HUN1201 Ch.11 Final
Bone Growth
an increase in bone size, completed by age 14 in girls, 17 in boys
osteoblasts
"Bone builders" Cells that prompt the formation of new bone matrix by laying down the collagen-containing component of bone that is then mineralized.
hypermagnesemia
A condition marked by abnormally high concentration of magnesium in the blood.
collagen
A PROTEIN that forms strong fibers in bone and connective tissue.
hypocalcemia
A condition characterized by an abnormally low concentration of calcium in the blood.
hypomagnesemia
A condition characterized by an abnormally low concentration of magnesium in the blood.
calcium tetany
A condition in which muscles experience twitiching and spasms due to inadequate blood calcium levels.
hypercalcemia
A condition marked by an abnormally high concentration of calcium in the blood.
fluorosis
A condition marked by staining and pitting of the teeth; caused by an abnormally high intake of fluoride.
cortical bone (compact bone)
A dense bone tissue that makes up the outer surface of all bones as well as the entirety of most small bones of the body. 80% of the skeleton, outer surface of the bone
osteoporosis
A disease characterized by low bone mass and deterioration of bone tissue, leading to increased bone fragility and fracture risk.
calcium rigor
A failure of muscles to relax, which leads to a hardening or stiffening of the muscles; caused by high levels of blood calcium.
parathyroid hormone (PTH)
A hormone secreted by the parathyroid gland when blood calcium levels fall. It is also known as parathormone, and it increases blood calcium levels by stimulating the activation of vitamin D, increasing reabsorption of calcium from the kidneys, and stiumulating osteoclasts to break down bone, which releases more calcium into the bloodstream.
calcitonin
A hormone secreted by the thyroid gland when blood calcium levels are too high. Calcitonin inhibits the actions of vitamin D, preveting reabsorption of calcium in the kidneys, limiting calcium reabsorption in the intestines, and inhibiting the osteoclasts from breaking down bone.
fluorohydroxyapatite
A mineral compound in human teeth that contains fluoride, calcium, and phosphorous and is more resistant to destruction by acids and bacteria than hydroxyapatite.
trabecular bone (spongy or cancellous bone)
A porous bone tissue that makes up only 20% of the skeleton and is found within the ends of the long bones, inside the spinal vertebrae, inside the flat bones (breastbone, ribs, and most bones of the skull, and inside the bones of the pelvis.) BASICALLY inside of bones (scaffolding) that supports the outer cortical; also faster turnover rate than cortical bone.
matrix Gla protein
A vitamin K-dependent protein that is located in the protein matrix of bone and also found in cartilage, blood vessel walls, and other soft tissues.
osteocalcin
A vitamin K-dependent protein that is secreted by osteoblasts and is associated with bone turnover.
Nutrients for Bone Health
Calcium (most recognized), vitamin D, Vitamin K, Phosphorus, Magnesium, fluoride
osteoclasts
Cells that erode the surface of bones by secreting enzymes and acids that dig grooves into the bone matrix.
dual energy x-ray absorptiometry (DXA or DEXA)
Currently the most accurate tool for measuring bone density. Results are compared to average peak bone density of 30 year old healthy adult. Recommended for postmenopausal women.
female athlete triad
Refers to the interrelationship between three conditions seen in female athletes: inadequate energy intake, menstrual dysfunction (for example, amenorrhea), and reduced bone strength 9for example stress fractures, osteopenia, osteoperosis).
Functions of Bones
STRUCTURE AND SUPPORT, protect vital organs and support muscles and allow movement. METABOLIC PROCESSES, acts as a storage for minerals like calcium, phosphorus and fluoride, and can reduce bone mass. Most of the blood cells needed in our bodies are produced in the marrow of out bones!!!!!!!!!!!
Bone density
The degree of [compactness of bone tissue], reflecting the strength of the bones.
bioavailability
The degree to which our bodies can absorb and utilize any given nutrients.
phylloquinone
The form of vitamin K found in plants.
menaquinone
The form of vitamin K produced by bacteria in the large intestine.
calcitriol
The primary active form of vitamin D in the body.
resorption
The process by which the surface of bone is broken down by cells called osteoclasts.
Bone Remodeling
The two-step process by which bone tissue is recycled; includes the breakdown of existing bone and the formation of new bone. Bone resorption and formation are balanced in young healthy adults. After age 40, resorption exceeds bone formation, density begins to decrease.
osteomalacia
Vitamin D-deficiency disease in adults, in which bones become weak and prone to fractures.
rickets
Vitamin D-deficiency disease in children. Symptoms include deformities of the skeleton such as bowed legs and knocked knees.
ergocalciferol
Vitamin D2, a form of vitamin D found exclusively in plant foods.
cholecalciferol
Vitamin D3, a form of viatmin D found in animal foods and the form we synthesize from the sun.
Turnover Rate
how quickly the bone tissue is broken down or replenished.
Bones
living organisms that contain bone tissues, nerves, cartilage, and connective tissue. Blood vessels supply nutrients to the bone to support it's activities. They provide strength and flexibility containing 65% minerals (bone hardness) and 35% organic structure (strength, durability, and flexibility)
hydroxyapatite
mineral crystals around collagen designed to bear weight.
Peak bone density
point at which bones are strongest because they are at their highest density.. Factors associated with a lower peak bone density include: late pubertal age in boys, late onset menstruation in girls, inadequate calcium intake, low body weight, physical inactivity during pubertal years
Bone Modeling
shaping of the bone, completed by early adulthood, exercise and overweight can increase bone thickness
T-score
used to assess a person's risk for fracture and diagnose osteoporosis