Week 4 - Joints (Chapter 9)
Types of Joints:
Fibrous, Cartilaginous, Synovial
This joint's structure is dense irregular connective tissue (Collagen Fibers -movement ranges from immovable to slightly movable
- Subtypes: sutures, syndesmoses
Fibrous
This joint's structure is hyaline or fibrous cartilage
- Movement ranges from immovable to slightly movable
- Connecting material is solid piece of cartilage
- Present in epiphyseal cartilage/epiphyseal line
- Subtypes: synchondroses, symphysis
Cartilaginous
This joint's structure is characterized by a two layered articular capsule and an articular cavity with lubricating synovial fluid
-movement ranges from slightly movable to freely movable
-types: plane, hinge, pivot, ellipsoid, saddle, ball and socket joints
Synovial
Joints are classified based on the type of ________/_______ in which the articulating bones are united
material/manner
Type of fibrous joint
- Only occur between bones of the skull
- Are joints that form as the numerous bones of the skull come in contact during development
- Important for growth and shock absorption in the skull
- Are replaced by bone are called synotosis or bony joint
Sutures
A type of fibrous joint where the bones are farther apart and connected by dense connective tissue rather than a suture.
Syndenmoses
All cartilaginous joints' bones are held together by _____
Cartilage
________ Is a cartilaginous joint in which the ends of the articulating bones are covered with hyaline cartilage
- Connected by a broad dise of fibrous cartilage
- All of these are located in the midline of the body (pubic symphysis, intervertebral joints) and they are slightly movable
Symphysis
Structure of a ________ joint: 2 layers in the articular capsule— the fibrous layer on the outside and the synovial membrane inside. The synovial fluid lubricates the joint cavity, which is found between the synovial membrane and the articular cartilage.
Synovial Joint
_________ surrounds synovial joints, enclosing the articular cavity & connecting articulating bones. May include adipose tissue accumulations (articular fat pads)
Articular Capsule
The synovial membrane secretes ______ fluid
Synovial
This fluid is clear/pale yellow & viscous-like
- It consists of hyaluronic acid secreted by synovial cells (synoviocytes) in the synovial membrane & interstitial fluid filtered from blood plasma
- Forms a thin film over surfaces within the articular capsule
Synovial Fluid
Crescent-shaped pads of fibrous cartilage between the articular surfaces of bones, attached to the fibrous capsule
Articular discs/menisci
Articular discs/menisci functions:
- Shock absorption
- Enhancing fit between articulating surfaces
- Providing adaptable surfaces for combined movements - Distributing weight over a larger contact area
- Helping distribute synovial fluid across articular surfaces
Labrum helps ______ joint socket & _______ the area of contact between socket & the ball like surface of the numerous head at the shoulder joint
Deepen and increases
Joints are innervated by the same nerves that supply the ______ _______ moving the joint
Skeletal muscles
_____ endings transmit pain signals to spinal & brain
Nerve
Many cartilaginous components are __________
Avascular
Saclike structures that are situated to alleviate friction
in some joints (shoulder, knee). Their walls consist of an outer fibrous layer of thin, dense irregular connective tissue lined by a synovial membrane
-They are filled With a small amount of fluid
-Fluid filled bursal sacs cushion the movement between body parts
Bursae
Bursae locations
Between skin and bones, tendons a bones, muscles & bones or ligaments and bones
______ Sheaths also reduce friction around joints & are tubelike bursae
- Wrap around tendons experiencing significant friction in tunnels formed by connective tissue & bone
-3 Types
Tendon sheaths
Tendon sheath types:
Visceral layer -Inner layer attached to the tendon surface
Parietal layer -Outer layer attached to bone
Cavity -contains synovial fluid to lubricate the tendon
Where are tendon sheaths located?
Where tendons pass through articular cavities
- at wrist and ankle where multiple tendons are confined
- in digits of hands and toes where high movement occurs
Types of movements at synovial joints:
Gliding, angular, flexion, extension
In _____ movements, there is an increase or decrease in the angle between articulating bones
Angular
6 Types of Synovial Joints:
Plane, Hinge, Ellipsoid, Saddle, Ball & Socket, Pivot
______ Joints: articulating surfaces are flat or slightly curved Back and forth & side to side movements; may allow rotation - Biaxial & triaxial
Examples: Intercarpal, Intertarsal, Acromioclavicular (scapula & clavicle) Sternocostal (sternum & ribs) Vertebrocostal (ribs & thoracic vertebrae)
Plane Joints
These joints have convex surfaces; one bone fits into the concave surface of another, allowing for a simple open-and-close motion.
- Typically uniaxial, permitting only flexion and extension, as seen in the elbow, ankle, and fingers.
Hinge joints
Convex oval shaped bone that fits into an oval shaped depression of another
- Biaxial; permits flexion-extension & abduction-adduction & limited circumduction
- Example: radiocarpal joint and metacarpophalangeal joints
Ellipsoid joints (condylar joints)
One bone's particular surface is saddle shaped, other fits into the saddle movements are same as ellipsoid joints
- Examples: carpometa carpal
Saddle joints (sellar joints)
Ball like surface of one bone fitting into a cuplike depression of another bone
- Triaxial (flexion -extension, abduction -adduction, rotation) - Examples -glenohumeral (shoulder joint) and hip joint
Ball and socket joints
Rounded/pointed surface of one bone articulating with a ring formed by another bone & ligament
- Uniaxial; allows rotation around its own longitudinal axis - - Examples: Atlanto- axial joint and radioulnar joints
Pivot joints (trochoid joints)
Convex surface of bone fits into the concave surface of another Angular, open-closing Motion
- Typically unaxial
- Permit only flexion & extension (elbow, ankle, fingers)
Hinge joints
A combined hinge & plane joint
- Only freely movable joint between skull bones
Temporomandibular joint
the only bone that moves as the temporal bone is securely anchored to the skull
Mandible
Most of the stability of the _______ joint results from arrangement of the rotator cuff muscles
Glenohumeral
Ball & socket joint formed by head of the numerous & glenoid cavity of the scapula
Glenohumeral (shoulder) joint
Glenohumeral (shoulder) joint components:
Articular capsule, Coracohumeral, Glenohumeral ligaments, Transverse humeral lingament, Glenoid labrum, Bursae
