Anatomy and Physiology - Chapter 8 Joints and Movement

articulation of joint

place where two bones come together

freely moveable to no apparent movement

structure correlated with movement

how joints are named

according to bones or parts united at the joint

according to only one of the articulating bones

by latin equivalent of common name

structural classes of joints

based on major tissue type that binds bones

fibrous

cartilaginous

synovial

functional classes of joints

based on degree of motion

synarthrosis- immovable

amphiarthrosis- slightly movable

diarthrosis - freely movable

synarthrosis

usually fibrous joints

immoveable

amphiarthrosis

usually cartilaginous

slightly moveable

diarthrosis

usually synovial

freely moveable

characteristics of fibrous joints

united by dense fibrous connective tissue

between bones in close contact

have no joint cavity

move little or none (synarthrotic)

Types of fibrous joints

sutures

synedesmoses

gomphoses

sutures

seams between bones of the skull

not ossified in adults

synostosis

ossifed suture

epiphyseal plate

synedesmoses

bones farther apart than suture and joined by ligaments

some movement

radioulnar syndesmosis

gomphoses

specialized joints

pegs that fit into sockets

inflammations (gingivitis and periodontal disease)

tooth in socket (inflammation causes tissue destruction)

cartilaginous joints

unite two bones by means of cartilage

usually amphiarthrotic

sychondrosis

symphysis

synchondrosis

joined by hyaline

little or no movement (synarthrotic)

epiphyseal plate

joint between the first rib and sternum

symphysis

pubic symphysis

intervertebral discs

junction between manubrium and the body of the sternum

synovial joints

allow considerable movement (diarthrotic)

most joints that unite bone of appendicular skeleton

complex

bursae

complexity of synovial joints

articular hyaline cartilage

joint cavity and capsule

synovial membrane and fliud

bursae of synovial joints

pockets of synovial fluid

bursitis

types of synovial joints

plane or gliding

saddle

hinge

pivot

ball-and-socket

ellipoid (condyloid)

plane or gliding joints

monoaxial (movement in 1 plane)

articular processes between vertebrae, intercarpal and intertarsal joints

pivot joints

monoaxial

articulation between dens of axis (C2) and atlas (C1) of the spine

proximal radioulnar joint

saddle joints

biaxial

carpmetacarpal joint of the thumb

hinge joints

similar in structure and function to a door hinge

monoaxial

elbow and knee

ellipsoid (condyloid joint)

modified ball and socket

biaxial

atlantooccipital joint (where C1 meets the skull)

metacarpophalangeal joints of the hand (knuckles)

ball-and-socket joints

multiaxial - movement in all planes

shoulder and hip

movement in joints

when discussing types of movement, refer to the anatomical position, either starting in the anatomic position and moving away from that position or moving a part back towards the anatomic position

gliding

two surface glide over one another

intercarpal and intertarsal

angular movement

flexion and extension (hyperextension and plantar and dorsiflexion)

abbduction and adduction

circular movement

rotation

pronation and suppination

circumduction

flexion

occur in sagittal plane

angle gets smaller

usually bending

extension

occur in sagittal plane

angle gets bigger

usually straightening

dorsiflexion

like walking on heels

plantar flexion

ballerina on toes

abduction

moving of a body part away from the central axis of the body

adduction

moving of a body part toward the central axis of the body

rotation

occur about an axis

move head to right and left

pronation

forearms and feet

palms down

flat feet

suppination

forearms and feet

palms up

arched feet

circumduction

form a cone in space with a body part

elevation

shoulders and jaw

close mouth

depression

shoulders and jaw

open mouth

protraction

shoulders and jaw

shoulders forward

retraction

shoulders and jaw

shoulders back

excursion

cow chewing cud

opposition

bring thumb and pinky together

reposition

thump and pinky apart

inversion

ankle

turn sole of foot medially

eversion

ankle

turn sole of foot laterally

range of motion influenced by

shape of articular surfaces forming joint

amount and shape of cartilage covering surfaces

strength and location of ligaments and tendons

location of muscles associated with joint

amount of fluid in and around the joint

amount of use/disuse of joint

amount of pain in and around the joint

osteoarthritis

wear and tear

rheumatoid arthritis

caused by transient infection or autoimmune disease

lyme disease

tick vector

gout

metabolic disorders of unknown casue (idiopathic)

types of fibrous joints

-syndesmoses

-sutures

-gomphoses

syndesmoses

-bones are bound by a sheet

-somewhat flexible

-amphiarthrotic joint

suture

-found betwen flat bones of the skull

-bones grow together and unite by a thin layer of dense connective tissue (sutural ligament)

-sutures replace fontanels

-immovable, synarthrotic

gomphoses

-union of coneshaped bony process in a bony socket

-immovable, synarthrotic

cartilaginous joints

-connected by hyaline or fibrocartilage

-synchondroses

-symphyses

synchondroses

—bands of hyaline cartilage

-typically temp structures that disappear during growth

-once growth/ossification is complete, the joint becomes a synotosis, which is synarthrotic, immovable

symphysis

-articular surfaces are covered by a thin layer of hyaline cartilage

-connected by a pad of fibrocartilage

-limited movement when forces compress or deform the fibrocartilage pad (ex., pregnancy, intervertebral discs)

