Axial Skeleton and More
The two broad divisions of the skeletal system
axial skeleton
appendicular skeleton
The long bone of the upper arm
humerus
Lightweight, porous bone that consists of an intricate network of tiny struts and girders
spongy bone
The most freely movable joints in the body
ball-and-socket joints
The largest and strongest muscle in the body
gluteus maximus
Strong bands of fibrous connective tissue that connects bones to other bones
ligaments
The body's longest bone
femur
A group of muscle cells connected to a single motor neuron
motor unit
The most common cause of muscle atrophy
lack of exercise
The shoulder muscles that allow you to pull your shoulders back and help pull your head up
trapezius muscles
The U-shaped bone found in the neck
hyoid bone
The most prominent bones of the thoracic cage
ribs
The tough, translucent sheath that surrounds a skeletal muscle and binds it together
fascia
These joints only allow back-and-forth movement in a single plane
hinge joint
The type of involuntary muscle that is not striated
smooth muscle
The contraction machinery of muscle cells that is found inside long cylinders
myofibrils
The bones of the pectoral girdle
scapulae
clavicles
The long, straight shaft of a long bone
diaphysis
When the rounded head of one bone fits into an indentation on another bone, they form this joint
ball-and-socket joint
The groups of muscles in the front of the thigh that straighten the leg
quadriceps femoris
These are soft and provide less protection than bone (explains why a newborn can receive brain damage from a head injury more easily than an adult)
fontanels
Explain how you know which bone is the radius and which is the ulna
ulna is on the side with the pinkie
radius is on the side with the thumb
The bulged end of a long bone
epiphysis
The largest muscle of the calf
gastrocnemius
The individual contracting units of a skeletal muscle cell
sarcomeres