Joints of the body pt. 1
What are the 3 types of structural classifications of joints?
Fibrous - joined by dense connective tissue
Cartilaginous - joined by cartilage
synovial - presence of a joint cavity
Which type of synovial joint allows the greatest range of motion? What are two examples of this type of joint?
Ball-and-socket. Glenohumeral joint + hip joint
How many joint types make up the temporomandibular joint? what are they?
2 types of synovial joints
Gliding (plane) joint - allow protraction/retraction
Hinge joint - allow elevation + depression
What percentage of body mass is made up of muscle? What percentage of that is skeletal muscle?
50% total body mass
40% of that is skeletal muscle
Which two components regulate HOW contraction occurs? What two components regulate WHEN contraction occurs?
Actin + myosin (HOW)
Troponin + tropomyosin (WHEN)
What are the 3 types of functional classification of joints?
Synarthrosis - immovable
Amphiarthrosis - slightly movable
Diarthrosis - freely movable
List the 6 types of angular movements
flexion, extension, hyperextension, adduction, abduction, circumduction
How many articulations are included in the knee joint? does the femur articulate with the fibula at this joint?
3 articulations
The fibula + humerus do not articulate.
What are the 4 main functional properties of muscle?
Excitability
Contractility
Extensibility
Elasticity
True or false: Contraction can occur with ONLY Calcium present
False: calcium + ATP must be present in order for contraction to occur
What are the three types of fibrous joints? How is each defined functionally?
Sutures - synarthrosis
Syndesmosis - amphiarthrosis
Gomphosis - synarthrosis
There are 4 types of joints included in the vertebral column, what are they?
Symphysis joints - intervertebral discs
Synovial plane joints - between articular facets
Condyloid joints - Atlanto-occipital joint
Pivot joint - Atlantoaxial joint
What bones are included in the talocrural joint? What about the subtalar joint?
talocrural - tibia, fibula, talus
Subtalar - talus + calcaneus
What are the three connective tissue layers that cover skeletal muscle? What does each layer cover?
Endomysium - covers individual muscle fibers
Perimysium - covers fascicles
Epimysium - covers the entire muscle
What is a cross-bridge?
Myosin heads bind to actin to create a cross bridge
What are the two types of cartilaginous joints? Give an example of each
Synchondrosis (hyaline cartilage) - epiphyseal plate
Symphysis (fibrocartilage) - pubic symphysis
What are the 'special' movements that are able to be performed by both the mandible and the scapula?
Protraction + retraction
Elevation + depression
The smooth cartilage that covers the ends of bones is called articular cartilage. What type of cartilage is this?
Hyaline
The striated appearance of skeletal muscles are caused by:
actin + myosin myofilaments
Calcium binds to what in skeletal muscle to produce contraction? What does calcium bind to in smooth muscle to produce contraction?
Calcium binds to troponin in skeletal muscle
Calcium binds to calmodulin in smooth muscle
How are synovial joints defined functionally? What characteristic of synovial joints allows this functionality?
Diarthrosis (freely movable) - because of the presence of a joint cavity
what are the two articulations included in the elbow joint?
Humeroulnar (humerus + ulnar articulation)
Humeroradial (humerus + radial articulation)
True or false: joints are fully formed at birth, but continue to develop and strengthen as you grow
true
What structural part of the sarcomere defines the sarcomere boundaries?
Z-lines
What does the neuromuscular junction release to initiate muscle contraction?
A neurotransmitter - acetylcholine