Skeletal Muscle Flashcards
1
Q
Naming of muscles: Named by orientation of muscle fibers in muscle
A
a. rectus femoris
b. transverse abdominis
c. superior oblique
2
Q
Naming of muscles: Named by location in body
A
a. tibialis anterior
b. temporalis
c. epicranius (frontalis and occipitalis)
3
Q
Naming of muscles: Named by relationship to other similar muscles
A
- Size
i. Gluteus maximus
ii. Gluteus minimus - Relative location
i. medial rectus
ii. lateral rectus
4
Q
Naming of muscles: Named by number of origins
A
a. Triceps brachii
b. Biceps femoris
5
Q
Naming of muscles: Named by shape of muscle
A
a. Rhomboidius major
b. Deltoid
6
Q
Naming of muscles: Named by origin and insertion
A
a. Sternocleidomastoid
b. Pubococcygeus
7
Q
Naming of muscles: Named by action of the muscle
A
a. Supinator
b. Adductor magnus
8
Q
Muscles of Facial Expression: Epicranius (occipitofrontalis) *3 details
A
- divided into 2 parts - overlies top of skull
1. Frontalis - over forehead - consists of 2 bellies - draws scalp forward - wrinkles forehead - raises eyebrows
insertion: superficial fascia of eyebrow
origin: Galea aponeurotica (epicranial aponeurosis)
2. Occipitalis - over occipital bone - draws scalp backward (wiggles your ears)
insertion: Galea aponeurotica (epicranial aponeurosis)
origin: Occipital bone
9
Q
Muscles of Facial Expression: Orbicubris oris *3 details
A
- sphincter muscle surrounding mouth opening
- closes and compresses lips, protrudes lips, shapes for speech
origin and insertion - muscles arranged in circular pattern with variety of origins and insertions.
10
Q
Muscles of Facial Expression: Zygomaticus major
A
- runs obliquely across the front of the face from upper corner of mouth
- draws the angle of mouth upward and outward - assists in parting lips
- origin: zygomatic bone
- insertion: fascia around mouth’s angle (lateral corner)
11
Q
Muscles of Facial Expression: Levator labii superioris
A
- runs superior to lip, parallel to nose
- assists in raising and parting lips
- origin: near orbit, on maxillae
- insertion: fascia around upper lip
12
Q
Muscles of Facial Expression: Depressor labii inferioris
A
- depresses lower lip
- origin: mandible
- insertion: skin of lower lip
- lateral to mentalis
13
Q
Muscles of Facial Expression: Mentalis
A
(mentum=chin) - protrudes lower lip - elevates skin over chin - pouting muscle
- origin: mandible near lower lip
- insertion: fascia of chin
- medial to Depressor labii inferioris
14
Q
Muscles of Facial Expression: Buccinator
A
- (buce=cheek) - makes up most of mass of cheek
- compresses cheeks (blowing and sucking)
- origin: alveolar processes of maxilla and mandible and from pterygomandibular ligament (raphe)
- insertion: fascia of lower lateral face
15
Q
Muscles of Facial Expression: Platysma
A
- (platy=flat, broad) - very superficial muscle covering lower face and neck
- draws skin around mouth laterally and inferiorly
- origin: fascia over deltoid and pectoralis muscles
- insertion: fascia of lower lateral face
16
Q
Muscles of Facial Expression: Risorius
A
- (risor=laughter) - runs laterally from corners of mouth
- origin: fascia over parotid gland
- insertion: fascia at corners of mouth
17
Q
Muscles of Facial Expression: Orbicularis Oculi
A
- circular muscle around orbit
- origin and insertion: circular locations around orbit (many)
- functions sphincter like to close the eye
18
Q
Muscles of Facial Expression: Levator palpebrae superioris
A
- functions to elevate upper eyelid.
- actually a muscle of the orbit - courses over eyeball to eyelid
- origin: lesser wing of sphenoid (orbital root)
- insertion: superior tarsal plate of upper lid.
19
Q
Muscles of Facial Expression: Corrugator Supercilii
A
- small muscle deep to orbicular is oculi
- responsible for angry look
- origin: medial part of superciliary arch
- insertion: fascia and skin of eyebrow
20
Q
Muscles of Mastication: Masseter
A
- elevates the mandible - most powerful
- origin: zygomatic arch
- insertion: angle and ramus of mandible
21
Q
Muscles of Mastication: Temporalis
A
- elevates and retracts mandible
- origin: fan shaped over the temporal bone
- insertion: coronoid process and anterior border of ramus of mandible
22
Q
Muscles of Mastication: Medial pterygoid
A
- elevates and protrudes mandible - also functions in moving the mandible from side to side in chewing.
