Front Back
study of bone
Osseous Tissue
Bone tissue connective tissue in which the matrix is hardened by the depostition of calcium phosphate and other minerals
Make-up of Bone
osseous tissue blood bone marrow cartilage adipose tissue nervous tissue fibrous connective tissue
Living Skeleton
support for soft tissues contains nerves and blood vessels that provide nutrition
Components of the Skeletal System
Cartilage ligaments tendons bone
covers many joint surfaces in the mature skeleton hyaline of epiphyses between vertebrae to absorb shock
hold bone to bone
hold muscle to bone
Functions of Skeletal System
support protection movement electrolyte balance acid-base balance blood formation
Flat-Shape Bone
tend to be curved, wide, thin (skull) enclose and protect soft organs and provide broad surfaces for muscle attachment cranial bones, ribs, sternum, scapula, hip bones
Long Bone
longer than wide, act as levels to produce body movement femur, ulna, radius, humerus, metacarpals and phalanges, tibia, fibula, metatarsals
Compact Bone
Dense white osseous tissue that composes the outer shell of the bone Composes 3/4 of bone weight in body
Shaft of bone provides leverage
Head end of each bone Enlarged to strengthen joint and provide extra surface area for attachment of muscles
Songy (cancellous) Bone
Ends of bone in more central space Loosely organized form of osseous tissue Composes 1/4 of bone weight in body trabeculae arranged along bone's lines of stress
external sheath that covers bone that has an outer fibrous layer of collagen and an inner osteogenic layer of bone-formming cells
Thin layer of reticular connective tissue with cells that dissolve osseous tissue and others that deposit it found on the internal surface of the bone
Epiphyseal Plate
growth plate Area of hyaline cartilage that separates the marrow spaces of the epiphysis and diaphysis in children and adolescents Lines mark where the plate used to be in adults
Short Bone
Equal in length and width with limited motion Glide across one another carpal, tarsal
Irregular Bones
elaboratly-shaped bones that do not fit into other categories sphenoid, vertebrae, ethmoid
Medullary Cavity
marrow cavity, contains bone marrow
Articular Cartilage
Layer of hyaline cartilage found at joint surface Enables joint to move far more easily
Nutrient Foramina
Blood vessels and nerves supply exit and enter through this Tiny openings in periosteum
Perforating Fibers
collagen fibers that penetrate the bone matrix
Spongy layer in cranium that can absorb impact of blow to the skull
Osteogenic Cells
Bone stem cells (osteoprogenitor) Found in endosteum and inner layer of periosteum Arise from undifferentiated embryonic mesenchymal cells Multiply continually Lay down matrix
Nonmitotic cells Lay down bone matrix Bone forming cells Synthesize soft organic matter of the bone matrix Stress and fractures stimulate osteogenic cells to produce more Secrete osteocalcin
Bone matrix eating cells found on the surface of the bone Hematopoetic origin Formed by the fusion of several stem cells ruffled border increases surface area and efficiency of bone reabsorption
Osteoblasts that got stuck in matrix Lacunae communicate through cancliculi Connected by gap junction so they can pass nutrients and chemical signals to each otehr and pass their metabolic wastes to the nearest blood vessels for disposal reabsorb matrix deposit matrix strain sensor…
Bone Marrow
General term for soft tissue that occupies the marrow cavity of a long bone
Red Marrow (myeloid tissue)
Hemopoietic tissue (tissue that produces blood cells) Fills nearly every bone in a child Limited to skull, vertebrae, ribs, sternum, part of the pelvic girldle and the proximal heads of the humerus and femur in an adult
Yellow Marrow
Found in adults Fat cells replace healthy red cells Bone marrow responds to metabolic needs. Process can be reverted if needed by body No longer produces blood cells, can transform back into red marrow in the event of sever or chronic anemia
Intramembraneous Ossification
Replacement of embryonic CT with bone condensation of mesenchyme into soft sheet permeated with blood capillaries. Start connecting to form a network of soft sheets called trabeculae Deposition of osteoid tissue by osteoblasts on mesenchymal surface. Entrapment of first osteocyte; forma…
Endochonical Ossification
Replacement of cartilage with bone Bone develops from preexisting model composed of hyaline cartilage early cartilage model (precursor) Formation of primary ossification center, bone collar and periosteum Vascular invasion, formation of primary marrow cavity and appearance of secondar…
