Joints, Cartilage, Muscles Flashcards
what are the three classifications of joints ?
fibrous, cartilaginous and synovial
the skull is an example of what type of joint ?
fibrous
the pubic symphysis is an example of what type of joint ?
cartilaginous
a finger is an example of what type of joint ?
synovial
what are fibrous joints ?
articulating bones connected by fibrous tissue with limited movement
what are the three examples of fibrous joints ?
the skull, the syndesmosis and gomphosis
what are cartilaginous joints ?
articulating bones united by hyaline or fibrocartilage
what are synovial joints ?
articular surfaces = hyaline cartilage (most common type of joint)
how many synovial joint classes are there ?
6
by what are synovial joints reinforced by ?
ligaments + special structural elements
what does each synovial joint have ?
joint capsule (lined by synovial membrane)
what do synovial membranes contain ?
synovial fluid
what are the 6 synovial joints ?
- saddle
- ball and socket
- condyloid
- pivot
- hinge
- plane
example of where saddle joint is present ?
at the base of the thumb
example of where a ball and socket joint is present ?
shoulder or hip
example of where a condyloid joint is present ?
wrist
example of where a pivot joint is present ?
the radial head next to the ulna in your elbow
example of where a hinge joint is presnet ?
humerus and ulna articulating at the elbow or knee
example of where a plane joint is presnet ?
between the carpals and the tarsals
what are the three factors that affect the stability or range of motion of joints ?
- shape and arrangement of articulating surfaces
- ligaments crossing the joint
- tone of surrounding muscles
what is atrophy ?
muscle wasting
describe the movement of a ball and socket joint
- multi-axial
- synovial joint
- high mobility
- low stability
which ball and socket joint has more range of motion ?
shoulder
where on the pelvis creates the socket for the ball and socket joint of the hip ?
bony acetabular rim
how many axis does a hinge joint get ?
only one single axis
describe the movement of a hinge joint
- uniaxial joint
- more stability
- less range of motion
what’s an example of a simple and a complex hinge joint ?
simple = elbow and complex = knee
how many structures are synovial joints made of ?
5
what are the 5 structures that come together to allow synovial joints to function ?
- bones
- tendons/muscles
- ligaments +capsule
- intra-articular structures
- bursae
what are ligaments ?
connective tissue structures that bind bones together
when do joint injuries occur ?
damage occurs when forces exceed their strength
what is damage to a muscle tendon called ?
strain
what is a grade 1 ligament tear ?
stretching or slight ligament tearing with mild tenderness, swelling and stiffness
what is a grade 2 ligament tear ?
incomplete tear with moderate pains welling and bruising
what is a grade 3 ligament tear ?
complete tear of ligaments with severe swelling, bruising and instability
what is damage to a muscle ligament called ?
sprain
what is the treatment for a joint injury ?
PRICE
what does PRICE stand for ?
protection, rest, ice, compression, elevation
what do articular discs do ?
- absorb shock
- better fit between bony surfaces
- distribute weight
what is the term defined as a rim of soft tissue or fibrous cartilage that surrounds the socket of a ball and socket joint to make it more stable ;
labrum
where do bursitis’ occur ?
at synovial joints
what are bursas’ ?
fluid filled sacs that reduce friction between moving parts
where are bursar found ?
anywhere in the body where you have a lot of friction between two surfaces
what is bursistis ?
chronic inflammation of a bursa
what causes a bursistis ?
- irritation from repeated excessive exertion of a joint
- trauma
- acute chronic infection
- rheumatoid arthritis
describe the function of a fibrous joint :
tight, very limited movement
describe the function of a cartilaginous joint :
some movement, allow growth for new bone
describe the function of a synovial joint :
free movement between bones
what type of joint is the most to least stable ?
fibrous = most
cartilaginous = middle
synovial = least
what is a feature of fibrous joints ?
smaller fibers; less movement
what is a feature of cartilaginous joints ?
