HSCI 3300 - chap 9: joints

what is a joint

• also called an articulation or arthrosis

what is a joint

• a point of contact between

joints can have points of contact between

• two or more bones

joints can have points of contact between

• cartilage and bone

joints can have points of contact between

• teeth and bone

joints can be classified in 2 ways

• functionally

• structurally

functionally classified joints are based on

•  the type/amount of movement that is permitted - around joint (some lots, some little, some no movement)

structurally classified joints have the

•  presence or absence of a space between articulating bones (synovial cavity)

structurally classified joints are based on

• the type of connective tissue that binds the bones together

classification of structure can be classified in 3 ways

• fibrous

classification of structure can be classified in 3 ways

• cartilaginous

classification of structure can be classified in 3 ways

• synovial

for fibrous joints bones are held together by

• dense (regular or irregular) collagen fibers

for fibrous joints the degree of movement is

•  usually/mostly immovable to slightly moveable

cartilaginous joints are bonds held together by

• cartilage

cartilaginous joints are usually

• hyaline or fibrous cartilage

cartilaginous joints range in movement between

•  immoveable to slightly moveable

synovial joints are surrounded by a

• 2-layer articular capsule that unite the bones

synovial joints are most of the

• joints in the body

synovial joints are very

• moveable

synovial joints range in

• movement between slightly moveable to freely moveable

fibrous joints lack

•  cartilage and a synovial cavity and are held closely together by dense irregular connective tissue

fibrous joints permit

• little to no movement

the two main fibrous joints are

• sutures

the two main fibrous joints are

• syndesmoses

a suture is a

• seam

sutures are made of a fibrous joint composed of

• a thin layer of dense irregular tissue between bones of the skull

what is an example of a suture

•  the coronal suture between the frontal and parietal bones

in sutures what gives them their added strength

• the irregular interlocking edges of the sutures

sutures form as

•  numerous bones of the skull come in contact during development

in older adult, sutures are

• immoveable

in children and infants, sutures are

• slightly moveable (since not fully fused)

since sutures interlock its harder for

• bone to move

sutural ligaments _________ the bones together

• bind

what are sutural ligaments made of

• dense irregular tissue

syndesmosis is a

• band or ligament

in syndesmoses there is a greater distance between the

• articulating surfaces, unlike sutures

syndesmoses have more

• dense irregular tissue than a suture

what are the 3 main types of syndesmoses

• interosseous ligament

what are the 3 main types of syndesmoses

• interosseous membrane

what are the 3 main types of syndesmoses

• gomphosis

an interosseous ligament

• closely holds bones together

• made of fibrous tissue

interosseous ligaments permit

• limited movement

an example of an interosseous ligament is the

• distal tibiofibular joint (anterior tibiofibular ligament)

an interosseous membrane is a

• sheet of tissue that binds neighboring long bones

interosseous membranes permit

• limited movement

interosseous membranes provide

• attachment for muscle

an example of an interosseous membrane is the

• membrane between the forearm and leg bones

the gomphosis is the joint between

• the roots of teeth and their sockets (alveoli) in the maxillae and mandible = unique joint

gomphosis joints are held together with

• dense irregular connective tissue (periodontal ligament)

gomphosis permits

• slight shock absorbing movements

gomphosis is a

• dentoaveolar joint

cartilaginous joints lack a

• synovial cavity - no space between bones, if there is there will be cartilage

in cartilaginous joints the articulating boned are held together with either

• a solid piece of hyaline cartilage or fibrous cartilage

cartilaginous joints permit

• little to no movement - depends on type of cartilage present

the two types of cartilaginous joints are

• synchondroses

the two types of cartilaginous joints are

• symphyses

synchondrosis is

• chondro = cartilage

synchondroses are a joint in which

• the connecting material is made up of a solid piece of hyaline cartilage

synchondroses joints allow for

• little to no movement

examples of synchondroses joints are the

• 1st sternocostal joint

• epiphyseal cartilages

the sternocostal joint is the joint

•  between the 1st rib and the manubrium of the sternum

the sternocostal joint is

• slightly moveable

for the sternocostal joint the other

• rib joints are synovial

the epiphyseal cartilages are

• Hyaline cartilage between growth centers during endochondral bone formation (ossification)

the epiphyseal cartilages is an

• immoveable joint

symphysis is

• growing together

in a symphyses joint the ends of

• articulating bone are covered in hyaline cartilage

a symphyses is a broad, flat disc of

•  fibrous cartilage (fibrocartilage) connects the bones - cartilage is between bones

symphyses are

• slightly moveable

different examples of symphyses are

• The pubic symphysis (between the 2 pubic bones)

different examples of symphyses are

• Joint between the manubrium and body of the sternum

different examples of symphyses are

• Joints between bodies of vertebrae (intervertebral discs)

synovial joints are the

• most common type of joint

• lots of different movement takes place in these joints

synovial joints are more

• complex than fibrous or cartilaginous joints

synovial joints have a space called the

•  articular cavity (or joint capsule) separates the articulating bones

the articulating (synovial) cavity has

• Bones are connected by ligaments that form a capsule around the joint

the articular cavity is filled with

• a lubricating fluid

articular (hyaline) cartilage covers the

•  the articulating surfaces of bones but does not bind them together

articular (hyaline) cartilage reduces

• friction between bones in the joint during movement and help absorb shock

synovial joints range from

• slightly to freely moveable

the articular capsule is only found in the

• synovial joints

the articular capsule is a

• sleeve-like articular capsule surrounding a synovial joint

the articular capsule encloses the articular cavity an

• unites the bones

the articular capsule is made of 2 layers

• outer = fibrous

the articular capsule is made of 2 layers

• Inner, synovial membrane (not made of epithelium but made of synovial cites - secretes synovial fluid into the space between bones)

the fibrous layer in the articular capsule is a

• thickened continuation of periosteum between the bones = ligaments

the flexibility of the fibrous layer of the articular capsule permits

• considerable movement

the synovial membrane of the articular capsule is made up of

•  areolar connective tissue with collagen and elastic fibers

the synovial membrane is the layer that secretes the

• lubricating fluid called synovial fluid

synovial fluid is a

• viscous, clear or pale-yellow fluid that resembles uncooked egg whites

the function of the synovial fluid is to

• Reduce friction and lubricating the joint - allows bones to move freely

the function of the synovial fluid is to

• Supply oxygen and nutrients to and removing wastes from the chondrocytes within the articular cartilage

the synovial fluid has to supply the joint capsule with nutrients since

• cartilage is not very vascular

synovial fluid contained

• phagocytes that remove microbes and the debris that results from normal wear and tear in the joint

Warming up before exercise stimulates

•  the production and secretion of synovial fluid

cracking and popping is the joints is thought to be the result of

• gas bubbles in the fluid

Many synovial joints also contain accessory ligaments called

• extracapsular (exterior) ligaments and intracapsular (interior) ligaments

examples of extrascapular (exterior) ligaments are

• lateral and medial collateral ligaments of the knee joint (LCL or MCL)

examples of intracapsular ligaments are

• Interior examples: anterior and posterior cruciate ligaments of the knee joint (ACL or PCL)