Chapter 6 Bones Flashcards
What kind of tissue are cartilages? Where are hyaline cartilages, elastic cartilages, and fibrocartilage found?
- connective tissue
- hyaline: ends of bones/joints
- elastic: ear
- fibrocartilage: vertebral disc
List the functions of skeletal system (6)
- Support: for the body and soft organs
- Movement: levers muscle action
- Protection: for brain, spinal chord, vital organs
- Storage
- mineral bank for Ca and phosphorus
- triglyceride storage in bone cavities (yellow marrow)
- growth hormone - Blood cell formation: (hematopoiesis) in red marrow cavities
- Production of osteocalcin: hormone that regulates bone formation and increases insulin sensitivity
What kind of tissues are in bones? (6)
- osseous tissue
- nervous
- cartilage
- fibrous connective
- muscle
- epithelial cells in blood vessels
Diagram: Illustrate the major features of a long bone including the following: diaphysis, epiphyses, epiphyseal line, Epiphyseal plate, periosteum, endosteum, medullary cavity, nutrient foramen
What kind of marrow is found in the central medullary cavity of infants and adults?
- infants = red bone marrow
- adults = yellow bone marrow
Where is red marrow found in an adult bone? (4)
trabecular cavities of spongy bone and diploe of flat bones (ex. sternum), heads of femur/humerus only
what is produced in the red bone marrow? What is the process called?
- WBC, RBC, platelets
- hematopoiesis
Periosteum. What are its two layers?
- outer fibrous layer with dense irregular CT
2. inner osteogenic layer with osteogenic cells, osteoblasts, osteoclasts
What is endosteum? What bone cells are found here? (2)
- delicate membrane on internal surfaces of bone
- osteoblasts & osteoclasts
Discuss the Haversian (Osteon) System as the structural unit of compact bone using the following terms: osteocytes, lacunae, lamellae, Haversian canal, blood vessels, bone matrix, and canaliculi, perforating (Volkmann’s) canals
- The strucural unit of a compact bone is called an osteon or the haversion system.
- Osteocytes are mature bone cells that occupy cavities (lacunae) and help maintain the matrix.
- Each osteon is placed in weight-bearing, column-like matrix tubes called lamellae, laid by the osteoblasts.
- The central canal of the osteon is also called the haversion canal, and it contains veins, arteries, lymph vessels, and a nerve.
- Canaliculi are hair like canals that connect lacunae to each other and the central canal that helps them communicate with each other.
- Perforating (volkman’s) canal run at right angles to the central canal and connets the blood vessels/nerves of the periosteum and central canal.
What are monocytes? What do monocytes mature into? How do they use their arms? What organelle do they contain most?
Notes
- WBC
- when mature, makes macrophages
- arms used to attach, move towards, and engulf target
- have more lysosome because have digestive acids that removes Ca
Describe the anatomy of spongy bone in terms of trabeculae (8)
- found in irregular, flat, short bone
- matrix secreted irregularly (no lamellae)
- no osteon
- needle projections (spicules) form trabeculae
- sandwiched in between 2 compact bones
- red marrows between the trabeculae
- called “diploe” in flat bones
- capillaries in endosteum supply nutrients
Osteogenic cells origin (1), location (2), function (2)
- mesenchymal cells in the bone marrow
- in periosteum and endosteum
- stem cells, actively mitotic
- give rise to osteoblasts
Osteoblasts origin (1), location (2), and function (2) - what kind of cells are they?
- osteogenic cells
- endosteum, periosteum
- synthesize and secrete a collagen matrix (bone-forming) and calcium salts (makes it hard)
-immature
Osteocytes origin (1), location (1), and function (1)
- mature from osteoblasts
- trapped in lacunae with canaliculi
- maintains the bone matrix
Osteoclast origin (2), location (1), and function - where does it go? (2) structure (2)
- a WBC, stemming from multiple monocytes and marophages
- found in compact bones
- break down, bone-resorbing with acids that convert calcium salts into soluble forms (bad guy, removed Ca from bone matrix and makes them soft)
- goes to red blood cell
- ruffled border increase SA for enzyme degradation of bone
- have multiple nuclei to make more proteins to make more digestive enzymes which increase resorption of ca
What makes up matrix of bone (osteoids)? (3, 3)
- Organic part of Osteoid
- secreted by osteoblasts
- consists of collagen fibers that provide tensile strength and flexibility
- ground substance containing proteoglycans and glycoproteins - Inorganic part of Osteoid
- consists of hydroxyapatites (mineral salts)
- mainly calcium phosphate crystals
- gives hardness & rigidity
What makes bone hard?
hydroxyapatites
What prevents it from being brittle?
Ca
Define the term hematopoiesis and name the major skeletal locations where it occurs.
- production of red blood cell
- femur, humerus, sternum, iliac*
Name the important function that the trabeculae in spongy or cancellous bones allow
-a network of supporting beams that provides strength and support the bones
Define ossification.
process of bone tissue formation
Flat bones are formed by _____ ossification? Describe the basic process in two sentences, including from what tissue these bones form.
- fintramembranous
- The process begins within the fibrous membranes (formed from mesenchymal cells)
1. ossification centers appear in the mesenchymal cells
2. bone matrix (osteoid) is made and calsifies
3. Woven bone is made and periosteum forms
4. Spongy bone is formed and red bone marrow appears.
All bones except flat bones are formed by _____? What do they do? Describe the basic process in four sentences, including from what tissue these bones form.
- endochondral ossification
- replaces the hyaline cartilage
1. primary ossification center appears
2. bone collar forms
3. calcification in center of diaphysis and cavities drop
4. periosteal bud (blood vessel) invades internal cavities
5. Medullary cavities form and diaphysis elongates
6. After birth secondary ossification centers appear in the epiphysis and form the epiphysis
