A&P module 3 exam joints and articulations

Articulation

Site where two or more bones meet

Functions of joints

Gives skeleton mobility

Holds skeleton together

The more movable the joint the weaker it is

Synarthroses

Immovable joints. Less mobility makes for a stronger joint

Amphiarthroses

Slightly movable joints

Diarthroses

Freely moveable joints. Increased mobility makes for a less stable joint

Fibrous joints are joined by what

Dense fibrous connective tissue

Fibrous joints do not have what?

They do not have a joint cavity

Most fibrous joints are what?

Synarthrotic which means they are immovable. Few are amphiarthrotic

What are the types of fibrous joints

Sutures, Syndesmosis, Gomphoses

Sutures

Rigid interlocking joints containing short connective tissue fibers. They are fibrous and non moveable joints

Fontanelles

Allow for growth during youth. Sutures in a newborn (Soft spots) in the membranous area

Synostoses

When sutures ossify during middle age and a join in which the two bones grow together to form a single bone

Syndesmosis

Bones connected by ligaments (bands of fibrous tissue) Movement varies from immovable to slightly movable

Examples of Fibrous syndesmosis

Synarthrotic distal tibiofibular joint

Amphiarthrotic interosseous connection between radius and ulna

Gomphoses

Peg-in-socket joints of teeth in alveolar sockets

Fibrous connection is the Periodontal ligament

Cartilaginous joints

Bones united by cartilage. No joint cavity

Types of cartilaginous joints

Synchondroses and symphyses

Synchondroses

A bar of plate of hyaline cartilage that unites the bones. Most are synarthrotic (non-moveable) and most are temporary.

Bone replaces the cartilage tissue

Over time, synchondroses become what?

Synostosis (bone on bone)

Symphyses

Hyaline cartilage that covers the articulating surfaces of the bones and is fused to a intervening pad of fibrocartilage

strong flexible amphiarthroses

All synovial joints are what?

Diarthrotic (freely moveable)

Synovial joints include what joints

All limb joints: upper and lower. most joints of the body are synovial

All synovial joints are constructed with what?

A synovial joint capsule (articular capsule)

Synovial joints present in the upper body

The shoulder girdle between humerus, scapula and clavicle

What is the only synovial joint present in the skull

The TMJ joint

Distinguishing features of synovial joints

A joint cavity (inside joint capsule) and a joint capsule made of a fibrous capsule and synovial membrane

Fibrous capsule

A component of joint capsule made of dense irregular connective tissue

Synovial membrane

Component of the joint capsule made of loose connective tissue (areolar connective tissue) which secretes synovial fluid

Articular cartilage

Hyaline cartilage covering the ends of bones

Synovial fluid

Fills the joint capsule and is secreted by the synovial membrane.

It is a viscous slippery filtrate of plasma plus hyaluronic acid

Lubricates and nourishes articular cartilage

uniaxial/monoaxial

Movement in one plane

Biaxial

Movement in two planes

Multiaxial

Movement in or around all 3 planes

Plane synovial joint

Plane/gliding nonaxial joint which consists of the articular processes between the vertebrae and intercarpals

Saddle synovial joint

Biaxial joint located in the carpometacarpal joint of pollex

Hinge synovial joint

Hinge uniaxial/monoaxial joint which consists of a convex cylinder against concave surface in the elbow and knee joints

Pivot synovial joint

Pivot uniaxial and monoaxial joint in the proximal radioulnar joint and dens process of the atlas and axis

Ball and socket joint

Multiaxial(triaxial) joint located in the shoulder and hip bones

Ellipsoidal joint

Also known as condylar joints. Biaxial found in the atlanto occipital joint

Flexion

Decreases angle of joint

Extension

Increases angle of joint

Plantar flexion

Pointing toes downward

Dorsiflexion

Pointing toes upward

Abduction

Movement away from midline

Adduction

Movement toward midline

Rotation

Turning a structure around it’s long axis

Pronation

Inward roll of the foot/Downward rotation of the forearm

Supination

outward roll of the foot/upward rotation of forearm

Circumduction

flexion + abduction + extension + adduction of a limb so as to describe a cone in space

Inversion

Turn sole medially

Eversion

Turn sole laterally

Elevation

Move superiorly

Depression

Moving inferiorly

Protraction

Anterior movement (shoulders pulled forward)

Retraction

Posterior movement (shoulders pulled back)

Lateral excursion

Moving mandible right or left

Medial excursion

Returning mandible to middle position

Opposition

Touching thumb to little finger

Sprains

Ligaments stretched or torn. Partial tears repair themselves while complete ruptures require surgery

Cartilage tears

Due to compression and stress. Fragments may cause joint to lock/bind. Cartilage rarely repairs itself and requires surgery

Bursae

Flattened, fibrous sacs lines with synovial membranes. Contain synovial fluid. Acts as ball bearings where ligaments, skin, tendons or bones rub together

Bursitis

Inflammation of bursae

Active range of motion

ROM accomplished by the person. Self mobility

Passive ROM

Someone else accomplishing the motion for you. PROM

Movement of knee joint

Flexion, extension, some rotation when knee is partially flexed.

