Test 1 (topic 2 - Fascia, Tendons, Ligaments & Cartilage) Flashcards
Fascia:
Layers of connective tissue which support and surround organs (such as muscles, bones, and nerves)
3 types of fascia:
Superficial fascia
Deep fascia
Visceral/subserous fascia
Superficial fascia:
Subcutaneous layer (hypodermis) of the skin
Superficial fascia composed of:
Loose connective tissue and adipose tissue
Superficial fascia attaches:
Skin to underlying strxs and allows it to move easily over the underlying strxs
Superficial fascia provides:
Insulation and padding/protection (thickness varies, from region to region within the body)
Deep fascia:
Dense connective tissue (slightly stretchable; also capable of contraction/stiffening
Deep fascia forms:
Tough sheets, wrapping around organs, providing support
i.e. Intermuscular septa which bundle muscles together into compartments; fibrous capsules/sacs surround organs such as the heart, kidneys, bones, muscles, blood vessels, nerves, and tendons
Deep fascia, all interconnected . . .
blending into each other
- transmits forces placed on one part of the body throughout the rest of the body
Deep fascia innervation and vascularization:
Richly innervated but not well vascularized
Deep fascia and interstitial fluids:
Can channel the flow of interstitial fluids; can contain/limit the spread of infections
Visceral/subserous fascia:
Loose connective tissue lying between deep fascia and the serous membranes lining internal body cavities (specifically)
Visceral/subserous fascia makes it possible for:
overlying musculature to contract and move easily over the serous membrane, without impinging upon the contents of the body cavities
Visceral/subserous fascia helps provide:
Support for organs/strxs it surrounds
Tendons:
Bundles of dense regular connective tissue connecting/anchoring a muscle to a bone
Tendons are
- strap/cord-like or a broad, sheet-like strx (aponeurosis)
- formed and continuations of the connective tissue coverings of the muscle
- fibers interweave into the periosteum and become part of the outer layers of bone tissue (Sharpey’s/perforating fibers)
- generally fxn under tensile conditions, can stretch slightly
- flexible, can be redirected around bony prominences
Tendon strx: composition
Collagen fibers; minimal ground substance; tenocytes (tendinocytes); small amts of fibrocartilage
Tendon strx; composition; collagen fibers
Predominantly type I collagen with some elastic and reticular fibers as well
a) energy-storing tendons may contain a slightly higher proportion of elastic fibers than positional tendons
Tenocytes (tendinocytes):
specialized elongated fibroblasts, scattered in-between the collagen fibers
Tendons; strx; composition: fibrocartilage loc.
at the jxn with a bone, and also at points of compression where the tendon curves around a bony feature
Tendons; strx; organization: a)
Small groups of collagen fibers form a fascicle and are surrounded by a membrane formed of loose connective tissue; within the coverings of loose connective tissue are scattered fibroblasts, small blood vessels, and nerve fibers
Tendons; strx; organization: b)
Groups of fascicles are bundled together to form the tendon, which is surrounded by epitendineum (epitenon, a layer of dense irregular connective tissue); within the epitendineum are scattered fibroblasts, small blood vessels and nerve fibers
Epitendineum:
- facilitates easy movement of the tendon within its surroundings
Synovial sheath:
where the epitendineum is made up of 2 layers, with a thin, viscous fluid in-between
- where tendon passes through a synovial joint cavity (long head of biceps brachii passing through gleno-numeral joint cavity
- where tendon or multiple tendons pass through a narrow/confined space (carpal tunnel)
_________ & __________ participate in the repair process when the tendon is damaged, but healing is slow due to the limited blood supply
Fibroblasts & tenocytes
Ligaments:
- Straps of dense regular connective tissue going from one bone to another
- organization and composition in comparison to tendons
- like tendons, ligament collagen fibers interweave into the periosteum of bone, and penetrate into the outer layers of bone tissue (perforating fibers; sharpey’s fibers)
Ligament organization:
- fibers tend to e more interwoven, rather than longitudinally directed
- proprotionately, fewer collagen fibers, more elastic and reticular fibers
- no internal layers of loose connective tissue, no outer covering of dense connective tissue, and no specialized fibroblasts scattered within the ligament
Ligament fxns:
- hold bones together
- stabilize bone joints; limit or prevent specific movements btwn the bones
Why are ligaments slow to heal?
