Skeletal System Flashcards
Axial Skeleton
skull, vertebral column, ribs, and sternum
Appendicular Skeleton
bones of limbs
Cartilage
avascular, connective tissue nourished by diffusion; a varying networks of extracellular fibers and cells located in small cavities
Functions of Cartilage (3)
1) support soft tissues
2) provide smooth gliding surface for bone articulation at joints
3) enable growth and development of long bones
What are the three types of cartilage?
Hyaline, Elastic, Fibrocartilage
Hyaline
most common, moderate collagen, found on the articulating surfaces of bones
Elastic
contains collagen and high number of elastic fibers, found in external ear
Fibrocartilage
low number of cells, really high levels of collagen, inextensible, found in vertebral discs
Bone
calcified, innervated, vascular (nutrient artery directly enters bone, usually 1/bone) connective tissue; contain collage and many types of cells
From what do bones arise?
Mesenchyme (via intramembranous ossification or endochondral ossification - starts with collagen, then mesenchyme then, finally, bone)
Function of bones (5)
1) support the body
2) act as levers for muscles to use to produce movement
3) reservoirs of calcium and phosphate
4) production of blood cells (bone marrow)
5) protect vital organs
Two types of bone
compact and spongy
Compact Bone
dense outer shell of all bones (surrounding spongy bone)
Spongy Bone
or cancellous bone; located deep to the compact bone, contains spicules of bone enclosed small cavities of blood producing cells (marrow)
What are the shapes of bones (5)?
flat, long, short, irregular, and sesmoid
Flat bones
two compact bone plates separated by spongy bone (skull)
Long bones
tubular in shape (limbs)
Short bones
cuboidal in shape (hand and ankle)
Irregular bones
no particular shape (facial bones)
Sesamoid bones
round or oval (found in tendons)
Periosteum
membrane covering all bones except where cartilage is present; highly innervated with vasomotor and sensory nerves; nourishes outer layer of bone via blood vessels and can form new bone if necessary
Fracture (ITC)
occurs when abnormal load/stress is applied and the bone gives way (OR when a normal load/stress is applied and the bone is of insufficient quality and gives way)
Greenstick Fracture (ITC)
partial disruption of cortical shaft (looks like tree branch)
Epiphyseal Fracture (ITC)
fracture that occurs along epiphyseal line (growth plate); common when there is a lot of growth (7-10+ years old) and is thus vulnerable to injury
What can compression at the epiphyseal line result in?
asymmetrical growth across joint region
Bone Marrow Transplants
radiation is used to kill patient’s blood producing cells, and a donors cells are implanted into the bones of the recipient
Red Marrow
myeloid tissue; most marrow is red, gives rise to RBCs, WBCs, and platelets (hemapoietic stem cells)
Yellow Marrow
contains fat globules, responsible for making a few WBCs
As we age, ____ marrow converts to ____ marrow.
red to yellow
Avascular Necrosis
lack of blood flow results in bone death and collapse
In what type of patient (and where in the patient) is avascular necrosis common?
elderly; femoral neck, loss of continuity of cortical medullary blood flow - we see juxta-articular bony sclerosis, subchondral cyst formation, and gluteal muscle wasting
Osteoporosis
decline in bone mineral density and leaves patients with increased risk for fracture
Who does osteoporosis commonly affect? Where in patients?
elderly (mainly post-menopausal women); femoral necks, wrists, and vertebrae
What hand is imaged to determine skeletal age?
most often the non-dominant (left) hand is imaged and compared to standards
When is skeletal maturity reached?
Around 20-25 years
What impacts skeletal maturity?
geography, socioeconomic factors, genetics, disease (malnutrition or hypothyroidism)
T or F : In healthy patients, bone age reflects actual age of patient.
TRUE