Femur, tibia and patella involved

Knee joint is stabilized by what?

Tendon of quadriceps muscle

Lateral and medial patellar retinacular ligaments

Patellar ligament

Intracapsular ligaments

ACL and PCL (anterior/posterior cruciate ligaments )

Prevents anterior/posterior displacement

Resides outside synovial cavity therefore not bathed in synovial fluid

Menisci

Lateral and medial meniscus

Intracapsular pads of fibrocartilage. sits on top of tibia

Absorbs shock during movement

Extracapsular ligaments

Helps prevent side to side movement

Collateral movement

Medial collateral or tibial collateral (MCL), Lateral collateral (LCL) or fibular collateral

3 most common knee injuries

ACL torn

Torn medial meniscus

Torn tibial collateral

Shoulder (glenohumeral) joint

Ball and socket joint which involves the head of the humerus and glenoid fossa of the scapula

Multiaxial, unstable joint. Stability sacrificed for greater freedom of movement

Multiple features stabilize this joint

Coracohumeral ligament

Shoulder joint stabilizing feature which helps support the weight of the upper limb

Three glenohumeral ligaments

Somewhat weak anterior reinforcements

Coracoacromial ligament

the third shoulder joint stabilizing feature

Tendon of the long head of the biceps

Travels through the intertubercular groove

Secures the humerus to the glenoid cavity

Glenoid labrum

A lip of cartilage that increases the depth of the articular capsule covering the shallow glenoid cavity and stabilizing the joint

4 rotator cuff tendons that encircle the shoulder joint and protect it posteriorly

Subscapularis

Supraspinatus

Infraspinatus

Teres minor

Radius and ulna articulate with what?

The humerus

The elbow joint is what type of joint

A hinge joint which is formed mainly by the trochlear notch of the ulna and trochlea of humerus. Flexion/extension only

Stabilizing features of elbow joint

Two capsular ligaments which restrict side to side movement

• Ulnar collateral ligament and radial collateral ligament

Annular ligament

• Surrounds head of radius

Hip Coxal joint

Ball and socket joint

Head of the femur articulates with the acetabulum

Acetabular labrum

Enhances the depth of the socket in the hip coxal joint

Reinforcing ligaments of the hip joint

Iliofemoral ligament

Pubofemoral ligament

Ischiofemoral ligament

Ligamentum teres

Temporomandibular joint (TMJ)

Mandibular condyle articulates with the temporal bone

movement of the TMJ

Hinge (Depression/elevation of the mandible)

Gliding (side to side/lateral excursion) grinding of teeth

Most easily dislocated joint in the body

Intervertebral joint

Vertebral bodies that form symphysis. made of Outer annulus fibrosus and inner nucleus pulposus

Outer annulus fibrosus

Outer collar composed of collagen and fibrocartilage

Inner nucleus pulposus

Inner gelatinous nucleus that gives the vertebral disc its elasticity and compressibility

Arthritis

Most widespread crippling disease in the US

Symptoms of arthritis

Pain, stiffness, swelling of a joint

Acute forms of arthritis

Caused by bacteria, treated w/ antibiotics

Chronic forms of arthritis

Osteoarthritis, rheumatoid arthritis, gouty arthritis

Osteoarthritis

Most common form of arthritis. Irreversible, degenerative form of arthritis

85% of all americans develop this

Rheumatoid arthritis

Chronic, inflammatory, autoimmune disease

Joint pain, swelling, anemia, osteoporosis, muscle weakness and cardiovascular problems

Gouty arthritis

Deposition of uric acid crystals in joints and soft tissues followed by inflammation

Typically affects the joint at the base of the great toe

Untreated, bone ends fuse and immobilize the joint

Lyme disease

Acute form of arthritis, caused by bacteria transmitted by bites of ticks

Skin rash, flu-like symptoms, foggy thinking

untreated, joint pain/chronic arthritis

Luxation

Separation of the joint

Subluxation

Partial separation of joint

The knee joint is actually 3 joints surrounded by a single joint cavity. These joints are what

Femoropatellar

Tibiofemoral

Menisci