Skeletal System 4 - Joints and Movement Flashcards
True or False. Joints are classified by their anatomical characteristics, functionality & type of movement
True
How are joints structural classified?
Fibrous
Cartilaginous
Synovial
Please give an example of a fibrous joint and what it is?
e.g. Skull | No synovial cavity | Held together by dense irregular connective tissue rich in collagen
Please give an example of a Cartilaginous joint and what it is?
e.g. Spine | No synovial cavity | Bones held together by cartilage
Please give an example of a synovial joint and what it is?
e.g. Knee | Bones forming joint have a cavity | United by dense irregular connective tissue & accessory ligaments
How are joints functionally classified?
Synarthrosis
Amphiarthrosis
Diarthrosis
What is Synarthrosis?
e.g. Skull | Immovable joint
What is Amphiarthrosis?
e.g. Pubic symphysis (of pelvis) | Joint capable of slight movement
What is Diarthrosis?
e.g. Knee | Joint is freely movable | All are synovial joints | Permit different types of movement
How are fibrous joints classified?
Classified as sutures, syndesmoses & interosseous membranes
What are sutures?
Thin layer of dense irregular connective tissue
Only occur between bones of skull
Irregular, interlocking edges –
Add strength & decrease fracture risk
Functional classification – Synarthrosis
What are syndesmoses?
Greater distance between the articulating surfaces & more dense irregular connective tissue
Contain more dense irregular connective
tissue arranged into bundles (ligaments)
Permit limited movement
What are interosseous membranes?
Sheet of dense irregular connective tissue that binds neighbouring long bones | Permit slight movement
What are the two types of cartilaginous joints?
Articulating bones tightly connected by hyaline cartilage or fibrocartilage
Synchondroses
E.g. Epiphyseal growth plate | Connecting material is hyaline cartilage | Functional classification synarthrosis
Symphysis
e.g. Pubic symphysis | Ends of articulating bones are covered with hyaline cartilage | Occur at the midline of the body | Functional classification amphiarthrosis
What are synovial joints functionally classified as?
All synovial joints are functionally
classified as diarthroses
Synovial joints – Have a synovial cavity between articulating bones to permit free movement
Reduces friction - Smooth, slippery surface that does not bind form free movement
Bones at synovial joints are covered in a hyaline cartilage known as?
Articular cartilage
Synovial joints have a synovial cavity between articulating bones to permit free movement. True of False?
True
Fibrous bundles can be arranged into parallel bundles = ?
Ligaments
Ligaments are highly resistant to strains
Ligaments hold bones close together in a synovial joint
Synovial cavity houses?
Synovial fluid
What is clear to pale yellow fluid secreted by synovial membrane?
Synovial Fluid
What is synovial fluid comprised of?
hyaluronic acid & fibroblast like cells and it forms a thin film over the surfaces within the articular capsule
Many synovial joints contain accessory ligaments & articular disks. True or False
True
What are the names of the accessory ligaments to synovial joints?
Extracapsular ligaments
e.g. fibular & tibial collateral ligaments
Lie outside the articular capsule
Intracapsular ligaments
e.g. Anterior cruciate ligament (ACL)
Occur within the articular capsule, but outside the synovial cavity
What are articular disks of synovial joints?
Pads of fibrocartilage that lie between the articular surface
Occur within the articular capsule, but outside the synovial cavity
Disks subdivide the synovial cavity into 2 spaces –
Allow separate movements
Allow two bones of different shapes to fit together more tightly
Do synovial joints contain nerve endings?
Yes
Nerves that supply a joint are the same
as those that supply skeletal muscles
Nerve endings convey information about
pain to the spinal cord & brain
Other nerve endings respond to the
degree of movement in a joint
Do synovial joints receive penetration from arteries and veins?
Yes.
Provide oxygen & nutrients
Remove CO2 & waste
What is gliding movement?
Side-to-side and back-and-forth motions
What movements can synovial joints allow?
Gliding, Flexion and extension, abduction, adduction, circumduction and rotation, pronation, supination, dorsiflexion, plantar flexion, inversion & eversion Retraction, protraction, elevation, depression & opposition
What are planar joints?
Permit back-and-forth & side-to-side movement between flat surfaces of bone
Many planar
joints are biaxial
(permit movement around 2 axes)
i.e second and third cuneiform and navicular
What are hinge joints?
Convex surface of one bone fits into a concave surface of another
Produce angular, opening & closing motions
What are pivot joints?
Rounded or pointed surface of 1 bone articulates with a ring formed partly by another bone & a ligament
Monoaxial (rotates around its own longitudinal axis)
What are condyloid joints?
Convex oval-shaped projection of one bone fits into an oval shaped depression of another
Biaxial
Flexion-extension
Abduction-adduction
What are saddle joints?
Articular surface of one bone is saddle shaped & articular surface of the other bone fits into the ‘saddle’
Triaxial – Movement around 3 axes
Flexion-extension | Abduction-adduction | Rotation
What are ball and socket joints?
Ball-like surface of one bone fitting into a cuplike depression of another bone
Triaxial
Flexion-extension | Abduction-adduction | Rotation
What factors affect contact and ROM?
Structure and shape of articulating bones
Strength and tension of joint ligaments
Arrangement and tension of muscles
Contact of soft parts
Hormones
Disuse
What do structure and shape of articulating bones affect during contact and ROM?
Determines how closely bones fit together | Complimentary relationship allows greater degree of movement (e.g. ball and socket of hip)
What do strength and tension of joint ligaments affect during contact and ROM?
Ligaments are tense & taught at certain joint positions | Can restrict ROM & direct movement of articulating bones (e.g. ACL taught & PCL loose when knee is straightened & vice versa)
What do arrangement and tension of muscles affect during contact and ROM?
Reinforces the restraint placed on a joint by its ligaments to restrict movement
What do contact of soft parts affect during contact and ROM?
Point at which the body surface contacts another (e.g. bending the arm at the elbow)
What do hormones affect during contact and ROM?
Relaxin produced by placenta & ovaries | Increases flexibility of fibrocartilage of pubic symphysis | Permit expansion of pelvic outlet to assist with delivery of baby
What does disuse affect during contact and ROM?
Joint not used for a prolonged period of time (e.g. elbow joint immobilised by cast, reducing ROM at the joint temporarily following removal of cast)
How does physical activity help synovial joints?
Synovial fluid stimulated & secreted in response to joint activity
Synovial fluid is viscous (gel-like) in immobile joints
Physical activity stimulates secretion of synovial fluid
Increased synovial fluid decreases joint stress when exercising
What happens to joints as we get older?
Ageing promotes the decreased production of synovial fluid
Articular cartilage becomes thinner
Ligaments shorten & lose flexibility
Age 80 – Almost all people develop degeneration of the knees, elbows, hips & shoulders
Osteoarthritis present in
almost all people over age of 70
Elderly people undergo degenerative changes of the vertebral column - ‘Hunched’ posture from kyphosis places pressure on nerve roots
What can help to minimise effects of ageing joints?
Stretching, aerobic & resistance exercise that attempt to maintain full ROM
