Articulation Flashcards
Joint (articulation)
Is the place where bones contact other bones, cartilage, or teeth.
Joints are classified by their _________ and their movements
Structure
What are the classification of joints by structure?
- Fibrous joint
- Cartilaginous joint
- Synovial joint
Fibrous joint
Exists where dense regular connective tissue holds bones together (Have no joint cavity & main function is to hold bones together)
Cartilaginous joint
Exists where cartilage holds bones together (Have no joint cavity & main function is to resist stress and act as shock absorbers)
Synovial joint
Exists where ligaments attach bones together & bones are covered with articular cartilage (Has fluid-filled joint cavity & main function is to support movement)
What classification of joints by movement?
- Synarthrosis
- Amphiarthrosis
- Diarthrosis
Synarthrosis
Joints do not move
Amphiarthrosis
Joints are slightly mobile
Diarthrosis
Joints move freely
As you increase mobility of a joint, the stability of the joint ___________
Decreases
What are the types of fibrous Joints?
- Sutures- found between certain skull bone
- Syndesmoses - joined by long strands of dense regular connective tissue
- Gomphosis - resembles a “peg in a socket” (Only one is in a tooth connection to the jaw)
What are the types of cartilaginous joints?
- Synchondrosis - joints are connected with hyaline cartilage and are all immobile
- Symphyses - joints have fibrocartilage between the bones; can be slightly mobile; acts as a shock absorber
Synovial Joint
Have a joint cavity that separates the bones in the joint
What are the common features of a joint cavity?
- Articular capsule
- Articular cartilage
- Synovial fluid
- Ligaments
- Tendons
- Fat pads
Articular capsule
Is a double-layered capsule that covers the joint (Contains a fibrous layer which is the dense connective tissue layer (outer) & Synovial membrane is a thin squamous epithelial layer (inner))
Articular cartilage
Is a thin layer of hyaline cartilage that reduces friction in the joint
Synovial fluid
Is an oily substance in the synovial joint ( Lubricates articular cartilage and work as a shock absorber)
Ligaments
Connect bones together, composed of dense regular connective tissue &stabilize and strength the joint
Extrinsic ligaments
Are outside of the articular capsule
Intrinsic ligaments
Result from thickening of the articular capsule
Tendons
connect muscle to bone; composed of dense regular connective tissue
Fat pads
Protect the joint by lining it with fat
Synovial joints move, and can be classified by their _____________
Movement
What are the types of synovial movements?
- Uniaxial joint - can move in only one axis (plane); Ex: elbow joint
- Biaxial joint - can move in two axes (planes); Ex: joints in wrist (carpal and tarsal bones)
- Multiaxial joint - can move in multiple axes (planes); Ex: shoulder joint
What are the six types of synovial joints? (From most mobile to least mobile)
- Plane joint
- Hinge joint
- Pivot joint
- Condylar joint
- Saddle joint
- Ball-and-socket joint
Plane joint
Are the least mobile joints; allows side-to-side movement (uniaxial)
Hinge joint
Fits concave and convex bone connections; uniaxial joint
Pivot joint
Connects rounded bones into a ligament/bone ring; uniaxial joint
Condylar joint
Fits concave and convex bone connections; biaxial joint
Saddle joint
Connects concave and convex bones that resemble saddles; biaxial joint
Ball-and-socket joint
Connects a spherical shaped bone with a cup-like socket of another bone; multiaxial
What are the 3 types of levers?
- First-class levers - Fulcrum sits in the middle between the effort and resistance (ex Neck Joints)
- Second-class levers - Resistance sits between fulcrum and effort (standing on toes)
- Third-class levers - : Effort sits between fulcrum and resistance (ex elbow)
What are the 4 movements of the synovial joint?
- Gliding Movement
- Angular motion
- Rotation Movement
- Special movement
Gliding
Is a movement that consists of two surfaces sliding back and forth; wrist bones (carpals, tarsals)
Angular motion
Is a movement that changes the angle between two bones
What are the types of angular motions?
- Flexion
- Extension
- Hyperextension
- Lateral flexion
- Abduction
- Adduction
- Circumduction
Flexion
Decreases the angle between the bones (ex: your head to look at your feet
Extension
Increases the angle between the bones (ex: your head looking straight ahead)
Hyperextension
Increases the angle able 180o (ex: glance up at ceiling
Lateral flexion
Occurs when trunk moves laterally away from the body
Abduction
Laterally moves the body part away from the body midline (spreading your fingers out)
Adduction
Laterally moving the body part towards the body midline
Circumduction
Is sequential movements where proximal remains stationary, and distal end circles
What are the types of rotational movements?
