CH11 Flashcards
(76 cards)
The moveable end of the muscle that attaches to the bone being pulled is called what?
Insertion: The moveable end of the muscle
The end of the muscle attached to a fixed bone is called what?
Origin: the end of the muscle attached to a fixed (stabilized) bone
Fulcrum
the fixed point when a force is applied, joints
Load
any resistance to a movement (e.g. bones, tissue, resistance to movement, etc.)
Effort
force applied by the contracting muscle at its insertion. Motion occurs when the effort exceeds the load
First-class lever
uncommon; the load and force sit on either side of the fulcrum in the same way as a seesaw.
EX: head resting on the vertebral column which acts as the fulcrum, the contraction of the posterior neck muscles provides the effort, the anterior portion of the skull (load) is lifted
Second-class lever
uncommon; the load is between the fulcrum and the effort.
EX: is raising yourself on your toes. The fulcrum is based at the front of the foot, the load is the weight of the body, and the force is applied through the Achilles tendon in the heel. This creates a mechanical advantage because the load is closer to the fulcrum than the effort as in a wheelbarrow
Third-class lever
common; the force is applied between the load and the fulcrum.
EX: biceps brachii. When flexing the elbow, the elbow is the fulcrum and the force applied by the contracting biceps brachii muscle is the effort. The weight of the forearm and any object a person is carrying in their hand is the load
Which lever is most common in the human body?
Third class lever
Compartment Syndrome
- ainful condition when pressure within the muscles builds to dangerous levels.
- Decreases blood flow and prevent nourishment and oxygen to nerve and muscle cells
- Cause: overuse, trauma, car accident
What are the sign/symptoms of compartment Syndrome?
- pain, pallor (pale skin tone)
- paresthesia (numbness feeling)
- pulselessness (faint pulse)
- paralysis (weakness with movements)
compartment Syndrome most commonly found where?
anterior compartment of the leg
extensor muscles of the toes, tibialis anterior, deep peroneal nerve, and the tibial artery
Orbicularis Oris is what type of fascicle arrangement?
Circular (or sphincter) muscles: arranged in concentric rings around an opening or recess
Prime mover or agonist:
principal muscle involved
Antagonist
muscle with opposite action of agonist; relaxes or stretches when prime mover contracts to produce movement
Synergist
- muscle(s) producing similar motion to or in conjunction with agonist
- May add extra force or reduce unwanted force generated by agonist
- May act as fixation to bone or origin so agonist can work more efficiently
What are the two types of parallel muscles?
- Fusiform: spindle shaped, muscles tapers at each end. (Example: biceps brachii)
- Non Fusiform: more rectangular shaped (Example: Sartorius)
The rectus femoris is an example of what type of muscle arrangement?
Bipennate
Pennate (penna = feathers) muscles
attaches to the central tendon; the tendon runs through the length of the muscle
Unipennate
Extensor digitorum (in the forearm)
What is an example of a multipennate muscle?
deltoid
The word “rectus” means what?
straight
Muscles of face
Occipitofrontalis muscle
moves up the scalp and eyebrows. The frontalis is on the forehead and occipitalis is on the back of head
Muscles of the face
Orbicularis Oris
circles the mouth. Moves lips (kissing muscles!)