Match the muscle with its main action:
_____Sternocleidomastoid muscle     
_____Transversus abdominis muscle     
_____Internal oblique muscle     
_____Rectus abdominis muscle     
_____Splenius capitis muscle     
_____Quadratus lumborum muscle.
a. Laterally flexes the trunk
b. Flexes the trunk
c. Compresses the abdominal cavity
d. Extends the vertebral column
e. Flexes the head
f. Extends the head

Verified step by step guidance

1. Step 1: Understand the main actions of each muscle listed in the problem. For example, the Sternocleidomastoid muscle is responsible for flexing the head and rotating it to the opposite side.
2. Step 2: Review the anatomical location and function of the Transversus abdominis muscle. This muscle compresses the abdominal cavity, aiding in core stability and respiration.
3. Step 3: Examine the Internal oblique muscle, which is involved in trunk rotation and lateral flexion. It also assists in compressing the abdominal cavity.
4. Step 4: Identify the Rectus abdominis muscle, which is primarily responsible for flexing the trunk, such as during sit-ups or bending forward.
5. Step 5: Match the Splenius capitis muscle and Quadratus lumborum muscle with their actions. The Splenius capitis extends the head, while the Quadratus lumborum laterally flexes the trunk and stabilizes the lumbar spine.

Key Concepts

Muscle Actions

Muscle actions refer to the specific movements that muscles produce when they contract. Understanding the primary actions of different muscles is crucial for identifying their roles in body mechanics. For instance, muscles can flex, extend, rotate, or stabilize various parts of the body, and knowing these actions helps in matching muscles to their functions.

Anatomy of the Core Muscles

The core muscles include various muscle groups that stabilize the trunk and pelvis, playing a vital role in movement and posture. Key muscles such as the rectus abdominis, internal oblique, and transversus abdominis are essential for trunk flexion and stabilization. Familiarity with these muscles and their anatomical locations aids in understanding their specific actions.

Cervical and Lumbar Muscles

Cervical and lumbar muscles, such as the sternocleidomastoid and quadratus lumborum, are responsible for movements of the head and lower back, respectively. The sternocleidomastoid primarily flexes and rotates the head, while the quadratus lumborum laterally flexes the trunk. Recognizing the functions of these muscles is important for accurately matching them to their actions.