Transcript motivation-hunger-and-sexual

Motivation
Hunger
• Three hunger factors
– Biological
– Psychosocial
– Genetic
Hunger
• Biological
• Physiological changes in blood chemistry
and signals from digestive organs that
provide feedback to the brain, which, in turn
triggers us to eat or stop eating
– Hunger comes from Peripheral and Central
Cues
Hunger
• Peripheral Cues
• Changes in blood chemistry or signals from
digestive organs
– Stomach
• Monitors the amount and kinds of nutrients
our body needs in order to restore fuel
• Stomach’s walls are distended and their
stretch receptors signal fullness or time to
stop eating
Hunger
• Liver
– Monitors nutrients, especially glucose, in
blood
– When level of glucose falls, we are hungry;
when level rises, we are full
• Intestines
– Responds to the presence of food by
secreting hormones, CCK (cholecystokinin),
which inhibits eating
Hunger
• Fat cells
– Secrete a hormone that is monitored by the
brain
– Brain signals the person to eat or stop eating
so that a certain level of body fat remains
constant over a person’s lifetime
Hunger
• Central Cues
• Come from the activity of chemicals and
neurotransmitters in different areas of the
brain
– Hypothalamus
• Many different cells that are involved in a
number of different behaviors having to do
with motivation, such as thirst, sexual,
behavior, and regulation of hunger
Hunger
• Lateral Hypothalamus
– Group of cells that regulates hunger by
creating feelings of being hungry
• Ventromedial Hypothalamus
– Group of cells that regulates hunger by
creating feelings of satiety, or fullness
• Galanin- stimulates by eating fat
• Norepineprine- stimulates by eating
carbohydrates
Hunger
• Genetic Factors
– Come from inherited instructions found
in our genes
– Determines the number of fat cells or
metabolic rates of burning off the body’s
fuel, which pushes us toward being
normal, overweight, or underweight
Hunger
• Fat cells
– People who inherit a larger number of fat cells
have the ability to store more fat and are
more likely to be fatter than average
• Metabolic rate
– How efficiently our bodies break food down
into energy and how quickly our bodies burn
off that fuel
Hunger
• Set point
– Certain level of body fat that our bodies strive
to maintain constant throughout our lives
• Weight regulating genes
– Plays a role in influencing appetite, body
metabolism, and secretion of hormones that
regulate fat stores
Hunger
• Psychosocial Factors
– Learned associations
• We do not eat because we are hungry, but
because of other factors
– Socio-cultural influences
• Pressures to be thin
• Having money to eat
– Personality traits
• Bulimia, anorexia, depression
Sexual behavior
• Three factors of sexual behavior
– Genetic
– Biological
– Psychological
Sexual behavior
• Genetic Sex Factors
• Include inherited instructions for the
development of sexual organs, secretion of
sex hormones, and the writing of neural
circuits that control sexual reflexes
– Sex chromosome
• Contain instructions for determining the sex
of the child
Sexual behavior
• Human egg always contains an X
chromosome
• Human Sperm can have either X or Y
chromosomes
• Males- XY
• Females- XX
Sexual Behavior
• Differentiation
– Embryo is the same for the first four weeks
• Y chromosome has instructions for growing
testes that produce testosterone
– Testosterone triggers the development of the
male sex organ and programs the
hypothalamus for puberty
• The second X chromosome contains instructions
for developing ovaries, which do not contain
testosterone
Sexual behavior
• Biological influences
– Sex hormones- chemicals secreted by the
glands
• Males- androgens, testosterone
–Secondary sexual characteristics- facial
and pubic hair, muscle growth, and
lowered voice
• Females- estrogen
–Pubic hair, breast development,
widening of the hips
Sexual behavior
• Psychological factors
– Sexual or gender identity
• Individuals subjective experience and
feelings of being either a male or a female
– Gender role
• Traditional or stereotypic behaviors,
attitudes, and personality traits that society
designates as feminine or masculine
Sexual behavior
• Sexual orientation
– Refers to whether a person is sexually
aroused primarily by members of his or her
own sex, the opposite sex, or both sexes
– Genetic or environmental?