Skeletal Muscle Architecture and Muscle Naming Flashcards Preview

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Flashcards in Skeletal Muscle Architecture and Muscle Naming Deck (13)
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1

Fascicle Orientation: Circular

Circular (orbicularis oris, orbicularis oculi)
--sphincter
--surround external body openings
--close when they contract

2

Fascicle Orientation: Convergent

Convergent (latissimus dorsi, gluteus medius, pectoralis major)
--broad origin
--narrow insertion
--direction of pull can be changed b/c different groups of fibers can be activated

3

Fascicle Orientation: Parallel

Parallel (sartorius, sternocleidomastoid, brachioradialis, flexor digitorum superficiali [FDS])
--fascicles run parallel to long axis of muscle
--tapered at both ends
--strap
--high endurance, not very strong though

4

Fascicle Orientation: Pennate

Pennate (uni: extensor digitorum longus; bi: rectus femoris; multi: deltoid)
--fascicles short
--attach obliquely to tendon or raphe
--uni-, bi-, to mulitpennate
--stronger than parallel muscle of same size

5

Muscle Compartments

Dense, fibrous CTs divides muscles into compartments
Muscles in same compartment are often synergistic (similar actions)
Muscles in opposite compartments are usually antagonistic (opposite actions)
Usually, muscles in one compartment are innervated by a single nerve

6

Compartment syndrome

Damaged muscle swells, surrounding fascia (inelastic) constricts

Puts pressure on vessels and nerves (pain!), also prevents blood from entering or draining

Acute compartment syndrome (accident/injury) can lead to tissue loss (muscle or limb) due to a loss of blood supply

Chronic compartment syndrome is caused by overuse...resting until it heals is the best course

7

Naming Muscles: 1. Location

Biceps BRACHII (arm)
Quadriceps FEMORIS (femur)

8

Naming Muscles: 2. Shape

DELTOID (triangular...think Greek letter delta)
TRAPEZIUS (trapezoidal)

9

Naming Muscles: 3. Relative Size

Gluteus MAXIMUS (largest)
Adductor BREVIS (short)

10

Naming Muscles: 4. Direction of Fascicles and Fibers

RECTUS (straight) abdominus
External OBLIQUE

11

Naming Muscles: 5. Location of Attachments

CORACOBRACHIALIS (coracoid process and arm)

12

Naming Muscles: 6. Number of Origins/Heads

BICEPS (2 heads) brachii
QUADRICEPS (4 heads) femoris

13

Naming Muscles: 7. Action

FLEXOR digitorum longus
ADDUCTOR magnus
ABDUCTOR pollicis longus