HSC Lecture

Directional Terminology

  • Directional terminology is crucial for understanding anatomy.

  • Key terms include:

    • Superior: Closer to the head.

    • Inferior: Further away from the head.

    • Distal: Further away from the body.

    • Proximal: Closer to the trunk of the body.

  • Important to differentiate terms related to the trunk versus extremities for better clarity.

Movements and Body Part Regions

  • Focus will be on joint movements in various body regions, particularly the shoulder joint and shoulder girdle for the upcoming exam.

  • Each body part region will exhibit different types of movements.

Spine and Thorax

  • Anatomy of the spine:

    • Comprised of three parts: Cervical, Thoracic, and Lumbar spines.

    • Shoulder girdle's muscles originate sometimes from the cervical and thoracic vertebrae.

  • Movements associated with the spine include:

    • Flexion and Extension: Illustrated by a sit-up (flexion) or back extension exercises.

    • Rotation: Turning the spine.

    • Lateral Flexion: Moving sideways away from the midline.

  • Planes of Movement:

    • Sagittal Plane: Divides body into left and right sections; associated with flexion and extension.

    • Transverse Plane: Divides body into top and bottom sections; associated with rotational movements.

    • Frontal Plane: Divides the body into anterior and posterior sections; involved in lateral flexion.

Rib and Thorax Movements

  • Ribs expand (elevate) and contract (depress) during breathing.

  • Movement allows for air intake and expulsion controlled by the autonomic nervous system.

Scapulothoracic Joint

  • The scapula (shoulder blade) articulates with the thorax (ribcage).

  • Movements of the scapula include:

    • Elevation: Lifting the scapula (as in a shrug).

    • Depression: Lowering the scapula (returning to resting position).

    • Protraction: Moving scapulae away from the midline.

    • Retraction: Moving scapulae towards the midline.

    • Upward Rotation: Inferior angle of the scapula moves upward.

    • Downward Rotation: Scapula returns to its resting position.

  • Important to maintain scapula function to prevent shoulder joint problems.

Glenohumeral Joint (Shoulder Joint)

  • Also known as the glenohumeral joint.

  • Articulates between the humerus and the glenoid fossa of the scapula.

  • Primary movements include:

    • Flexion and Extension: Movement in the sagittal plane.

    • Abduction and Adduction: Movement in the frontal plane.

    • Medial and Lateral Rotation: Movement in the transverse plane.

    • Horizontal Abduction and Adduction: Requires arm to be elevated before executing.

  • Rotation and range of motion are attributed to shoulder's ball and socket structure.

Elbow and Forearm Movements

  • Movements of the elbow joint:

    • Flexion and Extension: Simple movements through one plane.

  • Forearm movements:

    • Pronation: Palm facing down.

    • Supination: Palm facing up.

  • Important to distinguish wrist movements from forearm rotations; they are controlled by the radioulnar joint.

Wrist Movements

  • At the wrist, there are several movements:

    • Flexion and Extension: Bending forward and backward.

    • Ulnar Deviation: Moving wrist towards the ulnar bone (inner side).

    • Radial Deviation: Moving wrist towards the radius bone (outer side).

Hand and Finger Movements

  • The thumb has unique movements:

    • Flexion and Extension: Along the plane of the hand.

    • Adduction and Abduction: Movement relative to the hand’s midline.

    • Opposition: Touching thumb to fingertips.

  • Other fingers can perform similar flexion, extension, adduction, and abduction.

Temporomandibular Joint Movements

  • The jaw exhibits specific movements:

    • Elevation and Depression: Jaw opening and closing.

    • Protraction and Retraction: Moving jaw forward and backward.

    • Lateral Deviation: Side-to-side movement of the jaw.

Types of Movable Joints

  • Six classifications of movable joints:

    1. Ball and Socket Joints: Examples include shoulder and hip joints; allow for wide range of movement.

    2. Hinge Joints: Example: elbow; allows movement in one plane (flexion and extension).

    3. Modified Hinge Joints: Example: knee; primarily hinge action with some rotational capabilities.

    4. Ellipsoid Joints: Example: wrist; permit flexion/extension and adduction/abduction but not rotation.

    5. Saddle Joints: Example: thumb joint; allows for multi-directional movement.

    6. Pivot Joints: Example: radioulnar joint; allow rotation around a single axis.

Skeletal System Overview

  • Two main categories of skeletal system:

    • Axial Skeleton: Composed of the skull, spinal column, rib cage, and thorax.

    • Appendicular Skeleton: Comprised of limbs and girdles (clavicle, scapula, arms, hands, pelvis, legs, and feet).

Muscular System Structure

  • A muscle attaches to bone via a tendon (muscle to bone connection).

  • Ligament connects bone to bone, providing joint stability.

  • Fascia surrounds and separates muscles; often referred to as the "saran wrap" for muscles.

  • Retinaculum holds tendons in place to prevent them from 'popping up.'

  • Bursa is a fluid-filled sac reducing friction in joints (e.g., around the knee).

Conclusion

  • Keep in mind terms for directional terminology and basic joint motions for the exam.

  • Understanding scapula and shoulder joint mechanics is crucial for functional and clinical assessments.