1. How are bones classified?
By location (axial or appendicular skeleton), shape (long, short, flat, sesamoid, irregular), and internal
structure (compact or spongy).
2. What are the functions of skeletal cartilages and what are their important structural components?
Cartilage of the skull is avascular. It is nourished by the perichondrium which is in the outer layer and is
connective tissue that contains blood vessels and collects wastes from the cartilage itself. It is limited by
the thickness meaning it cannot nourish the layers that are too deep. It takes a long time to heal because
there are no nerves or blood.
There are 3 types of cartilage:
1. Hyaline: where bones meet .. articular cartilage .. most common
2. Elastic: ear flaps, epiglottis
3. Fibrocartilage: strongest, vertebrae, knees, pubic sympasis .. shock absorber
3. What are the functions of bone?
1. Support - structural framework for body
2. Protection - protects internal organs from injury
3. Movement- skeletal muscles pull on bones
4. Mineral Homeostasis -calcium and phosphorus stored and released
5. Blood Cell Production -red bone(spongy bone) marrow produces blood cells
6. Energy Storage - triglycerides stored in yellow marrow
4. What are the major structural differences between compact and spongy bone?
Spongy bone: found in diaphysis, inside of bone,..functional unit is tracbeculae, porous, reduces weight,
red bone marrow ; blood, yellow bone marrow; fat
Compact bone: found in epiphysis, outside of bone,..functional unit is osteon, concentric lamellae,
protection and support
5. Which are the major cells involved in bone physiology? What are their functional differences?
Osteogenic cell: unspecialized, start of bone production
Osteoblast: bone forming cell, synthesize and secrete collagen, initiate calcification
Osteocyte: mature osteoblast after calcification, most numerous
Osteoclast: bone destroying cell, don’t generate from any other cells, concentrated in endosteum
6. What are the major constituents of bone matrix?
Inorganic: 65% of bone mass (2/3), mineral salts (calcium carbonate and calcium phosphate are why the bone is hard)
Organic: osteoblast, osteoclast, etc. 1/3 of bone mass is unmineralized collagen, glycoproteins, etc.
7. What are the main differences between intramembranous and endochondral ossification?
Intramembranous: flat bones of skull and mandible, soft spots on fetal skull, simple
Endochondral: all other bones, replacement of hyaline cartilage by bone, begins in second month of
development, hyaline cartilage bone models are used
8. How does a bone grow in length?
Epiphyseal plate turns into line..cartilage replaced by bone
9. How do PTH and calcitonin regulate bone remodeling?
Parathyroid hormone: if hypocalcemia occurs, PTH is stimulated to promote osteoclast activity
Calcitonin: Slows down osteoclast activity
10. What is the anatomical and functional significance of fibrous joints?
Fibrous: dense irregular connective tissue
1. Sutures: thin layer
2. Syndesmoses: connected as a bundle or sheet
3. Gomphoses: periodontal ligament found in teeth
11. What are the major structural components of synovial joints?
Joints in which articulating bones are separated by synovial fluid. Allows for a lot of movement between
increasing and decreasing angles.
Structural classification: Diarthrosis
All limb joints, most joints in the body
Articular capsule 2 layered joint capsule
Fibrous capsule- dense irregular connective tissue (mainly collagen) that attaches to periosteum of
articulating bones. flexibility of fibrous capsule permits movement at joint while tensile stregth (resistance
to stretching) prevents dislocating.
Synovial membrane- areolar connective tissue with elastic fibres.
Articular cartilage surrounds synovial joint and connects articulating ends of bone
-smooth slippery surface to protect the ends of bone. Shock absorbers and reduces friction.
Joint (synovial) cavity contains synovial fliud
Synovial fluid slippery lubricating fluid to reduce friction. absorbs shocks, supplies oxygen and nutrients to
and removes CO2 and wastes from chondrocytres within articular cartilage. Removes microbes and debris
from normal wear and tear of joint
Accessory structures Reinforcing ligaments holds everything together. Gives strength and flexibility. Inside and outside of
Bursae – provides extra pads of lubricant as they slide over each other
12. Contrast fibrous vs cartilaginous vs synovial joints
Fibrous (dense irregular connective tissue)
*sutures: thin layer found only in the skull, synarthrosis (not movable), replaced by osseous tissue during
* syndesmoses: found between tibula&fibia and ulna&radius, as a bundle (ligament), or sheet
(interosseous membrane), greater distance between articulating bones and denser fibrous connective
tissue in comparison with a suture, amphiarthrosis
* gomphoses: periodontal ligament found in teeth, amphiarthrosis (slightly movable)
* synchondroses: made out of hyaline cartilage, found in ribs and epiphyseal plate of long bones
* symphyses: composed of tough fibrocartilage, end of bone surface, between bones, amphiarthrosis
Synovial joints in which articulating bones are separated by fluid containing joint cavities, diarthrosis, all
limb joints and most joints of the body, allow for lots of movement, stability is determined by articular
surfaces and ligaments
* planar: nonaxial movement, carparls, intertarsals
* hinge: monaxial, knee, ankle, elbow
* pivot: monaxial, atlas & axis
* condyloid: biaxial, wrist, between metacarpals 2-5
* saddle: biaxial, thumb
* ball and socket: multiaxial, shoulder, hip joint
13. Describe all the levels of skeletal muscle organization from the innermost sarcomere up to the outermost
connective tissue layer.
Fascia: sense sheet or broad band of irregular connective tissue that lines the body wall and limbs and
supports and surrounds muscles and other organs of the body. Fascia holds muscles with similar functions
together. Allows free movements of muscles, carries nerves, blood vessels, lymphatic vessels, fills spaces
Connective tissue layers: extend from fascia
Epimysium: connective tissue that covers muscle externally (outermost layer) circles entire muscle
Perimysium: layer of dense irregular connective tissue, surrounds groupds of 10-100 muscle fibers,
separating them into bundles called fascicles, characteristic grain
Endomysium: penetrates the int