Nervous System
Fight or Flight
Nature vs. Nurture
Sensory, Motor, Interneuron
Psychology Approaches
200

You see your phone light up across the room and decide to pick it up. Your brain makes the decision and sends the message through your spinal cord before the message reaches the nerves in your arm.

Central Nervous System

200

Daniel is walking to his car at night when he hears someone suddenly sprinting behind him. His heart starts pounding, his breathing speeds up, and his pupils widen before he even knows what is happening.

Sympathetic Nervous System

200

Marcus and his older brother were raised in the same home by the same parents. Marcus is naturally very outgoing, while his brother is much quieter. Their parents treated them similarly and they attended the same schools. Their differences seem to exist even though much of their environment was shared.

Heredity / Nature

200

Ava walks barefoot across her kitchen and steps on a small piece of glass. Receptors in her foot immediately send information about pain toward her spinal cord.

Sensory Neuron / Afferent Neuron

200

Jordan becomes extremely anxious before tests. A psychologist studies his brain activity, hormone levels, and whether anxiety tends to run in his family.

Biological Approach

400

After your brain decides to pick up the phone, the message leaves the spinal cord and travels through nerves in your shoulder, arm, and hand until your fingers move.

Peripheral Nervous System

400

Daniel realizes the person running behind him was only trying to catch a bus. A few minutes later, his heart rate slows and his body begins returning to normal.

Parasympathetic Nervous System

400

Lena grew up in a family where no one played music. When she was 12, she joined band, practiced every day, and eventually became an excellent pianist. Her skill developed mostly because of years of practice and experience.

Environment / Nurture

400

After the pain signal reaches Ava's spinal cord, another neuron carries a message from the CNS toward the muscles in her leg so she can pull her foot away.

Motor Neuron / Efferent Neuron

400

Every time Maya finishes her homework, her parents let her play video games. After several weeks, she begins completing homework much more consistently.

Behavioral Approach


600

During soccer practice, Ana sees the ball coming toward her and intentionally moves her leg to kick it. She is consciously controlling her skeletal muscles.

Somatic Nervous System

600

Sofia finishes a huge meal and lies down on the couch. Her body is relaxed, her heart rate is low, and her digestive system becomes more active.

Parasympathetic Nervous System

600

Two identical twins were separated as babies and raised in different states. When they met as adults, both had similar personalities, similar hobbies, and even similar career interests. Researchers use cases like this to study the influence of genetics.

Twin Study / Heredity

600

The pain signal entering Ava's spinal cord does not go directly from the sensory neuron to the muscle. A neuron inside the spinal cord helps connect the incoming sensory message to the outgoing motor response.

Interneuron

600

Ethan fails one quiz and immediately thinks, "I'm terrible at this class. I'm probably going to fail the whole course." A psychologist focuses on how those thoughts affect his emotions and behavior.

Cognitive Approach

800

While Ana is playing soccer, her heart beats faster, she sweats, and her breathing increases without her having to consciously control any of it.

Autonomic Nervous System 

800

Before giving a speech, Carlos feels his palms sweating, his heart racing, and his stomach feels strange because digestion has slowed while his body prepares for stress.

Sympathetic Nervous System

800

A child experiences long-term stress while growing up. Years later, scientists find that the stress did not change the child's basic DNA sequence, but it did affect how some genes were turned on or off.

Gene-Environment Interaction / Epigenetics

800

You accidentally touch a hot pan. Before you consciously think, "That is hot," your hand is already moving away from the pan because the spinal cord quickly coordinated the response.

Reflex Arc

800

A researcher notices that students from different cultures have very different ideas about family roles, dating, and independence. She studies how cultural expectations shape behavior.

Sociocultural Approach

1000

After practice, Ana sits down, drinks water, and relaxes. Her heart rate slows, her breathing returns toward normal, and her body begins calming down.

Parasympathetic Nervous System

1000

After the speech is over, Carlos eventually returns to his normal heart rate, breathing, and body temperature. His body is restoring its normal internal balance.

Homeostasis

1000

A researcher argues that humans may be naturally cautious around snakes because ancestors who avoided dangerous animals were more likely to survive and have children.

Evolutionary Perspective / Natural Selection

1000

A student says, "The brain had to fully process the burn first before my hand moved." Which concept shows why that explanation is incorrect?

Reflex Arc

1000

A therapist believes that an adult's fear of disappointing authority figures may be connected to unresolved childhood experiences and unconscious conflict.

Psychodynamic Approach