Chapter 5 Flashcards
Cephalocaudal Principle of Development:
The upper portion of the body develops quicker than the lower part of the body
Some Examples:
Infant can use upper body parts before lower body parts.
Head control before sitting up or walking.
Mouth manipulation before hand manipulation.
Greater upper body strength before lower body.
Newborn’s head represents about ___ of total body length
1/4
Adult’s head represents about ___ of total body length
1/7
Proximodistal Principle of Development:
The middle part of the body develops quicker than the outer part of the body.
Some Examples:
Newborn’s trunk more developed than limbs.
Well coordinated Shoulder movement before arm movement.
Well coordinated arm movement before hand movement.
Orthogenetic Principle (Hierarchical Integration)
Growth proceeds from a global undifferentiated mass to a series of discrete parts which become integrated and coordinated with one another.
Target seeking principle (catch up growth)
The final level of physical growth is only minimally affected by environmental factors
Nutrition, viruses, sickness, etc. may have strong temporary effects… but if deficiency is alleviated, growth will occur rapidly to compensate for the loss.
Functional Asymmetry Principle
The development of the body (left-right) is not symmetrical…
What develops on the left does not necessarily develop on the right and vice versa.
Functional Asymmetry Principle: handedness
Infant (B-2yrs)… Ambidextrous
End of 2nd year… Shows preference for Right or Left
4-5 years… Preference is used in most situations
Functional Asymmetry Principle: brain lateralization
Brain Lateralization:
Newborn Infant… very little differentiation between right and left hemisphere
During first 6 months… specialization occurs in left and right hemispheres
Left… analytical/logic, verbal, language
Right… perception, intuition, artistic
If damaged before 6 months… after 6 months
self regulating fluctuation principle
Development does not proceed at an even pace… one system may show very rapid growth while other systems do not.
self regulating fluctuation principle examples
Difference periods of rapid growth during prenatal development
Newborn reflexes
Puberty
pituitary gland
release the most important hormones for human growth. It is located at the base of the brain near the hypothalamus. The hormones act directly on body tissue to induce growth, or they stimulate the release of other hormones from endocrine glands located elsewhere
growth hormone
the only pituitary secreation produced continuously throughout life, affects development of all tissues except the central nervous system and genitals. This doubles during puberty
Thyroid-stimulating hormone
promotes the thyroid gland in the neck to release thyroxine, which is necessary for brain development and for GH to have its full impact on body size
estrogen
female hormone
androgens
male hormone
secular trends in physical growth
changes in body size from one generation to the next
neurons
nerve cells that store and transmit information
synapses
tiny gaps where fibers from different neurons come close together but do not touch
neurotransmitters
neurons send messages to one another by releasing chemicals called neurotransmitters, which cross synapses
programmed cell death
as synapses form, many surrounding neurons die- 20 to 80 percent, depending on the brain region
glial cells
responsible for myelination
myelination
the coating of neural fibers with an insulating fatty sheath that improves the efficiency of message transfer
glial cells multiply rapidly from
the fourth month of pregnancy through the second year of life
