Bone & Muscle ~ Histology Flashcards
Inorganic constituents of bone matrix
Calcium hydroxyapatite (calcium phosphate)
Gives Rigidity to Bone
Extensions from lacunae are called
Canaliculi
Which joins with other canaliculi arising from neighbouring lacuni
Space between the lamellae is called
Lacunae
Osteoblast derived from
Osteogenic precursor cells
Canaliculi contains
Processes from osteocytes (located in the canaliculi)
Aggregation of muscle fascicle is called
Muscle
Organic constituents of bone matrix made up of
Dense bundle of collagen Fibres embedded in the ground substance
So, collagen and ground substance together is called Osteoid
The bone is made up of many layers
Called Lamellar Bone/Lamellae
Thin bony plate, In which calcium and collagen are deposited in ground substance
Osteocytes located in the
Lacuna
Characteristic of compact bone
Made up of lamellae, which has lacunae and canaliculi
Lamellae~arranged in concentric rings
In the Centre of ring ~ Haversian canal
Yellow Bone Marrow present in
Compact bone
Structures passing through Haversian canal
Nerves and blood vessels
Haversian canal along with lamellus is called
Osteon
Canal which connects 1 Haversian canal with the other Haversian canal or with Bone Marrow
Volkmann’s canal
Covering of each muscle is called
Epimysium
Cancellous bone / Spongy bone characteristic
Haversian canal is absent
Bone is arranged in the form of Trabeculae
Red bone marrow in spongy/cancellous bone present in
Inter trabecular space
Trabeculae of spongy/cancellous bone has
Lacunae
Lucunae in turn consist osteocytes
Margins of Trabeculae has numerous osteoblasts and osteoclasts
Compact bone is mainly found in the
Diaphysis
Cancellous/spongy bone mainly found in the
Epiphysis
Marrow cavity and space in the cancellous bone are filled with?
Bone Marrow
Red bone marrow present in
Cancellous / Spongy bone
Each muscle fibre is covered by
Endomysium
Aggregation of muscle fibres is
Fascicle
Trabecular System present in
Cancellous/Spongy Bone
Consistency of Compact And Cancellous Bone
Hard/Ivory like ~ Compact bone
Spongy like ~ Cancellous Bone
Skeletal Muscle Characteristics
Fibres run Parallel to each other
Flat Nucleus, found in periphery
Syncytium ~ formed by fusion of cells cytoplasmic mass containing numerous nuclei
Haversian system Present in
Compact Bone
Each fascicle is covered by
Perimysium
Part of myofibril between 2 adjacent Z - Band
Sarcomere
What is mineralization
Is a process in which calcium salts are deposited into the matrix under the influence of osteoblasts
On the basis of pattern of development of bone, the bone is divide into
Three categories;
Membranous bones
Cartilaginous bones
Membranocartilaginous bones
Membranous bones ossification?
These bones ossify from highly vascular membrane of primitive mesenchyme
At the centre of ossification, mesenchymal stem cells differentiate into osteoprogenitor cells which give rise to osteoblasts
Eg; skull and facial bones
Ossification of cartilaginous bones
Bones ossify from hyaline cartilage
The deeper layers of the perichondrium surrounding the cartilage contain osteoprogenitor cells which help in the bone formation
Eg; bones of limbs, vertebral column, thoracic cage
Ossification of membranocartilaginous bones
Ossify partly from cartilage and partly from mesenchymal condensations
Eg; clavicle, mandible, occipital, temporal, sphenoid
A single sarcomere is defined as
The distance between two Z lines
Cytoplasmic processes send signals to and exchange nutrients and waste products with the osteocytes within neighbouring lamellae via
Gap Junctions
Thin (actin) filaments in the I-band are bound to structural proteins at the
Z-line
Thick (myosin) filaments in the A-band are bound to structural proteins at the
M-line
The region of the sarcomere in which myosin does not overlap with actin
H-band
The region of the sarcomere in which actin does not overlap with myosin
I-band
