Flashcards in Chapter 9 Muscle Deck (72)
What is endomysium?
the thin layer of ECM that surrounds each muscle cell or fiber
What is a fascicle?
between 10-100 muscle cells in a bundle
what is epimysium?
the outer fibrous connective tissue wrapping that enclose all the perimysium wrapped fascicles that make up muscle.
What is perimysium?
A connective tissue that bundles fascicles together.
What are the 6 arrangement patterns of fascicles?
1. Parallel: evenly spaced fascicles attaching to a tendon of similar width. Ex: Sartorius
2. Convergent: Broad triangular shaped muscle that tapers to a single tendon. Ex: Pec major
3. Pennate: fascicles attach to tendon on an angle and look like a feather. Includes unipennate (flexor pollicis), bipennate: Rectus Femoris, and multipennate (Deltoid).
4. Circular: aka sphincters (obicularis oculi)
5. Spiral: Twisted appearance. Wrap around another structure such as a bone. Ex: supinator
6. Fusiform: fatter in muscle belly, thinner on ends. Ex: biceps brachii
What is an agonist?
a prime mover. It provides most of the force required for a given movement.
What is an antagonist?
usually lies on the other side of the joint from the agonist, and slows movements down. Results is control, and graceful movement.
What is a synergist?
work together with agonists to help minimize unwanted deviations. Help stabilize joints.
What is a fixator?
hold bones in place to reduce risk of injury.
What are muscle origin and insertion?
origin: usually the stable, non-moving end
insertion: is where the muscle attaches to another structure that will be moved.
What is a first-class lever? In what direction is the load moved relative to the applied force?
Fulcrum is between load and force (see saw) The force is applied in the opposite direction of movement. Ex: triceps brachii moving the forearm at the elbow. *mechanical advantage*
What is a second class lever? In what direction is the load moved relative to the applied force?
Fulcrum - Load - Force. The force is in the same direction as movement produced. Ex rising up on toes. *Mechanical advantage*
What is a third-class lever? In what direction is the load moved relative to the applied force?
Fulcrum - Force - Load. The force is in the same direction as movement produced. Ex pulling up on a fishing rod. *Mechanical disadvantage*
Name the 9 different ways that muscles are named.
Shape, appearance, size, position, the number of separate heads, location, what structures they attach to, what they do, historical origins.
Contraction of the diaphragm muscle is a vital function associated with the ..... system
Skeletal muscles in the throat initiate....
Sphincters composed of skeletal muscle allow ...... control over the opening and closing of body openings
The ...... is a large sheet of connective tissue that links the smaller frontalis and occipitalis muscles to form the epicranius.
What are the main actions of the epicranius?
To raise the eyebrows and skin of the forehead.
What is the job of obicularis oculi, levator palpebrae superioris, and corrugator supercilii?
Move the skin and tissues around the eye.
Zygomaticus major and minor, levator labii superioris, and risorius all function in......?
All function in movement of the mouth.
What is the action of the orbicularis Oris?
Controls fine movements of the lips critical for eating drinking whistling and proper speech
What are the three muscles involved in facial expressions that convey negative emotions?
1. Depressor anguli Oris
2. Depressor Labii inferiorus
Which muscle compresses the cheeks and are involved in manipulating food while chewing?
Name the broad flat sheet of muscle covering the anterior neck. What is the action of this muscle?
Platysma. Action is To produce the open mouth jaw-dropping look of horror that tightens the skin of the neck.
Each eye has how many muscles attached to its outer surface allowing for quick and accurate movements that direct our vision?
Name the four rectus muscles of the eye. In what direction does each of these muscles move the eyeball?
1. Superior rectus: Move the eyeball superiorly and medially.
2. Inferior rectus: Move the eyeball inferiorly and laterally.
3. Medial rectus: Move the eyeball medially
4. Lateral rectus: Move the eyeball laterally
The superior oblique runs from its origin in the posterior I threw a common tenderness ring that also surrounds the posterior bellies of each rectus muscle through the ......... which serves as a pulley, just before the muscle inserts into the anterior eyeball. In what direction does the superior oblique move the eyeball?
Trochlea. Downward and laterally
The inferior oblique does not originate from the posterior orbit, but from the anterior and medial aspect of the orbit and runs underneath the anterior eyeball to insert into the posterior and lateral aspect of the eyeball. In what direction does the inferior oblique move the eyeball?
Upward and laterally