Structure of Long Bones
A strong, flexible connective tissue that protects your joints and bones. On the epiphyses of long bones.
articular cartilage
Compact bone is made of what concentric structures?
osteons
How are long bones classified by structure? Give 2 examples of each in the body.
Long bones are longer than they are wide. two epiphyses, one diaphysis and spongy bone on both ends. Humerus, femur, fibula, tibia, radius, ulna, phalanges, metacarpals, metatarsals...
Open vs closed fracture?
Open means the fracture breaks through the skin. Closed means it does not break through the skin.
After a bone is fractured, what is the first step in the healing process?
The first step is when the hematoma is formed to be the temporary frame for healing. The hematoma is formed by the burst blood vessels in the bone (bc of the fracture) clotting.
What is different about the structure of cortical vs cancellous bone? Where are they found in the long bone?
Cortical or compact bone is dense and made up of osteons. It is found in the diaphysis of long bones. Cancellous or spongy bone is less dense and soft, and is made up of a webbed structure with specialized canals within it. Spongy bone is found in the epiphyses of long bones.
Osteons are made up of __________.
osteoclasts
How are short bones classified by structure? Give 2 examples of a short bone in the human body?
Short bones are cube-shaped, spongy bone covered by thin layer of compact bone. Examples include carpals and tarsals.
Displaced vs non-displaced fracture?
displaced fracture is when the fracture isn't straight. Nondisplaced is when the fracture is still straight.
What is the second step in bone healing?
A fibrocartilage callus forms.
Where is red bone marrow found in long bones? What important things are found in red marrow, and what important function does it have?
Red marrow is found in the spongy bone of long bones. It contains the stem cells that differentiate into all blood cells- RBCs, WBCs or platelets. It is responsible for creating new blood cells.
What is the difference between osteoblasts and osteoclasts. What are their roles in the formation/healing of bone tissue?
Osteoblasts are specialized cells that build up new bone tissue for bone growth or remodelling after a fracture. Osteoclasts are specialized cells that break down bone to initiate normal remodelling or to dissolve calcium when the body needs it.
How are flat bones classified by structure? Give 2 examples.
Flat bones are thin; flat or curved bones; two layers of compact bone with middle layer of spongy bone. Scapula, cranial bones, ribs.
Transverse vs linear
Transverse is a fracture that is horizontally across this bone. Linear is a fracture that is vertical on the bone.
The third step is the progression of the fibrocartilage callus into a bony callus, made up of dense connective tissue. What happens over the next few weeks in the healing process?
bone remodelling. osteoblasts begin forming new bone around the fibrous tissue, calcifying it into new dense bone tissue.
Long bones have a hollow cavity that runs down the diaphysis. It contains yellow bone marrow? What is this structure called and what is important about yellow marrow?
This is called the medullary cavity. Yellow marrow contains the body's stem cells; cells that can differentiate their structure to become specialized cells like erythrocytes, lymphocytes, etc.
The microscopic structure of spongy bones has a webbed structure that are connected by a series of canals. What important structures run through these cells that help aid in the nutrition and communication of bone cells?
Blood vessels (arteries, veins) and nerves
How are irregular bones classified by structure? Give 2 examples.
Irregular bones don’t fit into any of other classifications; mostly spongy bone and layers of compact bone. Vertebrae, axis, atlas.
oblique nondisplaced vs oblique displaced
oblique means a diagonal fracture. nondisplaced means the diagonal fracture is still straight. displaced means that the diagonal fracture is not straight and the bone is not in contact where the fracture is.
An athlete suffers from a mild greenstick fracture on their ulna after outstretching their arm to break a fall at a game. After casting the fracture, what other things should the physician recommend the athlete do? Select all that apply.
A: after a few days begin light exercise
B: take calcium and vitamin supplements
C: lie in the sun for extra vitamin D
D: schedule a physical therapy appt.
E: give a prescription for medicinal marijuana
B and D
To determine the age of an unknown skeleton, what specific structures might a forensic anthropologist look at in a long bone?
growth plate/epiphyseal lines. Looking at the stage of growth that these are in will help create a better approximation of the age. the amount of spongy bone vs compact bone can also indicate the age of a skeleton. Younger bones will still have more spongy bone as the bones have not fully calcified yet. An older skeleton would have more compact bone since it is more developed. This could also show age-related bone breakdown.
Based on the osteoclasts' function, and ability to break down bone tissue, how do you think these cells are able to do this. What do they use to break down the bone tissue?
osteoclasts secrete acidic compounds and enzymes that break down the organic matrix of bone tissue
How are sesamoid bones classified by structure? Give 2 examples of each. (there literally are only 2)
Sesamoid bones are a small bone found within muscle or tendon that forms because of ossification. Patella + the sesamoids (the one in ur feet)
Define the following fractures:
. greenstick
. spiral
. comminuted
. greenstick: when a fracture is caused by the bone bending
. spiral: a twisted fracture that typically runs up/down the bone
. comminuted: a fracture where the bone breaks into multiple pieces
Identify the types of fractures on the xrays.
1: nondisplaced oblique
2: displaced oblique
3: comminuted
4: linear skull fracture
5: greenstick ulnar fracture