- origin: medial side of lateral pterygoid plate and from maxilla
- insertion: medial surface of angle of mandible
23
Q
Muscles of Mastication: Lateral pterygoid
A
- pulls mandible forward to open mouth and also assists in side to side movement.
- origin: greater wing of sphenoid and lateral side of later pterygoid plate
- insertion: condyle of mandible and articular disk of T.M.J.
24
Q
Muscles of Mastication: Mylohyoid
A
- flat muscle making up lower floor of mandible - elevates floor of mouth
- origin: inferior portion of mandible
- insertion: a midline raphe and the hyoid bone
25
Muscles of Mastication: Stylohoid
- elevates and retracts the tongue
- origin: styloid process of temporal bone
- insertion: body of hyoid bone
26
Muscles of Mastication: Genioglossus and Geniohyoid
- Protracts the tongue and depresses the tongue
- origin: anterior inferior portion of the mandible (superior genial tubercle)
- insertion: fans out into the mass of the tongue - some to tip - some to dorsum of tongue - some posterior. Geniohyoid inserts on hyoid bone
27
Muscles of Mastication: Styloglossus
- elevates and retracts the tongue
- origin: Styloid process
- insertion: fibers merge into the side and under surface of the tongue
28
Muscles of Mastication: Hyoglossus
- Depresses the tongue
- origin: Body and cornu of hyoid bone
- insertion: fibers merge with fibers of other muscles in the side of the tongue
29
Muscles That Move The Head: Sternocleidomastoid
- flexes the neck or rotates head from side to side
- origin: sternum and clavicle
- insertion: mastoid process
30
Muscles That Move The Head: Semispinalis Capitis
- extends the head at the neck or rotates from side to side
- origin: seventh cervical, and first 6 thoracic vertebrae
- insertion: occipital bone
31
Muscles That Move The Head: Splenius Capitis
- extension or rotation of head
- origin: Ligamentum nuchae and seventh cervical and first 4 thoracic vertebrae
- insertion: occipital bone
32
Muscles of Anterior Abdominal Wall: Rectus Abdominus
- strap-like muscle on medial abdomen.
- origin: pubic symphysis and pubic crest
- insertion: cartilage of sixth and seventh ribs and xyphoid.
- anterior surface is crossed by linea alba vertically at midline and by several horizontal "tendinous intersections"
- functions to flex vertebral column
- encased within "Rectus Sheath"
33
Muscles of Anterior Abdominal Wall: External Oblique
- courses obliquely downward across abdomen
- most outer layer of muscle
- compresses abdomen or may assist in lateral bending
- note: aponeurosis forming rectus sheath crosses over rectus muscle
- origin: lower 8 ribs
- insertion: midline aponeurosis
34
Muscles of Anterior Abdominal Wall: Internal Oblique
courses oblique in upward direction across abdomen
- function = same as external
- aponeurosis forming rectus sheath divides and goes both over and under rectus abdominus muscle
- origin: Lumbar fascia; iliac crest, and partially from inguinal ligament
- insertion: lower borders of lower 3 ribs and their cartilages
35
Muscles of Anterior Abdominal Wall: Transversus abdominus
- lies deep to internal oblique
- fibers run horizontally and forward
- aponeurosis forming rectus sheath passes posterior to rectus abdominus
- origin: Lumbar fascia, iliac crest, inner part of last 6 ribs and cartilage
- insertion: xyphoid process, rectus sheath, pubis
36
Muscles of Pelvic Floor: Levator ani
- divided into 2 parts - funnel shaped
1. Pubococcygeus - Pubis - coccyx
2. Iliococcygeus - Ilium - coccyx
3. (some authors include the Puborectalis)
37
Muscles of Pelvic Floor: Coccygeus
- Ischial Tuberosity - Coccyx (sometimes called Ischiococcygeus)
38
Perineum: Urogenital diaphragm
- musculofacial diaphragm situated in anterior part of perineum. Formed by the following muscles which are enclosed with fascia above and below
1. Sphincter Urethrae
2. Deep Perineal muscles
* these muscles may assist in helping prevent flow of materials out of urethra - also assist in ejaculating remaining fluid (semen or urine
39
