to identify objects in the world; to tell where one object begins and another ends

Phoneme

The smalles unit of sound that carries meaning in a language

Perceptual Tuning

The process of becoming less sensitive over time to stimuli that are not in the typical environment; also called perceptual narrowing

Kwashiorkor

A condition that results from extreme starvation; symptoms include swolen bellies and feet, hair loss, and lack of energy

Marasmus

A condition that results form extreme stravation, in which the body becomes extremely thin and fragile

Food insecurity

Uncertainty about whether enough food will be available when it is needed

Sudden Infant Death Syndrome (SIDS)

The sudden unexplained death of an otherwise healthy infant

Colic

A condition in which infants who are otherwise normal show excessive crying; usually for at least 3 days per week, for at least 3 weeks

Otitis Media

Ear infection