Intro to Skeletal System

Question 1

Functional Roles of Skeletal System (5)

Answer 1

Support of body. Protection of internal organs. levers for skeletal muscles. production of blood cells. Storage of minerals.

Question 2

Bone: composition

Answer 2

composite = made of diff things. 70% inorganic calcium phosphate crystals (strong, inflexible, resistant to compressive stress. 30% organic collagen fibers (tough but flexible, resits stretching, bending and twisting stresses.

Question 3

Bone: remodeling

Answer 3

will remodel under influence of forces, will change its shape depending on activity (Ex throwing arm vs serving arm which is thicker b/c lots of force is applied.

Question 4

Bone: anisotropic (not isotropic)

Answer 4

(isotropic=constant properties) has different strength and hardness depending on its orientation, like wood - so can resist stress in some directions better than others.

Question 5

Bone cells (4)

Answer 5

connective tissue: osteocyte, osteoblast, osteoclast, osteoprogenitor cells

Question 6

Osteocyte

Answer 6

mature bone cells that maintain protein and mineral contents in bony matrix

Question 7

osteoblast

Answer 7

cuboidal bone cells found on outer and inner surfaces of a bone, secrete bone material called osteoid (immature) - organic material. responsible for osteogenesis

Question 8

osteoclast

Answer 8

bone cells responsible to remove bony matrix and releasing minerals into body. large, multinucleated. - osteolysis

Question 9

osteoprogenitor cells

Answer 9

bone cells found in outer and inner layers of a bone, important role in fracture repair, “just in case” cells, can form osteoblasts

Question 10

Structure of Bone: two types

Answer 10

spongy aka trabecular or cancellous - open network of struts and plates, hoolow space is where marrow lives. compact bone - dense and solid

Question 11

Medullary Cavity

Answer 11

in middle of bone: yellow marrow (adipocytes = fat) and red marrow (mature and immature red and white blood cells)

Question 12

periosteum and endosterum

Answer 12

every bone is covered with a fibrous, thin and transparent layer: covered outside and inside

Question 13

Osteon aka haversian System

Answer 13

basic functional unit of mature compact bone - osteocytes organized in cocentric layers around a central canal containing blood vessels supplying the osteon

Question 14

3 types of joints

Answer 14

fibrous, cartilaginous, synovial

Question 15

Hinge vs ball and socket joints

Answer 15

hinge joint: unaxial - permits only flexion and extension, like elbow joint. ball and socket: multiaxial - rounded head into concavity, movement on several axis like hip joint

Question 16

Fibrous Joints

Answer 16

connected by dense connective tissue like collagen - like cranial sutures and inteosseous membranes (syndesmosis) - unites long bones like between radius and ulna. fixed, immovable

Question 17

Cartilaginous Joints

Answer 17

connected entirely with cartilage, more movement than fibrous but less than synovial

Question 18

Primary cartilaginous joints

Answer 18

aka Synchondrosis: temporary cartilaginous union between bones - growth plates between ossification centers in long bones, might ossify with age.

Question 19

Secondary cartilaginous joints

Answer 19

aka Symphysis: permanent - intervertebral discs, pubic symphysis

Question 20

Synovial Joints

Answer 20

most common, allow movement: bones are united by capsule containing synovial fluid - less viscous than motor oil

Question 21

bone aka?

Answer 21

osseous tissue - is a type of supporting connective tissue

Question 22

balance between osteoblast and osteoclast

Answer 22

osteoclast removes matrix and releases minerals, osteoblasts produce matrix that quickly binds minerals

Question 23

major difference between compact and spongy bone

Answer 23

spongy bone is arranged into parallel struts/branching plates called trabeculae

Question 24

spongy vs compact bone functional difference

Answer 24

compact: resists a lot of strength from epiphysis to epiphysis, but impacts can easily cause fractures. spongy bone - not as massive, but resists stress applied from many different directions