Unit 7 : Bone Tissue Flashcards
Bone Tissue
Aspects of the bone tissue includes:
- It’s a Dynamic tissue that continually remodels itself
- Its a grouping of connective tissue with a matrix hardened by minerals
- Bones make up the skeletal system
Functions of the skeletal system
Functions of the skeletal system includes:
- Supports the body.
- Facilitates movement.
- Protects internal organs.
- Produces blood cells.
- Stores and releases minerals and fat.
- Buffers blood against excessive pH changes
Structure of Long bones
Long Bones Structures includes:
- Epiphysis (ends), they are Distal and Proximial
- Diaphysis (shaft)
- Medullary (bone marrow) cavity
Articular Cartilage
Hyaline cartilage covers the surface of joints the Epiphysis (distal and proximal Epiphysis) allowing for articulation of bones.
Long bones
Long Bones are:
- Longer than wide
- Rigid levers acted upon by muscles
- Assist in creating our Limbs
Short bones
Short bones are:
- Articuluation of Joints
- Equal in length and width
- Glide across one another in multiple directions
- Designed for strength and compactness
Flat bones
Flat bones are:
- Assist in Articulations
- Protect soft organs
- Curved but wide & thin
Irregular bones
Irregular bones are:
- Elaborate shapes that don’t fit into the other categories
- This includes the Sphenoid bone (bones of bones)
Bone Cell Types
There are (4) four Bone Cell types:
- Osteoprogenitor
- Osteoblasts
- Osteocytes
- Osteoclasts
Osteoprogenitor Cells
is a specialized cell that could dividing into two stem cells. They could become any type of bone cells.
Osteoblasts Cells
Osteo-Blasts (building of bones)
- Osteoblasts are the younger cells
- are the structural cells that form new bone.
- They also come from the bone marrow and secrete collagen
Osteocytes Cells
- They come from osteoblasts.
- Some of the osteoblasts turn into osteocytes while the new bone is being formed.
- These cells can sense pressures or cracks in the bone and help to direct where osteoclasts will dissolve the bone.
Osteoclasts Cells
- Osteoclasts are older cells that are broken down
- are large cells that dissolve / breakdown / reabsorb the bone.
- They come from the bone marrow and are related to white blood cells.
Bone Matrix Composition
25% water
25% protein fibers
50% minerals
Bone Matrix Contains
Bone Matrix contains some:
- Calcium carbonate, calcium phosphate
- but mostly hydroxyapatite, which is the PRIMARY salt that makes bone hard.
Hydroxyapatite
is the PRIMARY mineral of salt that form calcium making bone hard
Bone Matrix Deposited Where
Matrix is deposited in a framework of collagen fibers, calcification (calcium and salts) or mineralization
- Salts confer hardness on bone
- Collagen fibers give bones Tensile strength (being able to bend a little without breaking)
Bones
- Bone are made up of several different tissues (connective) working together:
- Bone
- Cartilage
- Dense connective tissue
- Epithelium
- Various blood forming tissues
- Adipose tissue
- Nervous tissue.
- Each individual bone is an organ; the bones, along with their cartilage, make up the skeletal system.
Bone Type
There are (4) Four types of bones:
- Long bones
- Short bones
- Flat bones
- Irregular bones
Type of Bones
Bone may be categorized as compact or spongy
Osteons
Osteons are cylindrical structures that contain a mineral matrix and living osteocytes connected by canaliculi, which transport blood.
Lamellae
The Lamella is a Cylinders of tissue area of Matrix that sits between the rings of the Osteocytes.
Compact Bone
Dense bone tissue consists of osteons, know as the Haversian systems = the basic structural unit (STEPS):
- Lamellae - Cylinders of tissue formed from layers
- Central Canal / Haversian- Contains, Vains, Artiery, Nerves (VAN).
- Osteocytes connected to each other and by tiny canals called “canaliculi”
Spongy Bone
- is made up of Trabeculae which is what gives sponge like appearance – the spaces is filled with red bone marrow.
- Provides strength with little weight for bone structure.