__________ joint formed by the connection between the scapula and the clavicle, linking the shoulder to the trunk.
Acromioclavicular Joint
__________ ligament between the coracoid process of the scapula & clavicle
Coracoclavicular
___________ joint allows flexion, extension, hyperextension, abduction, medial rotation, lateral rotation, circumduction of the arm.
Glenohumeral
A hinge joint formed by the trochlea & capitulum of the humerus, the trochlear notch of the ulna, & the head of the radius, also the pivot joint between head of the radius & the radial notch of the ulna
Elbow Joint
The elbow joint is formed by parts of three bones:
Numerous, ulna, radius
Ball & socket joint formed by head of the femur & the
acetabulum (the socket in the hip bone that holds the ball of the thigh bone, allowing your leg to move) of the hip bone
Hip Joint
The ________ of the hip joint is one of the strongest structures in the body
articular capsule
Movements of the hip joint:
Flexion, extension, abduction, adduction, lateral rotation, medial rotation, circumlocution
Largest, most complex joint in the body, it is a modified hinge joint consisting of three joints within a single synovial cavity
Knee
- Lateral Tibiofemoral Joint: The joint between the outer condyle of the femur, the lateral meniscus, and the outer condyle of the tibia.
- Medial Tibiofemoral Joint: The joint between the inner condyle of the femur, the medial meniscus, and the inner condyle of the tibia.
- Patellofemoral Joint: The joint between the kneecap (patella) and the front surface of the femur.
The 3 joints of the knee
The 5 Ligaments of the Knee
Anterior Cruciate Ligament (ACL)
Posterior Cruciate Ligament (PCL)
Medial Collateral Ligament (MCL)
Lateral Collateral Ligament (LCL)
Patellar Ligament
Connects the front of the tibia to the back of the femur.
- It stops the tibia from sliding forward and prevents the knee from bending too far back
- Commonly injured in serious knee injuries
- Prevents the tibia from sliding forward and provides stability during rotation.
Anterior Cruciate Ligament (ACL)
It connects the back of the tibia to the front of the femur. It stops the tibia from sliding backward and keeps the femur from sliding forward when the knee is bent, helping to stabilize the knee.
Posterior Cruciate Ligament (PCL)
Articular discs of the knee (Menisci)
Medial Meniscus & Lateral Meniscus (Both menisci help improve joint stability and absorb shock)
Nearly circular, attached at the intercondylar eminence of the tibia and connected to the medial meniscus by the transverse ligament of the knee.
Lateral Meniscus
Prepatellar Bursa: Between the patella and skin.
Infrapatellar Bursa: Between the superior part of the tibia and patellar ligament.
Suprapatellar Bursa: Between the inferior part of the femur and the deep surface of the quadriceps femoris muscle.
Bursae of the Knee
Connects the kneecap (patella) to the tibia and helps with knee extension.
Patellar Ligament
Types of Syndenmoses Joints (3):
Interosseous Ligaments - Connects bones with limited movement
Interosseous Membrane - Sheet of connective tissue that binds long bones together for stability/attachment
Gomphosis - Mobile peg-and-socket joints (Teeth)
The distinguishing feature of a synovial joint is the:
Articular capsule
Functions of synovial fluid:
- Secretion lubricates joints & nourishes articular cartilage
- Reduces friction
- Absorbs shock
- Supplies oxygen/nutrients to chondrocytes
- Contains phagocytes that eliminate microbes
The joint cavity is also known as ______ cavity and possess the joint
articular
_______ capsule – has inner synovial and outer fibrous membrane.
- Synovial membrane attaches to the margins of the joint surfaces at the interface between cartilage & bone & encloses the articular cavity. Highly vascular producing synovial fluid that lubricates & nourishes the joint
Joint
movement is limited across one plane.
Uniaxial
movement is limited to two planes
Biaxial
Movement across multiple directions/planes.
Multiaxial
These are the basic movements:
Flexion and extension
Movements of the forearm:
______ is when the palm of the hand faces backward, forearm is in pronated position.
______ is when the palmar surface is facing forward or upwards (like asking for soup in the form of a gesture).
Pronation & Supination
_________ & Adduction – medial
or lateral movement from the
body. ______ moves the limb laterally away from the centreline
while adduction is the opposite movement
Abduction
________ & retraction – anterior & posterior
movements of the scapula, mandible.
Protraction
_______ & reposition – thumb movement that brings the tip of
the thumb in contact with the tip of a finger. Occurs at the level of carpometacarpal joint.
Opposition
________ fracture (or open fracture)
- Iinvolves a break in the bone that pierces through the skin, creating an open wound and increasing the risk of infection
Compound
______ fracture – skin stays intact. No puncture or open
wound.
Closed
bone breaks into two or more pieces, & gets misaligned.
Displaced
Subfracture Types:
Transverse fracture – fracture line is perpendicular to the shaft of the bone.
Oblique fracture – bone breaks at an angle.
Pathologic fracture – caused by an underlying disease (e.g. osteoporosis).
Stress fracture – hairline crack.