Perineum: Muscles associated with genitalia
1. Bulbospongiosis (Bulbocavernosus)
| 2. Ischiocavernosus
40
Perineum: Sphincter ani externus
- keeps anal orifice closed
| - origin and insertion unimportant
41
Muscles of Shoulder: Pectoralis Major
- some function in flexing arm - but mostly for adduction and medial rotation
- origin: clavicle and sternum and partly from some costal cartilage
- insertion: greater tubercle of humerus
42
Muscles of Shoulder: Pectoralis Minor
- deep to Pectoralis Major
- Primary action is to fix the scapula - also accessory muscle for respiration
- origin: medial ends of ribs 2-4
- insertion: coracoid process of scapula
43
Muscles of Shoulder: Subclavius
- depresses the clavicle and steadies it during movements of shoulder girdle - relatively unimportant muscle
- origin: first rib
- insertion: clavicle
44
Muscles of Shoulder: Serratus Anterior
- functions to draw the scapula forward and lateral on thoracic wall - also, due to greater pull on inferior angle causes lateral rotation
- origin: anteriolateral surface of upper 8-9 ribs
- insertion: the medial anterior border of scapula
45
Muscles of Shoulder: Deltoid
- triangularly shaped muscle that abducts the arm primarily
- origin: clavicle, acromion, and spine of scapula
- insertion: deltoid tuberosity of humerus
* actually actions of deltoid are many besides abduction of arm, either flex and medially rotate or extend and laterally rotate the arm depending on which part contracts. Can also assist in adduction.
46
Muscles of Shoulder: Trapezius
- an elevator of lateral angle of the scapula - enabling one to touch head - also retracts scapula and can extend the head.
- origin: occipital bone and ligamentum nuchae and spinous processes of thoracic vertebrae.
- insertion: spine and acromion of scapula and lateral 1/3 of clavicle
47
Muscles of Shoulder: Levator Scapulae
- elevator of the superior angle of scapula. In doing so tends to retract and elevate scapula.
- origin: first 3-4 cervical vertebrae
- insertion: superior angle of scapula
48
Muscles of Shoulder: Rhomboideus Major and Minor
- these two muscles are frequently fused to form 1 muscle. Chief actions - retraction and elevation of the scapula (adduction).
- origin: lower ligamentum nuchae and spinous processes of upper 5-6 thoracic vertebrae.
- insertion: medial border of scapula
49
Muscles of Shoulder: Latissimus Dorsi
- adductor, medial rotator, and extensor of arm
- origin: very extensive, from spinous processes of lower thoracic, lumbar, and sacral vertebrae. Also from posterior iliac crest.
- insertion: wraps around medial side of humerus and inserts on intertubercular groove of humerus.
50
Muscles of Shoulder: Supraspinatus
- abductor of the arm (some slight abduction is associated with almost all movement of arm)
- origin: bony walls of the supraspinatus fossa of scapula. Passes laterally inferior to acromion to;
- insertion: upper greater tubercle of humerus
51
Muscles of Shoulder: Infraspinatus
- primary function is lateral rotation of humerus
- origin: infraspinatus fossa of the scapula - courses around outside of humerus to:
- insertion: greater tubercle
52
Muscles of Shoulder: Teres Minor
- primary action is lateral rotator of humerus (like infraspinatus)
- origin: lateral (axillary) border of scapula
- insertion: greater tubercle of humerus
53
Muscles of Shoulder: Teres Major
- acts as an extensor, adductor, and medial rotator of humerus
- origin: inferior angle of scapula - fibers course medial to humerus to
- insertion: with Latissimus dorsi in intertubercular groove.
54
Muscles of Shoulder: Subscapularis
- medial rotator of arm
- origin: subscapular fossa of scapula
- insertion: lesser tuberosity of humerus
55
Rotator Muscles (8)
```
Pec. Major
Ant. Deltoid
Anterior Subscapularis
Latis. Dorsi
Posterior Teres Major
Posterior Deltoid
Infraspinatus
Teres Minor
```
56
"Rotator Cuff"
= four scapular muscles which form a musculotendinous cuff around the shoulder joint. The muscles are the supraspinatus, infraspinatus, teres minor, and subscapularis.
