Introduction to joints and muscles Flashcards
What are joints
A site where 2 or more bones join together, whether or not a movement occurs between them. Joints may be classified according to the structure (the tissue that lies between the bones).
What are the 3 basic joints
fibrous, cartilaginous, synovial
what are fibrous joints
bones held together by fibrous connective tissue (strong), with no joint cavity
examples of fibrous joints- sutures
sutures- unmovable junction: only in skull- coronal suture
examples of fibrous joints- syndesmosis
tough band of tissue that bonds 2 bones together, this limits movement and supports the 2 bones, for example between radius and ulnar of forearm
examples of fibrous joints- gomphosis
teeth roots
2 types of cartilaginous joints
synchondrosis, symphysis
2 types of cartilaginous joints- synchondrosis
bones are held together by hyaline or fibrocartilage, with no joint cavity. Primary cartilaginous joint- temporary in immature bones
2 types of cartilaginous joints- symphysis
bones are held together by fibrocartilaginous fusion, with no joint cavity. Secondary cartilaginous joint- flat disc of fibrocartilage between bones, in the body midline
what are synovial joints
bones are held together by a fibrous capsule and accessory ligaments Has a synovial joint capsule
features of a typical synovial joint
articular cartilage/ capsule, synovial membrane, ligaments, articular discs, synovial sheaths and bursa, ,fat pads, muscle and tendons
features of a typical synovial joint- joint junction
this is the middle of each bone, with articular cartilage on either end. The shape of the joint is important, each bone needs to be complimentary to the other
features of a typical synovial joint- joint space
the joint space inside the junction is filled with synovial fluid, this provides nutrition and allows smooth movement (lubricates the joint between 2 articular surfaces)
features of a typical synovial joint- fibrous joint capsule
this provides inherent stability; the inner aspect is coated with synovial membrane- which produces and excretes synovial fluid
features of a typical synovial joint- ligaments
tough bands of fibrous tissue that go from one side to the other, and controls physiological movements.
how might ligaments be limiting
may be limiting by putting the end to normal physiological movement and preventing unwanted movement
features of a typical synovial joint- muscle
create movement
how are tendons formed
the muscle belly forms a tendon which inserts into a bone. the musculotendinois junction is where the muscle goes from being muscle and turns into a tendon. This then goes into tenoperiosteal junction- which is where tendon joins to bone. The insertion tends to mark bone
features of a typical synovial joint- bursa
a bursa is a fluid filled bag (filled with synovial fluid) it has a lighter capsular material around it. this helps to prevent friction
what is a bakers cyst
this is where synovial fluid escapes the joint and becomes a fluid filled sack on the surface of skin
When can a lump on outside of joint be dangerous
when it is pulsating as this could indicate an aneurism of one of the large vessels, this would require a physio to refer to whoever is going to look after patient
when can a bakers cyst become damaging
if it ruptures- due to gravity the fluid will drop down into the posterior aspect of the knee. this is into the muscles and the tissues and it sets up a fierce inflammatory reaction. this can lead to deep vein thrombosis
features of a typical synovial joint- ligaments
ligaments on either side of the joint are co lateral ligaments
classification of synovial joints- ball and socket joint
ball is always convex and the joint is always concave. This joint can move in 3 degrees of freedom (all 3 planes and axis)
example of ball and socket joint
the hip joint is a synovial ball and socket or multiaxial joint with3 freedoms with 3 degrees of freedom
classification of synovial joints- ellipsoid joint
has a convex surface being received by a concave surface but there will be more constrain. only 2 degrees of freedom
example of ellipsoid joint
the wrist joint can be classified as an synovial ellipsoid with 2 degrees of freedom.
