Chapter 6 Flashcards
How many bones in the human body?
206
Axial Skeleton
Contains kull, vertebrae, thorax (80 bones)
Appendicular Skeleton
Shoulder girdle, pelvic girdle (126 bones)
Functions of skeletal system
- Support
- Storage of minerals
- blood cell production
- protection of vital structures
- movement
Endoskeleton
hard inside
Exoskeleton
hard outside, soft inside (like a M&M)
6 types of bones
- Flat
- Sutural
- Long
- Irregular
- Sesamoid
- Short
Example of flat:
sternum
Sutural:
between cranial bones
Long:
twice as long as it is wide
ex: femur
Irregular:
vertebrae
sesamoid:
bone within a tendon
ex: patella
short:
carpals and tarsals
Long bones include:
epiphysis, diaphysis, metaphysis, spongy bone, compact bone, periosteum
Epiphysis
end of the bone
Diaphysis
Shaft of the bone
Metaphysis
where the diaphysis and epiphysis meet (growth plate)
Spongy bone
helps to redirect forces that are on the bone
Medullary cavity
bone marrow
Red bone marrow
red blood cells, young
yellow bone marrow
storage of fats
Trabeculae
lattice work, arranged to resist force
Osteon
Functional unit
periosteum
sits on top of compact bone
nutrient artery
supplies blood to the bone
3 types of cells
Osteocyte, Osteoblast, Osteoclasts
Osteocyte:
- -Mature bone cells
- -Maintain normal bone function
- -Sit in lacunae (pockets)
Osteoblast
- -immature cells
- - make new bone
Osteoclasts
break done the bone
Collagen:
stretchy, bendy, 1/3 of body weight
hydroxyapatite:
responsible for bone hardiness
2 types of bone growth
Appositional and Endochondral Ossification
Appositional:
growth in width
Endochondral Ossification
bone growth from a cartilage precursor,
Epiphyseal plate:
responsible for bone growth in length
Pituitary growth failure: (dwarfism)
inadequate growth hormone
Marfan’s syndrome
long stretchy limbs
Gigantism:
over production of growth hormone
clubfoot:
babies feet turn in
Two main minerals stored in the bone:
Phosphorus and calcium
Calcium
- –Most abundant body mineral
- —99%
- –Also used for muscle contraction, formation of nerve impulses, and more
- –Absorbed in small intestine
2 hormones
PTH (parathyroid hormone) and Calcitonin
PTH (parathyroid hormone)
activates osteoclasts, chews up bone a releases calcium into the blood (think of pacman) and increases blood pressure*****
Calcitonin
produced by thyroid gland, inhibits osteoclast formation, don’t break down the bone, calcium stays in the bone, Decrease blood calcium levels
how many milligrams of calcium per day do we need to maintain normal bone physiology?
12 milligrams
