22-09-21 - MS System: Joints and Muscles Flashcards
What is the definition of a joint?
Where are joints found?
What are the functions of joints?
How many joints are in the body?
What word is anything related to joints?
- Joints are where two or more bones meet to allow movement
- Can be found connecting bones or connecting bone to cartilage
- Functions of joints:
- Facilitate growth
- Hold bones together
- Transmit forces
- Enable various levels of movement
- There are approximately 230 joints in the body. This changes as we grow
- ‘Arthro’ is the word associated with anything to do with joints
What are the 3 classifications of joints by movement?
What is the movement associated with each type?
What are features of each type?
Where can each type be found?
- Synarthroses – immovable/fixed joints – joined together by tough fibrous proteins that interlock to allow close connection and prevent movement – can be found strongly connecting adjacent bones together in the skull
- Amphiarthroses – limited movement – sandwich of hyaline cartilage and fibrocartilage known as intervertebral disks used in joint – used to join bodies of vertebrae
- Synarthroses and amphiarthroses are typically found in the axial skeleton
- Diarthroses – variety of moveable joints – Found in the appendicular skeleton, such as in the limbs

What are the 3 classifications of cells by soft tissue structure?
What is the movement associated with each type?
What are features of each?
Where can each type be found?
- Fibrous – virtually no movement – joined together by tough fibrous proteins that interlock to allow close connection and prevent movement, considered to be a solid joint – can be found strongly connecting adjacent bones together in the skull
- Cartilaginous – limited or no movement – can be synarthroses or amphiarthroses, but broadly considered to be classed as solid – found joining bodies of vertebrae
- Synovial – a variety of movement – can be hinge joints or ball and socket joints – found in the appendicular skeleton in limbs.

What are the 3 types of fibrous joints?
What are they composed of?
What are their purposes?
- Sutures – thick connective tissues compose of mainly type 1 collagen fibres – gives protection to the brain by strongly joining adjacent bones in the skull
- Gomphoses – Collagen fibres in the periodontal ligament that secure teeth into bone of the tooth socket (means nail/bolt)
- Syndesmoses – fibrous membrane that exists between adjacent bones – interosseus ligament that are radioulnar or tibiofibular joints

What are the 2 types of cartilaginous joints?
What are they made from?
What kind of movement do they allow?
Where can they be found?
- Synchondroses
- Primary cartilaginous joint
- Made from Hyaline cartilage – allows bone growth during adolescence and eventually ossifies – allows for limited movement
- Found in the epiphysis/diaphysis of long bones and rib cage (epiphyseal growth plate is a temporary synchondroses)
- Symphyses
- Secondary cartilaginous joint
- Made from hyaline and fibrocartilage -provides limited movement, can absorb shock
- Forms the pubic symphysis, found as intervertebral discs between adjacent vertebrae, makes up manubriosternal joint connecting manubrium and sternum (manubriosternal joint)

What are synchondroses?
What are they made from?
What kind of movement do they allow?
Where are they found?
- Synchondroses are primary cartilaginous joints made from hyaline cartilage
- Synchondroses are made from Hyaline cartilage and allow for limited movement
- They form the costochondral joint in ribs 1-10 and the first costosternal joint in rib 1, which connects rib 1 to the sternum.
- This prevents the ribs from moving too much and gives them support
- The costosternal joint in ribs 2-7 are synovial joints, which allow for more movement when breathing
- Synchondroses also form the epiphyseal plates in growing bones.

What are symphyses joints?
What are they made from?
What kind of movement do they allow?
Where are they found?
- Symphyses are secondary cartilaginous joints
- Made from hyaline and fibrocartilage - provides limited movement, can absorb shock
- Found in the axial skeleton
- Found in the manubriosternal joint (joining of sternum and manubrium)
- Separates bodies of vertebrae as intervertebral disks, which are sandwiches of hyaline cartilage and fibrocartilage
- Found in the pubic symphysis

