Skeletal System Flashcards
What is the most abundant cartilage
Hyaline cartilage
The human skeleton is initially what?
Cartilages and fibrous membranes
How many bones make up the adult skeleton?
206
How many bones make up the axial skeleton?
80
How many bones make up the appendicular skeleton?
126
Bone functions:
–Support and protect softer tissues –Provide points of attachment for muscles –Produce blood cells –Storing organic salts
Parts of a long bone
–epiphysis – diaphysis – metaphysis – compact bone (cortical bone) – spongy bone (cancellous bone) – articular bone – periosteum – endosperm – medullary cavity (bone marrow)
Function of epiphysis (part of long bone)
Either end of a long bone
Diaphysis (Part of a long bone)
Shaft of a long bone
Compact bone (Part of a long bone)
?
Bone cell osteocytes
Mature bone cell; transports nutrients and wastes; reside in lacunae within the trabeculae
Osteoblast
Bone-forming cell
Osteoclasts
Bone destroying cells
Spongy bone
?
Articular cartilage
?
Periosteum
?
Endosteum
?
Medullary cavity
Bone marrow red and yellow;
Parts of a compact bone
– osteon – haversian system – central canal – perforating canal – Volkmann’s canal – osteocytes – lamellae – bone matrix – canaliculi
Spongy bone
Bone that consists of bars and plates separated by irregular spaces; cancellous bone
Bones form when Bone tissue replaces existing connective tissue in one of two ways
Intramembranous bones Endichondral bones
–These bones originate with sheet like layers of connective tissues (membrane) –they are broad flat, bones
Intramembranous ossification
–Bones begin as hyaline cartilage – firm models for future blend – these are most bones of the skeleton
Endochondral ossification
Closest to the end of epiphysis, resting cells, anchors epiphyseal plate to epiphysis
Zone of resting cartilage (1st layer of cells)
Many rows of young cells, undergoing mitosis
Zone of proliferating cartilage (2nd layer of cells)
Older cells, left behind when new cells appear, cells enlarging and becoming calcified
Zone of hypertrophic cartilage (3rd layer of cells)
Thing, dead cells, calcified extracellular matrix
Zone if calcified cartilage (4th layer of cells)
Action of osteoclasts
Bone resorption action of osteoblasts
Action of osteoblasts
Bone deposition
Retards bone development
Vitamin A deficiency
Results in fragile bones
Vitamin C deficiency
Tickets, osteomalacia
Vitamin D deficiency
Dwarfism
Insufficient growth hormone
Gigantism, acromegaly
Excessive growth hormone
Delays bone growth
Insufficient thyroid hormone
Promote bone formation; stimulate ossification of epiphyseal plates
Sex hormones
Stimulated bone growth
Physical stress
– gives shape to head –supports body’s weight – protects lungs, ect. – bones and muscles interact when limbs or body parts move
Support, protection and movement
Blood cell formation occurs in the red bone marrow
Hematopoiesis
Most abundant salt is calcium phosphate Other salts: magnesium ions, sodium ions, potassium ions, carbonate ions
Inorganic salt storage
A condition that results from loss of bone mineral
Osteoporosis
- skull -hyoid bone - thoracic cage - cerebral column
Axial skeleton
- Pectoral girdle - upper limbs - pelvic girdle - lower limbs
Appendicular skeleton
7 vertebrae in this column
Cervical vertebrae
12 vertebrae in this column
Thoracic vertebrae
4-5 fused segments in this vertebral column
Sacral column
3-4 fused segments in this vertebral column
Coccygeal column
Curvatures of the vertebral column
-cervical curvature - thoracic curvature - lumbar curvature - sacral curvature
