Anatomy Lab 2

1st Class Lever

the fulcrum is in the middle, like play-ground see-saw

2nd Class Lever

the load in the middle, like a wheelbarrow

3rd Class Lever

the force is in the middle, like a shovel

Diaphysis

long central shaft of the bone

Epiphysis

enlarged end of bone

Articular Cartilage

smooth cartilage covering joint surface

Epiphyseal Plate/line

site of longitudinal bone growth

Medullary Cavity

hollow space containing bone marrow

Compact Bone

dense, strong, outer bone tissue

Spongy (cancellous) bone

porous bone containing open spaces

Trabeculae

thin body struts forming spongy bone

Osteon

structural unit of compact bone

Osteocyte

mature bone cell that maintains the bone

Central (Haversian) Canal

contains blood vessels and nerves

Perforating Canals

connects central canals with bone surface

Concentric Lamellae

rings of bone surrounding central canal

Circumferential Lamellae

bone layers surrounding the entire bone

Interstitial Lamellae

remnants of old osteons between osteons

Lacuna

small spaces housing osteocytes

Canaliculi

tiny, channels connecting osteocytes and blood supply

Endosteum

membrane lining internal bone surface

Periosteum

membrane lining outer bone surface

Perforating fibers

hold periosteum to bone

Muscle fiber

single elongated skeletal muscle

Endomysium

connective tissue surrounding muscle fibers

Epimysium

connective tissue surrounding entire muscle

Muscle Fascicle

bundle of muscle fibers

Perimysium

connective tissue surrounding each muscle fascicle

Tendon

cord connecting muscle to bone

Aponeurosis

broad, flat sheet connecting muscle to structure

Neuromuscular Junction

site where motor neuron activates muscle fiber

Different Types of Articulations

fibrous, cartilaginous, & synovial

Fiber

bones connected by dense connective tissue: little to no movement

Cartaliginous

bones connected by cartilage: limited movement

Synovial

bones seperated by fluid-filled joint cavity: freely moveable

Articular Capsule

connective tissue enclosing entire joint

Synovial Membrane

inner membrane producing synovial fluid

Joint Cavity

space containing lubricating synovial fluid

Bursae

fluid-filled sacs reducing friction

Ligaments

connective bone-bone: stabilizing joints

Gliding (plane)

bones slide past each other: non-axial

Ex: wrist or ankle bones

Hinge

open and close like door hinges: uniaxial

ex: elbow or knee bones

Pivot

allows your head to rotate: uniaxial

ex: neck

Condyloid

Moves side-side and back-fourth, but not full rotation: biaxial

ex: wrist bones

Saddle

move back-fourth and side-side: biaxial

ex: thumbs

Ball-and-Socket

moves in almost every direction: multiaxial

ex: shoulder and hip bones

Synarthrosis

immovable joints

Amphiarthrosis

slightly movable joints

Diarthrosis

freely moving joints

Flexion

bend a joint → decreases angle

ex: bending your elbow

Extension

Straighten a joint → increases angle

ex: straightening your elbow

Abduction

move away from the body’s midline

ex: raising your arm out to the side

Adduction

move toward the midline

ex: bringing your arm back to your side

Rotation

bone turns around its axis

ex: turining your head left/right

Circumduction

limb moves in a circle/cone

ex: making big circles with your arm

Pronation

palm turns down

ex: palm facing the floor

Supination

palm turns up

ex: palm facing the ceiling

Inversion

bottom of foot turns inward

ex: turning sole toward the other foot

Eversion

bottom of the foot turns outward

ex: turning sole away from the other foot

Dorsiflexion

toes move up toward shin

ex: pulling up toes

Plantarflexion

toes point down

ex: standing on tiptoes

Opposition

thumb moves across palm to touch fingers

ex: touching tumb to pinky

Reposition

thumb moves back to normal position

ex: moving thumb away from fingers

Elevation

move something up

ex: shrugging shoulders

Depression

move something down

ex: lowering shoulders