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MODULE 8:
NERVOUS TISSUE
PART 1 OF 7
PlaceholAge 35, T-boned at an intersection. ER imaging clear; discharged as “lucky” with a muscle strain. Two days later a hot line of pain ran from her low back down the back of her left leg.der
Slide 1 Transcript
PATIENT CHART
STINA
THIS PART
Age 35
PRESENTING WITH
Numbness, tingling, and a hot stripe of pain down her left leg, slowly creeping, symmetric foot numbness
DIAGNOSIS
Anti-MAG peripheral neuropathy
DRUGS ORDERED
Rituximab
CHART CLUES
COLLECTED AS YOU GO
Radiating Leg Pain & Numbness After a ‘Clear’ Crash
Symmetric Loss of Light-Touch & Vibration
Slowed Nerve Conduction
Synapse Intact — the Fault Is Upstream
Anti-MAG Antibodies
A Map Pointing at Two Nerve Roots
Anti-MAG, Sensory-Predominant Peripheral Neuropathy
Put your money down: A clear scan — proof she’s fine?
If her bones were fine and the scan was clear, was Stina truly uninjured — or is something wrong with the wiring?
Pick the answer you believe now. We’ll come back to it later!
The Crash the Scans Called Lucky
Stina was thirty-five when another car ran the light and caught her door. The ER did its job — scans were clear, nothing broken — and the resident called her lucky and sent her home with ibuprofen and a note about whiplash. For a day she believed him. Then, on the second morning, a hot, electric line of pain switched on from her low back and traveled straight down the back of her left leg, and a patch of her shin and foot felt oddly muffled, like it was wearing a sock that wasn’t there. “Pinched nerve from the accident,” the follow-up clinic said. It was the first sentence in a much longer story.
How It’s Organized
The map that tells you where to look — brain-and-cord versus the nerves, signals coming in versus going out.
Slide 2 Transcript
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Drag the Words: Drag each label into the sentence that defines its division.
Anatomy of a Neuron
One cell, built to carry a signal fast and far — four working parts, in order.
Slide 3 Transcript
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Fill in the Blanks: Fill in the neuron’s four parts, from signal-in to signal-out.
Two Divisions, Two Directions of Traffic
To follow that story you have to know how the nervous systemThe organ system that controls body functions using electrical and chemical signals. is organized. It splits into two great divisions: the central nervous systemComposed of the brain and spinal cord; integrates and processes information. (CNS) — the brain and spinal cordThe central nervous system structure that relays signals between the brain and body., the processing core — and the peripheral nervous systemPNS All nervous tissue outside the CNS; includes nerves and ganglia. (PNS) — the nerves that branch out to the body. Traffic runs two ways. Sensory (afferent) neuronsThe functional cells of the nervous system that transmit signals. carry information inward, toward the CNS — touch, temperature, the ache of a strained muscle. Motor (efferent) neurons carry commands outward, to muscles and glands.
Classifying Neurons
Neurons sorted two ways — by shape, and by the job they do.
Slide 4 Transcript
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Multiple Choice: Which functional class carries Stina’s pain toward the cord?
Ion Channels on the Membrane
The hardware that makes a neuron excitable — three kinds of gate, and the bare spots between the insulation.
Slide 5 Transcript
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Flip Cards: Flip each channel to reveal what makes it open.
A Sensory Problem Means Look at the Wiring
Stina’s symptomsSubjective experiences reported by the patient (e.g., nausea, fatigue). are a sensory complaint: the pain and numbness are messages arriving at the cord, not movements failing to leave it. That distinction tells us where to look — not at her muscles, but at the wires carrying sensation from her leg. This page opens Chart Clue #8 and the whole nervous-system arc by asking a simple question the ER skipped: if the bones are fine, what is wrong with the wiring?
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Slide 6 Transcript
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Slide 7 Transcript
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FINDING!
Radiating Leg Pain & Numbness After a ‘Clear’ Crash — a Wiring Problem
Sharp, radiating pain and a patch of numbness in one leg, arriving after an ER visit that found no fractureBreaks in bones due to stress or injury. and called her lucky. New evidence reframes the ‘muscle strain’: a normal X-ray clears bone, not the nervous system. Numbness and radiating pain are sensory (afferent) signsObjective clinical findings observable by a provider (e.g., edema, fever). — the trouble lives in the wiring, not the frame.
Confirm or refute your bet:
If her bones were fine and the scan was clear, was Stina truly uninjured — or is something wrong with the wiring?
Now that you’ve read the story, confirm or overturn it — step by step, with the evidence in hand.
Slide 8 Transcript
NEXT PART
If the bones are intact, the problem lives in the wires — so we need to know exactly how a wire is built. Next: the neuron and the insulation that lets it work.
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Overview
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QUICK QUESTIONS
QUICK QUESTIONS
List of terms
- nervous system
- central nervous system
- spinal cord
- peripheral nervous system
- neurons
- symptoms
- fracture
- signs