Chapter 10: The Muscular System Flashcards
(51 cards)
1
Q
7 different ways/criteria that is used when naming a skeletal muscle
A
- shape
- location
- size
- direction of muscle fibers or fascicles
- number of origins
- location of attachments
- muscle action
2
Q
Naming criteria: muscle location
A
- bone or body region with which muscle is associated
- ex. temporalis (over temporal bone)
3
Q
Naming criteria: muscle shape
A
- distinctive shapes
- ex. deltoid muscle (deltoid = triangle)
4
Q
Naming criteria: Muscle size
A
- maximus (largest)
- minimus (smallest)
- longus (longest
5
Q
Naming criteria: Direction of muscle fibers or fascicles
A
- ex. rectus (fibers run straight)
- transversus (fibers run at right angles)
- oblique (fibers run at angles to imaginary defined axis)
6
Q
Naming criteria: number of origins
A
- ex. biceps (two origins)
- triceps (three origins)
7
Q
Naming criteria: Location of attachments
A
- named according to point of origins and insertion (origin is first part of name)
- ex. sternocleidomastoid attaches to sternum and clavicle
- origin on sternum and clavicle (sternocleido-)
- insertion on mastoid process (-mastoid)
8
Q
Naming criteria: muscle action
A
- named for action they produce
- ex. flexor (causes flexion)
- extensor (causes extension)
9
Q
How else are muscles named?
A
- several criteria can be combined
- extensor carpi radialis longus- extensor (extends) carpi (wrist) radialis (radius) longus (length is long)
10
Q
Epicranius: general
A
- epi = over; cran = skull
- 2 part muscle with distinct anterior and posterior positions
- epicranial aponeurosis (connective tissue sheath that connects muscle to bone) connects 2 bellies
11
Q
2 parts of epicranius
A
- frontal belly (anterior)
- Occipital belly (posterior)
12
Q
2 parts of epicranius: frontal belly
A
- anterior
- O: epicranial aponeurosis
- I: skin of eyebrows and root of nose
- Action: raises eyebrows
13
Q
2 parts of epicranius: Occipital belly
A
- posterior
- O: occipital and temporal bones
- I: epicranial aponeurosis
- action: pulls scalp posteriorily
14
Q
Orbicularis oris
A
muscle of lips
15
Q
Orbicularis oris: action
A
closes lips, purses and protrudes lips
16
Q
Buccinator
A
- thin, horizontal cheek muscle
- principal muscle of cheek, deep to masseter
17
Q
Buccinator: action
A
- compresses cheek (for whistling and sucking- important for infant feeding)
- also important during chewing
18
Q
Suprahyoid muscles
A
- 4 deep muscles involved in swallowing
- form floor of oral cavity
- anchor tongue
19
Q
Suprahyoid muscles: what structures do these muscles move
A
- elevate hyoid bone
- move larynx during swallowing
20
Q
Infrahyoid muscles
A
4 straplike muscles
21
Q
Infrahyoid muscles: what structures do these muscles move
A
- depress hyoid bone and larynx during swallowing and speaking
22
Q
Pectoralis major
A
large, fan-shape, anterosuperior chest
23
Q
Pectoralis major: what joint does it cross and what is its primary action
A
- crosses shoulder (glenohumeral) joint
- action: prime mover of arm adduction; flexion and medial rotation of arm
24
Q
Latissimus dorsi
A
- posterior muscle
- broad, flat, triangular, lower back
- O: lower 6 thoracic vertebrae, lumbar vertebrae, iliac crest
- I: medical humerus (axilla area)
25
Latissimus dorsi: what joint does it cross and what is its primary action
* crosses the shoulder (glenohumeral) joint
* action: prime mover of arm extension; prime mover of arm adduction (powerful); medially rotates arm
* important during hammering, swimming, rowing, with arms extended upwards: pull body upwards- chin-ups
26
Deltoid
thick, multipennate, forms rounded shoulder (anterior to posterior around shoulder)
27
Deltoid: what joint does it cross and what is its primary action
* crosses the shoulder (glenohumeral) joint
* action: prime mover of arm abduction when all fibers contract simultaneously; antagonist of pectoralis major and latissimus dorsi (arm abductors)
