Chapter 1: Physical-Biological Theories
The concept that behavior is an expression of neural activity is central to the philosophy of
The mind represents a range of brain functions—simple to complex, including
physical, sensory, cognitive, and affective functions
The brain controls
behavior—how we perceive, think, feel, behave, act, and interact
Consciousness is a
dynamic result of brain activity, neither identical with, nor reducible to, the neural events of which it is composed.
Consciousness is an active integral part of the cerebral process;
it exerts control over the biophysical and chemical activities at subordinate levels
The huge quantity and vast range of sensory information that is transmitted to the cerebral cortex and the way in which the brain sorts, classifies, organizes, and interprets sensory information; handles input and output; considers expectations, past experiences, and other sources of information; and sends messages throughout the body are complex and not fully understood.
Genetics is the study of
individual genes and their functions, the effects of heredity, and the combined impact of genes on disorders or specific characteristics.
Where do recent genetic data come from?
Recent data come from direct visual examination of chromosomes, biochemical analyses of genetic material and enzymatic processes, and study of genes and DNA through the Human Genome Project.
An understanding of genetic concepts is essential in order to
effectively educate the client about health promotion and development.
The Mendelian Law of Inheritance states
that a dominant gene for a trait of characteristic in at least one parent will cause, on the average, 50% of the children to inherit the trait. If both parents have the dominant gene, 75% of their children will inherit the trait.
When the trait is attributed to a recessive gene
the offspring does not manifest it unless the gene was received from both parents.
If the gene was received from only one parent
the offspring is not affected but will probably pass on the gene to the next generation child (the grandchild)
If the parents are heterozygous for a recessive gene
(both received the same gene type from only one of their parents)25% of the children probably will be affected.
If the parents are homozygous for the recessive gene
(the same gene type was received from both of their parents), all the children probably will inherit the trait of characteristic.
The Mendelian law explains the occurrence of many
physical traits, such as eye color and height, and may explain certain physiologic characteristic or behavioral tendencies.
To isolate environmental factors from genetic effects, researchers have used several methodologic designs, such as
the family resemblance method, the twin study method, and a combination of the two.
The family resemblance method look for
similarity between a person with a disorder and his or her relatives.
The twin study method relies on
differences between the two groups: monozygotic twins and dizygotic twins.
from a single ovum and therefore identical and have been found to resemble each other more in mood level and lability than dizygotic
from two ova fertilized by two sperm and therefore not identical, i.e., fraternal twins.
threadlike package of genes and DNA in the cell nucleus; contains instructions to make all the proteins a living being needs. Humans have 46 chromosomes (23 pairs - 44 autosomes and two sex chromosomes)