ANATOMY & PHYSIOLOGY - CLUTCH CH. 10 -...

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ANATOMY & PHYSIOLOGY - CLUTCH

CH. 10 - JOINTS

CONCEPT: JOINT CLASSIFICATIONS

● A joint (articulation) is the place where bones contact other bones, cartilage, or teeth. □ Joints are classified by their ___________________________ and their movements

□ Classification of joints by structure:

- Fibrous joint exists where dense regular connective tissue holds bones together

- No joint cavity

- Main function is to hold bones together

- Cartilaginous joint exists where cartilage holds bones together

- 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

EXAMPLE: Three types of joints


CH. 10 - JOINTS

□ Classification of joints by movement:

- Synarthrosis joints do not move (ex: some skull bone articulations)

- Two fibrous joints, and one cartilaginous joints fall into this category

- Amphiarthrosis joints are slightly mobile (ex: intervertebral discs articulations)

- One fibrous joint, one cartilaginous joint fall into this category

- Diarthrosis joints move freely

- All synovial joints

□ As you increase mobility of a joint, the stability of the joint ______________________

EXAMPLE: Three types of joint movement


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CONCEPT: FIBROUS JOINTS

● There are ____________________ types of fibrous joints □ Sutures: found between certain skull bones

- Have irregular edges that increase strength, reduce fractures, and allow the skull to grow

- In adults, sutures become synostoses (bone fusion) through ossification of sutures

□ Syndesmoses: joined by long strands of dense regular connective tissue.

- Found in the forearm (radius and ulna) and leg (tibia and fibula)

- These can move slightly (amphiarthroses)

- Bound by an interosseous membrane that covers both bones and allows for movement

□ Gomphosis: resembles a “peg in a socket.”

- The only one in the human body is a tooth connection to the jaw

- Periodontal membranes surround the tooth root and hold it in place

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: CARTILAGINOUS JOINTS

● There are two types of cartilaginous joints. □ Synchondrosis joints are connected with hyaline cartilage and are all immobile

- Ex: epiphyseal plate of long bones, skull bones (occipital bone), costochondral joint: ribs and sternum

- As we age, cartilage growth ______________, and synchondrosis is replaced with bone

□ Symphyses joints have fibrocartilage between the bones; can be slightly mobile; acts as a shock absorber

- Ex: connects right and left pubic bones (pubic symphysis), intervertebral joints

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: SYNOVIAL JOINTS

Joint Cavity

● Synovial joints have a joint cavity that separates the bones in the joint. There are several common factors of a joint cavity: □ Articular capsule is a double-layered capsule that covers the joint

- Fibrous layer is the dense connective tissue layer (outer)

- Synovial membrane is a thin squamous epithelial layer (inner); lacks basement membrane

□ Articular cartilage is a thin layer of hyaline cartilage that reduces friction in the joint; Has no perichondrium

□ Synovial fluid is an oily substance in the synovial joint. Produced from the synovial membrane

- Lubricates articular cartilage and work as a shock absorber

- Nourishes _____________________________ in articular cartilage

- Bursa contains the synovial fluid. Elongated bursas are called tendon sheaths

□ 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

EXAMPLE:


CH. 10 - JOINTS

Classification of Synovial Joints

● Synovial joints move, and can be classified by their _________________________ □ When describing synovial joint movement, we can talk about it in terms of axes

- 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

EXAMPLE:

● There are six types of synovial joints, classified by how ___________________ they move □ 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


CH. 10 - JOINTS

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: LEVERS

● Levers are rigid objects that rotate around a fixed point (fulcrum) □ Levers are used to _____________________ synovial joint movement and muscle contraction

□ Lever movement occurs because effort is applied at one place and resistance to movement occurs at another

- Effort arm is the point where the force is applied to the fulcrum

- Resistance arm is the point where resistance occurs to the fulcrum

□ In the body:

- Lever: long bone

- Joint: fulcrum

- Effort: muscle attached to bone

EXAMPLE:


CH. 10 - JOINTS

● There are three types of levers □ First-class levers: Fulcrum sits in the middle between the effort and resistance (ex: scissors)

- Neck joints (atlanto-occipital joint of the neck)

□ Second-class levers: Resistance sits between fulcrum and effort (ex: wheelbarrow)

- Standing on tip toes

□ Third-class levers: Effort sits between fulcrum and resistance (ex: tweezers)

- Elbow

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: SYNOVIAL JOINT MOVEMENT

Gliding and Angular Motion

● There are four movements of synovial joints □ Gliding is a movement that consists of two surfaces sliding back and forth; wrist bones (carpals, tarsals)