1 and 2 degree classes
what is a feature of synovial joints ?
joint capsule present
is cartilage present in fibrous joints ?
no! fibers instead
is cartilage present in cartilaginous joints ?
both hyaline and fibrocartilage
is cartilage present in synovial joints ?
hyaline
what are the three cartilage types ?
- hyaline/artivular cartilage
- elastic cartilage
- fibrocartilage
which of the three cartilage types is the strongest in the body ?
fibrocartilage
which of the three cartilage types is the weakest in the body ?
hyaline
the following characteristics define which cartilage type ? “most abundant, yet weakest, smooth surface flexibility and support at joints” :
hyaline/articular caartlage
the following characteristics define which cartilage type? “specialized tissue with elastic fibers, provide strength +elasticity to maintain shape of structures”
elastic cartilage
the following characteristics define which cartilage type? “shock absorber, very durable; lots of collagen, support + join structures, strongest type”
fibrocartilage
hyaline/articular cartilage is a metabolically active tissue that has :
- no blood supply
- no lymph channels
- no neurological supply
which cartilage type is it difficult to identify injury or damage ?
hyaline
what is the function of hyaline/articlar cartilage ?
distributes mechanical load over a wider area to decrease stress/pressure on joint surfaces and reduce fries ion to minimize wear and allow relatively free movement of the opposing joint surfaces
what is the composition of hyaline cartilage ?
cells and extracellular matrix
what makes up the extracellular matrix of hyaline cartilage ?
- interstitial fluid
- collagen
- proteoglycans
what are the three sons of the ECM of hyaline cartilage ?
- superficial tangential (distribute force) “10 - 20%”
- middle (fluid storage) “40 - 60%”
- deep (bony connection) “30%”
where does nutrient exchange occur within cartilage loading ?
between the joint capsule to the synovial membrane + fluid
what are the two types of arthritis ?
osteoarthritis (OA) and rheumatoid arthritis (RA)
what is osteoarthritis ?
- joint cartilage is gradually lost
- wear and tear
- most common type of arthritis
- can be unilateral
what is an example of cause of osteoarthritis ?
long distance running
what is rheumatoid arthritis ?
- global cartilage inflammation
- autoimmune disease
- typically bilateral
- joint fusion possible
which type of arthritis is it when bone ends rub together ?
osteoarthritis
which type of arthritis is it when the knee is swollen/inflammed ?
rheumatoid
what is hyaline/articular cartilage well suited for ?
- bear weight and transfer load
- reduce friction during joint motion
what type of cartilage has no blood, lymph or nerve supply ?
hyaline
what are the three types of muscle ?
skeletal, cardiac and smooth
describe skeletal muscles :
- found in skeletal muscles
- striated
- voluntary control
- multi-nucleated
describe cardiac muscles :
- found in the heart
- striated
- involuntary control
- single nucleus
describe smooth muscles :
- found in viscera + blood vessels + skin
- not striated
- involuntary control
- single nucleus
which muscle types are striated / unstriated ?
skeletal and cardiac are striated while smooth is not striated
what are the four functions of muscle tissue ?
- produce body movements
- stabilizing body positions
- producing heat
- storing + moving substances in the body
what are the four properties of muscle tissues ?
- electrical excitability
- contractility
- elasticity
- extensibility
muscle tissues have electrical excitability that are able to respond to stimuli… what are the two types of signals ?
electrical and chemical signals
what are electrical signals of muscle tissues ?
autorhythmicity in the heart
what are chemical signals of muscle tissues ?
action potential signals receives at neuromuscular cleft
what type of tissue are blood vessels and nerves carried in ?
connective tissue
what is the muscle organization in our bodies from largest to smallest:
muscle, fascicle, myofibril, and myofilaments
what is the sarcomere ?
contractile unit
what is the M-line ?
where two sets of myosin fibers are going to join together
what is a region of the sarcomere that only myosin is present ?
