Chapter 2 Flashcards
How many bones is the skeletal system composed of ?
206
what is the skeletal system responsible for?
-body support
protection
-movement
-blood cell protection
how much percentage does the skeletal system contain of the bodies total phosphorous
75 percent
how much percentage does the skeletal system contain of the bodys total calcium
98 percent
how many bones does the axial skeleton contain
80 bones
how many bones does the appendicular skeleton contain
126 bones
what is the axial skeleton contain of
head, neck, back, and chest
what does the appendicular skeleton consist of
bones in the shoulders, pelvis, and limbs
what bone marros is responsible for production of erythrocytes and leukocytes
red bone marrow
where is red bone marrow typically found
found primarily in the bones of the trunk
by what age is the red bone marrow replaced by the yellow bone marrow composed mainly of fat
20
is specific to the cancellous bone with in the skull (spongy layer between the inner and outer compact layers of the flat bones of the skull
Diploe
the spongy substance found within a bone, it gives a characteristic appearance to bony detail, it is the web-like bony structure visible on a x-ray
Trabeculae
where is bone marrow located
is located within the medullary canal
what type of tissue is bone
connective tissue
what is bone classified as
compact (dense)
what does cancellous mean
spongy
what kind of bone is the outer portion
outer portion is composed of compact bone
what kind of bone is in the inner portion,
The inner portion, the medullary canal is made of cancellous bone
what type of cells form new bones
Osteoblast
what cells dissolve old bones
osteoclasts
Are bone forming cells that line the medullary canal and interspersed throughout the periosteum
osteoblast
Cells which are associated with absorption and removal of bone
osteoclasts
name some long bones
- humerus
-clavicle
-phalanges
-femur
the presence of extra digits
polydactyly
gives the appearance of web tows or fingers
syndactyly
*Occurs during fetal development
*Failure of toes/finger to separate
*Usually repaired surgically
Syndactyly
Hereditary disease with abnormal dense bone with common occurrence of fractures
OSTEOPETROSIS
*Abnormally heavy compact but brittle
*All bones are affected especially, long bones of extremities, vertebrae, pelvis, and base of skull
*Increase bone density with reduction of marrow space
OSTEOPETROSIS
Most common inherited disorder involving cartilage formation in the fetu
Achondroplasia
*Results in bone deformity and dwarfism
*There is an impairment to the longitudinal growth of the bone
*Affects cartilage in the epiphytes
*Adults usually are not more than 4 ft with lower extremities usually half the normal length
*Other manifestation – lumbar lordosis, bow legs, bulk forehead
Achondroplasia
*Starts years after birth
*Usually stops in adulthood
*Radiological evaluation will show multiple fractures in various stage of healing
*Bone cortex is thin and porous *Trabecula are thin, delicate, widely spread
Osteogenesis imperfecta tarda
*Present at birth
*Usually have multiple fractures at birth
*Results in limb deformities, dwarfism
*May lead to death
Osteogenesis imperfecta congenita
“Brittle Bone Disease”
Osteogenesis Imperfecta
*Bone mineral densitometry for the evaluation of osteoporosis
DEXA (double energy xray absorbtiometry)
It readily evaluates the bone mass of the distal radius, femoral neck, and lumbar spine
dexa
Then with the use of a combination lab test of blood and urine a determination of bone loss can be evaluated
dexa
*Advantage over CT and MRI in that you look at the entire body at one time in a conventional fashion
*It gives the ability to tell if it is a new or old problem by the activity uptake.
*It is the standard of care for examination of metastatic process, demonstrates metabolic reaction of bone to the disease process.
Nuclear Medicine
*It is quicker, noninvasive
*It has the ability to define the presence and extent of the fracture or dislocation, joint abnormalities and spinal disorders
*MRI-has no signal for cortical bone, but CT can visualize bony detail
*Display bony margins and trabecula patterns, so you can assess both bony and soft tissue involvement of tumors
CT
*Useful in imaging of skeletal pathology particularly in soft tissue detail.
*There is superior contrast resolution
*Modality of choice for detection and staging of soft tissue tumors of the extremities.
*Useful in evaluation of the joints (knee, shoulder)
*Bone marrow imaging done with MRI is superior to older bone scan (especially for subtle abnormalities like edema
MRI
Image Considerations
-proper labeling
-film/screen technique
-motion
-Soft tissue is important in diagnosing –could demonstrate muscle wasting, soft tissue swelling, calcification, foreign bodies, air.
Congenital malformation of the foot
Club foot
another name for club foot
Talipes
*Prevents normal weight bearing
*Most commonly the foot is turned inward to the ankle
*Seen in males more often
*Casting. Splinting the foot in correct anatomic position
Club foot
*The acetabulum does not completely form
*The head of the femur displays superiorly and posteriorly
Congenital Dislocation of the hip
*Often the ligaments and tendons are affected for placement of the femoral head
*Most often treated with casting or splinting the affected hip
*Use of the Pavlic harness-it tightens ligaments and stimulates normal hip growth
Congenital dislocation of the hip