Muscles Flashcards
1
Q
Muscle tissues’ arrangement of fibers may be divided into 4 principle categories….
A
- Parallel
- Radiating
- Pennate
- Circular
2
Q
Parallel
A
- great range of motion due to elongated muscle fibers running in the same direction
3
Q
Radiating
A
- muscle bundles converge or diverge at a certain point
- powerful muscles, but sacrifice the range of motion
4
Q
Pennate
A
- muscle bundles converge into a central running tendon (leaf like)
- abdomen
5
Q
Circular
A
- sphincter type muscle
- surrounds an area
- eyes, lips, eye lids
6
Q
Origin
A
- point of muscle attachment that is fixed/stable
- engages in lesser movement
7
Q
Insertion
A
- point of muscle attachment that moves during an action
- the part of the muscle that is attached to the structure being acted upon/wants to move
- when muscle contracts it shortens
8
Q
Skeletal muscle usually produces a movement by acting upon a…..
A
JOINT that lies somewhere between the origin and insertion
9
Q
Agonists
A
- muscles perform the same action
10
Q
Antagonist
A
- muscles working against each other
- perform the opposite action
11
Q
Organization of Muscle Tissue
A
- elongated cells
- primary mediator of all movement in nervous system
- accounts for 40% of body weight (on avg)
- must be switched on/off by CNS
12
Q
The smallest functional unit of muscle tissue is the…
A
Muscle Fiber!
13
Q
How big is a muscle fiber?
A
10-100 microns in diameter, being 1/millionth of a meter
14
Q
Muscle Fibers contain a lot of..
A
Mitochondria, which supplies energy
15
Q
The Muscle Fiber is composed of
A
Myofibrils!
16
Q
Myofibrils
A
- protein filaments
- arranged in parallel with each other
- composed of specific protein groups known as myosin and actin
17
Q
Endomysium
A
- membrane surrounding individual muscle fibers
18
Q
Perimysium
A
- fibrous membrane that ncapsulates a group of muscle fibers together
- a grouping of muscle fibers is known as a fasciculus
- separates faciculi
19
Q
Epimysium
A
- fibrous envelope that wraps around an entire muscle bundle or group of fasciculi
20
Q
Fascia
A
- sheet of fiber tissue that envelopes and encloses groups of muscle bundles
21
Q
All of these layers are eventually continuous with …
A
- tendonous attachment to bone via periosteum
22
Q
Functions of these layers on tissue
A
- segregates different groups of muscle bundles
- provides slippery surface so muscle tissue can slide easily over each other
- adds structure and framework
- distribute force evenly
- prevent muscle bundle from tearing apart during periods of great contraction
23
Q
A