- Spongy bone have few osteons
- Blood Vessels go through spongy bones real easy, so it doesn’t need a haversian systems.
Intramembranous Ossification
- Intramembranous ossification directly converts the mesenchymal tissue to bone and forms the flat bones of the skull, clavicle, and most of the cranial bones.
- Intramembranous ossification does not not go through Cartilage.
Endochondrial Ossification
Endochondral ossification begins with mesenchymal tissue transforming into a cartilage, the growing cartilage is replaced by bone to form the growing skeleton.
-
is involved in:
- embryonic bone formation
- growth in length of long bones
- and fracture healing
Bone Formation Steps
Most bone is formed by Endochondral Ossification or osteogenesis (Inside then outward):
- Step 1 = Cartilage forms
- Step 2 = Cartilage grows
- Step 3 = Bone replaces the cartilage from the inside center outward.
Bone Mineral Resorption
- Bone is the major reservoir for calcium (Ca++)
- If blood levels get to low, the body will pull from the bones
- Blood level of calcium ions is very important in cardiac, nerve, enzyme, blood
Human Growth Hormone
Human Growth Hormone (GH) stimulate bone deposition, in addition to thyroid hormone, parathyroid hormone, and calcitonin
Thyroid Hormone
- Thyroid Hormone - promotes growth and maturity
- Calcitonin aka thyroid gland - promotes bone formation, inhibits osteoclast activity.
Parathyroid Hormone
Promotes bone resorption and increase activity of + osteoclasts
Bone Remodeling
Bone remodeling involves the replacement of old bone tissue with new bone tissue by:
- Destroyed by osteoclasts
- Constructed by osteoblasts
Bone Homeostasis
- Increased osteoclasts activity / decreased osteoclasts activity causes bone loss
- Increased osteoblasts activity / decreased osteoblasts activity causes bone creation
Ossification
is basically bone tissue formation
Bone Resorption
Bone resorption is the action of osteoclasts and parathyroid.
Bone Growth & Remodeling
Bones grow and remodel themselves throughout our lives.
Greater bone Density and bone mass are found in Athletes and those who gave Manual Labors.
Bone is Formed via..
Most bone are formed by Edochondral Ossification (
Mesenchymal Tissue
Intramembranous - VS - Endochondrial
-
Intramembranous
- Froms Flat bones like the Skull, Sternum, Mandible, and clavicle
-
Endochondrial
-
Stress Fractures
Stress fracture is a break caused by abnormal trauma to a bone, this includes - car accident, fall, athletics, etc
Pathological Fracture
Pathological fracture is a break in a bone that is weakened by some disease - This includes bone cancer or osteoporosis
Fracture - Open Displaced
Greenstick - Fracture
Fracture - Comminuted
Linear - Fracture
Transverse Non-Displaced - Fracture
Oblique NonDisplaced - Fracture
Spiral - Fracture
Colles - Fracture
Pott - Fracture
Healing of Fractures
- Fractures takes on average 8 - 12 Weeks to heal (Longer in seniors)
- Electrical stimulation is used on fractures that take longer than 2 months to heal
- Horsetail Herb is used in helping to repair fractures
Fracture Healing Stages
Stages of healing
- First - Fracture Hematoma
- Second - Granulation tissue
- Third - Callus formation
Bone Diseases
- Osteoporosis: is the most common bone disease
- Rickets Disease - is abnormal softness of bones in children and is called Osteomalacia in adults
Bone Nutrition
Good nutrition for bones includes:
-
Vitamins:
- A - Controls activity of Osteoblast and Osteoclasts
- D - Promotes removal of Calcium from Bones//
- C - Matain Matrix
-
Minerals
- Calcium + Phosphorus - Make the bone Matrix Hard
- Magnesium - deficiency inhibits osteoblast
- Manganese - Supports liagments
Bone Exercise
- Weight-bearing activities help build and retain bone mass
- Removal of mechanical stress weakens bone through demineralization
- Response to mechanical stress increases deposition of mineral salts and production of collagen fibers (aids in avoiding osteoporosis).
