#AP Psychology: Nervous System & Neurons - The Night Before 🌃

Hey! Let's get you feeling confident for tomorrow's exam. We're going to break down the nervous system and neurons into bite-sized, easy-to-remember pieces. Let's do this!

#1. The Nervous System: Your Body's Command Center 🧠

This is a HUGE topic on the AP exam! Make sure you understand the different parts and how they interact.

The nervous system is your body's super-fast communication network. It uses electrical and chemical signals to send messages all over your body. Think of it as the internet of your body! 🌐

#1.1 Central Nervous System (CNS) 🔗

• The CNS is the brain 🧠 and spinal cord 🦴. It's the main processing center.

• Brain: The control center, processing information and making decisions.

• Spinal Cord: A highway 🛣️ connecting the brain to the rest of the body, also handles reflexes.

• Reflexes: Automatic responses controlled by the spinal cord. They're super quick because they bypass the brain initially. Think of pulling your hand away from a hot stove 🔥.

Image Courtesy of Lecturio

#1.2 Peripheral Nervous System (PNS) 🔗

• The PNS connects the CNS to the rest of the body. It's like the branches of a tree.🌳

• Somatic Nervous System: Controls voluntary movements of skeletal muscles 💪. Think about moving your arm or leg.

• Autonomic Nervous System: Controls automatic functions of internal organs, like your heart beating ❤️ and lungs breathing. It's always working without you thinking about it.

• Sympathetic Nervous System: The "fight or flight" system. It gets you ready for action 🏃. Increases heart rate, breathing, etc.

• Parasympathetic Nervous System: The "rest and digest" system. It calms you down after the excitement is over. Returns you to a neutral state.🧘

Image courtesy to Wikimedia Commons

#2. Neurons: The Messengers ✉️

Neurons are the basic building blocks of the nervous system. They transmit information through electrical and chemical signals.

#2.1 Types of Neurons 🔗

• Sensory (Afferent) Neurons: Carry incoming information from the senses to the CNS. Think of them as the reporters 📰.
• Interneurons: Process information within the CNS. They're the decision-makers 👨‍⚖️.
• Motor (Efferent) Neurons: Carry outgoing information from the CNS to muscles and glands. They're the messengers who carry out the orders 🏃.

Image courtesy to Wikimedia Commons

#2.2 Action Potential 🔗

• Action Potential: The electrical signal that travels down the axon of a neuron. It's how neurons communicate.
• Neuron's Threshold: The minimum level of stimulation needed to trigger an action potential. Like flipping a switch 💡.
• All-or-None Response: A neuron either fires completely or not at all. There's no half-firing.
• Depolarization: The process of the neuron becoming more positive, allowing the action potential to travel.

#2.3 Neurotransmitters and Synapses 🔗

• Neurotransmitters: Chemical messengers that travel across the synapse. They're like the mail carriers ✉️.
• Synapse: The gap between two neurons where neurotransmitters are released.
• Electrical Synapse: Relays quick messages. Think of a fast text message 🐆.
• Chemical Synapse: Sends messages slowly. Think of a letter in the mail 🐌.

Image Courtesy of CNS

#Final Exam Focus 🎯

• High-Priority Topics: Nervous system divisions (CNS, PNS, autonomic, somatic, sympathetic, parasympathetic), neuron types (sensory, motor, interneurons), action potential, neurotransmitters, and synapses.
• Common Question Types: MCQs on identifying parts of the nervous system and their functions, FRQs on explaining how the nervous system responds to a stimulus, and applying concepts to real-life scenarios.
• Time Management: Quickly identify the key concepts in the question, prioritize questions you know well, and don't get bogged down on a single question.
• Common Pitfalls: Confusing sympathetic and parasympathetic nervous system functions, not understanding the all-or-none principle, and misidentifying neuron types.

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Practice Question

#Multiple Choice Questions

1. Which part of the nervous system is responsible for slowing down the heart rate after a stressful event? a) Somatic Nervous System b) Sympathetic Nervous System c) Parasympathetic Nervous System d) Central Nervous System

2. Which type of neuron carries signals from the brain to the muscles? a) Sensory Neuron b) Interneuron c) Motor Neuron d) Afferent Neuron

3. What is the "all-or-none" principle referring to? a) The speed of neurotransmitter release b) The strength of a nerve impulse c) The threshold of a neuron d) The response of a neuron to a stimulus

#Free Response Question

Scenario: A student is walking home late at night and hears a loud noise behind them. Their heart starts racing, and they begin to sweat.

Task:

a) Identify the division of the nervous system that is primarily responsible for the student's initial reaction. (1 point) b) Explain how the autonomic nervous system is involved in this response, including the specific roles of its two subdivisions. (2 points) c) Describe the role of neurotransmitters in this response. (2 points) d) Explain how the student's body would return to a normal state after the threat has passed. (2 points)

Scoring Rubric

a) 1 point: The student correctly identifies the sympathetic nervous system as primarily responsible for the initial reaction. b) 2 points: The student explains that the autonomic nervous system controls involuntary functions, and correctly identifies the sympathetic nervous system as increasing heart rate and sweating, and the parasympathetic nervous system as returning the body to a normal state. c) 2 points: The student describes that neurotransmitters are released to transmit signals across synapses to activate the response (e.g., adrenaline/norepinephrine). d) 2 points: The student explains that the parasympathetic nervous system will return the body to a normal state by decreasing heart rate and sweating.

You've got this! Take a deep breath, trust your preparation, and go ace that exam! 💪