hap exam 3

Fibrous joints

Bones joined by dense connective tissue, no joint cavity.

Suture

Thin layer of dense connective tissue between flat bones.

Syndesmosis

Ligament or interosseous membrane connects bones.

Gomphosis

Peg-in-socket joint anchored by periodontal ligament.

Craniosynostosis

Condition when sutures close too early, leading to abnormal skull shape and sometimes increased intracranial pressure.

Cartilaginous joints

Bones joined by cartilage.

Synchondrosis

Hyaline cartilage joins bones.

Symphysis

Fibrocartilage joins bones.

Synovial joints

Bones separated by fluid-filled joint cavity.

Joint cavity

Space filled with synovial fluid in synovial joints.

Diarthrosis

Freely movable joint.

Joint capsule

Enclosure around a joint providing lubrication and stability.

Epiphyseal plate

Growth plate made of hyaline cartilage.

Costal cartilage

Cartilage connecting the first rib to the sternum.

Pubic symphysis

Joint where two pubic bones are joined by fibrocartilage.

Intervertebral discs

Fibrocartilage pads between vertebrae.

Examples of synovial joints

Shoulder, knee, hip, elbow, etc.

Joint (articular) capsule

Outer fibrous layer + inner synovial membrane; encloses joint cavity, stabilizes joint.

Synovial membrane

Inner layer of capsule; vascular connective tissue that produces synovial fluid.

Articular cartilage

Hyaline cartilage covering bone ends; reduces friction, absorbs shock.

Synovial fluid

Viscous, clear fluid filling cavity; lubricates joint, nourishes cartilage, absorbs shock, removes waste.

Flexion

Decrease angle between bones; example joints include elbow, knee, neck.

Extension

Increase angle; example joints include elbow, knee, neck.

Abduction

Move limb away from midline; example joints include shoulder, hip.

Adduction

Move limb toward midline; example joints include shoulder, hip.

Circumduction

Circular movement (cone shape) combining flexion, extension, abduction, adduction; example joints include shoulder, hip.

Rotation

Movement around longitudinal axis; example includes turning head side to side (atlas-axis), shoulder rotation.

Pronation

Palm down, radius crosses over ulna; occurs in the forearm.

Supination

Palm up, radius & ulna parallel; occurs in the forearm.

Inversion

Sole of foot turned inward; occurs at the ankle.

Eversion

Sole turned outward; occurs at the ankle.

Dorsiflexion

Toes up toward shin; occurs at the ankle.

Plantar flexion

Toes pointed downward; occurs at the ankle.

Elevation

Move part upward; example includes shoulders shrug.

Depression

Move part downward; example includes shoulders relax.

Protraction

Move part forward; example includes jaw, scapula.

Retraction

Move part backward; example includes jaw, scapula.

Opposition

Thumb touches fingertip; occurs in the hand.

Reposition

Thumb returns to anatomical position; occurs in the hand.

Hinge joint

Convex surface fits into concave surface; allows flexion and extension; examples include elbow, knee, interphalangeal joints.

Pivot joint

Rounded bone fits into sleeve or ring; allows rotation; examples include atlas-axis (C1-C2), proximal radius-ulna.

Saddle joint

Two saddle-shaped surfaces fit together; allows biaxial movements: flexion/extension, abduction/adduction, circumduction; example includes thumb (1st carpometacarpal joint).

Condyloid (ellipsoidal) joint

Oval surface fits into elliptical cavity; allows biaxial movements: flexion/extension, abduction/adduction, circumduction; examples include wrist joint, metacarpophalangeal (knuckles).

Gliding (plane) joint

Flat surfaces slide over each other; allows sliding and slight movement; examples include intercarpal, intertarsal joints.

Ball-and-socket joint

Round head fits into cup-like socket; allows multiaxial movements in all directions (flex, extend, abduct, adduct, rotate, circumduct); examples include shoulder, hip.

Knee joint

Largest and most complex synovial joint; type: modified hinge joint; articulations: femur, tibia, patella; movements: flexion, extension, slight rotation.

ACL (Anterior Cruciate Ligament)

Prevents anterior (forward) sliding of tibia on femur.

PCL (Posterior Cruciate Ligament)

Prevents posterior (backward) sliding of tibia.

MCL (Medial Collateral Ligament)

Prevents inward (valgus) stress; connects femur to tibia.

LCL (Lateral Collateral Ligament)

Prevents outward (varus) stress; connects femur to fibula.

Menisci

Medial and lateral fibrocartilage pads between femur and tibia; function: absorb shock, improve fit/stability, reduce friction.

Unhappy Triad

Injury to ACL + MCL + medial meniscus, usually from lateral blow to the knee.

Shoulder (Glenohumeral)

Ball-and-socket joint with a shallow socket, making it the most mobile joint but unstable.

Acromioclavicular (AC)

Plane/gliding joint located between the acromion of the scapula and the clavicle.