These are all rotators of the shoulder except the supraspinatus, however this muscle is used with most movements of the shoulder and is the most frequently injured in rotator cuff injuries
57
Muscles of Upper Extremity: Biceps Brachii
- arises from 2 heads (origin)
short head - coracoid process of scapula
long head - supraglenoid tubercle of the scapula
*these two bellies fuse for common insertion at radial tuberosity
*since muscle crosses 2 joints - can have some function at either joint. However, as is the case with most 2 joint muscles - strongest action is at the distal joint. Acts as flexor and supinator of forearm. (at shoulder helps in adduction and flexion of arm)
58
Muscles of Upper Extremity: Brachialis
- flexion of forearm is sole function.
- origin: from lower 1/2 of humerus on anterior side
- insertion: coronoid process of ulna
59
Muscles of Upper Extremity: Coracobrachialis
- adduction and flexion of arm
- origin: from coracoid process of scapula to:
- insertion: medial border of the humerus about "mid-arm"
60
Muscles of Upper Extremity: Triceps Brachii
- arises from 3 heads
1. lateral head - posterior surface of upper humerus
2. long head - infraglenoid tubercle of scapula
3. medial head - deep to other two heads - from posterior surface of humerus inferior and medial to origin of lateral head.
* primary function - extension of forearm (however long head may act to extend arm)
- insertion: olecranon process
61
Muscles of Upper Extremity: Brachioradialis
- flexor of the forearm
- origin: supracondylar ridge of the humerus (lateral side)
- insertion: just superior to the styloid process of the radius
62
Muscles of Upper Extremity: Pronator Teres
- pronates the forearm
- origin: Medial epicondyle of the humerus and coronoid process of ulna.
- insertion: Shaft of the radius (middle of lateral side)
63
Muscles of Upper Extremity: Supinator
- supinates the forearm (note: Biceps is chief supinator)
- origin: lateral epicondyle of the humerus and posterior portion of ulna
- insertion: shaft of the radius
64
Muscles of Upper Extremity: Flexors of wrist and digits
ventral forearm
65
Muscles of Upper Extremity: Extensors of wrist and digits
dorsal forearm
66
Muscles of Upper Extremity: Dorsal and Palmar interossei muscles
- between metacarpals of hand - responsible for adduction and abduction of digits (not in book)
67
Muscles Used in Breathing: Diaphragm
- form roof of abdominal cavity and floor of the thoracic cavity. Works like a bellows to create negative pressure in lungs and thus inspiration, then positive pressure for expiration.
- origin: lumbar vertebrae, lower six ribs and cartilages and xyphoid
- insertion: central tendon of diaphragm
68
Muscles Used in Breathing: External Intercostals
- run obliquely downward from lateral to medial. Draw ribs together thus elevating them and assisting to create negative pressure in thorax for inspiration.
- origin and insertion: rib to rib
69
Muscles Used in Breathing: Internal Intercostals
- same as external except run obliquely downward from medial to lateral
- lay directly beneath external intercostals (deep to them) - pull ribs together in forced expiration.
70
Muscles of the Lower Extremity: Gluteus Maximus
- extends and laterally rotates the thigh
- mostly used during action requiring considerable muscular effort - used when raising from sitting or stooping position.
- origin: iliac crest, sacrum, coccyx, (and sacrotuberus ligament)
- insertion: lateral side of femur and the iliotibial tract (lateral thickening of fascia lata)
71
Muscles of the Lower Extremity: Gluteus Medius and Minimus
- origin: both from Ilium
- insertion: superior lateral surface of greater trochanter
*for the most part - abduction of hip also both medial rotators of hip
*most important function is to stabilize the pelvis during walking as opposite foot leaves the ground.
(work with tensor fascia lata)
72
Muscles of the Lower Extremity: Tensor fascia lata
- origin: iliac crest
- insertion: into iliotibial tract which inserts near lateral condyle of tibia.
- enclosed within fascia lata - a flexor and abductor of the hip.
- extends the knee
73
Muscles of the Lower Extremity: Iliopsoas
Iliopsoas - composed of Psoas and Iliacus muscles
Psoas - arises from lumbar vertebral bodies and transverse processes
Iliacus - fan-shaped - comes from upper part of iliac fossa
- insertion: fibers fuse and insert via common tendon on the lesser trochanter of femur.
