Chapter 7

Obesity

Determined by body mass index. Children in the 95th percentile or higher (for their age and sex) are considered obese. Children between the 85th and 94th percentile are classified as overweight.

Myelin

A white fatty substance that encases cell axons. It provides insulation and improves transmission of signals.

Neuron

A cell that carries information across the body and brain, as well as back and forth within the brain.

Strabismus

A condition in which a child's eyes are crossed toward the nose or veer toward the ears. If not corrected by eyeglasses before the age of five, the child will not develop normal depth perception.

Autism Spectrum Disorder

A disorder that can range from mild to severe, characterized by problems with social interaction, verbal and nonverbal communication, and repetitive behavior.

Marasmus

A form of malnutrition in which individuals are not receiving enough protein or enough calories.

Kwashiorkor

A form of malnutrition in which individuals have an adequate intake of calories, but an inadequate intake of protein.

Cortisol

A hormone secreted when individuals are exposed to stress.

Synaptogenesis

A key process in the brain involving the development of connections between neurons through the growth of axons and dendrites.

Normative Development

A pattern of development that is typical, or average.

Sensitive Period

A time in development during which the organism is especially open to environmental influence.

Mirror Neuron

A type of brain cell that fires when the individual performs an action or the action is performed by another.

Fine Motor Skills

Abilities required to control smaller movements of the hand and fingers, such as picking up small objects and tying one's shoes.

Gross Motor Skills

Abilities required to control the large movements of the arms,legs, and feet, or the whole body, such as running, jumping,climbing, and throwing.

Norms

Average outcomes rather than actual for even ideal ones.

Body Mass Index

BMI calculated by dividing weight(measure in kg) by height (measured in meters) squared, or wt/ht(squared).

Dendrites

Branched extensions of a neuron that pick up signals from other neurons.

Maturation

Growth that proceeds by a genetic timetable.

Frontal Lobes

Sometimes called the "executive" of the brain, the frontal lobes are responsible for planning and organizing new actions, problem solving, and regulating emotions, as well as focusing attention.

Hemispherectomy

Surgery in which one hemisphere of the brain is removed.

Effortful Control

The ability to withhold a first response and choose another.

Synapse

The connection between one neuron's axon and another neuron's dendrite.

Corpus Callosum

The connection between the two halves or hemispheres of the brain.

Brain Plasticity

The degree to which the brain can be altered by experience.

Lateralization

The localization of a function to one of the hemispheres of the brain.

Axon

The part of the cell that carries signals away from the cell body toward other neurons. At their tips, axons divide into many axon terminals.

Synaptic Pruning

The process of elimination of unused and unnecessary synapses.

Myelination

The process through which cell axons become sheathed in myelin.

Individual Differences

The variation among individuals on a characteristic.