-amphiarthrotic

synovial joints

-most joints of the skeletal system are classified as this

-diarthrotic

-articular cartilage, joint capsule, synovial membrane which secretes synovial fluid

articular cartilage

-thin layer of hyaline cartilage

-resists wear

-minimizes friction

-covers the end of bones in a synovial joint

ligaments

-bundles of strong collagen fibres

-stabilizes joint & binds articular ends of bones

-help prevent excessive movement at the joint

-inelastic, tightens when the joint is stressed

joint capsule

-holds together the bones of synovial joints, prevents bone ends from being pulled apart

-2 layers

- outer fibrous layer consists of dense connective tissue that attach to the periosteum

-inner layer consists of loose connective tissue called the synovial membrane

-covers all surfaces of the joint besides the parts covered by articular cartilage

synovial membrane

-covers the synovial cavity into which it secretes synovial fluid

-can have vili which increase surface area

-can store adipose tissue & form movable fatty pads in the joint

-reabsorbs fluid, which helps when joint cavity is injured or infected

-thin, only a few cells thick

synovial fluid

-contains stem cells, which may help in ligament regeneration

-consistency similar to uncooked egg white

-moistens the smooth cartilaginous surfaces of the joint

-supplies articular cartilages with nutrients obtained from blood vessels of synovial membrane

menisci

-synovial joint divided into two compartments

-articluar discs of fibrocartilage

-attaches to the fibrous layer of the joint capsule

-cushions the articulating surfaces of the knee joint and help distribute body weight

bursae

-fluid filled sacs

-inner lining of synovial membrane

-contain synovial fluid

-found between the skin and underlying bony prominerces (olecranon, knee)

-cushion and aid movement of tendons and ligaments

-names of bursae indicate locations

shapes of synovial joints

-ball and socket

-condylar

-plane

-hinge

-pivot

-saddle

ball and socket joints

-bone with egg shaped head that articulates with a cup shaped cavity of another bone

-allows for a wider range of motion than any other type of bone

-multiaxial movement

-hip and shoulder

condylar joints

-also called an ellipsoidal joint

-ovoid bone end fits into the elliptical cavity of another bone

-joints between the metacarpals & phalanges

-biaxial movement (back and forth & side to side)

plane joints

-articulating surfaces are nearly flat or slightly curved

-nonaxial movement (back-and-forth + twisting)

-joints in wrist, ankle, articular process of vertebrae, sacroiliac, sternocoastal regions

hinge joints

-convex surface of one bone fits into the concave surface of another bone

-uniaxial

-elbow, joints between phalanges, knee

-bending and straightening motion

pivot joints

-also called trochoid joint

-cylindrical surface of one bone rorates in a ring formed of bone and ligament

-uniaxial

-radius & ulna, neck

saddle joints

-forms between bones with concave & convex regions

-joint between carpal, metacarpal betwen thumb

insertion

movable end of a muscle

origin

fixed end of a muscle

abduction

moving away from the midline

adduction

moving toward the midline

flexion

bending parts at a joint so that the angle between them decreases and the parts come closer together

extension

moving parts at a joint so that the angle between them increases and the parts move farther apart

hyperextension

extension of parts at a joint beyond anatomical position (bending the head back beyond the upright position) abnormal extension beyond normal range of motion resulting in injury

dorsiflexion

movement at the ankle that moves the anterior portion of the foot closer to the shin (rocking on heels)

plantar flexion

Movement at the ankle that moves the anterior portion of the foot farther from the shin (walking on one's toes).

rotation

Moving a part around an axis (twisting the head from side to side). Medial (internal) rotation is the turning of a limb on its longitudinal axis so its anterior surface moves toward the midline, whereas lateral (external) rotation is the turning of a limb on its longitudinal axis in the opposite direction.

circumduction

Moving a part so that its end follows a circular path (moving the finger in a circular motion without moving the hand).

supination

Rotation of the forearm so the palm is upward or facing anteriorly (in anatomical position). Supine refers to the body lying face up

pronation

Rotation of the forearm so the palm is downward or facing posteriorly (in anatomical position). Prone refers to the body lying face down.

eversion

Turning the foot so the plantar surface faces laterally.

inversion

Turning the foot so the plantar surface faces medially

protraction

Moving a part forward (thrusting the head forward).

retraction

Moving a part backward (pulling the head backward).

elevation

Raising a part (shrugging the shoulders).

depression

Lowering a part (drooping the shoulders).

glenohumoral (shoulder) joint

-ball-and-socket joint

-rounded head of humerus and shallow glenoid cavity of ulna

-protected by the coracoid and acromion processes of the scapula

-held together by dense connective tissue of ligaments & muscle

-capable of large range of movement

-flexion, extension, adduction,rotation, abduction, circumduction, extension

joint capsule of shoulder

-attached along the surface of the glenoid cavity

-very loose

-muscles, ligaments and tendons surround and reinforce it

rotator cuff

-formed by the tendons of several muscles

-supports + reinforces shoulder joint

-sports related movements can injure the cuff

-if injury occurs and rest + meds dont work surgery might be needed

coracohumeral ligament

-broad band of connective tissue

-connects coracoid process to the greater tubercle

-strengthens superior portion of joint capsule

glenohumeral ligament

-3 bands of fibers that appear as thickenings in ventral wall of joint capsule

-xtend from the edge of the glenoid cavity to the lesser tubercle and the anatomical neck of the humerus.