Elbow

Hinge joint formed by the humerus, radius, and ulna; has a strong capsule and ligaments.

Hip

Ball-and-socket joint with a deep acetabulum and strong ligaments, providing more stability and less mobility.

Temporomandibular Joint (TMJ)

Hinge and gliding joint where the mandibular condyle fits into the mandibular fossa of the temporal bone.

Ankle

Hinge joint where the talus articulates with the tibia and fibula, allowing dorsiflexion and plantarflexion.

Tennis elbow

Common injury associated with the elbow, also known as lateral epicondylitis.

Inflammatory joint disorders

Conditions such as arthritis (rheumatoid, osteoarthritis, gout) that affect mobility and daily activities.

Origin (muscle)

The fixed or less movable attachment of a muscle, typically anchored to a bone.

Insertion (muscle)

The movable attachment of a muscle, which is the bone that moves during contraction.

Tendons

Dense regular connective tissue that attaches muscle to bone and transmits force to produce movement.

Agonist (Prime Mover)

The main muscle responsible for a movement, such as the biceps brachii during elbow flexion.

Antagonist

The muscle that opposes the prime mover to control or slow movement, such as the triceps brachii during elbow flexion.

Synergist

A muscle that assists the prime mover by adding extra force or reducing undesirable motion, like the brachialis assisting biceps brachii.

Fixator

A muscle that stabilizes a joint to allow precise movement, such as postural muscles stabilizing the trunk during limb movement.

Sternocleidomastoid (SCM)

Neck muscle with origin at the sternum and clavicle, insertion at the mastoid process of the temporal bone, action includes flexing the neck and rotating the head.

Splenius capitis & cervicis

Neck muscles that extend, hyperextend, and rotate the head.

Semispinalis capitis

Neck muscle that extends the neck and rotates the head to the opposite side.

Trapezius

Shoulder girdle muscle with origin at the occipital bone and thoracic vertebrae, insertion at the clavicle and scapula, action includes elevating, retracting, and depressing the scapula.

Levator scapulae

Shoulder girdle muscle with origin at C1-C4 and insertion at the superior angle of the scapula, action includes elevating the scapula.

Rhomboids (major/minor)

Shoulder girdle muscles with origin at C7-T5 and insertion at the medial border of the scapula, action includes retracting and stabilizing the scapula.

Pectoralis minor

Shoulder girdle muscle with origin at ribs 3-5 and insertion at the coracoid process, action includes protracting the scapula.

Serratus anterior

Shoulder girdle muscle with origin at ribs 1-8 and insertion at the medial border of the scapula, action includes protracting the scapula and stabilizing it against the thoracic wall.

Abdominals

Rectus abdominis, External oblique, Internal oblique, Transversus abdominis - Flex and rotate trunk, compress abdomen, maintain posture

Erector spinae

Iliocostalis, Longissimus, Spinalis - Extend vertebral column; maintain upright posture

Deltoid

Origin: Clavicle & scapula; Insertion: Deltoid tuberosity of humerus - Abducts arm; flexion & extension

Latissimus dorsi

Origin: Lower spine, iliac crest; Insertion: Humerus - Extends, adducts, and medially rotates arm

Pectoralis major

Origin: Clavicle, sternum, ribs; Insertion: Humerus - Flexes, adducts, and medially rotates arm

Teres major

Origin: Inferior angle of scapula; Insertion: Humerus - Extends and adducts humerus

Flexors (anterior)

Origin: Medial epicondyle of humerus; Insertion: Carpals, metacarpals, phalanges - Flex wrist & fingers

Extensors (posterior)

Origin: Lateral epicondyle of humerus; Insertion: Carpals, metacarpals, phalanges - Extend wrist & fingers

Quadriceps (anterior)

Rectus femoris, Vastus lateralis, Vastus medialis, Vastus intermedius - Knee extension (Rectus femoris also flexes hip)

Hamstrings (posterior)

Biceps femoris, Semitendinosus, Semimembranosus - Flex knee, extend hip

Anterior Lower Leg Muscle

Tibialis anterior - Dorsiflexion, inversion

Posterior Lower Leg Muscle (superficial)

Gastrocnemius, Soleus - Plantarflexion

Posterior Lower Leg Muscle (deep)

Tibialis posterior, Flexor digitorum longus, Flexor hallucis longus - Plantarflexion, toe flexion

Lateral Lower Leg Muscles

Fibularis longus & brevis (peroneals) - Eversion, plantarflexion

Frontalis

Raises eyebrows, wrinkles forehead

Orbicularis oculi

Closes eyes

Orbicularis oris

Closes lips, puckering

Zygomaticus major/minor

Smiling

Buccinator

Compresses cheeks (blowing/sucking)

Supraspinatus

Initiates abduction

Infraspinatus

External rotation

Teres minor

External rotation

Subscapularis

Internal rotation

Rectus abdominis

Flexes trunk ("sit-up muscle")

External oblique

Flexes & rotates trunk