Appendicular Muscles anatomy origins insertions and actions for Anatomy and/or Physiology Courses

Summary

This script delves into the appendicular musculature, detailing its role in stabilizing girdles, limb movement, and shock absorption. It categorizes muscles into pectoral and pelvic groups, explaining their origins, insertions, and functions. The script also discusses factors influencing muscle function, like action lines and muscle types, using examples from shoulder and hip joints. It further breaks down muscle groups by their movements, from large stabilizers to smaller, intricate hand and foot muscles, providing a comprehensive view of the muscular system's complexity.

Takeaways

• 💪 The appendicular muscles are crucial for stabilizing the pectoral and pelvic girdles, moving the limbs, and absorbing shocks during movement.
• 🏃‍♂️ There are two main groups of appendicular muscles: those associated with the pectoral girdle and upper limbs, and those with the pelvic girdle and lower limbs.
• 🦿 The muscles of the pectoral girdle and upper limbs include those that position the girdle, move the arm, forearm, and hand, as well as intrinsic and extrinsic muscles of the hand and fingers.
• 🦵 The muscles of the pelvic girdle and lower limbs include those that move the thigh, leg, and foot, with distinctions between extrinsic and intrinsic muscles of the foot.
• 🔍 Action lines of joints, such as the shoulder and hip, dictate the direction of muscle pull and the types of movements they facilitate.
• 💪 The deltoid, biceps brachii, and triceps brachii are key muscles affecting the shoulder joint's movements, with specific roles based on their positions relative to the joint.
• 🏋️‍♀️ Spurt and shunt muscles play different roles; spurt muscles are closer to the joint and primarily move it, while shunt muscles, located further away, stabilize the joint in addition to moving it.
• 🧭 The gluteal group and other muscles around the hip joint are responsible for a variety of movements including extension, abduction, and rotation.
• 🤚 The muscles that move the forearm and hand include the extensor carpi ulnaris, triceps brachii, biceps brachii, and others, each with specific actions like extension, flexion, and supination.
• 👣 Intrinsic muscles of the hand, such as the adductor pollicis and flexor digiti minimi brevis, originate on carpal and metacarpal bones and are responsible for精细手部动作.
• 🚶‍♂️ The muscles of the lower limbs are more powerful than those of the upper limbs, reflecting the greater strength needed for supporting body weight and locomotion.

Q & A

What are the primary functions of the appendicular muscles?

The appendicular muscles are responsible for stabilizing the pectoral and pelvic girdles, moving the upper and lower limbs, absorbing shocks and jolts during movement, and aiming and strengthening the joint area.

How are the appendicular muscles divided into groups?

The appendicular muscles are divided into two major groups: the muscles of the pectoral girdle and upper limbs, and the muscles of the pelvic girdle and lower limbs.

What is the role of the pectoral girdle muscles in relation to the axial skeleton?

The muscles that position the pectoral girdle originate on the axial skeleton and insert on the clavicle and scapula.

Which muscles are responsible for moving the arm and where do they originate and insert?

The muscles that move the arm originate on the pectoral girdle and the thoracic cage and insert on the humerus.

What is the difference between extrinsic and intrinsic muscles of the hand?

Extrinsic muscles of the hand primarily originate on the humerus, radius, and ulna and insert on the metacarpals and phalanges. Intrinsic muscles of the hand originate primarily on the carpal and metacarpal bones and insert on the phalanges.

How do action lines affect appendicular muscle function?

Action lines dictate the direction of pull and the specific movements such as flexion, extension, abduction, adduction, and rotation at various joints.

What is the function of the deltoid muscle in relation to the shoulder joint?

The deltoid muscle abducts the shoulder, with the clavicular portion flexing and medially rotating the shoulder, and the scapular portion extending and laterally rotating the shoulder.

What are spurt and shunt muscles, and how do they differ?

Spurt muscles insert close to the joint and primarily move that joint, while shunt muscles insert further away and stabilize the joint in addition to moving it.

How does the location of a muscle's insertion affect its function at a joint?

A muscle that inserts close to the joint is typically a spurt muscle, moving the joint, while a muscle inserting further away is a shunt muscle, providing stability and movement.

What are the three factors affecting appendicular muscular function mentioned in the script?

The three factors affecting appendicular muscular function are action lines, the existence of spurt and shunt muscles, and the action lines existing at the hip joint.

Which muscles are involved in moving the thigh and what are their origins and insertions?

The muscles that move the thigh include those originating in the pelvic region and typically inserting on the femur. They are part of groups such as the gluteal group, lateral rotator group, adductor group, and iliopsoas group.