- Angle of bones doesn’t change, and only _________________ movement is possible

□ Angular motion is a movement that changes the angle between two bones

- 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

EXAMPLE:


CH. 10 - JOINTS

- 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

EXAMPLE:


CH. 10 - JOINTS

Rotational Motion

□ A rotation is a longitudinal turning movement (rotating head)

- 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

EXAMPLE:


CH. 10 - JOINTS

Special Movements

● There are several types of movements that only occur at specific joints □ Elevation occurs when moving a body part superiorly (up); ex: closing your mouth, shrugging shoulders

□ Depression occurs when moving a body part inferiorly (down); ex: opening your mouth, lowering shoulders

EXAMPLE:

□ 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

EXAMPLE:


CH. 10 - JOINTS

□ Protraction occurs during anterior movement of a body part; ex: jutting your jaw

□ Retraction occurs when posterior movement of a body part; ex: pulling your head back

EXAMPLE:

□ 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

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: TEMPOROMADIBULAR JOINT

● The temporomadibular joint (TMJ) is where the jaw (mandible) articulates with the skull (temporal bone) □ Only _______________ joint in the skull

□ The TMJ has several important features

- 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

□ The TMJ moves using a hinge, gliding, and pivot movements

- Hinge movement: chewing causes depression and elevation

- Glide movement: grinding food or biting

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: SHOULDER JOINT

● There are three joints that allow for shoulder movement 1. Sternoclavicular joint joins the sternum to the the clavicle bone (sternal end) □ Articular disc forms two separate synovial cavities allow for a wide range of movement

- Movements include depression, elevation, and circumduction

EXAMPLE:


CH. 10 - JOINTS

2. Acromioclavicular joint joins the clavicle (lateral end) and the acromion of the scapula

□ Also has an articular disc

□ Several ___________________ provide support to the joint

- Acromioclavicular ligament sits superiorly to provide strength

- Coracoclavicular ligament connects clavicle to scapula

□ Provides movement to the upper limbs

EXAMPLE:


CH. 10 - JOINTS

3. Glenohumeral joint is the ball-and-socket joint that connects the scapula (glenoid cavity) and humerus (ball-and-socket)

□ Articular capsule covers the joint

□ Glenoid labrum is a fibrocartilaginous cover that covers the glenoid cavity

□ Several ligaments include:

- 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

□ Has the ____________________ range of motion in the body, and is also the least stable joint in the body

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: ELBOW JOINT

● The elbow joint has 3 articulations that occur between three bones (humerus, radius, ulna); covered by hyaline cartilage 1. Humeroradial joint connects the humerus (capitulum) with the radius (head) 2. Humeroulnar joint connects the humerus (trochlea) with the ulna (trochlear notch)

3. Proximal radioulnar joint: connects the radius and ulna

□ The elbow joints are very stable, but not extremely mobile

□ There are __________________ main ligaments

- 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

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: HIP JOINT

● A hip joint (coxal joint) is the articulation between the femur (head) and the os coxae (hip bone) - Is a ball-and-socket joint

□ Acetabular labrum is a fibrocartilaginous covering over the socket (acetabulum) of the os coxae

□ Contains strong articular capsule that surrounds the joint

- Retinacular fibers make up the articular capsule

□ Contains _________________ ligaments

- 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

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: KNEE JOINT

● The knee joint consists of two articulations; it is the largest synovial joint in the body 1. Tibiofemoral joint connects the femur and the tibia 2. Patellofemoral joint connects the femur and the patella

□ Contains articular capsule that covers all sides except for the anterior surface

□ There are several ligaments that cover the articular capsule

- 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

EXAMPLE:


CH. 10 - JOINTS

□ Two fibrocartilage pads stabilize and cushion articular surface; constantly changing shape as the bones move

- Medial meniscus sits medially

- Lateral meniscus sits laterally

□ Two ____________________ exist deep in the articular capsule

- Cruciate ligaments are a group of 2 ligaments that limit anterior/posterior movement of femur/tibia (X)

- Anterior cruciate ligament (ACL) prevents hyperextension of the knee

- Posterior cruciate ligament (PCL) prevents hyperflexion of the knee

EXAMPLE:


CH. 10 - JOINTS

CONCEPT: ANKLE JOINT

● The ankle (talocrural) joint is a hinge joint with two articulations in one capsule (between tibia, fibula, and talus) 1. Distal end of tibia and talus

2. Distal end of fibula and talus

□ Includes several ligaments

- 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

EXAMPLE:


CH. 10 - JOINTS

ANATOMY & PHYSIOLOGY - CLUTCH CH. 10 -...

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