Lecture 2 materials - joints Flashcards
What is an articulation?
Junction of 2 or more bones or cartilages
What are the 3 joint types?
Fibrous, cartilaginous, synovial
What joints have the most freedom of movement?
Synovial
Describe fibrous joints
Little to no movement. Skeletal components are united by fibrous connective tissue
What are the 3 subtypes of fibrous joints?
Sutures, gomphoses, syndesmoses
Where is a suture joint found?
Joint between the flat bones of the skull
Why are sutures important in young animals?
Allow deformation of skull during partuition
Allow growth of the skull
Where is a gomphosis joint found?
Dental implantations (between roots of teeth and alveoli)
Formed by the periodontal ligament
Where is a syndesmosis joint found?
All other fibrous joints except face bones (suture) and teeth (gomphosis).
Example: fibrous tissue between metacarpal bones
Describe cartilaginous joints
Permits limited movement such as compression or stretching
Skeletal components are united by cartilage
Name the 2 subtypes of cartilage
Hyaline cartlage, fibrocartilaginous joints
What is a hyaline cartilage joint?
Hyaline cartilage unites connective tissue
Many hyaline joints disappear with age (ossification).
Example: physes of growing bones ossify, costochondral junctions remain throughout life
Describe fibrocartilaginous joints
Unites connective tissue
Example: Pelvic symphysis, mandibular symphysis, intervertebral discs
Describe synovial joints
Free moveable
Skeletal components are separated by synovial fluid at joints
The capillary film allows the synovial joint to slide
What are the 2 subtypes of synovial joints?
Simple joints (two skeletal components), compound joints (more than 2 skeletal components)
What are the basic features of a synovial joint?
Joint cavity, joint capsule (outer fibrous layer and inner synovial membrane), synovial fluid, articular cartilage
Does the bones of the synovial joint touch?
No, the articular cartilage on each bone touches except for the thin layer of synovial fluid
What is articular cartilage?
Hyaline cartilage appears ‘glassy’ and covers the articular surfaces of bones
Hyaline cartilage does not appear on radiographs, and does not have blood or nerve supply
Describe the fibrous layer of the joint capsule
Composed mainly of white fibrous tissue with yellow elastic fibers
Blends with the periosteum ner the articular cartilage
Thin and loose in mobile joints, and thick in less mobile joints
What does the fibrous layer of the synovial joint capsule form on less mobile joints?
Discrete ligaments
Describe ligaments
A band or cord of connective tissue that unites two or more bones or cartilage
Also acts as membranous connections between visceral structures
Describe tendons
A band or cord of connective tissue that unites muscle with bone
What is the function of ligaments?
Stabilize and unite skeletal components
Extracapsular ligaments are outside the fibrous portion of the joint capsule
Intracapsular are located inside the fibrous part of the joint capsule (genual joint)
Describe collateral ligaments
Extracapsular, derived from thickened fibrous portion of the joint capsule.
Found in most appendicular synovial joints.
Generally present medially and laterally to stabilize but allow cranial/caudal movement
Describe the synovial membrane
Produces synovial fluid
Vascularized and innervated
Lines the inner surface of the fibrous joint capsule
Does the synovial membrane cover the articular cartilage?
No, synovial membrane is not present on articular cartlage or wheree fibrocartilaginous plates contact each other
What does the synovial membrane do in response to aggravation?
Overproduction of synovial fluid which can result in joint distension
What is the primary source of pain in joint disease?
The rich innervation of the synovial membrane
What are the primary functions of synovial fluid?
Lubricate contact surfaces of synovial joints, nourishment, removal of waste
Describe fibrocartilaginous plates
Fibrocartilaginous structures located between articular surfaces
These help stabilize, distribute synovial fluid and improve shock absorption
What is an example of a fibrocartilaginous plate?
Fibrocartilaginous plates are located in temporomandibular joints as (2) articular discs
2 menisci are found in each genual (knee) joint
What are the joints of the thoracic limb?
Humeral joint (shoulder), cubital joint (elbow), carpal joint complex, digital joints
Describe the humeral joint
Capable of movement in any direction but functions primarily as flexion/extension
Does not have collateral ligaments but is stabilized by the supra- & infra-spinatus muscles laterally, and subscapularis and coracobrachialis muscles medially
Describe the cubital joint
Compound joint
Formed by humeral condyle, head of the radius and trochlear notch of the ulna.
Very little lateral movement due to collateral ligaments
Name the joints of the carpal joint complex
Antebrachiocarpal joint, middle carpal joint, carpometacarpal joint, metacarpophalangeal joint, proximal/distal interphalangeal joint
Where does the majority of movement occur in the carpal joint complex?
antebrachiocarpal joint
What are the joints of the pelvic limb?
Coxal (hip), Genual (knee), Tarsal joint complex, digital joints
Describe the coxal joint
Great range of movement due to ball-and-socket construction
No lateral collateral ligaments
Liagment of the head of the femur anchors the femoral head to the acetabulum and is intracapsular
Where does the ligament of the femoral head attach to the femur?
Fovea capitis femoris
Describe the genual joint
This is an instable joint due to bones not fitting together properly.
2 menisci in each knee stabilized at the distal end of the femur
How many ligaments are in the genual joint?
10 ligaments
8 intracapsular
2 extracapsular
Name the meniscal ligaments
Cranial tibial ligament of medial meniscus, caudal tibial ligament of the medial meniscus, cranial tibial ligament of the lateral meniscus, caudal tibial ligament of the lateral meniscus, transverse ligament, meniscofemoral ligament
Name the femorotibial ligaments and location
Medial collateral ligament (extracapsular), lateral collateral ligament (extracapsular), cranial cruciate ligament (intracapsular), caudal cruciate ligament (intracapsular)
What is cranial drawer?
When one of the cruciate ligaments is damaged, the tibia can move more easily
Which genual ligament is the most commonly damaged?
Cranial cruciate ligament
Name the joints of the tarsal complex
Tarsocrural joint, Talocalcaneocentral joint, talocalcaneal joint, calcaneoquartal joint, centrodistal joint, tarsometatarsal joint
Describe the atlantoocciptal joint
Synovial. Between C1 and the occipital bone, nods head yes
Describe the atlantoaxial joint
Synovial. Between C1 and C2, rotation of head, shake head no
What type of joint is an intervertebral disc?
Fibrocartilaginous
What are the 2 parts to the intervertebral disc?
Anulus fibrosus (outer), nucleus pulposus (inner)
How many times does the rib articulate with the vertebrae?
3 until T11, then only 2
Tranverse process and cranial/caudal costal fovea
Rib articulations are synovial
