Chapter 5: Skeletal System Flashcards
functions of skeletal system
Support of the body Protection of soft organs Movement due to attached skeletal muscles Storage of minerals and fats Blood cell formation
characteristics of compact .vs. spongy bone
Compact bone: Homogeneous
Spongy bone:Small needle-like, pieces of bone, Many open spaces
4 types of bones
Long bones: Typically longer than wide, Have a shaft with heads at both ends, Contain mostly compact bone
Examples: Femur, humerus
Short bones: Generally cube-shape, Contain mostly spongy bone
Examples: Carpals, tarsals
Flat bones: Thin and flattened, Usually curved, Thin layers of compact bone around a layer of spongy bone
Examples: Skull, ribs, sternum
Irregular bones: Irregular shape, Do not fit into other bone classification categories
Example: Vertebrae and hip
gross anatomy of long bone
Diaphysis and Epiphysis
Diaphysis
Shaft
Composed of compact bone
Epiphysis
Ends of the bone
Composed mostly of spongy bone
structures of a long bone
Periosteum, Sharpey’s fibers, Arteries, Articular cartilage, and Medullary cavity
Periosteum
Outside covering of the diaphysis
Fibrous connective tissue membrane
Sharpey’s fibers
Secure periosteum to underlying bone
Arteries
Supply bone cells with nutrients
Articular cartilage
Covers the external surface of the epiphyses
Made of hyaline cartilage
Decreases friction at joint surfaces
Medullary cavity
Cavity of the shaft
Contains yellow marrow (mostly fat) in adults
Contains red marrow (for blood cell formation) in infants
Microscopic Anatomy of bone
Osteon (Haversian System), Central (Haversian) canal, Perforating (Volkman’s) canal, Lacunae, Lamellae, and Canaliculi
Osteon (Haversian System)
A unit of bone
Central (Haversian) canal
Opening in the center of an osteon
Carries blood vessels and nerves
Lacunae
Cavities containing bone cells (osteocytes)
Arranged in concentric rings
Lamellae
Rings around the central canal
Sites of lacunae
Canaliculi
Tiny canals
Radiate from the central canal to lacunae
Form a transport system
Perforating (Volkman’s) canal
Canal perpendicular to the central canal
Carries blood vessels and nerves
bone cells
Osteocytes, Osteoblasts, and Osteoclasts
Osteocytes
Mature bone cells
Osteoblasts
Bone-forming cells
Osteoclasts
Bone-destroying cells
Break down bone matrix for remodeling and release of calcium
types of bone fractures
Closed (simple) fracture – break that does not penetrate the skin
Open (compound) fracture – broken bone penetrates through the skin
comminuted fracture
bone breaks into many fragments
compression fracture
bone is crushed
depressed fracture
broken bone portion is pressed inward
impacted fracture
broken bone ends are forced into each other
spiral fracture
ragged break occurs when there are excessive twisting forces are applied to the bone
greenstick
bone breaks incompletely
Repair of Bone Fractures
1) Hematoma (blood-filled swelling) is formed
2) Break is splinted by fibrocartilage to form a callus
3) Fibrocartilage callus is replaced by a bony callus
4) Bony callus is remodeled to form a permanent patch
The Axial Skeleton
Divided into three parts
Skull
Vertebral column
Bony thorax
where is the foramen magnum located
hollow opening in the occipital bone (seen in superior view)
The Fetal Skull
- The fetal skull is large compared to the infants total body length
- has Fontanelles
Fontanelles
- fibrous membranes connecting the cranial bones
- Allow the brain to grow
- Convert to bone within 24 months after birth
The Vertebral Column
- Vertebrae separated by intervertebral discs
- The spine has a normal curvature
- Each vertebrae is given a name according to its location
where is the cervical curvature
first 7 vertebrae
where is the thoracic curvature
12 vertebrae (8-19)
where is the lumber curvature
5 vertebrae (20-24)
where is the sacrum
5 fused vertebrae following the lumbar curvature
where is the coccyx
4 fused vertebrae following the sacrum
order of the vertebral column
cervical curvature thoracic curvature lumbar curvature sacrum coccyx
appendicular skeleton
appendages (limbs), pectoral girdle, pelvic girdle
Bones of the Pelvic Girdle
Composed of three pair of fused bones
Ilium
Ischium
Pubic bone
The Pectoral (Shoulder) Girdle
Composed of two bones
Clavicle – collarbone
Scapula – shoulder blade
The Bony Thorax
-Forms a cage to protect major organs
-Made-up of three parts
Sternum
Ribs
Thoracic vertebrae
True Ribs
ribs 1-7, attaches to sternum from vertebrae
False Ribs
8-12, attaches to costal cartilage from vertebrae
Floating RIbs
11 and 12, does not attach to anything from vertebrae
order of ribs
true, false, floating
Functional Classification of Joints
Synarthroses
Amphiarthroses
Diarthroses
Synarthroses
immovable joints
Amphiarthroses
slightly moveable joints
Diarthroses
freely moveable joints
Osteoarthritis
Most common chronic arthritis
Probably related to normal aging processes
Rheumatoid arthritis
An autoimmune disease – the immune system attacks the joints
Symptoms begin with bilateral inflammation of certain joints
Often leads to deformities
Bone Growth
- Epiphyseal plates allow for growth of long bone during childhood
- New cartilage is continuously formed
- Older cartilage becomes ossified
- Cartilage is broken down
- Bone replaces cartilage
Bone remodeling
1) bone reabsorbed
2) bone added by appositional growth
3) bone reabsorbed
coronal suture
between parietal bone and frontal bone
lambdoidal suture
between the occipital bone and the parietal bone
squamous suture
between parietal bone and temporal bone
two largest bones of the foot
calcaneus and talus
difference between female and male pelvis
- female inlet is larger and more circular
- female ilia flare more laterally
- female sacrum is shorter and less curved
- female ischial is shorter
- female pubic arch is greater than 90 degrees
what causes osteoporosis
Osteoporosis occurs when there is an imbalance between new bone formation and old bone resorption. The body may fail to form enough new bone, or too much old bone may be reabsorbed, or both. Two essential minerals for normal bone formation are calcium and phosphate
what is osteoporosis
a medical condition in which the bones become brittle and fragile from loss of tissue, typically as a result of hormonal changes, or deficiency of calcium or vitamin D.
