Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types, while seemingly inert, is an active, growing, and changing part of the human body, in addition to being the body's primary calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli. In the correct homeostatic conditions, bone can remodel in response to damage, stress, or hormonal signaling ( parathyroid Parathyroid The parathyroid glands are 2 pairs of small endocrine glands found in close proximity to the thyroid gland. The superior parathyroid glands are lodged within the parenchyma of the upper poles of the right and left thyroid lobes; the inferior parathyroid glands are close to the inferior tips or poles of the lobes. Parathyroid Glands: Anatomy hormone and calcitonin Calcitonin A peptide hormone that lowers calcium concentration in the blood. In humans, it is released by thyroid cells and acts to decrease the formation and absorptive activity of osteoclasts. Its role in regulating plasma calcium is much greater in children and in certain diseases than in normal adults. Other Antiresorptive Drugs). Osteocytes Osteocytes Mature osteoblasts that have become embedded in the bone matrix. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi. Bones: Development and Ossification located deep in the bone sense damage and signal bone-lining cells that will begin the process of remodeling. This process is vital not only for damage repair but also to adapt to a new environment and conditions.
Last updated: 9 Mar, 2022
Bone anatomy:
Bones are covered in a layer called the
periosteum
Periosteum
Thin outer membrane that surrounds a bone. It contains connective tissue, capillaries, nerves, and a number of cell types.
Bones: Structure and Types, composed of
fibrous
Fibrous
Fibrocystic Change and cellular layers. Below the
periosteum
Periosteum
Thin outer membrane that surrounds a bone. It contains connective tissue, capillaries, nerves, and a number of cell types.
Bones: Structure and Types is the
endosteum
Endosteum
Bones: Structure and Types, a complex architecture constructed on a mineral scaffold (the bony matrix) and composed of
osteocytes
Osteocytes
Mature osteoblasts that have become embedded in the bone matrix. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi.
Bones: Development and Ossification,
osteoclasts
Osteoclasts
A large multinuclear cell associated with the bone resorption. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in cementum resorption.
Bones: Development and Ossification, and
osteoblasts
Osteoblasts
Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone.
Bones: Development and Ossification.
Bone-remodeling diagram
Bone remodeling begins with the
osteocytes
Osteocytes
Mature osteoblasts that have become embedded in the bone matrix. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi.
Bones: Development and Ossification sensing microdamage. This process causes their
apoptosis
Apoptosis
A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Ischemic Cell Damage, which is concurrently sensed by
bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types-lining cells. These cells
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology chemoattractants, and
osteoclasts
Osteoclasts
A large multinuclear cell associated with the bone resorption. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in cementum resorption.
Bones: Development and Ossification group together in the damaged area to
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology calcium and
phosphate
Phosphate
Inorganic salts of phosphoric acid.
Electrolytes. As soon as
osteoclasts
Osteoclasts
A large multinuclear cell associated with the bone resorption. An odontoclast, also called cementoclast, is cytomorphologically the same as an osteoclast and is involved in cementum resorption.
Bones: Development and Ossification finish their work,
osteoblasts
Osteoblasts
Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone.
Bones: Development and Ossification begin recruiting the
bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types tissue. The process also traps some of the cells and forms a new lining by converting
osteoblasts
Osteoblasts
Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone.
Bones: Development and Ossification into
osteocytes
Osteocytes
Mature osteoblasts that have become embedded in the bone matrix. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi.
Bones: Development and Ossification and
bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types-lining cells.
Signaling microdamage and activation:
Osteocytes at the site of microdamage undergo
apoptosis
Apoptosis
A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
Ischemic Cell Damage.
Bone-lining cells then digest underlying osteoid to expose mineral and lift off the surface.
Osteoclast precursor
recruitment
Recruitment
Skeletal Muscle Contraction:
Osteoclast precursors
bind
BIND
Hyperbilirubinemia of the Newborn
receptor
Receptor
Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell.
Receptors activator of nuclear factor kappa B (RANK) ligand (
RANKL
RANKL
A tumor necrosis factor receptor family member that is specific for rank ligand and plays a role in bone homeostasis by regulating osteoclastogenesis. It is also expressed on dendritic cells where it plays a role in regulating dendritic cell survival. Signaling by the activated receptor occurs through its association with tnf receptor-associated factors.
Paget’s Disease of Bone) and coalesce to form an osteoclast.
Absorption
Absorption
Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation.
Digestion and Absorption:
Osteoclasts digest
minerals
Minerals
Electrolytes with acid, releasing
Ca
CA
Condylomata acuminata are a clinical manifestation of genital HPV infection. Condylomata acuminata are described as raised, pearly, flesh-colored, papular, cauliflower-like lesions seen in the anogenital region that may cause itching, pain, or bleeding.
Condylomata Acuminata (Genital Warts)2+ and PO43–.
Deposition:
Osteoblast precursors become
osteoblasts
Osteoblasts
Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone.
Bones: Development and Ossification and lay down new osteoid.
Osteoid
Osteoid
Bones: Development and Ossification mineralizes and forms new
bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types.
New
bone
Bone
Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy.
Bones: Structure and Types:
Trapped
osteoblasts
Osteoblasts
Bone-forming cells which secrete an extracellular matrix. Hydroxyapatite crystals are then deposited into the matrix to form bone.
Bones: Development and Ossification become
osteocytes
Osteocytes
Mature osteoblasts that have become embedded in the bone matrix. They occupy a small cavity, called lacuna, in the matrix and are connected to adjacent osteocytes via protoplasmic projections called canaliculi.
Bones: Development and Ossification and extend
dendrites
Dendrites
Extensions of the nerve cell body. They are short and branched and receive stimuli from other neurons.
Nervous System: Histology.