Musculoskeletal System Flashcards
Function of skeletal system
Support Movement - levers that muscle can attach to Protection Production of blood cells Storage of minerals & fats
Macroscopic structure of long bone
Consists of ; Diaphysis - middle epiphysis - ends periosteum - outer layer cylinder of compact bone - used for fat storage and YBM compact bone on outside central region contains spongy bone
Bone
connective tissue
consists of cells separated from each other by large amounts of matrix
Spongy bone structure
irregular arrangement of trabeculae
bone cells occupy space in trabeculae
nerve & blood vessels pass through irregular spaces in matrix
compact bone structure
contain osteons
centre of each osteon is a central canal through which nerves & blood vessels pass
osteons located in lacuna - arranged in lamellae - have cannaliculi -> extensions that allow them to transfer nutrients & communicate
types of bone
long, short, flat, irregular, sesamoid
cartilage structure
chondroblasts - produce matrix trapped in small spaces called lacunae
collagen fibres - embedded in a firm matrix of chondrin
matrix provides structure
fibre provided flexability
Types of cartilage
hyaline - strong & tough - absorbs shock
elastic - thicker and elastic - support & shape
fibrocartilage - thick & coarse - withstand high pressure
define joints
a place where 2 bones meet and articulate with each other held together by tough fibres called ligaments
types of joints
Fixed
Slightly movable
Immovable
TYPES OF TYPES OF JOINTS
Ball & Socket - freely movable Hinge - 1 plane movement Pivot - one bone rotates on another Gliding - one flat surface moves over another saddle - side to side & back and forth
Muscular system function
Produce movement Maintain posture Produce heat (shivering)
Properties of Muscles
Excitability - response to chemicals
Contractability - can get shorter to generate force
Extensibility - can be stretched w/o damage
Elasticity - return to original length
Muscles in situations
Tendon - connect muscle to bone
ligament - joins bone to bone
belly - fleshy portion of muscle
synergists - muscles that steady a joint during a specific movement
origin - end of muscle connected to a stationary bone
Insertion - end of a muscle connected to a moving bone
Agonist/prime movers
cause movement in a given direction
antagonistic
a muscle that has an action opposite to the agonist
Muscles in Action pairs
Act in ANTAGONISTIC PAIRS
one muscle (agonist) contracts and the other (antagonistic) relaxes
muscle contracts, pulls on a bone in one direction & must be accompanied by another muscle that pulls the bone in the opposite direction
types of movement
Extension - increasing the angle between 2 joints
Flexion - decreasing the angle between 2 joints
Abduction - movement of a limb away from the mid line of the body
Adduction - movement of a limb towards the mid line of the body
Muscular breakdown
Skeletal muscle - muscle fibres - myofibrils - myofilaments
structure of muscle
muscle cells held together in bundles surrounded by connective tissue
1 muscle fibre = 1 muscle cell
thin transparent plasma membrane - sacrolemma
containts cytoplasm - sarcoplasm
inside sarcoplasm is mitochondria & lots of myofibrils
myofilaments - made of protein - units involved in contraction of muscle
two types of myofilaments
thick - myosin
thin - actin
Sacromere
unit of contraction
divides myofibrils into unites
made up of contactile proteins between z-lines
contractile units are actin & myosin
define sliding filament theory
explains the mechanism of muscle contraction based on muscle proteins that slide past each other to generate movement
