Exam 2 Flashcards
(55 cards)
Long bones
Greater in length than width, e.g: femur, humerus
Short bones
Length nearly equal to width, e.g carpals and tarsals
Flat bones
Flat, thin surfaces, may be slightly curved, e.g. cranial bones
Irregular bones
Elaborate, sometimes complex shapes; e.g. vertebrae
Hematopoiesis
blood cell production
Osteoprogenitor cells
Stem cells that mature to become osteoblasts
Osteoblasts
Immature cell that secretes osteoid
Osteocytes
Mature bone cell that maintains the bone matrix
Osteoclasts
Multinucleate cell that secretes acids and eyzmes to dissolve bone matrix
Osteogenesis/Ossification
Formation and development of bone
Osteons
Basic functional and structural unit of mature compact bone
Trabeculae
Highly porous form of bone tissue that is organized into a network of interconnected rods and plates which surrounds pores that are filled with bone marrow
Endochondral Ossification (6 steps)
- 8-12 weeks: fetal hyaline cartilage model develops
- Fetal period: cartilage calcifies and a periostal bone collar forms around diaphysis
- Fetal period: primary ossification center forms in diaphysis
- Newborn to child: secondary ossification centers form in epiphysis
- Child: bone replaces cartilage except articular cartilage
- Late teens to adult: epiphyseal plates ossify and form epiphyseal lines
Intramembranous Ossification (4 parts)
- Ossification centers form within thickened regions of mesenchyme
- Osteoid undergoes calcification.
- Woven bone and surrounding periosteum form.
- Lamellar bone replaces woven bone as compact and spongy born form.
Compact bone components
- central canal: cylindric canal in center
- concentric lamellae: parallel to blood vesels and nerves
- osteocytes: mature bone cells
- canaliculi: tiny interconnecting channels within bone connective
Spongy bone components
- trabeculae: meshwork of criss cross bars and plates of small bone plates, evenly distributes weight
- parallel lamellae
NO OSTEONS
Axial skeleton
- composed of bones along central body axis
External occipital protuberance
Attachment site for neck ligaments and muscles, occipital bone
Occipital condyles
Articulate with first cervical vertebrae, occipital bone
Superior and inferior temporal lines
Attachment sites for termporalis muscle, on parietal bone
Squamous part of frontal bone
Attachment of scalp muscles
Frontal sinuses
Lighten bone, moisten inhaled air, and give resonance to voice, on frontal bone
Petrous part of temporal bone
Protects sensory structures in inner ear, temporal bone
Squamous part of temporal bone
Attachment site of some jaw muscles, temporal bone
