- [Instructor] So there are
many factors that affect and regulate our intake
of food, sex, and drugs. But let's talk about two categories that regulate food, sex, and drugs. The first are biological factors. And biological factors
regulate food, sex, and drugs, include hormones. The brain regulates each of these drives by controlling them
automatically and unconsciously. At the same time, our
conscious choices and desires play a role in how we express these needs, and these are what we call
are socio-cultural factors. Okay, so let's take a
look at the biological and socio-cultural factors
that regulate food. So when we're hungry,
the lateral hypothalamus, right here in the yellow, signals to the stomach
that we start eating through positive feedback mechanism. On the other hand, when we're full, the ventromedial hypothalamus,
over here in the turquoise, is going to signal for us to stop eating. Now when we're full, the hormone leptin is present
in high amounts in our blood. And leptin is what we call the
appetite-suppressing hormone. Another important hormone in
regulating food is insulin. So the brain can actually
detect the level of insulin to see the amount of fat
stores and sugar in our blood. Our metabolisms are extremely important in regulating food biologically. So during periods of
dieting or starvation, our body burns fuel slower. The slowdown in metabolism
actually makes it easier for people to gain weight
when resuming normal eating. And we also have a genetic
predisposition to our weight. We have a certain set point that biologically is
influenced from our parents. Now people eat for many different reasons, and one of the biggest reasons
people eat socio-culturally is for different occasions, whether they be religious holidays or certain events to commemorate. And we also eat depending on the time. We're constantly looking
at our clocks all day to find the right time to eat, whether that's breakfast,
lunch, or dinner. People also eat because
of a desire to eat. They have a desire to
eat, maybe comfort foods, spicy or sweet foods, either
Mexican or Italian foods. Food must also have some sort of appeal. So we eat depending on if the
food looks appetizing or not. And we also eat food
depending on the availability. So certain foods are available during certain times of
the year, such as fruits. But then, geographically, certain foods are only
present in certain regions of a country or even
certain parts of the world. And economically, people may
not have access to all foods. Let's dive into the
factors that affect sex. So in the 1960s, two
scientists, Masters and Johnson, studied hundreds of male
and female volunteers during sexual activity. They monitored the
physiological indicators and they eventually turned those results into what we call the
sexual response cycle, which I've drawn right here in the white. So the first part of this
cycle is the excitement phase, which is this uphill slope. And that's usually marked
by increased muscle tension, increased heart rate and blood pressure. The second is a plateau phase,
which is this flat line. The third is orgasm, at the peak. And the fourth is the
resolution or refractory period. Now Masters and Johnson also
noticed that sexual drive is related to testosterone levels in both males and females. They noticed that sexual activity increased testosterone levels and testosterone levels, in
turn, increased sex drive. So socio-culturally, sexual
responses vary by age. They also vary by cultural background. Certain practices are acceptable in certain cultures and not in others. Now the excitement
phase, over here in one, is initiated by some sort of stimulus. And this stimulus depends
on how responsive we are to either visual or tactile stimuli. Other socio-cultural factors
that regulate sex are emotions. Our emotions and our psychological
influence play a role, as well as our desires. Our desires to either procreate or not. So the last topic to look at is the effect that biological and socio-cultural
factors have on drugs. So there are various biological
and psychosocial factors that can initiate a substance
abuse in an individual. And one of these is our family history or genetic predisposition. If an individual has a family member or a history of mental
disorder or drug abuse, then that individual has a higher chance of possibly also abusing a drug. Withdrawal effects also
have a biological basis. Withdrawals and cravings. There are many biochemical factors that affect drug use, whether that's an imbalance in our brains. So drugs like heroin and marijuana can biologically mimic
natural transmitters in our brains to activate our neurons. However, cocaine, another drug,
causes the abnormal release of natural neurotransmitters,
such as dopamine. And you've probably heard of dopamine as being the happy drug. That's his nickname. So when dopamine floods our brain, it can over simulate
the region of the brain that controls our movement, emotion, cognition, motivation, and pleasure. So it's affecting our
limbic system in our brain. And our limbic system is
actually what activates or is activated when we use these drugs. So this is why we perceive many emotions and it also explains the
mood-altering properties that many drugs have. So when we take these drugs, we become in a state of euphoria, and the dictionary definition
is total happiness. And if we continue to repeat
the behavior of using a drug, then we eventually abuse the drug. And this is called the reinforcing effect because we want to feel that
happiness, we wanna feel good. We're gonna constantly
stimulate our brains to reach that euphoric
state by taking drugs. Now, there are many reasons,
you're probably aware of, of why people use drugs socio-culturally. It could just be out of mere curiosity or because the drug's a novelty. It could be to rebel socially. It could be because the
user has poor control. It could be a way to manage
stress and cope with it. It could also be because the
person has a low self-esteem, and we talked about self-esteem as being one of Maslow's orders
in his hierarchy of needs. So in order to fulfill that level of need, a person may use drugs. They may also use it to relieve
themselves from fatigue, to just plain feel good. And the use of drugs has also been seen to be more prevalent in
areas of higher poverty.