anat & phy - Module 6: Articulations

Axial Skeleton

Skull, vertebral column, rib cage; supports/protects vital organs.

Appendicular Skeleton

Limbs + girdles (shoulder & pelvic); movement.

Crest

Narrow, prominent ridge.

Line

Narrow ridge, less prominent than a crest.

Process

Any bony prominence.

Spine

Sharp, slender projection.

Trochanter

Large, blunt projection (femur only).

Tubercle

Small, rounded projection.

Tuberosity

Large, rough projection.

Condyle

Rounded articular projection.

Facet

Smooth, flat surface.

Head

Expanded, rounded end of a bone.

Fossa

Shallow basin.

Sulcus / Groove

Furrow-like depression.

Fissure

Narrow slit.

Foramen

Round/oval opening.

Notch

Indentation at bone edge.

Canal

Tunnel-like passage.

Meatus

Canal-like passageway.

Articular capsule

Encloses joint; 2 layers

- Fibrous Layer

- Synovial Membrane

Joint cavity

Space with synovial fluid.

Synovial fluid

Lubricates, nourishes cartilage, shock absorber.

Articular cartilage

Hyaline cartilage at bone ends; reduces friction.

Ligament

Dense CT connecting bone to bone; strengthens joint.

Sprain

Overstretch/tear of ligament.

Bursae

Fluid-filled sacs; reduce friction at joint.

Fat pad

Cushioning at the joint.

Tendon sheath

Elongated bursa around tendon.

Uniaxial

Movement in 1 plane/axis.

Biaxial

Movement in 2 planes/axes.

Multiaxial

Movement in 3 planes/axes.

Transverse axis

Side-to-side (flexion/extension).

Anteroposterior axis

Front-to-back (abduction/adduction).

Vertical axis

Top-to-bottom (rotation).

Plane joint

Gliding movement (carpals).

Hinge joint

Flexion/extension (elbow, knee).

Pivot joint

Rotation (atlas/axis, radioulnar).

Condylar (ellipsoid) joint

Flex/extend, abduct/adduct (wrist).

Saddle joint

Flex/extend, abduct/adduct, circumduction (thumb CMC).

Ball-and-socket joint

Multiaxial; most movement (shoulder, hip).

Gliding

Sliding motion.

Angular motion

Change in angle.

Flexion

Decrease angle.

Abduction

Away from midline.

Adduction

Toward midline.

Circumduction

Circular movement.

Rotation

Bone turns around axis.

Medial rotation

Toward midline.

Lateral rotation

Away from midline.

Depression

Lowering body part.

Elevation

Raising body part.

Protraction

Moving anteriorly.

Retraction

Moving posteriorly.

Supination

Palm upward (radius & ulna parallel).

Pronation

Palm downward (radius over ulna).

Dorsiflexion

Foot upward.

Plantarflexion

Foot downward (tiptoes).

Inversion

Sole inward.

Eversion

Sole outward.

Opposition

Thumb touches fingers.

Epicondyle

Projection above a condyle.

Extension

Increase angle.

Fibrous Layer

Outer dense connective tissue.

Synovial Membrane

Inner lining; secretes synovial fluid.