The Skeletal System Flashcards
what does the skeletal system include?
bone and cartilage
what’s the difference between bone and cartilage?
bone is a hard, dense connective tissue that forms the adult skeleton. whereas, cartilage is a semi-rigid connective tissue that provides flexibility and smooth surfaces for movement
what is the function of the skeletal system?
- support the body
- support movement
- protect internal organs
- store and produce minerals
how do bones facilitate movement?
they serve as points of attachment for muscles
how do bones protect organs?
they cover or surround them just like in the skull or the rib cage and vertebral column
how are bones a storage for minerals?
the bone matrix is a reservoir for calcium and phosphate, which are stored for when needed in physiological processes
why is calcium significant to the skeletal system?
because it is important for muscle contraction and the control of ion flow in nervous signal transport
what does the bone marrow constitute?
the bone marrow is divided into:
Yellow marrow: has adipocytes which store triglycerides as energy
Red marrow: responsible for the production of blood cells (haematopoiesis)
how many bones are there in an adult vs in a newborn?
adult = 206
newborn = 300
list all bone classifications
long bone: humerus, ulna, femur, tibia, fibula
short bone: carpals, tarsals
Flat bones: skull, scapulae, sternum
irregular bone: vertebrae, sinus bones
sesamoid: tendons, patella
compare the diaphysis with the epiphysis
Diaphysis: tubular shaft between proximal & distal ends of the bone
composed of compact bone
has medullary cavity, which houses the yellow marrow
–
Epiphysis: wider section at each end of the bone
composed of spongey bone
has red marrow which fills the spaces of spongey bone
define endosteum
A membrane lining the inner surface of the bony wall
what is the endosteum important for?
- bone growth
- bone repair
- bone remodeling
what is metaphysis?
region whereby epiphysis meets diaphysis. and contains, the epiphyseal plate, hyaline, and cartilage in growing bone
what happens to cartilage at age 18-20?
cartilage is replaced by osseus tissue, and the epiphyseal tissue becomes and epiphyseal line
what is outer surface of bone covered with?
periosteum, contains blood vessels, nerves, lymph vessels
what is the function of periosteum?
connects tendons and ligaments
what is an articular cartilage?
thin layer of cartilage that reduces friction and absorbs shocks
how do flat bones protect the brain?
flat cranial bones contain spongey tissue on both sides of the compact bone, these two layers protect the brain, in case of fracture the brain would still be protected
what are the 3 different bone markings?
- articulation (bone-bone connection)
- holes (entry of nerves and vessels to bone)
- projections (attachment points for tendons/ligaments)
what gives bones their hardness?
hydroxyapatite, it incorporates salts such as magnesium, fluoride, and sulfate as it crystallizes/calcifies on collagen fibers
what are the types of bone cells?
- osteoblasts
- osteocytes
- osteogenic cells
- osteoclasts
what is the function of each bone cell?
osteoblast: new bone formation & growth portions and maintain concentration of matrix
osteocyte: primary cell of mature bone (most common)
osteogenic: mitotic activity and differentiate into osteoblasts
osteoclast: responsible for resorption and breakdown of bone
which cells do osteoclasts originate from?
monocytes and macrophages
what is the function of canaliculi
aids in bone cell communication and receiving nutrients
what is the difference between compact bone and spongey bone
compact bone is dense, can withstand compression, it’s strong, located in periosteum and diaphysis. structural unit is an osteon (lamellae) and osteocytes are arranged in concentric circles
spongey bone has holes, can withstand shift in weight distribution, and the holes balance to compact bone, it is also located in the red marrow protected by trabeculae. osteocytes are arranged in a lattice network (trabeculae)
what is the nutrient foramen?
small openings in the diaphysis where arteries enter
what is the role of nerves in bones?
regulating blood supply and sense pain