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Ch. 10 The Muscular System
Hoehn - Marieb Human Anatomy & Physiology, 12th edition
Hoehn, Haynes, Abbott12th EditionMarieb Human Anatomy & PhysiologyISBN: 9780138242732Not the one you use?Change textbook
All textbooksHoehn, Haynes, Abbott 12th EditionCh. 10 The Muscular SystemProblem 10
Chapter 10, Problem 10

A prime mover of thigh flexion is the:
a. Rectus femoris
b. Iliopsoas
c. Vastus muscles
d. Gluteus maximus

Verified step by step guidance
1
Step 1: Understand the term 'prime mover' in anatomy. A prime mover, or agonist, is the muscle primarily responsible for producing a specific movement at a joint.
Step 2: Identify the movement in question, which is thigh flexion. Thigh flexion refers to the action of lifting the thigh forward at the hip joint.
Step 3: Review the functions of each muscle option: Rectus femoris assists in thigh flexion but mainly extends the knee; Iliopsoas is a major hip flexor; Vastus muscles primarily extend the knee; Gluteus maximus is mainly responsible for thigh extension, not flexion.
Step 4: Determine which muscle is the main contributor to thigh flexion by comparing their primary actions. The Iliopsoas is known as the strongest and most important muscle for hip (thigh) flexion.
Step 5: Conclude that the prime mover of thigh flexion is the Iliopsoas based on its anatomical function and role in hip movement.

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Key Concepts

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

Thigh Flexion

Thigh flexion refers to the movement that decreases the angle between the thigh and the pelvis, typically lifting the leg forward. It is a fundamental motion in activities like walking, running, and climbing stairs.
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Bones of the Thigh and Leg

Iliopsoas Muscle

The iliopsoas is a deep muscle group composed of the psoas major and iliacus muscles. It is the primary and most powerful flexor of the thigh at the hip joint, playing a crucial role in lifting the leg.
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Introduction to Muscles and Muscle Tissue Example 1

Role of Other Muscles in Thigh Movement

The rectus femoris assists in thigh flexion but mainly extends the knee; vastus muscles primarily extend the knee; gluteus maximus is the main thigh extensor. Understanding their functions helps identify the prime mover in thigh flexion.
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Muscle Actions
Related Practice
Textbook Question

Which criterion (or criteria) is/are used in naming the gluteus medius?

a. Relative size

b. Muscle location

c. Muscle shape

d. Action

e. Number of origins

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Textbook Question

Muscles that depress the hyoid bone and larynx include all but the:

a. Sternohyoid

b. Omohyoid

c. Geniohyoid

d. Sternothyroid

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Textbook Question

Which of the following is a large, deep muscle that protracts the scapula during punching?

a. Serratus anterior

b. Rhomboids

c. Levator scapulae

d. Subscapularis

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Textbook Question

Intrinsic muscles of the back that promote extension of the spine (or head) include all but:

a. Splenius muscles

b. Semispinalis muscles

c. Scalene muscles

d. Erector spinae

Textbook Question

The prime mover of thigh extension against resistance is the:

a. Gluteus maximus

b. Gluteus medius

c. Biceps femoris

d. Semimembranosus

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Textbook Question

Several muscles act to move and/or stabilize the scapula. Which of the following are small rectangular muscles that square the shoulders as they act together to retract the scapula?

a. Levator scapulae

b. Rhomboids

c. Serratus anterior

d. Trapezius

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