All of the following organs have involuntary muscles except?

IGNOU Post B. SC. Nursing entrance-2019

Applied Anatomy

Easy

Appeared in: IGNOU Post B. SC. Nursing entrance-2019

Explanation

The skeleton is the body's framework, and its movement is produced by skeletal muscles.
Skeletal muscles are classified as voluntary muscles because their contraction is under conscious control, mediated by the somatic nervous system.
Actions like walking, lifting, or writing are all examples of voluntary skeletal muscle contraction.

Option A: The stomach wall contains smooth muscle, which is an involuntary muscle type. It contracts automatically to churn food and propel it through the digestive system (peristalsis).
Option B: The intestines are lined with smooth muscle that performs peristalsis, an involuntary wave-like contraction to move food and waste along the digestive tract.
Option D: The heart is composed of cardiac muscle, a unique type of involuntary muscle. It contracts rhythmically on its own (automaticity) without conscious effort to pump blood.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Types of muscle tissue and their control mechanisms (voluntary vs. involuntary) as background academic context rather than a clinical decision trigger.
Nurses must understand muscle types to anticipate the effects of medications. For example, anticholinergic drugs can decrease the involuntary contractions of smooth muscle in the gut, leading to constipation.
Assessing a patient's ability to perform voluntary movements (e.g., grip strength, walking) is a key part of a neurological assessment, evaluating skeletal muscle function and nerve integrity.
What if? A patient has a spinal cord injury. They may lose voluntary control over skeletal muscles below the injury level, but the involuntary functions of their heart (cardiac muscle) and digestive system (smooth muscle) will continue, as these are controlled by the autonomic nervous system.

How to Approach the Question

First, analyze the question's keyword: 'except'. This signals that you must find the option that does not belong to the group.
The group is defined as 'organs with involuntary muscles'. So, the task is to find the option with voluntary muscles.
Review each option's muscle type and control: Stomach (involuntary smooth muscle), Intestine (involuntary smooth muscle), Skeleton (moved by voluntary skeletal muscle), and Heart (involuntary cardiac muscle).
Identify the outlier: The skeleton is associated with voluntary muscle, while the other three are composed of or contain involuntary muscle.
Select the outlier, 'Skeleton', as the correct answer.

Concept Tested & Keywords

Concept Tested: Types of muscle tissue and their control mechanisms (voluntary vs. involuntary).
Stem keywords: organs, involuntary muscles
Lead-in keywords: except
Negative lead-in flag: The question uses 'except', asking for the option that does NOT fit the described category (organs with involuntary muscles).

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