* anterior fibers: prime mover of arm flexion, rotate arm medially (become synergist of pectoralis major)
* posterior fibers: prime mover of arm extension, lateral rotation
28
Erector spinae
3 muscles: iliocostalis (lateral), longissimus (intermediate), spinalis (medial)
29
Erector spinae: what happens if this muscle group is damaged
* lifting a load or moving suddenly from bent-over position can injure erector spinae muscle
* muscles can easily begin spasming after a back injury
30
Abdominal wall muscles: identify the one that is most important during mobility
* transversus abdominis: deepest abdominal muscle
* fibers run horizontally
* action: compress abdominal content
* when 4 abdominal muscles contract simultaneously they compress abdominal content and increase intra-abdominal pressure
* if airway closed this helps with urination, defecation, childbirth, sneezing, coughing, and burping
31
Rotator cuff muscles
* synergists and fixators
* O: scapula
* I: humerus
* main function: reinforce capsule, prevent dislocation of humerus
32
Rotator cuff muscles: what muscles are in this group
1. Supraspinatus: abduction of arm
2. Infraspinatus: prime mover for lateral arm rotation
3. Teres minor: prime mover for medial arm rotation
4. Subscapularis: prime mover for medial arm rotation
33
Triceps brachii
* only muscle of posterior arm compartment
* large fleshy, three-headed origin
* O: scapula, humerus x2 heads
* I: olecranon of ulna
34
Triceps brachii: primary action
prime mover of forearm extension (powerful) antagonist of forearm flexors
35
Biceps brachii
two-headed muscle
36
Biceps brachii: primary actino
* Prime mover of elbow flexion and supination of forearm
* bulges when forearm is flexed
37
Brachialas
* strongest arm flexor
* deep to and stronger than biceps brachii
38
Brachialis: primary action
major flexor of forearm, prime mover of elbow flexion
39
Hamstring Muscles
* fleshy, cross both hip and knee joint
* pulled hamstring = common sports injury
40
Hamstring muscles- what muscles are in this group
1. Biceps femoris (I: fibula and tibia); has 2 heads (biceps)
2. Semitendinosus (I: upper tibial shaft)
3. Semimembranosus (I: tibia and femur)
40
Hamstring muscles features
* all have common origin: ischial tuberosity
* prime movers of thigh extension and knee flexion
41
Sartorius
* longest muscle in the body
* straplike, runs obliquely across anterior surface
* crosses hip and knee joint
* O: iliac spine (pelvis)
* I: medial aspect of tibia
* Actions: flex, abduct, laterally rotate thigh
42
Sartorius: what sitting position is it used to create
helps produce the cross-legged position
43
Gastrocnemius
* has 2 heads
* action = plantar flexion
44
Gastrocnemius: insertion
* Instersts into posterior calcaneus via calcaneal tendon
* calcaneal tendon = achilles tendon, largest tendon in the body
45
Respiratory muscles: diaphragm: primary action
prime mover of inspiration (breathing in), flattens on contraction
* most important muscle of inspiration
* forms partition between thoracic and abdominopelvic cavities
46
Respiratory muscles: diaphragm: what happens when it is relaxed/contracts
Relaxed: dome shaped
When contracted: moves inferiorly and flattens to increase thoracic cavity volume (this action pulls air into lungs)
47
Respiratory muscles: External and internal intercostals: action
pulls ribs toward one another, important in inspiration and forced exhalation
48
External and internal intercostals: location
* between ribs
* external intercostals: superficial to internal intercostals. fibers run obliquely (downward and anteriorly)
* internal intercostals: fibers run at right angles to external intercostals, downward and posteriorly
* run in opposite directions
49
External and internal intercostals: what do they connect
connects a superior rib to inferior rib
50
What is considered the most powerful muscle in the body
quadriceps femoris
