Bones (7) Flashcards
The skeletal system consists of the
bones and cartilages
About ?% of the body weight is contributed by the bones.
18
The adult skeleton consists of ? bones.
206
the fetal skeleton has more than ? bones
270
hematopoiesis
Formation of blood cells
Cartilage water content
80%
Cartilage is
flexible connective tissue that protects your joints and bones
No nerve supply and blood supply
Types of cartilage
Hyaline elastic and fibro cartilage
Hyaline cartilage
Most abundant
Slightly flexible
extracellular material composed of chondroitin sulfate and protein fibers.
Mature cartilage cells in lacunae
Chondrocytes
Elastic cartilage
Around ear,
Fibrocartilage
Slightly movable joints
Lots of collagen fibers
Appositional growth
the chondroblasts located deep to the perichondrium secrete new ECM on the superficial surface of the cartilage, therefore, the new cartilage forms from outside in.
Interstitial Growth
Inside out
Compact/ivory
Strong, 80% in body
Spongy/cancellate /trabecular
Skull,vertebrae
Small bones
pisiform in the wrist, stapes in the ear.
Long bones
Femur tibia fibula foot finger toes
Large bones
Coxal(pelvis) most common
Flat bones
Sternum ribs
Short bones
Carpals tarsals
Irregular bone s
Vertebrae
Wormian/sutural
Back of skull, ossification centers
Sesamoid bone
Kneecap
Diaphysis
Middle part of long bone, made up of compact bone
Medullary cavity
Yellow bone marrow, where heemopoises takes place
Epiphysis
End of each long bone, compact bone (outside) spongy bone (inside)
Periosteum
Diaphysis of bones covering
insertion points of tendons and ligaments
Osteoblasts (bone forming)
and osteoclasts (dissolve old bone)
Endosteum
Inner surface
Bone cells
Osteoblasts,osteocytes,osteoclasts
Osteoblasts
Deposit new bone
Originate from osteoprogenitors
Secrete bone matrix-osteoid
Deposition of calcium
Calcification
Formation of bone
Ossification
Osteocytes
Originally the osteoblasts but trapped in bone matrix
Osteoclasts
Large and have a ruffled border secret axis dissolve the bone matrix during bone resorption
Old bone to new bone
compact bone
found in the walls of the diaphyses of long bones and forms the outer layer of all the bones.
dense and strong
composed of osteons
osteons
made of osteocytes, form the haversian system
spongy bone/ cancellated bone
no osteons/haversian system
made up of trabeculae
fetal development
the skeleton is made up of only hyaline cartilage, and formation of bone begins at about 6 weeks of pregnancy.
bone formation/ossification/osteogenesis types
intramembranous and endochondral
intramembranous ossification
formation of skull bones
Endochondral ossification
every bone except skull bones formation
long bones grow longer at
epiphyseal plates
Bone Growth in Width
The bones grow in width or diameter during the adult life.
bone remodeling
osteoclasts remodel old bone into new bone,
bone resorption
osteoclasts secrete acid, which dissolves the bone matrix during bone resorption, known as clastogenesis or osteoclastic activity
Parathyroid Hormone (PTH)
maintains the blood calcium
removes the calcium from the bone leading to an increase in blood calcium levels, hypercalcemia.
Calcitonin
maintains the blood calcium
secreted by the thyroid, and it lowers the blood calcium levels, hypocalcemia, by promoting incorporation of calcium into bone
Growth Hormone/somatotropin
-secreted by pituitary gland
-causes bones to brow
Thyroid Hormones
-bone development
-low of thyroid may cause dwarfism
estrogen
maintains bone density
lack causes bone to become porous
vitamin d3
absorption of calcium in the intestine
lack causes long bone curved
osteoporosis
bones are porous/weak
osteomalacia
bones are soft
osteopenia
decrease in bone density
Colle’s fracture
distal forearm
Pott’s fracture
ankle
Greenstick fracture
bone does not break into pieces
Comminuted fracture
bone breaks into more than 2 pieces
compression fracture
severe pain/loss of function
