Course: Anatomy & Physiology I (BIOL 2301 + BIOL 2101) · Silver Oak University (fictional sample) · Prof. Navarro
Module: Week 12 of 16 · Fall 2026 · in-person, two 75-minute lectures + one weekly lab
Objective covered: Objective 6 — Describe the structure of nervous tissue (the neuron and neuroglia), explain the resting membrane potential and the action potential as an ordered sequence of ion movements, and describe how a signal crosses the synapse.

This file holds two pieces: (A) the Module 12 Overview page ("Start Here") and (B) the Welcome Announcement that drips out when the module opens. Dates below assume a Tuesday/Thursday lecture pattern with Week 12 meeting Tue Nov 17 and Thu Nov 19, a lab that same week, and end-of-week work due Sunday Nov 22, 11:59 p.m. Adjust the day-of-week and times to match your section.

(A) Module 12 Overview — Start Here

Welcome to Week 12: How the Neuron Fires

This is your home base for the week. Read it first, then work the checklist below from top to bottom. Everything you need is linked inside the module.

This week we meet the cell behind every thought, sensation, and movement: the neuron. We've spent the course on structures that hold you up and move you (bones, joints, muscle); now we turn to the system that controls and coordinates all of it. Two ideas carry the week. First, the familiar one — structure determines function: a neuron's long, branched shape and its insulating myelin are exactly what let it receive a signal and race it down a nerve. Second, the new one — the action potential, the brief electrical event a neuron uses to fire. We keep it overview-level: which ions move, in which direction, in what order, and the voltage values that go with each phase. No equations.

The week's big question

"How does a single cell turn a touch into an electrical signal — and pass that message on to the next neuron?"

By Friday you'll name the parts of a neuron and what each does, explain the resting membrane potential (≈ −70 mV, inside negative), put the action-potential phases in order with the right ion for each, and describe how a signal crosses the synapse.

By the end of this week, you can…

Use this as a checklist. If you can do all four out loud, you're ready for the quiz.

• [ ] Name the parts of a neuron and their functions — dendrites (receive), cell body/soma (integrate), axon (conduct away), axon terminals (output), myelin sheath (insulate/speed), nodes of Ranvier — and list the major neuroglia (CNS: astrocytes, oligodendrocytes, microglia, ependymal; PNS: Schwann, satellite).
• [ ] Explain the resting membrane potential (≈ −70 mV, inside negative) and the Na⁺/K⁺ pump (3 Na⁺ out, 2 K⁺ in per ATP) that helps maintain it.
• [ ] Put the action potential in order — resting (−70 mV) → depolarization (Na⁺ IN, peak ≈ +30 mV) → repolarization (K⁺ OUT) → hyperpolarization → rest — and name the all-or-none principle (threshold ≈ −55 mV).
• [ ] Describe synaptic transmission — the impulse reaches the axon terminal → Ca²⁺ enters → neurotransmitter is released across the synaptic cleft → binds receptors on the next neuron.

What's due this week, and when

Work these in order — each one gets you ready for the next.

Heads-up on the AI tools: you'll use a chatbot to draft and explain, and then you judge its work against what we cover in class. Chatbots routinely scramble the action-potential phases, swap the ions (calling depolarization "potassium leaving"), say the resting potential is positive, or reverse the Na⁺/K⁺ pump. Catching the model is the point — in the tutorial, the assignment, and the lab.

Late policy reminder: 10% off per day late. If life happens, reach out before the deadline — I'd much rather hear from you early.

How to succeed this week

• Lead with the idea, not the jargon. A neuron is just a cell built to receive a signal and send it on fast; an action potential is just ions crossing the membrane in a set order. Get the picture first; the vocabulary clicks after.
• Memorize two tiny hooks. "Resting is negative — about −70." And "Sodium IN to fire, potassium OUT to reset."
• Treat the action potential as a sequence, not a blob. Rest → depolarize → repolarize → hyperpolarize, every time, in that order. Most of the quiz's difficulty is just keeping the order and the ions straight.
• Watch the minus sign. The biggest single error is thinking the inside is positive at rest. It is negative (−70 mV). Circle the minus until it's automatic.
• Treat the chatbot as a smart intern, not an oracle. It drafts; you check — especially the phase order and the voltage values. That habit is the whole semester in miniature, and in the clinic the stakes for catching an error are real.

You don't need any new math for this week — just a willingness to follow a sequence and keep a few numbers straight. Come to class ready to argue about which ion moves first. See you Tuesday.

(B) Welcome Announcement — Module 12

Release setting: post on the module's start day (offset = 0 days), i.e., Tue Nov 17, 2026 — not before. If your platform won't preserve the scheduled date on import, post this as a draft labeled "Release: Tue Nov 17."

Subject: Welcome to Week 12 — how does a cell make electricity? 🧠⚡

Hi everyone, and welcome to Week 12!

Quick warm-up before we start: you touch a hot stove and your hand pulls back before you feel the pain. How is that possible? A nerve cell turned the heat into an electrical signal and raced it down its axon faster than conscious thought. This week we open up that cell — the neuron — and watch exactly how it fires. Here's the twist most people don't expect: the "electricity" inside a neuron isn't electrons flowing down a wire. It's ions — sodium and potassium — moving across the cell membrane in a precise order. That's our whole week.

This week — Nervous Tissue, the Neuron & the Action Potential — we tackle the big question: How does a single cell turn a touch into an electrical signal, and pass that message on to the next neuron? By Friday you'll name the parts of a neuron, explain why the inside sits at about −70 mV at rest, put the action-potential phases in order with the right ion for each, and describe how the signal crosses the synapse.

Three things not to miss:
1. Lecture Tutorial 12 — work through the neuron and the action potential with one approved chatbot (Gemini, Claude, or ChatGPT) and submit the share link. You'll catch the model's mistakes — chatbots love to scramble the phases. Due Sun Nov 22.
2. Lab 12 ("Watch a Neuron Fire"), Quiz 12, Discussion 12, and Assignment 12 also close Sun Nov 22 — the lab uses the free PhET "Neuron" simulation (or an at-home reaction-time test), so start early and have fun stimulating a neuron and reading the voltage climb.
3. Open the Start Here page first — it lays out everything in order with due dates.

One promise: this is the most "alive" week of the course — you're watching a single cell generate a signal in real time. We keep it overview-level (which ions, which direction, what order — no equations), and we lead with the plain-language picture before any number. By Friday, the next time your hand jerks off a hot pan, you'll know the exact sequence of ions that made it happen.

Bring your curiosity (and the willingness to keep a minus sign straight) to class on Tuesday.

See you soon,
Prof. Navarro