The Skeletal System Flashcards
the study of bone
osteology
mature bone cells
osteocytes
composed of bones, cartilages, and ligaments
skeletal system
hold bones together at the joints
ligaments
attach muscle to bone
tendon
Functions of the Skeletal System (6)
- support
- protection
- movement
- electrolyte balance
- acid-base balance
- blood formation
connective tissue with the matrix hardened by calcium phosphate and other minerals
bone (osseous tissue)
type of bone:
-longer than wide
-rigid levers acted upon by muscles
long bone
type of bone:
-equal in length and width
short bone
type of bone:
-elaborate shapes that do not fit into other categories
irregular bones
type of bone:
-small, round bone
sesamoid bone
end of long bone
epiphysis
shaft (middle part) of long bone
diaphysis
found in the shaft of the long bone
compact bone
usually found at the ends of long bone
spongy bone
layer that covers the long bone (outside layer)
periosteum
lining of the medullary cavity in the long bone
endosteum
What are the two types of bone marrow?
red and yellow
central canal with surrounding structures
osteon
blood vessels and nerves
central canal
bone cells that live inside lacuna
osteocytes
cavities on lamallae
lacuna
canal that connect one lacunae with another
canaliculus
little channels that connect lacunae
canaliculi
concentric circles of lacunae
lamellae
What are the four principle types of bone cells?
- osteogenic cells
- osteoblasts
- osteocytes
- osteoclasts
bone-dissolving cells found on the bone surface
osteoclasts
soft bones due to deficiency of calcium salts
rickets
excessively brittle bones due to lack of protein, collagen
osteogenesis imperfecta or brittle bone disease
soft tissue that occupies the marrow cavity of a long bone and small spaces amid the trabeculae of spongy bone
bone marrow
produces blood cells and is composed of multiple tissues in a delicate, but intricate arrangement that is an organ to itself
hemopoietic tissue
type of bone marrow:
-produces blood cells
-in adults, found in skull, vertebrae, ribs, sternum, part of pelvic girdle, and proximal heads of humerus and femur
red bone marrow
type of bone marrow:
-found in adults
-most red bone marrow turns into this
-no longer produces blood
-found in long bones
yellow bone marrow
the formation of bone
ossification or osteogenesis
the formation of bone from membrane (produces flat bones)
intramembranous ossification
the formation of bone from cartilage (produce long bones)
endochondral ossification
blood calcium excess; has a wide variety of causes
hypocalcemia
What three hormones regulate calcium homeostasis?
calcitriol, calcitonin, parathyroid hormone
a form of vitamin D produced by the sequential action of the skin, liver, and kidneys (most active form of vitamin D)
calcitriol
lower blood calcium concentration in two ways
-osteoclast inhabitation
-osteoblast stimulation
calcitonin
increases blood calcium concentration
-released with low calcium blood levels
-raises calcium blood levels (binds receptors on osteoblasts)
parathyroid hormone
cause growth to stop
-epiphyseal plate “closes” prematurely
-results in abnormally short adult stature
anabolic steroids
break caused by abnormal trauma to bone (normal fracture)
-falls, athletics, and military combat
stress fracture
break in a bone weakened by some other disease (abnormal)
-bone cancer or osteoporosis
-usually caused by stress that would not break a healthy bone
pathological fracture
How are fractures classified?
direction of the fracture line, break in the skin, multiple pieces
treatment of fractures?
closed reduction, open reduction, cast
severe loss of bone density
-the most common bone disease
-bone loses mass and becomes brittle due to loss of organic matrix and minerals
-common in young female athletes with low body fat causing them to stop ovulating and ovarian estrogen secretion is low
osteoporosis
part of the skeleton that forms central supporting axis of the body
-skull, vertebrae, sternum, ribs, sacrum, and hyoid
axial skeleton
part of the skeleton that includes the pectoral girdle, upper extremity, pelvic girdle, lower extremity
appendicular skeleton
How many bones are in a typical adult?
206
How many bones does a normal person have at birth?
270
What are the four normal curvatures in the vertebral column?
cervical, thoracic, lumbar, pelvic
type of curvatures that are present at birth
-ex: thoracic and pelvic
primary curvatures
type of curvatures that develop later
-ex: cervical and lumbar
-lifting head as it begins to crawl develops cervical curvature
-walking upright develops lumbar curvature
secondary curvatures
What are some causes of abnormal spine curvatures?
disease, paralysis of trunk muscles, poor posture, pregnancy, or congenital defect
abnormal curvature of the spine
-developmental abnormality in which the body and arch fail to develop on one side of the vertebrae
-most common
-usually in thoracic region
-particularly of adolescent girls
scoliosis
ribs 1-7
-each has own costal cartilage connecting to sternum
true ribs
ribs 8-10
-lack independent cartilaginous connection to sternum
false ribs
ribs 11-12
-articulate only with the vertebral column
-no cartilaginous connection to the sternum or any of the higher costal cartilages
floating ribs
