anaphy lesson 6

Skeletal System

Part of connective tissue

Body Support

Function of the skeletal system that provides the framework of the body

Hematopoiesis

Process of blood cell production

Bones (Osteons)

Hard connective tissue consisting of living cells and a mineralized matrix

Spongy Bone

Bone with spaces between trabeculae resembling a sponge

Compact Bone

More solid bone with almost no spaces between lamellae

Long Bones

Bones longer than they are wide and produce movement

Short Bones

Bones as wide as they are long

Flat Bones

Bones with a thin and flattened shape

Irregular Bones

Bones with complex and unique shapes

Diaphysis

Central shaft of a long bone

Epiphysis

End of a long bone

Epiphyseal Plate

Growth plate composed of cartilage between epiphysis and diaphysis

Medullary Cavity

Cavity within bone containing marrow

Yellow Marrow

Bone marrow consisting mostly of adipose tissue

Red Marrow

Bone marrow consisting of blood-forming cells

Periosteum

Dense connective tissue covering bone containing blood vessels and nerves

Endosteum

Thin connective tissue lining the inner bone surface

Osteoclast

Bone cell responsible for bone breakdown

Osteoblast

Bone cell responsible for bone formation and repair

Osteocyte

Mature bone cell

Ossification (Osteogenesis)

Formation of bone by osteoblasts

Intramembranous Ossification

Bone formation within connective tissue membranes

Mesenchyme

Stem cells present in intramembranous ossification

Ossification Centers

Sites where ossification begins

Primary Ossification Center

Site where bone first appears in the diaphysis

Secondary Ossification Center

Site where ossification occurs in the epiphysis

Endochondral Ossification

Process by which most bones develop

Axial Skeleton

Forms the upright axis of the body

Skull

Protects the brain and houses the eyes, ears, nose, and mouth

Braincase

Part of the skull enclosing the cranial cavity

Facial Bones

Bones forming the structure of the face

Paranasal Sinuses

Air-filled spaces opening into the nasal cavity

Hyoid Bone

Floating bone with no direct attachment to the skull

Thoracic Vertebrae

Twelve vertebrae attached to the ribs

Lumbar Vertebrae

Five largest vertebrae carrying body weight

Sacrum

Fused vertebrae forming part of the vertebral column

Coccyx

Tailbone

Atlas

Vertebra responsible for nodding and side-to-side head movement

True Ribs

Ribs 1–7 attached directly to costal cartilage

False Ribs

Ribs 8–12 not attached directly to the sternum

Floating Ribs

Ribs 11–12

Sternum

Breastbone in the center of the rib cage

Appendicular Skeleton

Bones of the upper and lower limbs and girdles

Pectoral Girdle

Shoulder girdle consisting of scapulae and clavicles

Coracoid Process

Process providing attachment for arm and chest muscles

Humerus

Bone of the upper arm

Epicondyles

Distal projections of the humerus for muscle attachment

Pelvic Girdle

Ring of bone where lower limbs attach to the body

Pelvis

Includes the pelvic girdle and coccyx

Tibia

Larger bone of the leg

Fibula

Smaller bone of the leg

Metatarsals

Bones of the foot

Flexion

Movement decreasing the angle of a joint

Extension

Movement increasing the angle of a joint

Hyperextension

Extension beyond 180 degrees

Plantar Flexion

Movement of the foot toward the plantar surface

Dorsiflexion

Movement of the foot toward the shin

Abduction

Movement away from the midline

Adduction

Movement toward the midline

Rotation

Turning of a structure around its long axis

Pronation

Rotation of the forearm so the palm faces posteriorly

Supination

Rotation of the forearm so the palm faces anteriorly

Circumduction

Combination of flexion, extension, abduction, and adduction

Elevation

Movement of a structure superiorly

Depression

Movement of a structure inferiorly

Protraction

Anterior gliding movement

Retraction

Posterior gliding movement

Lateral Excursion

Movement of the mandible right or left of the midline

Medial Excursion

Return of the mandible to the midline

Opposition

Movement of the thumb toward a finger

Reposition

Return of the thumb to anatomical position

Inversion

Movement turning the sole of the foot medially

Eversion

Movement turning the sole of the foot laterally

Joints

Also called articulations

Synovial Joints

Freely movable joints containing a cavity and synovial fluid

Gliding Joints

Synovial joints with flat articulating surfaces

Hinge Joints

Synovial joints allowing flexion and extension

Pivot Joints

Synovial joints allowing rotation

Ellipsoidal Joints

Synovial joints allowing flexion, extension, abduction, adduction, and circumduction

Saddle Joints

Synovial joints found at the thumb

Ball and Socket Joints

Synovial joints allowing the greatest range of movement

Cartilaginous Joints

Joints connected by cartilage allowing little movement

Fibrous Joints

Joints connected by fibrous connective tissue with little or no movement