Human Anatomy - Joints Part 2 Flashcards
What are the different special structures of synovial joints?
Articular disc (ex: meniscus) Bursae and tendon sheaths
The articular disc allows bones of _______ ____ to ____ together.
It makes joints more _____ and minimizes _____ and _____ on joint surfaces.
It can _______ or _______ divide the joint cavity.
Consists of ________.
Different shapes to fit together tightly
Stable and minimizes wear and tear
Partially or completely
Fibrocartilage
The ______ is the most stressed joint in the body.
Knee
Where can you find articular discs?
Knee joint
Temporomandibular joint of the jaw
What do articular discs provide?
Where can you find them?
What do they consist of?
Function to allow bones of different shapes fit snugly.
Makes joints more stable and minimizes wear and tear.
Distributes the load more evenly.
Can fully or partially separate the joint cavity.
They are found in the knee (menisci) and in the temporomandibular joint of the jaw.
Consists of fibrocartilage.
What is a bursa?
Flattened, fibrous sac lined with synovial membrane containing a thin film of synovial fluid.
What is a tendon sheath?
Elongated bursa that wraps around a tendon that experiences friction on all sides.
Bursae and tendon sheaths aren’t strictly part of ______ but are associated with them.
These function to _______ (more than one word).
They are closed bags of _________.
Joints
reduce friction between body elements
Lubricant
Describe student’s elbow
How are severe cases treated?
Resting ones elbow on a desk can lead to swelling of the olecranon fossa.
This causes swelling and pain, which can lead to inflammation of the bursa.
Severe cases are treated by injecting inflammation reducing drugs into the bursa or by fluid removal.
What are the factors influencing joint stability?
Articular surfaces
Ligaments
Muscle tone.
Articular surfaces ______ play a major role in joint stability.
However, the ______, ______ and the _____ do provide stability due to ________ joint sockets.
Seldom (rarely)
elbow, ankle, hip
deeper
How do ligaments provide joint stability?
The more ligaments in a joint, the stronger it is.
What is the most important factor in joint stability?
Muscle tone, keeps tension on muscle tendons.
______ ____ supports the arches of the foot.
Muscle tone
What issues arise with ligaments?
Poorly vascularized so they don’t heal well.
Once they stretch past 6% of their resting length, they do not recoil. (dense regular)
What does double jointed really mean?
Not that the person has two joints.
Rather, the person has more elastic ligaments.
However, this might not impart the same structural integrity.
These individuals may be more prone to injury.
Describe a sprain?
Twisting of a joint that stretches or tears a ligament
No dislocation of the bones
May damage nearby blood vessels, tendons or muscles
Swelling and hemorrhage occur from broken blood vessels.
Common in the ankle.
What is a strain?
Overstretched or partially torn muscle.
What is the difference between a sprain and a strain?
Sprain is more serious, involving a ligament.
A strain is less serious, involves muscle.
Articular surfaces that are flat and allow only short gliding movements.
Non-axial
planar joint
Cylindrical projection of one bone fits into a trough-shaped surface on another.
Uniaxial
Hinge joint
The rounded end of one bone protrudes into a ring of bone and ligament.
Uniaxial
Pivot joint
The oval articular surface of one bone fits into a complemetary depression in another.
Condylar joint
Biaxial
Each articular surface has both concave and convex areas.
Saddle joint
Biaxial
Spherical or hemispherical head of one bone articulates with the cup-like socket of another.
Ball-and-socket joint
Multiaxial
Joints are classified by shape and movement.
What are the different movement classifications?
Planar (non-axial), uniaxial, biaxial, multiaxial
Describe a planar joint?
Non-axial
No specific direction
Two flat surfaces sliding across one another
Where can a planar joint be found?
Carpals and tarsals, between vertebrae
Describe a uniaxial joint.
Give examples of joint types that would fall in this category
One direction, one plane
Hinge or pivot joint
Where could we find a uniaxial joint?
Radius and ulna
radius can pivot in respect to ulna
Describe a biaxial joint.
Give an example of a joint type that falls in this category.
Give a location where this could be found.
Two planes of movement.
Abduct/adduct and flexion/extension.
Saddle joint
Joint between the carpals and metacapals.
Where would we find multiaxial joints?
Shoulder and hip
What is a gliding movement?
Where would we find an example of this?
What is an example movement?
One flat bone surface slips over another without much angulation or rotation.
Location: intercarpal joints of wrist
Example movement: Waving hello
What are the different angular movements?
Flexion, extension, hyperextension, abduction, adduction, circumduction
What is flexion, what plane does it use?
Movement along the SAGITTAL PLANE that decreases the angle of the joint and brings the articulating bones closer together.
What is extension? What plane does it use?
Movement along the sagittal plane that increases the angle of the joint and moves articulating bones further apart.
What is hyperextension?
Bending a joint beyond its normal ROM (past anatomical position)
Where can hyperextension occur?
At the shoulder and hip, when moving the limb past anatomical position (posteriorly)
Neck, leaned back further.
Torso leaned back further.
Wrist, pulled back
What is abduction? What plane does it follow?
Movement of a limb away from the midline, along the frontal plane.
How does abduction work for the fingers and toes?
Spreading them apart.
What is adduction? What plane does it follow?
Movement of a limb towards the midline, along the frontal plane.
What is circumduction? What plane does it use?
What joint types use this?
Combination of flexion, extension, adduction and abduction.
Involves different planes.
For ball and socket joints.
What is rotation?
What is medial rotation?
What is lateral rotation?
Bone revolves around its own longitudinal axis.
Medial rotation is directed towards the midline.
Lateral rotation is directed away from the midline.
What is supination?
Palms face anteriorly.
Radius and ulna are parallel.
What is pronation?
Palms face posteriorly.
Radius and ulna are crossed.
What is protraction? What plane does it use?
Non-angular anterior movement in the transverse plane.
What is retraction? What plane does it use?
Non-angular posterior movement in the transverse plane.
What is elevation?
Lifting a body part superiorly
What is depression?
Moving an elevated body part inferiorly
What is an example of elevation and depression>
Opening and closing the jaw.
What is opposition?
Touching thumb to fingers.
What is dorsiflexion?
Lifting the foot so the superior surface approaches the shin.
What is plantar flexion?
Depressing the foot, pointing the toes.
Dorsiflexion and plantar flexion are both movements at the ______.
Ankle
What is inversion?
Turning the sole medially.
What is eversion?
Turning the sole laterally.
