HAP Unit 3: Skeletal system

5 Bone Shapes and examples

Long (Humerus)

short (Carpels)

flat (Sternum)

Sutural ( interparietal)

Sesamoid bones. (Patella)

Irregular (vertebre)

Osteon

the basic unit of compact bone

Haversian Canal

Tunnels that contain blood vessels and nerves

Osteocytes

Mature bone cells located in lacunae that maintain bone tissue. star shaped.

Osteoblasts

Cells that build and pile up bones

Osteoclasts

Cells that break down and resorb bone tissue.

Hematopoiesis

Process of making new blood cells

Yellow Bone Marrow

Fat storage tissue located primarily in the medullary cavities of long bones.

Red Bone Marrow

Tissue responsible for producing red blood cells, white blood cells, and platelets.

Transverse Fracture

A straight fracture line that runs roughly perpendicular to the bone's axis; often caused by a force that bend or direct blow

Oblique fracture

A fracture line that runs diagonally across the bone; caused when one end of the bone is stationary and the other is twisted.

Spiral fracture

A fracture line that twits around the shaft of bone; caused by twisting force in which both ends of the bone are twisted.

Comminuted fracture

When the bone breaks into 3 or more major fragments; caused by a high energy impact

Greenstick Fracture

An incomplete fracture where one side of the bone breaks and the other bends.

Avulsion fracture

A piece of bone that is pulled away by a ligament or tendon; caused by a strong muscle contraction.

Stress fracture

A small crack caused by repetitive force; caused when a bone does not have enough time to remodel or recover

What type of bone develops via endochondral ossification?

Process where bone develops by replacing hyaline cartilage; usally in long bones

Intramembranous Ossification

Process where bone develops directly from sheet-like layers of connective tissue; usually in flat bones

Osteoid

The new soft unmineralized matrix of a bone.

Mineraization

When mineral (mainly calcium + phosphate) are deposited into osteoid to harden an strengthen the bone

Trabeculae

supporting bundles of bony fibers in cancellous (spongy) bone; the small beams of bone that create structure

Spicules

Tiny needle like spikes of new bone tissue that from during the early stages of bone development, made from osteoblasts secreting osteoids

Hypertrophy

The enlargement and swelling of chondrocytes

Perichondrium

The outside layer of bone made of cartilage

Periosteum

The outside layer of bone made of bone

Lacuna

The pocket of bone matrix where bone or cartilage cells (osteocytes + chondrocytes) are trapped in during the quiescence phase to maintain bone.

Epiphysis

End of a long bone; location of the secondary ossification center

Diaphysis

shaft of a long bone; Where the primary ossification center is

Activation phase (written)

pre-osteoclasts become fused + form multi nucleated osteoclasts

Resorption Phase (written)

Osteoclasts dig a resorption pit. As pit is dug, calcium id being absorbed into blood for use by body. Osteoclasts disappear when it is complete.

Reversal phase (written)

Osteogenic cells appear in the resorption pit. They multiply and differentiate into osteoblasts

Formation phase (written)

Osteoblasts are attached to the surface of resorption pit. They replace removed tissue with osteoid

Quiescence phase (written)

Osteoblasts fill pit with osteoids. Mineraization occurs. Trapped osteoblasts mature into osteocytes which maintain tissue.

Pivot joint (written)

A cylinder-shaped bone is able to rotate inside a ring-shaped bone on the axis

E.g, Cervical vertebre fit together in this manner to rotate neck + head on an axis

*know types of bones involved + types of movement (Flexion, extension, rotation)

Ball and Socket Joint (written)

Joint allowing a wide range of motion in multiple axes; spherical end f bone fits into a socket

E.g., Shoulder and hip

*know types of bones involved + types of movement (Flexion, extension, abduction, adduction, rotation)

Condyloid/sliding joint (written)

only allows for forward and back moment

E.g., wrist

*know types of bones involved + types of movement (Flexion, extension, abduction, adduction)

Hinge Joint (written)

Joint allowing movement in one plane (back and forth), similar to a door hinge

E.g., elbow and knee

*know types of bones involved + types of movement (Flexion + extension)

Abduction (written)

Movement away from the midline of the body

*know types of bones involved

Adduction (written)

Movement toward the midline of the body

*know types of bones involved

Flexion (written)

Moving to decrease angle of 2 body parts

*know types of bones involved

Extension (written)

increases the angle of a joint

*know types of bones involved

Rotation (movement)

Occurs at a pivot joint; a twisting movement where a bone turns around its own long axis

*know types of bones involved

Osteoporosis

Condition characterized by weak, porous bones due to bone resorption outpacing bone despostion/formation. Affects the inside of the bone, specifically the spongy part (causes the holes to be bigger and weaker)

Causes of osteoprosis

Vitamin D deficiency, inactive life style, age, low calcium

Steps of fracture healing (written)

1. hematoma forms

2. soft callus forms

3. bony callus forms

4. bone remodeling occurs

Stage 1 of fracture healing (written)

hematoma formation

bone breaks - blood clot forms in 6 to 8 hours - bone cells die due w/o nutrition

Stage 2 of fracture healing (written)

Soft callus formation

after a few days - new blood vessels grow - chodroblasts produce bulging cartilage matrix that connect ends - repair tissue called soft callus forms temporary splint

Stage 3 of fracture healing (written)

Bony callus formation

Within week osteoblasts begin producing osteoid - osteoid replaces soft callus w/ hard callus - after 2 months broken ends firmly connected

Stage 4 of fracture healing (written)

Bone remodeling

Must occur to clean away excess bone callus + hallow cavities - osetioclasts absorb injured and dead tissue - osteoblasts lay down new bone