Articulations Exam 2

Join (synovial) cavity

space between the two articulating bones

Articular capsule

provides foundational structure

double layered sheet of connective tissue structure surrounding the joint cavity

superficial layer: dense irregular CT, tough and resilient

deep layer: synovial membrane made of loose CT (makes lubricating fluid) 

Synovial fluid

liquid filling the joint cavity that is secreted by cells in the synovial membrane

functions: lubricate the joint, provides nutrients to cartilage, absorbs shock

Articular Cartilage

Hyaline cartilage that covers the surface of the bones within the joint cavity

function: protect the bone, absorb shock and reduce friction

helps with joint health

bursae + fat pads: small fluid filled sacs where friction would occur

Flexion

moves away from the anatomical position through sagittal plane

Extension

opposite of flexion returns to anatomical position 

Dorsiflexion

raises toes superiorly

Plantar flexion

moves the toes inferiorly

Abduction

moves away from the longitudinal axis in frontal plane

take limb away from midline

Adduction

opposite of abduction returns to anatomical position

addition

Rotation

turn around long axis of bone

head is along midline so we can rotate the head left or right

limbs can rotate lateral away from the midline or medial toward the midline

Pronation Vs. Supination

medial rotation of forearm, rotate palm to face downward

ex. type of keyboard 

return to anatomical position, turn palm upward

ex. hold a bowl of soup

radius moves around ulna 

Protraction

moves anterior

Retraction

moves posterior, opposite of protraction, move mandible forward

chew food, speak clearly

Elevation vs Depression

raise superior ex. closing the jaw

lower inferior, ex. opening the jaw

Pivot Joints

allows rotation only

ex. atlantoaxial joint between C1 and C2, proximal radioulnar joint

Hinge joints

allows angular motion of flexion and extension

allows movement in 1 plane only

ex. elbow or knee joints

Saddle joints

surface concave on one axis convex on others, enables flexion and abduction

ex. carpometacarpal joint between the trapezium and first metacarpal

lets thumb touch each finger (opposition)

Plant Joints

allows a small amount of sliding

ex. intertarsal joints intercarpal joints (flexibility of foot/spine)

Condyloid Joints

oval face in a depression, allowed flexion and abdiction

ex. wrist and emtacarpophalangeal joints

lets us play musical instrument 

Ball and Socket Joints

flexion, abduction, rotation, circumduction

femur head fits into pelvis

hip sacrifices mobility for stability, shoulder stability for mobility

Humeroulnar Joint

Elbow

very stable monoaxial hinge joint with a tight fit between the articular surfaces of the trochlea on the humerus and the trochlear notch of the ulna

further stabalized by thick capsule, strong ligaments, and the tendons the triceps brachii muscles, biceps brachii, and brachialis 

Humeroradial joint

Proximal Redioulnar Joint

smaller joint of the elbow formed by the capitulum of the humerus and the head of the radium

pivot joint produced by articulation between thee head of the radius and the radial notch of the ulna. stabalized by the anular ligament

Tibiofemoral (knee) joint

curved condyles on the femur fit into the flat articular surfaces of the tibia with a poor fit to form a hinge joint at the knee with relatively low stability.

Lateral meniscus and medial meniscus

c shaped pads of fibrocartilage that cover the tibial condyles improving stability by deepening articulator surface

Extracapsular ligaments

fibular/lateral collateral ligament: connects the femur to tibula

tibula/medial collateral ligament: supports medial side of the knee

Anterior Cruciate Ligament

connects from the anterior of the tibia to the
lateral condyle of the femur.

Posterior cruciate ligament (PCL)

connects from teh psoterior tibia to the medial condyle of the femur 

tensons of the hamstring muscle

on the posterior help to stabilize the knee 

Patellar tendon 

on the anterior where the quadriceps femoris group attaches to tibial tuberosity

patella is imbedded in this tendon and helps protect the anterior of the knee joint

Patellar LIgament

Quadriceps Tendon

patella to tibial tuberosity

quadriceps to patells

Glenohumeral (shoulder) joint

head of the humerud and the glenoid cavity of the scapula form a ball in socket joint that is highly flexible but instable and frequently dislocated

articulating surfaces fit loosely and blenoid fossa is shallow

Acetabulofemoral (hip) joint

Acetabular labrum 

head of the femur fits deeply into the acetabulum to form stable ball in socket joint

strong/dense capsule extend from the neck of the femur to the rim of the acetabulum. 

horseshoe shaped pad of fibrous cartilage that further increases the depth of the socket

Arthiritis

inflammation of the joints, resulting in pain and decreased ROM

cartilage (usually gives smooth and cushioned surface) wears away

Osteoarthritis

most common form, wear and tear to articular cartilage over time

Rheumatoid arthritis

autoimmune disease that involved the immune system attacking the tissues around synovial joints, damaging the articular cartilage

joint capsule swells

Gout 

excess uric acid, a waste product

crystallized and forms deposits in the connective tissue surrounding a joint 

sudden pain