Joint and Muscle Physiology Flashcards
What are the points of contact a joint can have?
between two bones, cartilage + bone, teeth + bone
What is arthrology?
study of joints
What is kinesiology?
study of motion
How can you classify joints?
structurally: based on presence of synovial cavity and type of connective tissue, or functional: is based upon movement
How can you structurally classify a joint?
fibrous, cartilaginous, or synovial
How can you functionally classify joints?
synarthrosis, amphiarthrosis, diarthrosis
What does synarthrosis mean?
immoveable
What does amphiarthrosis mean?
slightly moveable
What does diarthrosis mean?
freely moveable
What are the characteristics of a fibrous joint?
lacks synovial cavity, bones held together by fibrous connective tissue, synarthroses or amphiparthoses
What are the three structural types of a fibrous joint?
suture, syndesmosis, gomphosis
Describe a suture. How is it functionally and structurally classified?
a fibrous joint that is a thin layer of dense fibrous connective tissue unites bones of the skull, synarthrosis
Describe a syndesmosis? How is it structurally and functionally classified?
a fibrous joint where bones are united by a ligament or membrane, amphiarthrosis
The inferior tibiofibular joint and interosseous membrane is an example of what type of joint?
syndesmosis
Describe gomphosis. How is it structurally and functionally classified?
a fibrous joint where a ligament holds a cone-shaped peg in a bony socket, can be considered synarthrosis or amphiarthrosis
Where are gomphosis joints found?
teeth in alveolar processes
What are the characteristics of a cartilaginous joint?
lacks synovial cavity, allows litter or no movement, bones tightly connected by fibrocartilage or hyaline cartilage
Describe Synchondrosis. How is it structurally and functionally classified?
a cartilaginous joint, connecting material is hyaline cartilage, synarthrosis
an epiphyseal plate or joint between ribs and costal cartilages are examples of what type of joint?
synchondrosis
Describe Symphysis. How is it structurally and functionally classified?
a cartilaginous joint that is always in the midline, fibrocartilage is the connecting material, amphiarthrosis
Intervertebral discs and the pubic symphysis are examples of what type of joint?
Symphysis
What are the common features of synovial joints?
separates articulating bones, diarthrosis, articular cartilage, articular capsule, intrinsic ligament, synovial membrane, extracapsular/intracapsular ligaments, articular discs + menisci, bursa
What does articular cartilage in a synovial joint do?
reduces friction and absorbs shock
What does an articular capsule in a synovial joint do?
holds the bones together, surrounds the joint
What forms an articular capsule?
fibrous capsule + synovial membrane
What is an intrinsic ligament?
thickenings in a fibrous capsule, it is part of the capsule
What is a synovial membrane?
the lining of the capsule inside, it secretes synovial fluid
What does synovial fluid bring to the articular cartilage?
nutrients
What is joint effusion?
extra secretion of synovial fluid
extracapsular and intracapsular ligaments are examples of what?
extrinsic ligaments
Extracapsular ligaments are __________ the joint capsule
Extracapsular ligaments are OUTSIDE the joint capsule
Intracapsular ligaments are __________ the joint capsule
Intracapsular ligaments are INSIDE the joint capsule
What are the functions of articular discs and menisci?
attached to the edges of the capsule to allow the two bones of different shapes to fit tightly, increase stability
What is a bursa?
fluid-filled sac-like structure made by connective tissue that reduces friction between skin and bone or tendons and bone
What is bursitis?
inflammation to bursa
Why do joints need nerve supply
to detect position, pain, pressure, stretch
What is Hilton’s law?
nerve to joints are branches of nerves to the nearby mucscles
What are the types of synovial joints?
planar, hinge, pivot, condyloid/ellipsodal, saddle, and ball + socket
Describe a planar joint
bone surfaces are flat and slightly curved, side to side movement only, rotation is prevented by ligaments
Intercarpal, intertarsal and vertebrocostal joints are examples of what type of joint?
Planar synovial joints
Describe a hinge joint
the convex surface of one bone fits onto a concave surface of another, uniaxial, movements permitted are flex/ext
The elbow, ankle, and interphalangeal joints are examples of what type of joint?
hinge synovial joint
Describe a pivot joint
rounded surface of bone articulates with a ring formed by the other bone and ligament(s), monoaxial, allows only rotation around a longitudinal axis
The proximal radioulnar joint, and atlantoaxial joint are examples of what type of joint?
Pivot synovial joint
Describe a condyloid/ellipsoidal joint
oval-shaped projection fits into an oval depression, biaxial, movements permitted are flex/ext, AB/ADD
The wrist joint is an example of what type of joint?
ellipsoidal synovial joint
The MCP is an example of what type of joint?
condyloid synovial joint
Describe a saddle joint
one bone saddle-shaped and a second bone acts a jockey sitting on top, biaxial, movements permitted are flex/ext, AB/ADD, and some rotation
The joint between the trapezium and 1st metacarpal is an example of what type of joint?
saddle synovial joint
Describe a ball and socket joint
a ball fitting into a cup-like depression, multiaxial, movements permitted are flex/ext/ AB/ADD, rotation
The shoulder and hip joint are examples of what types of joint?
ball and socket synovial joint
What is muscle tone?
involuntary contraction of a small number of muscle fibres alternately active and inactive in a shifting pattern that keeps muscles firm when relaxed, does not produce movement, and is important in maintaining posture and BP
Define isometric
muscle contracts, produces force, but no gross movement, functionally to stabilize joints
Define isotonic
a contraction under which the tension remains constant, often used to describe contraction causing a joint to move through ROM, of two types: concentric and eccentric
Define isotonic concentric
muscle shortens while contracting, produces acceleration of body segments
Define isotonic eccentric
muscle lengthens while contracting, decelerate body segments and provide shock absorption
Define agonist
main mover producing a joint movement or maintaining posture, always contracts to produce isometric or isotonic concentric/eccentric contraction
Define antagonist
opposes agonist, neither assists nor resists but passively elongates/shortens to permit motion
Define synergist
assist agonist, may prevent unwanted movement, may act isometrically at joint far from primary motion to fix proximal joints so distal motions occur
