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Ch. 7 The Skeleton
Marieb - Human Anatomy & Physiology 11th Edition
Marieb, Hoehn11th EditionHuman Anatomy & PhysiologyISBN: 9780136874034Not the one you use?Change textbook
Chapter 7, Problem 12

Justiniano worked in a poultry-packing plant where his job was cutting open chickens and stripping out their visceral organs. After work, he typed for long hours on his computer keyboard, writing a book about his work in the plant. Soon, his wrist and hand began to hurt whenever he flexed it, and he began to awaken at night with pain and tingling on the thumb half of his hand. What condition did he probably have?

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1
Step 1: Identify the symptoms described: pain when flexing the wrist, nighttime pain, and tingling on the thumb side of the hand. These symptoms suggest nerve involvement, particularly in the wrist area.
Step 2: Understand the anatomy involved: the median nerve passes through the carpal tunnel in the wrist and provides sensation to the thumb, index, middle, and part of the ring finger. Compression of this nerve causes characteristic symptoms.
Step 3: Recognize that repetitive wrist movements, such as typing and manual labor involving wrist flexion, can lead to inflammation and swelling in the carpal tunnel, compressing the median nerve.
Step 4: Connect the symptoms and occupational activities to the likely diagnosis: carpal tunnel syndrome, which is caused by median nerve compression at the wrist.
Step 5: Conclude that the condition Justiniano probably has is carpal tunnel syndrome, characterized by pain, tingling, and numbness in the median nerve distribution, often worsened by wrist flexion and occurring at night.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Carpal Tunnel Syndrome

Carpal Tunnel Syndrome is a condition caused by compression of the median nerve as it passes through the carpal tunnel in the wrist. It leads to pain, numbness, and tingling, especially in the thumb, index, middle, and half of the ring finger. Repetitive wrist movements, like typing or manual labor, often trigger symptoms.
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Median Nerve Anatomy and Function

The median nerve runs through the carpal tunnel and controls sensation in the thumb, index, middle, and part of the ring finger, as well as motor function to some hand muscles. Understanding its pathway helps explain why compression causes specific symptoms in these areas.
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Repetitive Strain Injury (RSI)

Repetitive Strain Injury refers to damage caused by repetitive motions or sustained postures, often affecting muscles, tendons, and nerves. Jobs involving repetitive hand and wrist movements, like poultry processing and typing, increase the risk of conditions like Carpal Tunnel Syndrome.
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