- Lateral rotation turns anterior surface laterally
- Medial rotation turns anterior surface medially
- Pronation is medial rotation of forearm and the palm faces the posterior
- Supination is lateral rotation of forearm so palm faces anterior
What are the types of special movements?
- Elevation
- Depression
- Dorsiflexion
- Plantar flexion
- Protraction
- Retraction
- Opposition
- Reposition
Depression
Occurs when moving a body part inferiorly (down); ex: opening your mouth, lowering shoulders
Elevation
Occurs when moving a body part superiorly (up); ex: closing your mouth, shrugging shoulders
Dorsiflexion
Occurs when ankle joint bends and toes move up; ex: digging in your heels
Plantar flexion
Occurs when ankle joint bends and toes move down; ex: ballerina standing on her toes
Retraction
Occurs when posterior movement of a body part; ex: pulling your head back
Protraction
Opposition
Occurs when the thumb reaches across the palm; ex: grabbing an object
Reposition
Occurs when the thumb returns to its normal position; ex: letting go of an object
The temporomadibular joint (TMJ)
Is where the jaw (mandible) articulates with the skull (temporal bone)
What are the features of the temporomadibular joint (TMJ) ?
- Articular capsule surrounds the joint
- Articular disc is a thick region of fibrocartilage separating the bones; creates synovial cavity
- Sphenomadibular ligament extends from jaw (anteriorly) to skull
- Temporomadibular ligament extends from skull (posteriorly) to jaw
What are the three joints that allow our shoulders to move?
- Sternoclavicular joint joins the sternum to the the clavicle bone (sternal end)
- Acromioclavicular joint joins the clavicle (lateral end) and the acromion of the scapula
(Acromioclavicular ligament sits superiorly to provide strength & Coracoclavicular ligament connects clavicle to scapula)
- Glenohumeral joint- is the ball-and-socket joint that connects the scapula (glenoid cavity) and humerus (ball-and-socket)
Coracoacromial ligament
Attaches coracoid process to acromion
Coracohumeral ligament
Attaches coracoid process to humerus
Glenohumeral ligaments
A group of three ligaments; attach glenoid cavity with humerus
Rotator cuff
Is a group of muscles that surround the joint to provide support to the joint; No inferior cover
What are the 3 articulations in the elbow joint?
- Humeroradial joint connects the humerus (capitulum) with the radius (head)
- Humeroulnar joint connects the humerus (trochlea) with the ulna (trochlear notch)
- Proximal radioulnar joint: connects the radius and ulna
What are the ligaments in the elbow joint?
- Radial collateral ligament stabilizes the lateral surface; connects the humerus with radius (annular)
- -Ulnar collateral ligament stabilizes the medial surface; connects the humerus with ulna (annular)
- Annular ligament: surrounds the radius head and attaches to ulna
Hip joint (coxal joint)
Is the articulation between the femur (head) and the os coxae (hip bone)
What are the liagments in the hip joint?
- Iliofemoral ligament - provides strength to the anterior region of the joint; shaped like a Y
- Pubofemoral ligament -is a triangle shaped ligament that strengthen the inferior region of the joint
- Ischiofemoral ligament - is located on posterior side of the joint, spiral shaped
- Ligament head of femur - is a small ligament that attaches to the femur; provides an artery to femur
Tibiofemoral joint
Connects the femur and the tibia
Patellofemoral joint
Connects the femur and the patella
What are the ligaments in the knee joint?
- Patellar ligament - attaches to the patella and the tibia
- Fibular collateral ligament - stabilizes the lateral surface; connected to femur and fibula
- Tibula collateral ligament - stabilizes the medial surface; connects to femur and tibia
Anterior cruciate ligament (ACL) (Type of Cruciate ligaments)
Prevents hyperextension of the knee
Posterior cruciate ligament (PCL) (Type of Cruciate ligaments)
Prevents hyperflexion of the knee
What are the ligaments of the ankle joint?
- Deltoid ligament binds tibia to talus on medial side
- Lateral (calcaneofibular) ligament binds fibula to talus on lateral side
- Tibiofibular ligaments are two ligaments (anterior and posterior) that bind tibula to fibula