15.5
軸筋と付属筋
私たちの体の動きを担う骨格筋は、その位置と機能に基づいて、軸筋と付属筋の 2 つのグループに分類できますこの分類は、筋肉の構造や動きにおける主な役割を反映しています。
軸筋
体の正中線に沿って位置する軸筋は、頭蓋骨、脊椎、肋骨、胸骨を含む軸方向の骨格に複雑に接続されています。 これらの筋肉は顔の表情…
骨格筋は主に軸筋と付属肢の2つのグループに分けられます。
体の正中線に沿って存在する軸筋は、主に頭、首、および体幹の領域と接続されています。
頭と首では、軸筋は顔の表情、会話、食事、およびさまざまな頭の動きに不可欠です。
さらに、一部の首の筋肉は、脊柱の動きにおいて、一般に背筋と呼ばれる後体幹の筋肉を補助します。
胸部の筋肉は、直腸筋、斜筋、横筋などの腹筋とともに、体幹の前外側壁を確立します。
最後に、下部軸骨格には、仙骨と骨盤帯の間に伸びる筋肉があり、骨盤底を形成します。
一方、付属肢筋は、胸帯、骨盤帯、および四肢に関連する筋です。
これらの筋肉は、歩行、ランニング、およびその他の身体活動中に動く構造を安定させ、支えます。
上肢に関連する付属肢筋は肩から手まで、下肢の筋肉は腰から足までの範囲です。
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Q1: What is the main difference between axial and appendicular muscles?
Axial muscles are located along the body's midline and connect to the axial skeleton, including the skull, spine, ribs, and sternum. They control facial expressions, head and neck movements, speaking, and eating. Appendicular muscles, by contrast, attach to the pectoral girdle, pelvic girdle, and limbs, providing stability and enabling movement during activities like walking and running.
Q2: Which axial muscles form the walls of the trunk?
The thoracic muscles and abdominal muscles, including the rectus, oblique, and transverse muscles, form the anterolateral walls of the trunk. These muscles of the abdomen provide structural support and stability to the torso, protecting internal organs and enabling trunk movements and breathing.
Q3: What role do axial muscles play in head and neck movements?
Axial muscles in the head and neck are vital for facial expressions, talking, and eating. Additionally, some neck muscles work with posterior trunk muscles to assist in movements of the vertebral column. These muscles of the vertebral column coordinate to enable flexion, extension, and rotation of the spine.
Q4: How do appendicular muscles support limb movement?
Appendicular muscles stabilize and support moving structures during physical activities like walking and running. Upper limb muscles extend from the shoulders to the hands, enabling precise hand movements. Lower limb muscles stretch from the hips to the feet, providing mobility and balance during locomotion and weight-bearing activities.
Q5: What muscles form the pelvic floor?
The lower axial skeleton contains muscles that extend between the sacrum and pelvic girdle, creating the pelvic floor. These muscles of the pelvic floor and perineum provide support for pelvic organs and contribute to core stability during movement and posture maintenance.
Q6: Where are appendicular muscles located in the upper and lower limbs?
Upper appendicular muscles extend from the shoulders down to the hands, enabling intricate tasks and arm movements. Lower appendicular muscles stretch from the hips to the feet, ensuring mobility and balance. Both regions contain muscles that attach to the pectoral and pelvic girdles, respectively, allowing coordinated limb function.
Q7: How do axial muscles contribute to facial expressions and eating?
Axial muscles in the head and neck are essential for creating facial expressions and controlling jaw and mouth movements during eating. These muscles for facial expressions work in coordination with muscles around the mouth and eyes to produce the varied expressions humans use for communication and food manipulation.