GENERAL BONE STRUCTURE/RIB CAGE/VERTEBRAL COLUMN Flashcards
Tissues making up bones
- Osteocytes
- Cartilages
- Fibrous CT
- Blood vessels
- Nerves
- Lymphatics
Bone derives its compressional strength from
Hydroxyapatite
T/F: Bone matrix is continuously turning over
T
T/F: Bone is highly vascularized
T
Most sensitive part of a bone
- Why?
periosteum - higher vascularized and innervated
Periosteum
- What is the exception?
CT layer covering all bones
- except where bony areas are covered by articular cartilage or bony areas of ligament tendon attachment
Periosteum function
Provides underlying bone with nutrients
Compact/Cortical/Dense Bone
outer dense layer that’s thick and highly vascularized
Compact/Cortical/Dense Bone function
provides great Stregnth and density
Cancellous/Spongy/Trabecular Bone
- layer of spongy bone in center consisting of network of trabeculae arranged to resist external forces
Cancellous/Spongy/Trabecular Bone function
Thin sheets in medulla containing small filaments of bone material for structural support with minimal weight
Medullary Cavity
cavity in long bones that’s continuous with interstices of cancellous bone filled with red (hematopoietic) or yellow (fatty) marrow
Endosteum
single-cellular osteogenic layer that lines marrow cavity
Components of Axial Skeleton
skull, vertebral column (sacrum, coccyx, ribs, sternum)
Components of Appendicular Skeleton
hip bones, pectoral girdle, bones of upper/lower limbs
Structure of Long Bones
- consist of a shaft of compact bone with central medullary cavity
- Expanded ends are formed by cancellous bone covered with compact bone
Examples of Long Bones
Humerus, femur, radius, ulna, fibula, tibia
Structure of Short Bones
formed by cancellous bone with thin covering of compact bone
Examples of Short Bones
Carpal bones, tarsal bones
Structure of Flat Bones
thin layer of cancellous bone enclosed in two thin layers of compact bone
Location of Flat Bones
where there’s protection of underlying organs
Composition of Flat Bones as we age
As we age the bone marrow in long bones becomes fattier (more yellow bone marrow)
young = more red bone marrow
Examples of Flat Bones
Scapula, ribs, vault of skull
Structure of Irregular Bones
composed of cancellous bone surrounded by thin layer of compact bone
Examples of Irregular Bones
Vertebrae, facial bones, hip bones
4 main features of Long Bones
- Diaphysis (shaft)
- Epiphysis
- Epiphysis Cartilage (Epiphyseal Plate)
- Metaphysis
Diaphysis (Shaft)
portion of long bone between the ends, consists of tube of compact bone and enclosing medullary cavity
Epiphysis
end of long bone, usually wider than saft, either entirely cartilaginous or separated from shaft by cartilaginous disk
Epiphyseal Cartilage (Epiphyseal Plate)
cartilage seen during growing phase of bone, separated from epiphysis
Metaphysis
wide portion of long bone between epiphysis and diaphysis, contains growth plate (i.e., epiphyseal cartilage)
4 Arterial Supplies of bones
- Nutrient Artery
- Periosteal Arteries
- Metaphyseal Artery
- Epiphyseal Arteries
Nutrient Artery
- usually 1+, supplies inner 2/3 of cortex of long bones plus the medullary cavity
90% ______ bones have single nutrient foramen in middle third of shaft
long
Periosteal Arteries
numerous beneath muscular and ligamentous attachments
Metaphyseal Artery
supplies metaphysis area and anastomoses (join) with nutrient artery
Epiphyseal Arteries
mainly supply the epiphyseal plate
Venous Drainage of Bones
numerous venous channels accompany the arteries, eventually join/leave bone through nutrient foramen forming nutrient vein
Lymphatics of Bones
bones are drained by lymphatic vessels, which are abundant in the periosteum
Where are lymphatic vessels abundant?
periosteum
Innervation of Bones
nerves are widely distributed in periosteum and nerve fibers usually accompany the arteries
Cartilage
form of CT in which cells and fibers are embedded in gel-like matrix, latter being responsible for it’s firmness/resilience
3 types of Cartilage in bones
- Hyaline
- Fibrocartilage
- Elastic cartilage
Hyaline Cartilage
covers most of articular surfaces of nearly all synovial joints, great resistance to wear
- Incapable of repair when fractured - osteoarthritis
Fibrocartilage
found in disc within joints (TMJ)
- If damaged, repairs itself slowly with fibrous tissue
Elastic Cartilage
found in Auricle of ear and auditory tube, has large number of elastic fibers and is flexible
- If damaged, repairs itself with fibrous tissue
T/F: Cartilage is vascular and neural
F - it is avascular and aneural
How is nutrition supplied to cartilage?
nutrition is supplied to chondrocytes via diffusion
Cells of cartilage
chondrocytes
What is a unique characteristic of TMJ and sternoclavicular?
Interarticular Disc between joint - fibrocartilage
Joints
place of union/junction between 2+ rigid components (bones, cartilage, or parts of same bone)