Skeletal System Flashcards
Purpose of Bones
Support
Protection
Movement
Mineral Reservoir (calcium)
Hematopoesis (creation of blood)
Axial Skeleton 🩻
Skull
Vertebral column
Rib cage
Sacrum (is between hip bones)
Appendicular Skeleton 🦵
Pelvis
Upper, lower limbs
Scapula
Long bones
longer than it is wide
Articulate with other bones
Femur, humerus, radius, ulna, tibia, fibula, metacarpal, metatarsals and phalanges
Short bones
cube or box shaped
As broad as they are long
Wrist (carpal)
Ankle (tarsal)
Flat bones
Broad, thin, curved surface
Shoulder blades (scapulae)
Ribs
Sternum
Compact bone
Irregular bones
clustered in groups, various shapes and sizes
Vertebral (spine)
Facial bones
Sesamoid bones
develop in tendons close to joints, protect from friction
Patella
Pisiform
Thumb
Big toe
Compact bone
Dense and ‘solid’ in appearance
Cancellous bone
Open space and network of thin, branched crossbeams
Spongy bone or trabecular
LONG BONE
Diaphysis 🦴
Main shaft like portion
Hollow, cylindrical, thick compact bone
LONG BONE
Epiphyses 🦴 spongy/cancellous
Proximal and distal ends of long bone
Bulbous shape, muscle attachments
Gives stability to joints
LONG BONE
Articular cartilage 🦴 (top)
Smooth, thin layer of hyaline cartilage
Covers articular/joint surfaces of epiphysis
Cushions jolts and blows
Bone tissue aka
Osseous tissue
Consists of cells, fibers and
extracellular matrix (hard and calcified)
Contains collagen
Support and protective function
Extracellular matrix (ECM)
Hard, calcified
More abundant than bone cells and fibers
Structure supporting function
Made of inorganic salts (calcification) and organic matrix (collagen, proteins, polysaccharides = ground substance)
Gel like
Supports, sticks cells and bone fibers
Cell metabolism for bone growth, repair, remodeling
Osteoblasts
Create new bone 🦴
Osteoclasts
Break down bone, reabsorb
Osteocytes
Cells in lacunae
Bone development
Endochondral ossification
process turning cartilage to bone
Bone development
Intramembranous ossification
replacement of sheet-like connective tissue membranes with bony tissue
Between/within membrane, bone
(Baby’s head)
Bone Growth
Appositional growth (wider)
Adding more bone material to outside, gets bigger
Bone growth
Interstitial growth
Grow in length
Function of Bone Marrow
(myeloid tissue)
Red Marrow
Childhood bones mainly
Present in adult ribs, vertebrae, pelvis, upper humerus, upper femur
Function of Bone Marrow
(myeloid tissue)
Yellow Marrow
Replaces red marrow in adults
Can alter to red marrow if needed to increase blood supply
Bones and Homeostasis
Role of calcium homeostasis
Regulation of blood calcium
-> secretes parathyroid hormone
calcitonin (regulates Ca levels in your blood by decreasing it)
Calcium homeostasis
Primary balance between Ca breakdown by osteoclasts and reabsorption by osteoblasts
Calcium needed for
Normal blood clotting
Muscle contraction
Nerve transmission
