skeletal system Flashcards
when does bone growth cease?
once epiphyseal plates ossify growth ceases leaving an epiphyseal line
hyaline c,t remains at end of long bones “articular c.t)
what is ossification vs calcification?
ossification- process of creating bone
calcification - build up of calcium in soft tissue causing it to harden, can occur in damaged/diseased tissue as well as growing bone
is an aspect of ossification
what is bone remodelling?
ongoing osteoclast and osteoblast activity throughout life
influenced by several factors
what are the five factors related to bone-remodelling?
- hormones- parathyroid hormone and calcitonin
regulate calcium and phosphate levels in blood by putting excess calcium into bone or removing calcium from bones and estrogen/testosterone increase osteoblast proliferation and activity - mechanical stress- weight bearing exercise increases bone density (increases osteoblast activity)
- in responce to damage- fracture-osteoblast repair- bone callus reshaped by osteoclasts
- age- bone degration exeeds bone building (osteopenuia) at 40 bone thinning can progress to osteoporosis
- nutrition- calcium- required for bone formation/repair
vitamin d- required for absorption of dietary ca+
what are bone markings?
surface features
reflect functional relationship to soft structures (tendons, muscles, ligaments, nerves)
what are the three bone marking functional classifications?
- depressions and openings
- projections(processes) that form joints
- projections for muscle and ligament attachment
how many facial bones are there and what are they?
14
1. zygomatic (R&L cheekbones)
2. lacrimal (R&L foramina here drains tears)
3. nasal (R&L with nasal c.t from external nose)
4. vomer(with septal c.t forms nasal septum)
5.mandible(forms lower jaw and chin)
6.maxilla (forms upper jaw and hard palate)
7. ossicles ( malleus, incus, stapes of middle ear
8. hyoid bone (only bone that does not articulate with any other bones in the body)
vertebral column?
24 individual vertebrae + 9 fused vertebrae = 33 vertebrae
houses and protects spinal cord
separated by intervertebral discs (fibrocartilage)
normal s shape curve which functions like a spring
what are the two major divisions of the skeleton?
axial skeleton- skull, vertebral column, bony thorax ( ribs and sternum)
appendicular skeleton- pelvic girdle and legs, pectoral girdle and arms (clavicles and scapulae)
what bones and cavities does the skull contain?
cranial and facial bones
some skulls contain sinuses which are air-filled cavities lined in mucous membrane
what does the cranium house and how many bones does it consist of?
houses the brain which sits in the cranial cavity
8 large flat bones joined by fissures interlocking fibrous joints which permit growth of the skull and ossifiy in middle age
what are the 8 bones in the cranium?
1.frontal bone- forms forehead ]
2.parietal bone- R&L forms sides of cranium
3.occipital bone- back of head- occipital condyles articulate with vertebral column foraman magnum here
4. temporal bone- R&L temples auditory meatus entrance to ear, mastoid process for attachment of mastication muscles
5. sphenoid bone- forms floor of cranium and orbit of eye sella turica, pituitary sits here
6. ethmoid bone- forms orbit and nasal cavity with nasal conchae well as anterior floor of cranium: cribiform plate with olfactory foramina
what are the three regions of the vertebral structure?
7 cervical vertebrae c1-c7
12 thoracic vertebrae t1-t12
5 lumbar vertebrae l1-l5
what is atlas vs axis?
atlas c1articulates with skull
axis c2 articulates with atlas permits rotation of head
what does the sacrum consist of?
formed from fusion of s1-s5
center of gravity for body
4 pairs of foramina for passage of blood vessels and nerves
articulates with ilium of hip- sacroniac joint
difference between annulus fibrosus vs nucleus pulposus
annulus is outer ring of fibrocartilage on vertebrae
nucleus is the inner gelatinous material
what is the bony thorax?
thoracic vertebrae+ ribs+ sternum
framework of chest protects the heart/lungs
what is the sternum?
manubrium+ body(with xiphoid process)
protects the heart
what are the ribs?
bowed flat bones
attached to body of sternum by hyaline c.t (costal cartilage)
protects the lungs
head articulates with the thoracic vertebrae
12 pairs
describe the pairs of the ribs?
12 pairs
7 pairs of true ribs which attach directly to sternum
5 pairs false ribs
3 pairs attached to costal cartilage
2 pairs floating not attached to anything
what are the clavicles?
collarbones
articulates with sternum at sternal end and scapula acrominal end
curved long bones that brace shoulder
what are the scapulae?
shoulderblades
triangular flat bones
glenoid fossa-articulates with head of humerous
acromion- articulates with clavicle
what are the upper arms?
humerous articulates with glenoid fossa of scapula for form the shoulder joint
what are the lower arms?
ulna (medial) and radius (lateral)
artiulcate with humerous to form elbow joint