Where are ribs 11 and 12 located
What are they referred to as?
Why are they given this name?
- Ribs 11 and 12 are located below rib 10
- They are referred to as floating ribs, as they do not attach to the sternum, or to another rib
Where is the first thoracic vertebrae (T1) located?
What does it form with the first rib?
- The first thoracic vertebrae (T1) connects to the first rib
- This forms a circle known as the thoracic inlet
What are the 3 parts of the sternal body called?
What is the joint between the bottom 2?
- The top of the sternal body is the manubrium
- The middle of the sternal body is the sternum
- The bottom part of the sternal body is the xiphoid process
- The xiphisternum is the xiphoid process and the sternum together
- The joint between the sternum and the xiphoid process is the xiphisternal joint.
What are false ribs?
What ribs are false ribs?
- False ribs are ribs that do not join to the sternum directly
- the 8th, 9th and 10th ribs are all false ribs, as they do not connect to the sternum directly, but are connected to the 7th rib by cartilage.
What does the costal margin consist of?
Where does it attach?
- The costal margin is the medial margin formed by the cartilages of the 7th to 10th ribs, which extend inferolaterally from the xiphisternal joint
Where does the the diaphragm attach?
- The diaphragm attaches anteriorly to the xiphoid process and costal margin
- It attaches laterally to the 11th and 12th ribs
- It attaches posteriorly to the lumbar vertebrae
What are the only Synovial joints?
What is their main structure?
What is their purpose?
Where are they found in the body?
- Diarthroses and synovial joints are synonymous
- The main structure is a fibrous cavity filled with synovial fluid, with articular (hyaline) cartilage between the 2 bones
- Synovial joints enable a wide range of movement
- Synovial joints are found between bones that move against each other
- This includes joints of the limbs (shoulder, hip, elbow, knee)

What is articular cartilage made from in synovial joints?
Where is it found in the synovial joint?
What is its purpose?
How does it receive nutrients?
How does this affect recovery of injury?
- Articular cartilage in synovial joints is made from hyaline cartilage, which is smooth gel like tissue
- Hyaline cartilage is found between the 2 bones in the joint
- It creates a frictionless surface for the bones to move on
- Articular cartilage in the synovial joint withstands compressive, tensile, and sheer forces using collagen fibres
- There is no blood supplies, nerves, or lymphatic system in the cartilage
- The synovial fluid provides nutrients to and removes waste from the articular cartilage via diffusion
- This is not efficient as a blood supply, so injuries affecting the cartilage take longer to heal.

Label this diagram of a synovial joint


Where is the synovial membrane?
What is it made from?
What is it responsible for?
- The synovial membrane lines the articular cavity of synovial joints
- It is made from collagenous tissue
- It secretes synovial fluid, which supplies nutrients and removes waste from the articular cartilage.

What does synovial fluid consist of?
What is its consistency like?
Where is it found?
What is its purpose?
How does it respond to exercise?
- Synovial fluid contains Hyaluronic acid, lubricin (glycoproteins) and phagocytic cells.
- It possesses a highly lubricating egg-white like consistency
- It is found within the articular cavity of synovial joints.
- It reduces friction between articular surfaces (surfaces within the joint)
- It also provides the cartilage of the synovial joint with nutrients and removes its waste via diffusion.
- When exercising, the alignment of glycoproteins is altered
- Exercises decreases viscosity so that lubrication improves
- This property is known thixotropy (becoming less viscous when subjected to applied stress)

What are bursae made from?
Where are they found?
What is their purpose?
What is bursitis?
- Bursae are fatty closed sacs lines with a synovial membrane and are lubricated with fluid
- They are found where friction occurs such as between skin and bone, or tendons and bone
- They can be found between the fibrous capsule and bone/skin in synovial joints
- Their purpose is to allow smooth action and protection.
- Bursitis is the inflammation of these bursae

What are synovial sheathes?
Where are they found?
What is their purpose?
- Synovial sheaths are specialised bursae that fully surround tendons, where they are subject to pressure.
- They surround tendons that enable dexterity, such as those in the hands and feet.
- These synovial sheaths help protect tendons from abrasive damage as they move

What is the intra-articular disc?
What are they made from?
Where are they found?
What is their purpose?
- The Intra-articular disc is known as meniscus in synovial joints
- They are made form fibrocartilage
- It is found within the fibrous capsule of weight bearing joints or joints capable of rotatory movement (ball and socket joint – diarthroses)
- The disc provides a deeper socket for bone to move in, which reduces chances of dislocation
- The fibrocartilage of the intra-articular disc also cushions and facilitates smooth articulation (connection of bones in a joint)

What is hypermobility/double-jointedness?
What causes it?
What are the potential negative effects of it?
- Hypermobility is the condition in which joints stretch farther than normal.
- It is caused by a disorder of the collagen and connective tissue within the ligaments and joints, which allows for greater flexibility and range of movement.
- This increase range of movement can increase the chances of dislocation of joints

Where is the fibrous capsule?
What is it made from?
What is it responsible for?
- The fibrous capsule is found next to the periosteum of both bones in a synovial joint
- It contains strong connective tissue and a lot of collagen fibres and nerves
- Connective tissue from the fibrous capsule can form into ligaments to hold the 2 bones in the joint.
- This provides strength and integrity to joint and protects the bones from moving out of alignment.

What are tendons made from?
What do they connect together?
What is their purpose?
- Tendons are made from connective tissue that has a lot of strong collagen fibres in it
- Tendons attach muscle to bones
- Tendons are present to hold structures together and keep them stable









