Flashcards in Chapter 2 - Basic Exercise Science Deck (120)
What is synovial fluid? What is it's purpose? Where is it produced?
A fluid that resembles egg whites and works like engine oil.
It is secreted within joint capsule from synovial membrane to lubricate joint surfaces to reduce excessive wear and to nourish the cartilage cells that line the joint.
How many types of synovial joints are there? List them.
1. Gliding (plane)
2. Condyloid (condylar or ellipsoidal)
Explain a gliding (plane) joint's purpose and movement. Give examples.
-A nonaxial joint that has the simplest movement of all joints.
-Movement: Either back and forth or side to side.
1.Foot joint between the navicular bone and the second and third cuneiform bones
2. The carpals of the hand
3. The facet (spine) joints
Explain a condyloid (condylar or ellipsoidal) joint's purpose and movement. Give examples.
-Named because the condyle of one bone fits into the elliptical cavity of another bone to form a joint.
-Movement: predominately occurs in one plane (flexion and extension in the sagittal plane) with minimal movement in others (rotation in the transverse plane, adduction and abduction in the frontal plane).
1. Wrist between the radius and the carpals
2. The joints of the fingers (metacarpophalangeal).
Explain a hinge joint's purpose and movement. Give examples.
-A uniaxial joint allowing movement predominately in only one lane of motion, the sagittal plane.
2. Interphalangeal (toes)
Explain a sliding joint's movement, where it's located and how it got it's name. Give examples of movement planes.
-One bone looks like a saddle, the other articulating bone straddles it like a rider.
-Only found in the carpometacarpal joint in the thumb.
-Movement: predominantly in two planes of motion (flexion and extension in the sagittal plane, adduction and abduction in the frontal plane) with some rotation to produce circumduction (circular motion).
Explain a pivot joint's movement and location. Give examples of movement plane.
-Movement: in one plane of motion (rotation, pronation, and supination in the transverse plane.
1. in the atlantoaxial joint at the base of the skull (top of the spine)
2. In the proximal radioulnar joint at the elbow.
Explain why a ball-and-socket joint is the most mobile of the joints. Give an example.
-They allow movement on all three planes.
-Examples: shoulder and hip
What are nonsynovial joints, explain their movement and give examples.
Joints that do not have a joint cavity, connective tissue, or cartilage. *Exhibit little to no movement.
*Examples: sutures of the skull, the distal joint of the tibia and fibula, and the symphysis pubis (pubic bones).
Why do ligaments not repair or heal very well and may be slower to adapt to stress placed on the body?
-Poor Vascularity (or blood supply)
Explain the function of the ligament, what it is made of, and give an example.
- Primary connective tissue that connects bones together to provide static and dynamic stability, as well as input to the nervous system (proprioception), guidance, and the limitation of improper joint movement.
- Primarily collagen (a protein that runs parallel to the forces that are typically places on a ligament)
- With varying amounts of elastin (a second protein that provides flexibility or elastic recoil to withstand bending and twisting)
- Not all ligaments will have the same amount of elastin.
- Anterior cruciate ligament (ACL) of the knee contains very little elastin and is mostly collagen and is much better suited for resisting strong forces and making good stabilizing structure of the knee.
What is the Muscular System?
Series of muscles that moves the skeleton.
Define what "muscle" literally means. What are the 3 main types of muscles in the body?
- Multiple bundles of muscle fibers held together by connective tissue.
What is Epimysium? Where do they connect?
- The first bundle (actual muscle itself) wrapped by an outer layer of connective tissue (fascia), and an inner layer that is underneath the fascia and surrounds the muscle (epimysium).
- Fascia and epimysium are also connected to the bone and help to form the muscle's tendon.
- The outermost layer of connective tissue that surrounds the muscle.
- A grouping of muscle fibers that house the myofibrils.
What is Perimysium?
- The connective tissue that surrounds the fascicles.
What is Endomysium?
- The deepest layer of connective tissue that surrounds individual muscle fibers.
- Connective tissues that attach muscle to bone and provide an anchor for muscles to produce/exert force and control the bone and joint.
- Similar to ligaments: poor vascularity (blood supply)
What are myofibrils and where are they located?
A portion of the muscle that contains myofilaments located in the cell components of the Sarcolemma.
What are myofilaments?
The contractile components of muscle tissue known as actin (thin stringlike filaments) and myosin (thick filaments) that form a number of repeating sections within the myofibril. Each section is known as a Sacromere.
What is Sarcolemma?
- A plasma membrane that encase muscle fibers that contain cell components such as cellular plasma (sarcoplasm)
What is Sarcoplasm?
- Cell components, or cellular plasma, that contains glycogen, fats, minerals, and oxygen-binding myoglobin that are contained within the Sarcolemma.
What is tropomyosin and where is it located?
-Location: on the actin filament
-Function: block myosin binding sites located on the actin filament, keeping myosin from attaching to actin when the muscle is in a relaxed state.
What is troponin and where is it located?
-Location: on actin filament
-Function: plays a role in muscle contraction by providing binding sites for both calcium and tropomyosin when a muscle needs to contract.
What is the neuromuscular junction?
-"nerve to muscle"
-A specialized synapse (junction/point) at which the (motor) neuron meets and communicates the muscle (fibers) to allow the action potential to continue its impulse.
What is Neural Activation?
- The contraction of a muscle generated by neural stimulation.
What is a Sacromere?
- The functional unit of the muscle (much like the neuron is for the nervous system) that produces muscular contraction and consists of repeating sections of actin and myosin.
Define a Motor Unit.
- A motor neuron and all of the muscle fibers it innervates(connects).