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Skeletal System Salem Boytos Per.5 - Coggle Diagram
Skeletal System Salem Boytos Per.5
Disorders/Diseases
Osteomalacia and rickets
Bones are poorly mineralized
Osteoid is produced, but calcium salts not adequately deposited
Results in soft, weak bones
Pain upon bearing weight
Rickets (osteomalacia of children)
Results in bowed legs and other bone deformities because bones end
are enlarged and abnormally long
Cause is vitamin D deficiency or insufficient dietary calcium
Osteoporosis
Osteoporosis is a group of diseases in which bone resorption exceeds deposit
Matrix remains normal, but bone mass declines
Spongy bone of spine and neck of femur most susceptible
Vertebral and hip fractures common
Paget’s disease
Excessive and haphazard bone deposit and resorption cause bone to grow fast
and develop poorly
Called Pagetic bone
Very high ratio of spongy to compact bone and reduced mineralization
Usually occurs in spine, pelvis, femur, and skull
Rarely occurs before age 40
Cause unknown: possibly viral
Treatment includes calcitonin and bisphosphonates
Microscopic anatomy of bone tissue
Osteogenic cells
Also called osteoprogenitor cells
Mitotically active stem cells in periosteum and endosteum
When stimulated, they differentiate into osteoblasts or bone-lining cells
Some remain as osteogenic stem cells
Osteoblasts
Bone-forming cells that secrete unmineralized bone matrix called osteoid
Osteoid is made up of collagen and calcium-binding proteins
Collagen makes up 90% of bone protein
Osteoblasts are actively mitotic
Osteocytes
Mature bone cells in lacunae that no longer divide
Maintain bone matrix and act as stress or strain sensors
Respond to mechanical stimuli such as increased force on bone or weightlessness
Communicate information to osteoblasts and osteoclasts (cells that destroy bone) so bone remodeling can occur
Bone-lining cells
Flat cells on bone surfaces believed to also help maintain matrix (along with osteocytes)
Osteoclasts
Derived from same hematopoietic stem cells that become macrophages
– Giant, multinucleate cells function in bone resorption (breakdown of bone)
When active, cells are located in depressions called resorption bays
Cells have ruffled borders that serve to increase surface area for enzyme degradation of bone
Also helps seal off area from surrounding matrix
Anatomy of Long Bone
Epiphysis
Epiphyses: ends of long bones that consist of compact bone externally and
Articular cartilage covers articular (joint) surfaces
Between diaphysis and epiphysis is epiphyseal line
– Remnant of childhood epiphyseal plate where bone growth occurs
Membranes
Periosteum: white, double-layered membrane that covers external surfaces except joints
Endosteum is delicate connective tissue membrane covering internal bone surface
Diaphysis
Diaphysis: tubular shaft that forms long axis of bone
– Consists of compact bone surrounding central medullary cavity that is
filled with yellow marrow in adults
Bone Remodeling
Bone Deposit
Osteoclasts also phagocytize demineralized matrix and dead osteocytes
Bone Deposit: New bone matrix is deposited by osteoblasts
Bone Resorption
Occurs at surfaces of both periosteum and endosteum
Remodeling units: packets of adjacent osteoblasts and osteoclasts coordinate
remodeling process
Resorption is function of osteoclasts
Dig depressions or grooves as they break down matrix
Secrete lysosomal enzymes and protons (H+) that digest matrix
Acidity converts calcium salts to soluble forms
Joints
Plane
between phalanges and metacarpals
Hinge
Knee
Pivot
Shoulder
Condylar
neck
Saddle
Finger
Ball-and-socket
Shoulder
Movements allowed by Synovial Joints
Angular
Rotation
Gliding
Male vs. Female Skeleton
The main differences between male and female skeletons are in size, shape, and certain structural features. Male skeletons tend to be larger and more robust, with thicker bones. Female skeletons, on the other hand, have wider pelvises, a larger pelvic inlet, and a more rounded pelvic cavity to accommodate childbirth. Additionally, males generally have narrower hips and more pronounced brow ridges, while females have a more rounded forehead and smaller jawbones. Male coccyx is more upturned compared to female.
Bone Fracture Repair
Hematoma formation
Torn blood vessels hemorrhage, forming a mass f clotted blood cells called a hematoma; site is painful, swollen, and inflamed.
Fibrocartilaginous callus formation
Capillaries grow into hematoma
Phagocytic cells clear debris
Fibroblasts secrete collagen fibers to span break and connect broken ends.
Fibroblasts, cartilage, and osteogenic cells begin reconstruction of bone.
Create cartilage matrix of repair tissue; Osteoblasts form spongy bone within matrix.
This mass of repair tissue is called fibrocartilaginous callus
Bony callus formation
Within one-week, new trabeculae appear in fibrocartilaginous callus.
Callus is converted to bony (hard) callus of spongy bone.
Bony callus formation continues for about 2 months until firm union forms.
Bone remodeling
Begins during bony callus formation and continues for several months
Excess material on diaphysis exterior and within medullary cavity is removed
Compact bone is laid down to reconstruct shaft walls
Final structure resembles original structure
Responds to same mechanical stressors
Name of All the Bones
Torso
clacicle, scapula, spine(Th1-L5), ribs, sternum, pelvic girdle,
Pelvic Girdle(Ilium, ischium, pubis, sacrum, coccyx, coxal)
Arm
humerus, radius, ulna, caprals, metacarpals, phalangeles
Head
Skull bones, spine(C1-C7)
Skull(Frontal bone, parietal bones, occipital bone, temporal bones, sphenoid bone, ethmoid bone, nasal bones, zygomatic bones, maxilla, mandible, lacrimal bones, vomer, palatine bones, inferior nasal conchae)
Leg
Femur, tibia, fibula, tarsals, metatarsals, phalangeal, calcaneus, talus, patella
Types of Bones
Long Bones
femur
Short Bones
carpals
Flat Bones
skull bones
Irregular Bones
vertebrae