Flashcards in Chapter 6: The Skeletal System: Bone Tissue Deck (64)
What are the 6 functions of the skeletal system?
Support, protection, assistance in movement, mineral homeostasis, blood cell production, and triglyceride storage
How does the skeletal system support us?
Structural framework of the body. Supports soft tissue and provides attachment points for tendons of skeletal muscles
How does the skeletal system provide protection?
Protects internal organs from injury like cranial bones protect the brain
How does the skeletal system assist in movement?
Skeletal muscles attach to bones; when they contract they pull on bones to produce movement
How does the skeletal system provide mineral homeostasis?
It stores several minerals, especially calcium and phosphorus which contributes to strength of bones. On demand, bone releases minerals into the blood to maintain critical mineral balances (homeostasis) and distribute minerals to other body parts
How does the skeletal system produce blood cells?
Within certain bones, connective tissue called RED BONE MARROW produces RBCs, WBCs and platelets in a process called hemopoiesis. With increasing age, most red bone marrow turns to yellow. It's present in developing bones of the fetus and some adult bones. Like the hip (pelvic) bone, ribs, sternum, vertebrae, skull and ends of bones of the humerus and femur
How does the skeletal system function in triglyceride storage?
Yellow Bone Marrow consists mainly of adipose cells which store triglycerides
What are the 7 parts of the long bone?
Diaphysis, epiphysis, metaphysis, articular cartilage, periosteum, medullary cavity, endosteum
What is the diaphysis of long bone?
Bone's shaft/body (main part)
What is the epiphysis of long bone?
Proximal and distal ends of bone
What is the metaphysis of long bone?
Regions between the diaphysis and epiphysis. Contains an epiphyseal growth plate (in growing bone), a layer of hyaline cartilage that allows diaphysis to grow. Carilage in epiphyseal plate is replaced by bone... resulting bony structure called the epiphyseal line
What is the articular cartilage of long bone?
Thin layer of hyaline cartilage covering the epiphysis where the bone forms an articulation (joint) with another bone. Absorbs shock and freely movable joints. Lacks perichondrium and blood vessels to repairing damage is limited
What is the periosteum of long bone?
Tough connective tissue sheath and its associated blood suppply that surrounds the bone surface wherever it's not covered by articular cartilage. Protects bone, assists in fracture repair, helps nourish bone tissue, serves as an attachment point fr ligaments and tendons. It's attached to underlying bone via PERFORATING FIBRES (thick bundles of collagen that extend from periosteum into the bone ECM).
What is the medullary of long bone?
Hollow, cylindrical space within diaphysis that contains fatty yellow bone marrow and many blood vessels in adults
What is the endosteum of long bone?
Thin membrane that lines medullary cavity. Contains single layer of bone-forming cells and small amount of connective tissue
How is bone tissue (osseous tissue) formed
Bone tissue contains lots of ECM surrounding widely separated cells. Most abundant mineral salt is calcium phosphate which is combined with calcium hydroxide to form crystals of HYDROXYAPATITE. The crystals combine with minerals like calcium carbonate and ions like mg, flouride, P, sulfate. As the materials are deposited in the framework formed by collagen fibres of the ECM they crystalize and the tissue hardens (this is called CALCIFICATION and is initiated by osteoblasts). Calcification requires collagen fibres
What are the 4 types of cells present in bone tissue?
Osteogenic cells, osteoblasts, osteocytes, and osteoclasts
What are osteoprogenitor cells in bone?
Unspecialized bone stem cells derived from mesenchyme. Only bone cells that undergo division (resulting in osetoblasts). Found along inner part of periosteum, in the endosteum and in the canals within bone that contains blood vessels
What are the osteoblasts of bones?
Bone building cells. Synthesize and secrete collagen fibres and other organic components needed to build the ECM of bone tissue and initiate calcification
What are osteocytes of bone?
Mature bone cells. Maintains daily metabolism like exchanging nutrients and waste within the blood. No division
What are osteoclasts of bone?
Huge cells derived from fusion of many monocytes (a WBC). Concentrated in the endosteum. Plasma membrane folded into a ruffled border where the cell releases lysosomal enzymes that digest proteins and mineral components of the ECM. This breakdown of ECM is called resorption. Also helps regulate blood calcium levels. Carve out bone.
What are the 2 types of bone?
Compact or spongy
Briefly describe compact bone tissue
Contains osteons which consists of concentric lamellae around a central canal. Strongest. Concentric lamellae surround a netowkr of blood vessels and nerves in the central canal. Between concentric lamellae are small spaces called lacunae which contain osetocytes. Radiating from the lacunae is the canaliculi which contains the ECM... inside are finger life processes of osteocytes which communicate with eachother via gap junctions. Canaliculi contaiin lacunae with one another and with central canals which provide routes for nutrients and O2 to reach osteocytes and removing waste. Compact bone tissue is tickest in those parts of the bone where stress is applied in few directions
What are interstitial lamellae?
Fragments of older osteons partly destroyed by bone rebuilding. Areas of neighbouring osteons
What is circumferential. Lamellae?
Arranged around entire outer and inner circumference of the shaft of a long bone are lamellae called circumferential lamellae. Connected to periosteum by perforating fibres
Briefly describe spongy bone tissue
No osteons. Located in interior part of a bone protected by compact bone. Has lamellae arranged in irregular pattern of thin columns called trabeculae. Between trabeculae are macroscopic spaces filled with red bone marrow in bones that produce RBCs and yellow bone marrow (adipose tissue) in others. Trabeculae consists of concentric lamellae, osteocytes in lacunae and canaliculi. In long bones it forms core of epiphysis and narrow rim bordering the medullary cavity of diaphysis. Located where bones are not heavily stressed or where stress is applied in all directions.
Name 2 big ways that spongy bone differs from compact?
1) spongy bone is light so bone moves easier when pulled by skeletal muscles. 2)The trabeculae of spongy bone supports and protects red bone marrow
What is the periosteal arterties?
Small artieries accompanied by nerves enter the diaphysis through many perforating canals and supply the periosteum and out part of the compact bone
What is the nutrient artery?
Centre of the diaphysis. Passes through a hold in compact bone called nutrient foramen