Because they are poorly vascularized
Retinaculum:
Strap of dense regular connective tissue holding underlying muscle tendons in place
Cartilage:
Type of connective tissue with a semi-rigid matrix, containing a high concentration of fibers
Cartilage general characteristics:
Typically subject to compressive forces, resulting from weight-bearing and locomotion; fibrocartilage also deals with tensile forces
A) semi-rigid nature of the ground substance allows the tissue to deform under these forces, and then return to its original shape when force is removed
Chondroblasts:
Chondrocytes:
Cartilage matrix is generally manufacture by these and are found on the exterior
Cartilage matrix is maintained by these and are found within the interior
Cartilage matrix consists of:
ground substance (containing GAGs [with varying amts of hyaluronic acid and chondroitin sulfate], proteoglycans and glycoproteins) and diff types of fibers
Cartilage is usually enclosed by _________, (consisting of 2 layers: _____ & _______ )
Perichondrium
Fibrous layer
Cellular layer
Fibrous layer:
superficial composed of dense irregular connective tissue (main fiber type = type I congenital fibers) and scattered fibroblasts, small blood vessels, nerve fibers, and lymphatic vessels
Cellular layer:
deep, containing fibroblasts and progenitor cells (prechondroblasts)
Cartilage has no direct ______ ______ ; chondrocytes and chondroblasts are supplied by _____ ______ external to the cartilage strx, within the perichondrium (if there is one)
blood supply
blood vessels
Types of cartilage:
Hyaline cartilage
Elastic cartilage
Fibrocartilage
Hyaline cartilage:
Most prevalent type of cartilage within the body (nose cartilages, articular cartilages, costal cartilages, tracheal and bronchial rings, some of larynx)
a) also involved in formation of bones (endochondral bone formation); therefore, the epiphyseal pate of growing bones is composed of hyaline cartilage.
ECM of hyaline cartilage:
the most rigid of all 3 types of cartilage
Ground substance of hyaline cartilage:
Firm, hydrated gel composed of proteoglycans and glycoproteins
a) proteoglycans predominantly contain chondroitin sulfate, bonded to core proteins, which are then bonded to long molecules of hyaluronic acid
b) chondronectin: a glycoprotein involved in binding chondrocytes to surrounding matrix
c) fibers: high concentration of type II collagen fibers, with small amts of other types of collagen fibers as well (Type IX)
Hyaline cartilage is covered by:
perichondrium, except for the articular cartilages and the epiphyseal plates; blood vessels within the perichondrium provide nourishment for the cartilage cells
Hyaline cartilage
Articular cartilage is nourished by:
Epiphyseal plate is nourished by
nutrients contained within the synovial fluid of the joint cavity
nearby blood vessels in the adjacent bone tissue
Elastic cartilage
- Internal framework for the rigid portion of the external ear (auricle); making up the epiglottis, corniculate and cuneiform cartilages of the larynx, and the pharyngotympanic tube
- intermediate in rigidity, btwn hyaline cartilage and fibrocartilage
- i) ground substance similar in comp to that of hyaline cartilage
- ii) contains both elastic fibers and type II collagen fibers
- covered by perichondrium
What covers the elastic cartilage
Perichondrium
Fibrocartilage
Forming the pubic symphysis, articular disks, and annulus fibrosis of the intervertebral disks
- capable o resisting both compressive and tensile forces
Is intermediate in rigidity btwn hyaline cartilage and dense connective tissue
Fibrocartilage
Fibrocartilage ground substance:
Has lower concentration of proteoglycans and contains a high concentration of type I collagen fibers; no perichondrium
How does cartilage under growth & development & repair?
Interstitial growth
Appositional growth
Repair of damaged cartilage
Define interstitial growth:
chondrocytes within the lacunae undergo cell division, resulting cells manufacture new cartilage matrix; occurring primarily during the earliest stages of development, ending after birth
Define appositional growth
chondroblasts found on the inner surface of the perichondrium manufacture now cartilage matrix, adding layers of matrix to the outside of the cartilage strx; process continues until puberty
Repair of damaged cartilage:
Process resembles appositional growth: chondroblasts found on the inner surface of the perichondrium manufacture new cartilage matrix, adding layers of matrix to the outside of the cartilage structure.