- action: flexes the thigh (e.g. lifting leg or raising from lying to sitting position)
74
Muscles of the Lower Extremity: Adductors (longus, brevis, magnus)
- origin: pubis (magnus also from ischium)
- insertion: linea aspera of femur
* adductors of thigh - also flexors (magnus can extend)
75
Muscles of the Lower Extremity: Quadriceps femoris
- powerful group of muscles for extending the knee (rectus femoris also helps flex the hip)
Rectus Femoris - origin: anterior inferior iliac spine
Vastus Lateralis
Vastus Medialis
Vastus Intermedius
- origin: femur itself (upper portion)
- insertion: all muscles fuse into common Quadriceps tendon which ensheaths patella and forms part of the capsule of the knee and the patellar ligament. (inserts on tibial tuberosity)
76
Muscles of the Lower Extremity: Sartorius (tailor's muscle)
- runs obliquely across thigh from lateral to medial
- origin: anterior superior iliac spine
- insertion: medial surface of shaft of tibia
- acts at two joints
a. flexes, abducts, and laterally rotates thigh at hip
b. flexes and medially rotates leg at knee
77
Muscles of the Lower Extremity: Gracilis
- on medial side of thigh - adductor of thigh and flexor of leg
78
Muscles of the Lower Extremity: Hamstrings
- a collective grouping (for naming) of 3 large muscles in posterior compartment of thigh.
1. Biceps femoris
- origin: from two heads
a. long head - ischial tuberosity
b. short head - femur
- insertion: lateral condyle of tibia and head of fibula
2. Semitendinosis
- origin: ischial tuberosity
- insertion: medial shaft of tibia
3. Semimembranosis
- origin: ischial tuberosity
- insertion: medial condyle of tibia
* collectively the hamstrings all function to flex the leg and extend the thigh.
79
Muscles of the Lower Extremity: Gastrocnemius
- origin: lateral head - lateral condyle of femur
medial head - just above medial condyle of femur
- insertion: tendocalcaneus (Achilles tendon)
*plantar flexor of foot - also assists in flexion of the knee.
80
Muscles of the Lower Extremity: Soleus
- origin: posterior surface of tibia and head of fibula
- insertion: tendocalcaneus
* plantar flexor of foot
- together with plantaris and Gastrocnemius - it provides main forward propulsive force in walking and running by using foot as a lever
81
Muscles of the Lower Extremity: Tibialis Posterior, Flexor Digitorum Longus, and Flexor Hallucis Longus
- Three muscles of the deep portion of the posterior compartment
- Tendons wrap around the medial malleolus and insert on the bottom of the foot
82
Muscles of the Lower Extremity: Fibularis (Peroneus) Longus and Brevis
- both found in lateral compartment of the leg and are responsible for plantar flexion and eversion of the foot.
- origin: both arise from fibula with tendon wrapping under lateral malleus
- insertion: inferior aspect of foot
longus: medial cuneiform and first metatarsal
brevis: 5th metatarsal
83
Muscles of the Lower Extremity: Tibialis Anterior
- origin: upper 1/2 of lateral aspect of tibia and interossous membrane
- insertion: tendon passes through extensor retinaculum and attaches to medial cuneiform
84
Muscles of the Lower Extremity: Extensor Digitorum Longus
is a muscle in the anterior compartment of the leg that dorsiflexes the foot and extends the toes (passes through extensor retinaculum)
85
Muscles of the Lower Extremity: Extensor Hallucis Longus
is a muscle in the anterior compartment of the leg that extends the hallux (big toe)
86
Deep Muscles of the Back: Quadratus Lumborum
- flexes vertebral column laterally
- origin: iliac crest
- insertion: upper lumbar vertebrae and lowest rib
87
Deep Muscles of the Back: Sacrospinalis or Erector Spinae
- extends the vertebral column and maintains it in an erect position.
- extends from the iliac crest and sacrum to the neck and base of the skull - Divided into 3 major muscle groups.
1. Iliocostalis - most lateral of 3 groups
- made up of iliocostalis lumborum, iliocostalis thoracicus, and iliocostalis cervicus.
2. Spinalis (Spinalis thoracicus) - most medial of 3 muscle groups
3. Longissimus - intermediate between other 2 groups
- can be further divided into Longissimus thoracicus, Longissimus cervicus, and Longissimus capitis.
