CDIS 3010: Joints and Muscles in Class

joints-

mobile connections between structures where movement can occur

Where can joints be found?

between cartilage-cartilage, bone-bone, or bone-cartilage

What is the basic function of a joint?

to be able to move at a certain position

How can we functionally classify joints?

how moveable they are (degree of movement)

How can we structurally classify joints?

bone-bone, cartilage-cartilage, bone-cartilage

What are the 2 ways to classify joints?

structurally and functionally

What joints are least moveable in the body?

synarthrodial/ fibrous

Describe synarthrodial/ fibrous joints.

-structure: 2 bones come together to form a seam held together by fibrous tissue

-function: immovable after infancy

Describe amphiarthrodial/cartilaginous joints.

-structure: cartilage connects the ribs to the sternum creating a joint

-function: muscle contraction allows a very slight twisting movement of the cartilage between the ribs and the sternum

Describe diarthrodial/synovial joints.

-structure: the two structures that come together at these joints come together to form a joint cavity (synovial cavity)

-function: these joints allow the most movement of all the joints

What are the most moveable joints?

diarthrodial/synovial joints

What are the three main types of synovial joints related to the speech systems?

condylar joint, pivot joint, saddle joint

Where are condylar joints found?

between the jaw and the skull

what is the function of a condylar joint?

muscle contraction closes the jaw, also allow for side-to-side movement

Where is a pivot joint found?

between the first two vertebra

What is the function of a pivot joint?

muscle contraction allows rotation of the head to the left and right

Where are saddle joints found?

between the cricoid cartilage and the arytenoid cartilage of the larynx

What is the function of a saddle joint?

muscle contraction allows for sliding and rocking of arytenoid cartilages

muscle-

specialized tissue that can contract

How much can muscle contract?

can contract to up to 1/3 of its original length

What happens when the muscle is larger?

there are more muscle fibers within the muscle

What are the four descriptive aspects used to describe muscles?

origin, course, insertion, action

origin-

where the muscle's connection is; where it originates; attachment side with least amount of movement

course-

which way muscle fibers run from the origin point

insertion-

where the muscle courses to from the origin; point of attachment that has more mobility

action-

what happens when the muscle contracts

motor unit-

motor nerve and the muscle it innervates (communicates)

motor nerve-

specialized nerve cell that communicates with a muscle

What causes the muscle to contract?

motor neuron communicates to muscle it needs to contract for whatever action you want to perform

What are the four characteristics of skeletal muscles?

excitability, contractility, extensibility, elasticity

contractility-

muscle tissue is able to shorten and develop tension

excitability-

ability of a muscle cell to respond to a stimulus by producing electrical signals called action potentials

extensibility-

opposite of contractility; ability of muscle tissue to stretch without experiencing damage

elasticity-

the ability of the muscle to return to its resting length after contraction or extension

What are the different movements of muscles?

agonistic muscles, antagonistic muscles, synergistic muscles

agonistic muscles are ___________ ___________.

prime movers

agonistic muscles-

specific muscle contracted to perform a specific motor act

What is an example of an agonistic muscle?

muscles in the hand performing a thumbs up

antagonistic muscles are _____________ ____________.

movement opposers

antagonistic muscles-

muscles that oppose the contraction of another

synergistic muscles are ______________.

stabilizers

synergistic muscles-

stabilize structures during contraction

What is an example of a synergistic muscles?

muscles in the tongue

What are the three types of contraction?

isometric, concentric, eccentric

What are other types of movement in how muscles move structures?

flexion, extension, adduction, abduction

flexion-

bring surfaces or ends of the body closer together

extension-

bring surfaces or ends of the body apart or away from each other

adduction-

brings tissues to midline

abduction-

brings tissues away from midline