3.1 joints

joints are also known as ____

functions:

articulations, support & movement

structural categories of joints:

fibrous, cartilagenous, synovial

fibrous joints

-joined by ____

-mobile or immobile?

-examples: sutures, teeth to jaw

dense connective tissue, immobile: found in areas of body that require support rather than movement

cartilagenous joints

-joined by ____

-mobile or immobile?

-examples: pubic symphysis, intervertebral joints, ribs with costal cartilages

cartilage (hyaline or fibrocartilage), slightly mobile, 

synovial joints

-joint cavities enclosed by ____ ____

-articular cartilage provides _____

-makes up most joints in the body

joint capsules, cushioning

synovial joint structure

-joint capsule made up of ____ & ____

-purpose of synovial fluid inside joint cavity:

-ligaments strengthen joints

fibrous layer, synovial layer, lubrication

flexion

decreasing the angle that the body makes

ex: flexing biceps or flexing leg (decrease posterior angle)

extension

increase angle that the body makes

ex: extending arm (from flexed position)

hyperextension

past neutral position

ex: hyperextension of hip means bringing leg behind

abduction

moving limb away from midline

ex: lifting arms up or raising legs to the side, fingers: spreading

adduction

moving limbs towards midline

fingers: keeping them together

hyperadduction

crossing limbs

opposition in fingers

touching thumb to pinky

medial/ internal rotation

rotating limbs towards body

lateral/ external rotation

rotating limb away from body

supination

rotation of elbow so that palms face anterior

pronation

rotating elbows so that palms face posterior

eversion

sole of feet facing laterally

inversion

sole of feet facing medially

planar flexion/ ankle extension

pointing feet

dorsiflexion/ ankle flexion

flexing ankle

range of motion: degrees in which the joint can move

determined by

-structure of ____ surfaces

-structure and tension of ligaments and joint capsules

-action of ___ and ___

articular, tendons, muscles

plane joint

-description

-type of movement

-ex: carpals, tarsals, vertebral articular process

flat articular surfaces slide past each other, multidirectional movement

hinge joint: description, type of motion, examples

convex end of bone articulates with c-shaped depression, allows for flexion & extension, elbow, interphalangeal joints, ankle

pivot joint: description, type of motion, examples

rounded portion of bone partially enclosed by ligament, allows for rotation, proximal radioulnar joint, atlantoaxial joint

ball and socket joint: description, type of motion, examples

round head of bone fits into corresponding depression, multidirectional movement, shoulder, hip

shoulder joint, aka glenohumeral joint: bones involved, type of joint, a feature about this joint

between glenoid fossa (scapula) and head of humerus, ball and socket joint, glenoid labrum (cartilage that encases glenoid cavity) deepens glenoid fossa

why is it so easy to dislocate the shoulder?

because of the ball and socket joint structure as well as the glenoid labrum, the shoulder is able to exhibit larger range of motion, but this also fails to protect against detachment

elbow: bones involved, type of joint, a feature about this joint

humerus, radius, ulna, hinge joints (humeroulnar joint and huermoradial joint) allow for flexion & extension, radioulnar joint creates pivot joint for rotation of wrist

hip: bones involved, type of joint, a feature about this joint

acetabulum and femur, ball and socket, ligamentum teres (carries arteries to head of femur

difference between shoulder and hip joints

shoulder joints are more prone to dislocation because of its glenoid labrum, but hip joints are rarely dislocated because it’s tightly bound by ligaments and doesn’t exhibit wide range of motion

knee

-medial & lateral ___ ____ are on either side of the tibia to prevent ____ __

-cruciate ligaments: ____

-anterior cruciate  ligaments help to prevent ___

-posterior cruciate ligaments help to prevent ____

collateral ligament, lateral displacement, crossed ligaments, hyperextension, posterior displacement of tibia

ankle: bones involved, type of joint, a feature about this joint

tibia, fibula, talus, hinge joint composed from talotibial joint and talofibular joint, intertarsal joints/ plane joints allow for inversion & eversion