Unit 2- Anatomy Lecture Terms

Joint (Articulation)

any point where two bones meet - may be movable or non-moveable

Fibrous Joint (Synarthrosis)

a point at which adjacent bones are bound by collagen fibers (forms a non-moveable joint)

Cartilaginous Joint

two bones are linked by cartilage, have limited movement

Synovial Joint (diarthrosis)

joint in which two bones are separated by a joint cavity

Articular Cartilage

layer of hyaline cartilage that covers the facing surfaces of two bones

Joint Capsule

connective tissue that encloses the cavity and retains the fluid

Synovial Fluid

slippery lubricant in joint cavity

Tendon

a strip or sheet of tough collagenous connective tissue that attaches muscle to bone

Ligament

similar tissue that attaches one bone to another

Bursa

a fibrous sac filled with synovial fluid, located between adjacent muscles, where tendon passes over bone, or between bone and skin

Lever

any elongated, rigid object that rotates around a fulcrum

Fulcrum

Fixed point

Effort

applied force

Resistance

force opposing movement (load)

Ball and Socket Joint

smooth, hemispherical head fits within a cupcake socket (shoulder joint and hip joint) (multiaxial)

Hinge Joint

One bone with convex surface that fits into a concave depression on other bone (humero-ulnar, knee, finger, and toe joints) (monoaxial)

Pivot Joint

One bone has a projection that is held in place by a ring-like ligament (atlantoaxial and radioulnar joint) (monoaxial)

Plane Joint

Flat, articular surfaces in which bones slide over each other with relatively limited movement (usually biaxial joint) (carpal bones of wrist, tarsal bones of ankle, and articular processes of vertebrae)

Flexion

movement that decreases a joint angle

Extension

movement that straightens a joint

Abduction

movement of a body part in the frontal plane away from the midline of the body

Adduction

movement in the frontal plane back toward the midline

Range of Motion

the degrees through which a joint can move

Rotation

Twisting or pivoting movement where something is turning on its axis

Diploe

spongy layer in the cranium

Bone marrow

soft tissue that occupies the marrow cavity of a long bone and small spaces between the trabeculae of spongy bone

Yellow marrow

in adults replaces much red marrow

Rickets

soft bones due to deficiency of calcium salts

Osteogenesis imperfecta

“brittle bone disease” – excessively brittle bones due to lack of protein, collagen

Bone

connective tissue that consists of cells, fibers and ground substance

osteogenic (osteoprogenator) cells

stem cells found in endosteum, periosteum, and in central canals

Osteoblasts

Bone building cells - take calcium from blood into bone

Osteocytes

former osteoblasts trapped in the matrix they deposited

Osteoclasts

bone-dissolving cells found on the bone surface

ossification or osteogenesis

the formation of bone

Two methods bone forms by

Intramembranous ossification and endochondral ossification

Endochondral ossification

process in which bone develops from pre-existing cartilage model

Interstitial growth

Bones increase in length

appositional growth

osteoblasts on deep side of periosteum deposit calcium salts & collagen

Mineral deposition

the process in which calcium phosphate, and other ions are taken from the blood and deposited in bone tissue

Mineral resorption

the process of dissolving bone and releasing minerals into the blood

Normal calcium concentration

9.2 - 10.4 mg/dL

Hypocalcemia

Blood calcium deficiency that causes excessive excitability of muscles

Hypercalcemia

Blood calcium excess - causes sluggish reflexes and depression

Calcium Homeostasis

balance between dietary intake, urinary and fecal loses, and exchanges between osseous tissue

Three hormones that regulate calcium homeostasis

Calcitriol, calcitonin, and parathyroid hormone

Calcitonin

secreted by thyroid gland to lower blood calcium concentration

parathyroid hormone (PTH)

secreted by the parathyroid glands to raise calcium blood level

stress fracture

break caused by abnormal trauma to a bone

pathological fracture

break in a bone weakened by some other disease

Nondisplaced fracture

crack goes all the way across the bone, but the pieces remain aligned

Displaced fracture

at least one bone fragment is out of alignment

comminuted fracture

bone is broken into three or more pieces

greenstick fracture

crack is on one side of the bone and bend is on the opposite side

suture

immovable joint

Age that skull reaches adult size

8 or 9 years of age

pairs of ribs (costae)

12

True ribs

1-7

False ribs

8, 9, 10

Floating ribs

11, 12

Brachium

humerus

Antebrachium

radius and ulna

carpus

wrist

manus

hand

Femoral region

femur and patella (thigh)

crural region

tibia and fibula (leg proper)

tarsal region

ankle

pedal region

foot