Module 2 - Topic 3-4: Joints and Muscles Flashcards
Joints
hold bones together
facilitates movement
Ligament
bone to bone
Tendon
bone to muscle
Joint tissue - types
fibrous connective tissue
cartilage
mixture of both with synovial fluid
fibrous connective tissue
strength and support
Cartilage
cushioning, strength and flexibility
Mixture and synovial fluid
cushioning and lubrication
Joint Classification - composition
fibrous joints
cartilage joints
synovial joints
Fibrous Joints
no cavity
collagen fibres extend from matrix of one bone to another
eg. suture - held together by short fibres and interlocked bone edges
Cartilage Joints
no cavity
bones held together by cartilage
symphyses and synchondroses
symphyses
made of cartilage
synchondroses
bones united by hyaline cartilage
Synovial Joints
distinct cavity filled with fluid
bones seperated by cavity
eneclosed in double layered fibrous capsule
reinforced by ligaments
Articular cartilgae
outer fibrous layer, inner synovial membrane
bursae
small fluid sacs
where friction would occur
aids in gliding of tendons and muscles over bones
Core molecule in synovial fluid
hyaluronic acid, sugar that attracts water
Joint Classfication - Mobility
Synarthroses
Amphiarthroses
Diarthroses
Synarthroses
close together, no movement in joint
Amphiarthroses
little to some movement
Diarthroses
freel moveable, far apart
Ball and socket joint
allows movement in all direction
Hinge joint
allows joint to bend and straighten, does not rotate
saddle joints
fit together to allow all movement but rotation
gliding joints
two surfaces glide past each other
Gliding movement
bone glides over the other (ankle, wrist)
Angular Movement
when it changes angles between bones
Flexion
angle of joint has decreased
Extension
angle of joint has increased
Abduction
taken away from body
Adduction
towards body
Circumduction
going around
Rotational movement
movement of bone round own axis`
Supination
turning outwards
Pronation
turning inwards
Synovial Joints - 5 main parts
articular cartilage a synovial cavity synovial fluid articular capsule re inforcing ligaments
Hyaline cartilage in synovial cavity
acts as sponge
fluid is removed when joint is under pressure, placed back in when pressure is removed
main types of muscle tissue
skeletal
cardiac
smooth
muscle fibres
ability to convert chemical energy into mechanical energy
myoblasts
make up mature muscle cells
skeletal muscles
primarily attached to tendons
skeletal muscle fibres
straited appearance
contraction is voluntary
long, cylindrial and multi nucleated
Cardiac muscle fibres
striated appearance
involuntary
branching chains, one or 2 nuclei
intercalated discs
intercalated disc
intercellular junction
uniform contraction of the heart
Smooth muscle fibres
in the walls of tubular organs not striated involuntary contraction uninuclear unbranched and spindle shaped
skeletal muscle - organ level
made up of fascicles, individually wrapped and bound by connective tissue
fascicle
bundle of muscle fibres
tendons
similar to ligaments but connect bone to muscle
muscle fibres - make up
fusion of hundreds of myoblasts
multinucleated
sarcolemma
plasma membrane of skeletal muscle fibre
t tubules
extensions from sarcolemma, penetrate deep in cell
Sacrcoplasmic reticulum
a store of calcium ions which regulate the contraction of each fibre
Myofibrils
extend from one end to the other
are the contractile components
myofibril composition
thick filaments - myosin
thin filaments - actin
sarcomeres
thick and thin filaments overlapping
how muscles contract
thick and thin filaments slide past each other
muscle sliding process
actin and myosin bind to each other
myosin molecule bends dragging actin
energy from ATP
Tropomyosin
blocks the myosin binding on thin filaments
muscle stimulated to contract by nerve impulses
calcium are released
calcium binds to troponin and it changes shape
as shape change, it drags tropomyosin away
actin is now free to bind to myosin
smooth muscle
regulation of blood pressure
cells are spindle shaped and form sheets that run longitudinally
Peristalsis
rhythmical waves of compression that moves food through digestive system
smooth muscle makeup
myosin and actin filaments
intermediate filament outer netting
limited sarcoplasmic reticulum
caveoli (little cavities)
regulating contractions - smooth muscle
calmodulin and myosin light chain kinase provide calcium dependent mechaism
smooth muscle contraction
calcium is released from SR
bind to and activates calmodulin which actives MLC kinase
MLC kinase transfers phosphate from ATP to myosin cross bridges
myosin bridges interact with actin
muscle relaxtion
returns after calcium ions are reabsorbed by the SR
Muscular System functions
movement control of body openings and communication stability of posture stabilisation of joints heat production
Muscular System properties
excitability conductivity contractability extensibility elasticity
Perimysium
protective sheath around fascicle
endomysium
between individual cells
Sarcolemma
plasma membrane
Epimysium
whole muscle wrapping
Muscle Growth
fusion of myoblasts into large cells
t tubules
extensions of cell membrane into cell, allows muscles to receive signals at same time
Regulatory proteins
switch on or off contractions - troponin and tropomyosin
structural proteins
provides correct alignment, elasticity and extensibility (titin and dystrophin)
what helps anchor the filaments together
m line
z disc
titin
Myosin molecules
made of actin and ATP binding sites
Thin filaments
actin with sites for myosin attachment heads, hoever sites are blocked by tropomyosin ribbons
what happens when thick filaments pull the thin filaments
reduces other zones