ANHB1101__Bones__Joint___Movement_

BONES, JOINTS & MOVEMENT

• The skeletal system forms the framework of the body.

• Importance of Knowing Bone Names:

  • Helps locate and name anatomical features.

    • Example: Radial artery near the radius, ulnar nerve near the ulna.

  • Aids in comparative anatomy of primates and human ancestors.

  • Enhances understanding of evolutionary relationships.

Classification of Bones

• Bones classified by shape:

  • Long bones: Greater length than width.

  • Short bones: Nearly equal in length & width; cube-shaped.

  • Flat bones: Thin, protect organs, and provide muscle attachment areas.

  • Irregular bones: Complex shapes.

  • Sesamoid bones: Develop in tendons under friction, tension, and stress.

Divisions of the Skeletal System

• Axial Skeleton:

  • Primary function: Protection of internal organs.

• Appendicular Skeleton:

  • Primary function: Movement.

• Musculoskeletal system consists of bones, muscles, and joints.

Learning Objectives

• Identify various bones of the axial and appendicular skeleton.

• Understand the pectoral and pelvic girdles.

• Describe movements possible at joints.

Vocabulary for the Topic

• appendic: Hang onto

• sesamoid: Like a sesame seed

• mand: To chew

• tempor: Temple

• ab: Away from

• ad: Towards

• duc: To lead; carry

• circum: Around

• flex: To bend

• extens: Draw out

• pro: Forward

• re: Back

• trac: Pull in

• e: Outward

• vert: To turn

• pecto: Chest

• pelvis: Basin

• arthrosis: Articulation of bones, joint

• planto: Sole of the foot

Movements at Joints

• Movements occur in specific planes and often in pairs.

• Correct anatomical language is crucial.

  • Example: "Flexion of the leg at the knee."

Types of Movements

• Flexion:

  • Plane: Sagittal

  • Movement towards ventral surface, decreases joint angle.

• Extension:

  • Plane: Sagittal

  • Movement towards dorsal surface, increases joint angle.

• Hyperextension:

  • Plane: Sagittal

  • Movement past the anatomical position.

• Abduction:

  • Plane: Frontal

  • Movement away from the midsagittal plane.

• Adduction:

  • Plane: Frontal

  • Movement towards the midsagittal plane.

• Rotation:

  • Plane: Transverse

  • Bone spins on its longitudinal axis.

• Circumduction:

  • Multi-plane movement; proximal end stationary, distal end describes a circle.

• Pronation:

  • Plane: Transverse

  • Palm faces posteriorly.

• Supination:

  • Plane: Transverse

  • Palm faces anteriorly.

• Dorsiflexion:

  • Plane: Sagittal

  • Toes lifted off the ground, standing on heels.

• Plantar flexion:

  • Plane: Sagittal

  • Standing on toes.

• Elevation:

  • Plane: Frontal

  • Raises a body part.

• Depression:

  • Plane: Frontal

  • Lowers a body part.

• Eversion:

  • Plane: Frontal

  • Lateral side of foot raised off the ground.

• Inversion:

  • Plane: Frontal

  • Medial side of foot raised off the ground.

• Protraction:

  • Plane: Transverse

  • Moves body part anteriorly/forwards.

• Retraction:

  • Plane: Transverse

  • Moves body part posteriorly/backwards.

Axial Skeleton

• Consists of bones surrounding the body’s longitudinal axis.

• Skull:

  • Superior to vertebral column (2 answers).

  • Components: Cranium, Face.

• Vertebral Column:

  • Inferior to skull (2 answers).

  • Posterior to sternum (2 answers).

  • Heart is deep to ribs.

• Hyoid Bone:

  • Functionally not part of axial or appendicular skeleton, grouped with axial for convenience.

Cranial Bones

• Frontal: Forms forehead & parts of cranial floor.

• Parietal: Sides and roof of the cranium.

• Temporal: Inferior lateral aspect and part of cranial floor.

• Occipital: Forms posterior part of cranium.

• Sphenoid: Butterfly shape, articulates with all other cranial bones.

• Ethmoid: Sponge-like appearance in anterior cranial floor.

Facial Bones

• Maxilla: Forms upper jaw, articulates with every facial bone except mandible.

• Zygomatic: Cheekbones, articulates with several skull bones.

• Mandible: Lower jaw, only movable skull bone (excluding auditory ossicles).

Vertebral Column

• Composed of spinal bones (vertebrae).

• Regional Identification:

  • Cervical (7): Neck region; smaller than other vertebrae, has transverse foramen.

  • Thoracic (12): Chest region; larger; articulates with ribs.

  • Lumbar (5): Lower back; largest of unfused vertebrae.

  • Sacrum (5): Triangular bone formed by sacral vertebrae fusion.

  • Coccyx (4): Triangular, formed by coccygeal vertebrae fusion.

Functions of the Vertebral Column

1. Support of head and trunk (weight-bearing).

2. Protection of the spinal cord.

3. Attachment site for muscles (movement).

4. Attachment site for ribs and pelvis.

Appendicular Skeleton

• Composed of bones of the upper/lower limbs and girdles connecting them to the axial skeleton.

• Pectoral Girdles:

  • Attach upper limb bones to the axial skeleton.

  • Held in place by muscles, do not articulate with the vertebral column.

• Pelvic Girdle (Coxal Bones):

  • Connects lower limb bones to axial skeleton.

  • Formed from fusion of ilium, ischium, and pubis.

Pectoral Girdle Structures

• Clavicle: Articulates with scapula and sternum.

• Scapula: Articulates with humerus and clavicle.

Upper Limb Structures

• Proximal bones:

  • Humerus (arm).

  • Scapula (forearm).

  • Ulna and Radius (forearm).

Pelvic Girdle Structures

• Coxal Bones: Articulate with femurs and sacrum.

Lower Limb Structures

• Proximal bones:

  • Femur (thigh).

  • Tibia and Fibula (leg).

  • Tarsals, Metatarsals, and Phalanges (foot).

Exam Practice

• Identify and label joint movements shown in diagrams: abduction, flexion, inversion, etc.

• Name movements that produce circumduction: Flexion, Abduction, Extension, Adduction, Rotation (or reverse).

Future Study Suggestions

• Consider enrolling in level 2 units like ANHB2212, ANHB2214, or others related to Human Biology.

Career Pathways

• Roles in various fields such as:

  • Anatomist, Forensic Anatomist, Physiotherapist, Physician, Nurse, Paramedic, Occupational Therapist.