Lecture 8: Ligaments, fascia and tendons (Hayward) Flashcards
what is fascia classified as?
irregular dense connective tissue
what are fasciae, tendons and ligaments classified as?
dense connective tissue
what are tendons and ligaments classified as?
dense regular connective tissue
define ligaments
they are regular dense connective tissue that attach bone to bone.
what is the function of ligaments
to stabilize and strengthen joints and limit the movement of bones in certain directions
they can also bind tendons to bones
how are ligaments arranged?
they are taut when the joint is in the position of maximum stability.
what is the morphologic arrangement of collagen fibers and fibrocytes in ligaments?
there are smaller collagen fibers and variable numbers of elastic fibers.
what are elastic ligaments?
they consist mostly of elastic fibers, imparting considerable flexibility and recoil.
what are some examples of elastic ligaments?
ligamenta flava and ligamentum nuchae
are ligaments resistant to tensile (stretching) forces?
YES!
define fascia
the connective tissue surrounding the different sub-compartments of muscle.
all layers of fascia are in continuity with each other and converge to form a common bundle of fibers or the muscle tendon
what is the epimysium?
a sheet of dense connective tissue that completely surrounds and invests the muscle belly
what is the perimysium? what is it composed of?
a second order of collagenous connective tissue that invade the depths of the muscle belly to ensheath muscle fibers to form muscle fascicles or bundles.
it is composed of epimysial septae
what is the function of the perimysium?
it conveys blood vessels and nerve branches passing to and from the muscle fascicles.
what can you find within the perimysium?
muscle spindles, proprioceptors that function as stretch receptors in muscles.
define endomysium
connective tissue that surrounds each muscle fiber.
what is endomysium composed of?
primarily reticular fibers that harness the margins of the muscle fibers through connections with the external lamina that surrounds each muscle fiber
capillaries and nerve fibers pass within which type of fascia?
endomysial connective tissue
define myotendinous junction
mysial connective tissues located at the muscle’s insertion and origin that merge and become confluent to form tendons or aponeuroses.
define tendons
cylindrical regular dense connective tissue in which muscle fibers end and are attached to bones
what is the primary function of a tendon
to transmit forces developed by muscles to the skeleton
what can large tendons be used for in some animals?
they can be used to store elastic energy when stretched. the stored energy is recycled during subsequent movements (kangaroo is an example).
define aponeuroses
tendons that consist of flat sheets of dense connective tissue that typically attach flat muscles to bone
what are tendons composed of?
type I collagen fibers tightly packed into bundles.
what is the significance of the tight bundling of collagen fibers in tendons?
there is little amorphous ground substance located between fibers
how are fibrocytes aligned in mature tendons?
in parallel rows between bundles
how are collagen fibers organized in tendons? (endotenon, peritenon, epitenon, paratenon)
they are organized into bundles by loose connective tissue septae called endotenon which contain blood vessels and nerves.
several small bundles may be further organized into larger bundles by loose connective tissue septae called PERI-tenon
peritenon is continuous with an outer layer of DENSE connective tissue called epitenon.
epitenon is invested in PARA-tenon, which consists of LOOSE connective tissue that permits movement during locomotion.
how do vessels and nerves pass to tendons?
via paratendons
where will you typically find synovial tendon sheaths?
in areas where friction is enhanced by greater movement and/or pressure from adjacent structures
what reduces friction during movement?
synovial fluid located within the lumen of synovial sheaths
where do vessels and nerves pass from the paratendon to the epitendon when covered by synovial sheaths?
they pass within the mesotendon formed by reflection of the synovial membranes
what causes tendonitis?
under circumstances of repetitive movements, the lubricating function of the sheath can become exhausted and the tendon and sheath become irritated. this can be extremely painful and cause lameness
tendons and ligaments attachment sites are typically what?
fibrocartilage or bone
what are sharpey’s fibers?
collagen fibers of tendons that become embedded in newly formed bone during growth.
