Articulations Flashcards
What does it mean if a joint is ‘shallow’?
It’s less stable and more likely to dislocate but more mobile
What does it mean if a joint is ‘deep’?
It’s more stable but less mobile. Less likely to dislocate (Acetabulum)
What are the types of articulations?
Fibrous, Cartilaginous, Synovial
What are the types of Fibrous Joints?
Sutures, Sutural Ligament, Synostosis, Syndesmosis, Interosseous membranes
What are the types of Cartilaginous Joints?
Synchondrosis, Symphyses
What are synchondroses?
Hyaline cartilage connects two bones (ex: Epiphyseal growth plate)
What are symphyses?
the ends of 2 bones covered in hyaline cartilage then connected with fibrocartilage (pubic symphysis, intervertebral discs)
What structure is unique to synovial joints?
synovial cavity
What is an articular capsule (synovial joint)?
Ligamentous sac that surrounds the articular cavity, attached to the bones, encloses the joint, outer fibrous membrane, inner synovial membrane
What tissue composes articular capsules?
Dense irregular CT
The inner synovial membrane is composed of what?
Areolar CT, may include adipose tissue (protection), secretes synovial fluid
What does synovial fluid do?
decrease friction, nourishes synovial cells & articular cartilage, immune response as well (phagocytic cells)
True or False: Synovial fluid is watery and flows easily
False. Synovial fluid is viscous and thick, resistance to flow
Accessory ligaments can be divided into what two categories?
Intracapsular and Extracapsular
Explain the structure of articular cavities
The articular surfaces of each bone are covered with articular cartilage. The fibrous membrane surrounds the joint. The synovial membrane connects to the articular cartilage of each bone. Synovial fluid fills the gap.
What is gomphosis? Where can this type of joint be found?
type of syndesmosis
“peg” bone in socket
Found where the teeth connect to the alveolar process of the mandible
Held by a periodontal ligament
What are sutures?
Found in the skull, Dense irregular CT
What are synostoses?
Ossified sutures, fusion of 2 bones
What are syndesmoses?
2 parallel bones are connected with fibrous CT
Syndesmoses: 2 connected bones have a small gap between them. What unites the two?
Ligaments
Syndesmoses: 2 connected bones have a larger gap between them. What united the two?
Interosseous membrane (broad sheet of CT)
Where can you find a syndesmosis joint with a small gap?
near the ankle (tibiofibular joint)
Where can you find a syndesmosis joint with a larger gap?
Between the ulna and radius of the forearm
Which joint type of the 3 is the most common?
Synovial joint
What are the 2 layers that make up the articular cavity?
Outer fibrous membrane (dense irregular CT) and inner synovial membrane (areolar CT)
What is the function of the outer fibrous membrane?
Prevent dislocation, attached to periosteum
What comprised the synovial fluid?
Hyaluronic acid and interstitial fluid from platelets
What’s an articular disc?
a thin plate of fibrocartilage that divides a synovial into smaller spaces (not covered by synovial membrane)
ex: TMJ
What are the menisci?
C-shaped cartilage in knees that acts as a shock absorber
What are some of the functions of the articular discs?
Unite bones (sternoclavicular joint)
Shock absorption + cushioning (meniscus)
smooth movements (TMJ)
What are Bursae?
sacs made of CT that function to alleviate friction
filled with lubricating fluid
prevents structures from directly rubbing against each other
What are tendon sheaths?
Similar to bursae but smaller; tube-like and wrap-around tendons
Protect tendon from friction when passing through body canals
Contain lubricating fluid
