Muscle Anatomy Study Guide

Overview of Muscle Anatomy

• Focus on gross muscle anatomy
• Discussion of muscle shapes and fascicle arrangements
• Only the muscles covered in class will be important for examination

Histology of Muscle Anatomy

• Distinction between nervous components and muscular components is crucial; many questions may relate to anatomy of muscles (axons, neurotransmitters are not relevant)
• Understand the muscle as an organ, including fascicular arrangement attaching to bone

Muscle Shapes and Groups

• Familiarize yourself with different shapes of muscles
• Classify muscles by body regions:
  • Muscles of the Face and Neck
  • Focus on:
    • Masseter
    • Temporalis
    • Origin-Insertion-Action:
    • For both, masseter originates from the zygomatic bone, temporalis from the temporal line
    • Main action: closes the jaw
  • Muscles of the Trunk
  • Trapezius
    • Originates along the spine; attaches to occipital bone
    • Function: extension of the head
  • Sternocleidomastoid
    • Primary action: flexes head
    • Attaches at the sternum and clavicle
  • Muscles of the Upper and Lower Limbs
  • Key groups in arm: biceps brachii (flexes), triceps brachii (extends)
  • Recognize agonist (primary mover) and antagonist (opposing muscle) roles in movement
  • Indirect vs direct muscle attachments

Muscle Actions

• Understand the nature of muscle contractions:
  • Agonist and Antagonist:
  • For example, during flexion, biceps are agonists; during extension, triceps act as antagonists
• Flesh out the terms:
  • Isometric: muscle tenses without movement
  • Isotonic: involves actual movement
  • Concentric: shortening of muscles (e.g. lift)
  • Eccentric: lengthening of muscles (e.g. lowering)

Study Techniques for Anatomy

• Flashcards recommended for learning origins, insertions, and actions of muscles
• Use anatomical images from textbooks or online resources for visual learning
• Group similar looking muscles, focus on clear distinctions in attachment points

Cadaver Studies and Muscle Identification

• Focus on muscles represented in dissection: Recognize appearances (highlighted in purple)
• Familiarize with common cadaver muscle questions
• Understand complex groups such as SITS (supraspinatus, infraspinatus, teres minor, subscapularis)

Functional Significance of Muscle

• Roles in movement, stability, and heat production
• Dictates significance of diaphragm and intercostal muscles in respiration
• Importance of muscle movement in various activities (e.g., chewing referred to as mastication)

Common Muscle Groupings and Actions

• Abductors vs. adductors: awareness of their functions
• Flexors and extensors based on arm position: flexor is anterior, extensor is posterior

Conclusion

• Understanding muscle anatomy is key for effective movement and physiological function
• Implement effective study techniques to excel in understanding muscle origins, insertions, actions, and associations.
• Focus on the differences in muscle types to dissect similarities, particularly in complex muscle groups.