Zones of Metaphysis
zone of reverse cartilage zone of cell proliferation zone of cell hypertrophy zone of calcificaiton zone of bone deposition
Zone of Reverse cartilage
consist of typical hyaline cartilage that shows no sign of transforming yet
Zone of Cell Proliferation
chondrocytes multiply and arrange themselves into longitudinal columns of flattened lacunae
Zone of Cell Hypertrophy
Stopped dividing. Increasing by size. Walls of matrix between lacunae become very thin
Zone of Calcification
chondrocytes calcify (add minerals, hardens). DEposits are only temorary support for the cartilage.
Zone of Bone Deposition
walls of lacunae fall away- osteoblasts take over. Zone of spongy bone created at the end of the marrow cavity facing the metaphysis.
Appositional Growth
Bones increase in width throughout life Deposition of new bone at the surface limited amount of growth can occur in bone due to space similar to intramembraneous ossification
Orderly Bone Remodeling
balance between bone deposition and reabsorbtion disruptions in this balance can lead to done deformities
Paget's Disease
Osteitis Deformans Deformation of bone Too much bone deposition or absorption or both. Bone is thickening with small marrow cavity or vice versa. Weak bones due to increased rate of turnover Can cause bowed legs
Osteogenesis Imperfecta
Brittle Bones Autosomal dominant disorder of type 1 collagen lack of type 1 collagen or the production of defective type 1 collagen necessary ossification does not occur Leads to brittle bones that fracture easily can be limbs or axial bones
Thining of bone tissue and loss of bone density over time seems to have a greater effect on spongy bone (because of increased metabolic activity) space between the trabeculae becomes larger Common risk factors include: corticoid steroids, bedridden people, chronic kidney disease, vitam…
Achondroplastic Dwarfism
long bones have stopped growing limbs do not grow, the stay small forehead is prominent (in proportion to head and limbs) Torso is normal size caused by spontaneous mutation in chromosome (two normal people can have a dwarf child. I fa parent already had chromosomal mutation, increase…
Pituitary Dwarfism
no distortion of body proportions person has shorter, smaller stature lack or decrease in growth hormones
Mineral Deposition
A crystallization process in which calcium, phosphate, and other ions are taken from the blood plasma and deposited in bone tissue, mainly as crystals of hydroxipatite. Deposition begins in fetal ossification and continues through life.
Abnormal Calcification (Ectopic Ossification)
Bone-like material in random places i.e. plaque in the arteries, calulus (a calcified mass in a soft organ) in the lungs
Mineral Reabsorption
process of dissolving bone by releasing minerals into the blood making them available for other uses
Calcium deficiency. Causes excessive excitability of the nervous system and can lead to muscle tremors, spasm, or tetany (inability of the muscle to relax), heart arrhythmia
Blood calcium excess is rare Causes nerve and muscle cells to be less excitable than usual Can cause depression, emotional disturbances, muscle weakness, sluggish reflexes and cardiac arrest
Calcium homeostasis is regulated by ____, ____, and ____
Calcitrol Parathyroid Calcitonin
Study of bone disorders
Stress Fracture
Break caused by abnormal trauma to a bone
Pathological Fracture
break in a bone weakened by some other disease
Nondisplaced Bone Fracture
Separated but still in correct orientation
Displaced Bone Fracture
Break in bone, no longer in normal position
Comminuted Bone Fracture
Broken in several places in several pieces
Greenstick Bone Fracture
Break on one side of the bone while other side remains intact
Buckle Fracture
Cortex has buckled on both sides of the bone
Healing Process of Bone
Formation of hematoma and granulation tissue Formation of a soft callus Conversion to a hard callus. Takes 4-6 weeks. Important to have bone immobilized to prevent reinjury Bone remodeling can take 8-12 weeks or even up to 6 months for multiple fractures. Depends on the location and ty…

Access the best Study Guides, Lecture Notes and Practice Exams


Join to view and access 3M+ class-specific study document.

We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view and access 3M+ class-specific study document.


By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?