H-band
between myosin and acting which is thin/thick ?
myosin = thick and actin = thin
what does ATP do during the sliding filament theory ?
causes myosin head to physically move
what causes tropomyosin to move ?
troponin
how are muscles attached to bones ?
tendons
what happens to the bone when you contract a muscle ?
it pulls on the bone
what are tendons made of ?
same fascial layers that encase the muscle
how does a neuron travel to the desired muscle ?
one neuron starting in the brain travels down the spinal cord out to the desired muscle
how do motor signals travel ?
from brain to the muscle
what is a motor unit ?
motor neuron + all the fibers it innervates
what is the henneman size principle ?
the recruitment of motor units within a muscle proceeds from small motor units to large motor units
force production = _________
motor unit size + firing frequency
what are the three skeletal fiber types ?
- slow oxidative
- fast glycolytic
- fast oxidative
what is the type, fatigue rate and force of slow oxidative fiber type ?
- type 1
- slow fatigue rate
- low force
what is the type, fatigue rate and force of fast oxidative fiber type ?
- type 11a
- med fatigue rate
- med force
what is the type, fatigue rate and force of fast glycolytic fiber type ?
- type 11x
- fast fatigue rate
- high force
what is the sliding filament theory ?
repetitive cycle of muscle contraction of cross bridge formation (actin/myosin binding)
when does the sliding filmant theory occur ?
in the presence of elevated calcium and required ATP
what does the sliding filament theory cause ?
cause actin filaments to ‘slide’ over myosin thick filaments, creating a shortening effect
what are the 5 steps of the sliding filament theory ?
- bound state
- power stoke
- rigor state
- relaxed state
- binding state
what happens in the bound state ?
- ADP bound to myosin
- we release inorganic phosphate
- then were going to move to a contracted state
what happens in the power stroke ?
- we’ve released inorganic phosphate
- the myosin head is bent at the hinge section
- we’ve effectively now slid actin forward
what happens in the rigor state ?
- were bound to ADP
- myosin has already contracted
- when ATP binds, myosin is going to release from actin and is going to get ready to be able to bind again
- myosin has now completely dissociated from actin
what happens in the relaxed state ?
- once ATP id bound here, were in a relaxed state
- we’ve dissociated from actin
- now just waiting
what happens in the binding state ?
- ready to bind to actin again
- ready to start the cycle all over again
what two things cause muscle contractions ?
ATP and Calcium
why is ATP necessary for muscle contractions ?
necessary for myosin to bind actin and for power stroke
why is calcium necessary for muscle contractions ?
to bind with the troponin complex, which is going to remove the tropomyosin from the binding site
where is calcium stored ?
intracellularly in the sarcoplasmic reticullum
how does calcium move (conc. gradient)
calcium flows out and down its concentration gradient
what are the 5 simplest steps of muscle contraction ?
- AP arrives at neuromusclar junction
- calcium is released from SR
- tropomyosin slides off actin
- myosin hydrolyzes ATP to bind to actin
- muscle contraction occurs
what is a strain ?
tendon/muscle injury
describe the grading of a strain injury :
grade 1 = over-stretching
grade 2 = partial tear
grade 3 = complete tear
what are symptoms of a strain ?
- swelling/brusining or redness
- pain at rest
- inability to use muscle, or weakness
what is the first aid required for strains ?
PRICE
what does PRICE stand for ?
protection, rest, ice, compression, elevation
when does progressive muscle loss with aging occur ?
from 30 onwards
what are three causes of aging + muscle ?
- deceased voluntary neural control of muscle
- slower nerve conduction speed
- muscle fiber loss
how to improve muscles ?
exercise
what are 3 benefits of exercising for your bones/muscles ?
- increased bone density
- increased motor neuron firing rate
- hypertrophy of muscle fibers
what are the fundamental contractile unit for muscle cells ?
sarcomere
