Musculoskeletal System Flashcards
What is a muscle made up of
Whole muscle
Fasicle
Myofibril
Myofilaments (sarcomere)
Sliding filament theory
Myosin forms cross bridge and pulls actin to slide over it
Z lines drawn closer together
Sarcomere shortened
Myosin doesn’t move
Explain antagonist muscle pairs
Agonist: contracts and moves
Antagonist: relaxes and shortens
Fibrous joint characteristics
Do not allow movement
Held in place with fibrous tissue
Difficult to damage as very strong
(Skull and teeth)
Characteristics of cartilaginous joints
Held in place with cartilage
Allow slight movement
(Joints between ribs and vertebrae)
Synovial joints allow full range of movement
- Hinge joint: flex/extend, abduction (elbow and knee)
- Ball&socket: rotation, adduction (upper arm and upper leg)
- Pivot: rotation (neck and wrist)
- saddle: thumb
- condyloid: up/down & side to side (carpals)
Characteristics and functions of synovial fluid
Lubricates joint
Provides nourishment for cells
Keeps bone surfaces from making
contact with each other
What does the external structure of a long bone consist of
Cartilage
epiphysis
diaphysis
epiphysis
cartilage
What does the internal structure of a bone consist of
Spongy bone
Red bone marrow
Medullary cavity
Yellow bone marrow
Compact bone
Periosteum
Function of the lacunae
Small spaces in the matrix between the lamella to house an osteocyte
Function of a lamellae
Concentric layers of bony matrix
Function of the canaliculae
Tiny projections running between the lacunae to make contact with adjacent bone cells allowing material to pass from cells
Function of the central canal
Holds blood capillaries, nerves and lymph capillaries
