Bone Physiology Quiz 2 Flashcards
What are the 2 types of bone?
compact or spongy
What type of bone forms the external layer of all bones and the bulk of the diaphyses of long bones?
compact bone
What type of bone resists loading stresses?
compact bone
What are the basic structural unit of compact bone?
osteons
What are lacunae?
small spaces between the lamellae which contain osteocytes
What are lamellae?
rings of hard calcified matrix found around the central canals.
What are canaliculi?
tiny canals which radiate in all directions from the lacunae.
What connects the lacunae together and to the central canals?
canaliculi
What encircle the cortical region beneath the periosteum and encircle the medullary cavity?
circumferential lamellae
True or false: spongy bone contains osteons
False
What is the irregular framework of lamellae in spongy bone called?
trabeculae
What is contained in the space between the trabeculae?
red bone marrow
Where are the lacunae in spongy bone?
within the trabeculae
What are interstitial lamellae?
fragments of older osteons that have been partially destroyed during growth and remodeling
Where are interstitial lamellae found?
in between osteons
Spongy bone makes up most of the bone tissue in what type of bones?
short, flat and irregular bones
Where does the nutrient artery enter the bone shaft?
through the nutrient foramen
Where do nutrient veins exit the bone?
with their accompanying artery
What part of bone is particularly rich in sensory nerves?
the periosteum
What is bone formation called?
Ossification
What are the 2 ways bones grow?
length and width
How do bones grow longer?
interstitial growth which occurs by endochondral ossification
Where do bones grow longer?
the cartilaginous regions of long bones
What permits growth of the the diaphysis of long bones?
the epiphyseal growth plate
How do bones grow in width?
appositional growth. The bone grows in thickness by laying down new osteons beneath the periosteum.
What hormones contribute to bone growth?
growth hormone
estrogen
testosterone
What are the 2 components of bone remodeling?
bone resorption
bone deposition
What regulates bone remodeling?
hormones
What factors influence bone growth, remodeling and repair?
minerals
vitamins
hormones
What minerals are important to bone growth?
hydroxyapatite
magnesium
What vitamins are vital to bone growth?
Vitamin C
Vitamin D
What is caused by a deficiency in Vitamin C?
scurvy
What is caused by a vitamin D deficiency?
rickets in children and osteomalacia in adults.
What hormones are part of bone growth?
parathyroid hormone
sex hormone (in adults)
calcitonin
What does parathyroid hormone do for bone growth?
- increases blood calcium levels
- promotes bone reabsorption by increasing the number and activity of osteoclasts.
- enhances calcium recovery from urine
What do sex hormones do for bone growth?
promote deposition of new bone by stimulating osteoblast activity.
What does calcitonin do for bone growth?
- decreases blood calcium levels
- promotes calcium uptake by increasing the activity of osteoblasts and inhibiting the activity of osteoclasts
Who is most at risk of osteoporosis?
Older women
What are the steps of bone fracture healing?
- fracture hematoma
- fibrocartilaginous callus
- bony callus formation
- bone remodeling
What is osteoporosis?
reduced bone mass due to decreased bone synthesis relative to reabsorption.
What is joint inflammation brought about by wear and tear causing cumulative damage to articular cartilage?
Osteoarthritis
What is osteomyelitis?
infection or inflammation of bone and marrow
What does rickets or osteomalacia do?
causes bones to soften as it fails to calcify
What is osteogenesis imperfecta?
a genetic disorder leading to brittle or fragile bones
How does osteogenesis imperfecta affect bones?
it is an autosomal dominant disorder of type 1 collagen
