Chapter 8 - Joints Flashcards
Diarthrotic joints (freely movable) where the articulating bones are separated by a fluid-filled cavity
Synovial joints
“Synovial” means…
“joint egg” (egg-shaped pocket of fluid in a joint)
What is a major function of articular cartilage?
They absorb compression on the bone to prevent it from being crushed
Why is it called articular cartilage? What is it made of?
It is found where two bones articulate (meet at a joint). It is made of Hyaline cartilage.
True or false: Articular cartilage is thick cushioning
False, it is cushioning but only 1mm thick (very thin)
What is the appearance of Hyaline cartilage?
Glassy and smooth
What is the functional space containing fluid called in a synovial joint?
Articular or joint cavity
The joint cavity is a…..
potential space for synovial fluid
What is the function of the synovial membrane?
It produces synovial fluid from filtering blood
What is the texture and color of synovial fluid?
Yellowish, slippery egg white texture
Synovial fluid is obtained by _______ ________ from capillaries in the _______ ________.
Synovial fluid is obtained by FILTERING BLOOD from capillaries in the SYNOVIAL MEMBRANE.
What chemical causes the slippery texture of synovial fluid?
Hyaluronic Acid
True or false: synovial fluid is also found in articular cartilages
True
The joint cavity is enclosed in….
The two layered articular capsule or joint capsule
The outer layer of the articular capsule is composed of…
dense irregular connective tissue (sac) (fibrous connective tissue)
True or False: The fibrous connective tissue outer layer is continuous with the periostea of the articulating bones
True
THe inner layer of the articular capsule is called the _____ ______ and made of _______.
The inner layer of the articular capsule is called the SYNOVIAL MEMBRANE and made of LOOSE CONNECTIVE TISSUE.
The two layers of the articular capsule are the outer _____ and the inner ________.
The two layers of the articular capsule are the outer FIBROUS LAYER and the inner SYNOVIAL MEMBRANE.
What are the two classifications of joints?
Structural and Functional
What are the three types of structural joints?
Fibrous, Catilaginous, Synovial
What are the three types of functional joints?
Synarthroses/synarthrotic, Amphiarthroses/amphiarthrotic, and diarthroses/diarthrotic
What is the difference between a synarthrotic joint and an amphiarthrotic joint?
Synarthrotic joints don’t move or move only a tiny bit; amphiarthrotic can move a little bit
Increased range of movement in a joint makes it LESS/MORE stable?
Less stable
True or False: A high stability joint is likely to be highly movable
False: as the stability of a joint increases, the movability decreases
Fibrous joints are MORE/LESS movable than Synovial joints?
Fibrous allow for LESS movement than Synovial
True or False: Diarthrotic joints are mainly in the appendicular skeleton?
True
True or False: Cartilaginous Joints are always synarthrotic.
False. Cartilaginous can have varying amounts of movement, though less than synovial overall
Suture means _____ in Latin
“Seam”
Why do we have sutures in our skull?
They allow our skull to expand as our brain grows in development before sealing shut in adulthood
In Fibrous joints, bones are joined by _____ _______ of connective tissue
Collagen Fibers
A skull suture that has ossified is called a…
Synostosis (bony junction)
A synostosis is a…
area between bones that ossifies and closes
Fibrous joints are MOST/LEAST immovable of all
Most immovable (synarthrotic)
Three types of fibrous joints:
Gomphoses, Syndesmoses, Sutures
In adulthood/middle age, what happens with the skull?
Sutures fuse shut (ossifies) called Synostoses
Why are there fibrous gaps in the skull in babies?
It allows the skull to flex as it passes through the birth canal.
What are the two main locations for syndemoses?
radioulnar (2 per forearm) and tibiofibular (2 per leg)
What factor affects the movement possible in a syndesmoses?
It varies slightly by fiber length
What is a Gomphosis? Where is it located?
“Peg in socket” fibrous joint. Joint holding tooth in alveolar process
True or False: The shoulder is a gomphosis joint
False. Gomphoses are only in the teeth socket
Gomphoses, Syndesmoses, and Sutures are all examples of…
Fibrous Joints
“Chondro-“ prefix refers to…
Cartilage
What are the two types of cartilaginous joints?
Synchondroses and Symphoses
Do cartilaginous joints have a joint cavity?
No
What defines cartilaginous joints?
Articulating bones are held together by cartilage
What is a synchondrosis? Give an example of a synchondrosis.
A SYNARTHROTIC joint made of a BAR or PLATE of HYALINE CARTILAGE.
Ex: Epiphyseal plate in long bones of children before they ossify
Ex 2: Btw. costal cartilage of 1st rib and manubrium
What type of joint is the epiphyseal plate in children, and what does it become after puberty?
Synarthrotic synchondrosis becomes a synostosis.
What is the functional classification of a Symphysis?
Amphiarthrotic
What two factors define a Symphysis?
It contains HYALINE CARTILAGE plus ARTICULAR CARTILAGE on bony surfaces?
Give an example of a Symphysis.
- Intervertebral discs
- Pubic Symphysis
What defines a synovial joint?
A fluid filled articular capsule between the bones
Describe Weeping Lubrication
Synovial Fluid squishes out of articular cartilage under pressure to create a slippery, weight-bearing film and is reabsorbed when pressure is released.
What other interesting feature does synovial fluid contain?
It contains phagocytic cells that eat microbes and debris
What does the Synovial Fluid do for articular cartilage?
Cushions, produces slip, and nourishes
Reinforcing ligaments are _____-like in shape.
Reinforcing ligaments are STRAP-like in shape
What do ligaments connect?
Bone to Bone
Intracapsular ligaments are covered with _____ ______ and are never _____ _____ as a result.
Intracapsular ligaments are covered with SYNOVIAL MEMBRANE and are never INSIDE THE CAVITY as a result.
Thickened parts of fibrous cartilage that support a joint or attach bones are called _______
LIGAMENTS
Bursa means ______ in Latin
“Purse” in Latin
A BURSA is a ……
Flattened sac of fibrous membrane w/ synovial membrane and bit of synovial fluid
A Bursa’s job is to…
Reduce friction between ligaments and bones
True or False: A Bursa is part of a Synovial Joint?
False, it is a separate entity
An elongated Bursa that wraps around a tendon is called a…
Tendon Sheath
Tendon sheaths are found in areas of ____ _____ such as _____.
Tendon sheaths are found in areas of HIGH FRICTION such as WRISTS.
What type of tissue make up the fibrous membrane of Bursae?
Dense IRREGULAR (sac)
What 3 Factors affect Joint Stability?
1) Muscle Tone
2) Shapes of Articular Surfaces (how well bones fit together)
3) # and positioning of ligaments
When an articular surface is large or a socket is deep, how does this affect stability?
It is MORE STABLE
How is stability affected when articular surfaces are shallow or shapes are non-complementary?
LOWER stability
True or False: Stretched ligaments stay stretched
True
A higher number of ligaments leads to…
HIGHER STABILITY
What is the difference between ORIGIN and INSERTION points?
ORIGIN are for IMMOVABLE or LESS MOVABLE bones; INSERTION is for MORE MOVABLE bones (combine the two for movement)
Contraction occurs when muscle pulls the INSERTION/ORIGIN towards the INSERTION/ORIGIN.
Contraction occurs when muscle pulls the INSERTION towards the ORIGIN.