classification of synovial joints- plane
can only perform gliding and sliding. (no degrees of freedom as they can only slide)
example of plane synovial joint
the tarsal joint is classified as a plane synovial joint
classification of synovial joints- saddle
this is a biconcave, this is where the joint is concave on both sides. this joint has 2 degrees of freedom
example of saddle joint
the first carpal metacarpal joint is a saddle joint with 2 degrees of freedom
classification of synovial joints- hinge
only capable of flexion and extension
example of hinge synovial joint
the elbow joint is classified as a synovial hinge joint with one degree of freedom
classification of synovial joints- pivot
one in neck, this is only capable of rotation and there one degree of freedom
example of pivot joint
the superior and inferior radius ulna joints are classified as synovial pivot joints with one degree of freedom
types of joint movement- physiological movement
voluntary, sweeping movement of one bony segment in relation to another. Often a change in angle between 2 bones, this can be measured. For example flexion/ extension, abduction/ adduction
types of joint movement- accessory
involuntary, small gliding, adjustments between joint surfaces to facilitate smooth and full movement (without accessory movement you can’t have full physiological movement). this is where parts of the joints spin, roll, glide/slide
Factors limiting joint movement- tension
tension in ligaments- helps to prevent unsafe movement
tension in antagonistic muscle
Factors limiting joint movement- approximation
approximation of soft tissue
approximation of bony parts
What is the close pack position
as joint surfaces approach a position of full congruent (best fit), the joint is said to be in close pack position. Joint structures are tensioned, all structures are at the most stable. at the close pack position there will be no accessory movement, and the joint is stable
what is the loose pack position
in any position when the joint surfaces are not congruent, and structures are not under tension the joint is described as loose packed
3 types of muscle
cardiac, smooth, skeletal (1/3 of body weight)
3 types of muscle fibres
slo oxidative- type 1, fast oxidative- type IIa, fast glycolytic type- IIb
functions of skeletal muscle
produce movement and locomotion, stabilise the joint and limit movement, maintain posture against gravity, help produce body heat, store carbohydrates as glycogen, give contour to the body
how are muscles classified
muscles are classified according to their fibre arrangement
muscle classified- multiepennate
this provide a lot of power in a relatively small space, e.g. deltoid
muscle classified- fusiform
bicep brachii is fusiform- multiple insertions/ origins, wider in centre than at either end
muscle classified- bipennate
rectus femoris is bipennate- 2 lots of striation in one muscle with a tendon at either end
muscle classified- unipennate
unipennate muscles- only striations in one direction e.g. extensor digitorum
muscle classified- parallel
long fibres parallel over a long distance
muscle classified- convergent muscle
muscle fibres from multiple origins narrowing into a single small tendon, e.g. pectorallis major
muscle classified- circular muscle
arranged concentrically around an opening or recess. As the muscle contracts, the opening it circumvents gets smaller
how many points of attachment do skeletal muscle have
it has 2 or more points of attachment, these attach by tendons. Proximal (origin), distal (insertion), shape of tendon reflects shape of muscle
what do tendons allow
concentration of muscle pull, attachment to a small bony area, alteration of direction of muscle
example of muscle attachment- coracobrachiallis
proximal attachment- tip of the coracoid process to distal attachment: mid shift of humorous, action- adduction and weak flexion of arm, nerve supply- musculocutaneous (C5,6,7)
Muscle roles- agonist/ prime mover
responsible for movement
Muscle roles- antagonist
responsible for the movement opposing that of the agonist
Muscle roles- fixator
steadies the base; stabilise the proximal attachment of the agonist
Muscle roles- synergist
improves quality and control, by preventing unwanted movement in adjacent joints
what are isometric (static muscle work)
an increase in tension with no changes to the muscle length so no movement is produced
what are isotonic (dynamic muscle work
an increase in tension which changes muscle length, so movement is produced
isotonic- concentric
muscle shortens (origin gets closer to insertion)- internal muscle force } external
isotonic eccentric
muscle lengthens- internal muscle force { externeral
what is active insufficiency (agonist)
a muscle, which passes over 2 joints cannot actively shorten sufficiently to produce full range of movement at both joints
passive insufficiency- antagonist
a muscle, which passes over 2 joints, cannot be passively lengthened enough to allow full range of movement at both joints
