Lecture 7 - Muscular System

Question 1

What are fascicles and how do they affect muscles

Answer 1

• > they’re skeletal muscle fibres arranged in a muscle in bundles.
• > they give the muscle its shape and therefore its function

Question 2

Origin vs insertion

Answer 2

Origin: end of the muscle that is attached to an immovable bone
Insertion: end of the muscle which attaches to the movable bone

Question 3

What are the different muscle groups/ muscle actions, explain.

Answer 3

Prime mover/agonist - > contracts to cause the desired action
Antagonist - > stretches/extend to reverse action of prime mover
Synergists - > assist prime movers
Fixators - > stabilize the origin of the prime mover

Question 4

Motion executed by occipitofontalis

Answer 4

raise eyebrows and wrinkle forehead

Question 5

motion executed by corrugator supercilii

Answer 5

draws eyebrows down and medially

Question 6

motion executed by orbicularis oculi

Answer 6

serves to close the eye

Question 7

motion executed by levator palpebrae superioris

Answer 7

responsible for elevating upper eyelid; bugeyes

Question 8

motion executed by nasalis

Answer 8

flares the nostrils

Question 9

motion executed by levator labii superioris

Answer 9

elevates upper lip

Question 10

motion executed by orbiculairs oris

Answer 10

pucker lips/ duck lip

Question 11

motion executed by zygomaticus major and minor

Answer 11

draws angle of mouth up and out, allows smiles

Question 12

motion executed by platysma

Answer 12

draws lower lip down and out, flex neck

Question 13

list all muscle involved in mastication

Answer 13

• > masseter
• > temporalis
• > pterygoids (medial and lateral)

Question 14

motion executed by the masseter

Answer 14

elevates and retracts mandible

Question 15

motion executed by the temporalis

Answer 15

elevates and retracts mandible

Question 16

motion executed by the pterygoids

Answer 16

lateral and medial pterygoids allow mandible to lower and move side to side (cow thing)

Question 17

motion executed by the buccinator

Answer 17

compress cheeks when blowing air, trumpet mouth, suck milkshake

Question 18

name all extrinsic eye muscles

Answer 18

• > superior rectus (up)
• > inferior rectus (down)
• > medial rectus (in)
• > lateral rectus (out)
• > superior oblique (down and out)
• > inferior oblique (up and out)
  (rectus go the right way, oblique go the opposite)

Question 19

name the muscles of the neck and what they do

Answer 19

• > sternocleidomastoid (moves head down and to the sides)

- > trapezius (synergist to sterno….)

Question 20

name all the muscles involved in breathing and what each one does

Answer 20

Diaphragm - > contracts (inhale) and relax (exhale)
External intercostals - > pulls ribs upwards to increase volume (inhale)
Internal intercostals - > pulls ribs down to decrease volume (exhale)
Serratus posterior superior - > elevates posterior ribs during inspiration
Serratus posterior inferior - > depresses poserior ribs during exhalation

Question 21

name all the muscles of the abdominal wall and their function

Answer 21

• > rectus abdominis (abdominal flexor)
• > external obliques (superficial; rotates and flex spine)
• > internal oblique (deep; rotates and flex spine)
• > transverse abdominis (increases abdominal pressure)

Question 22

3 muscles groups that move the spine

Answer 22

1. Iliocostalis thoracic
2. Longissimus thoracic
3. Spinalis thoracic
   (extend vertebral column; I long for spinach)

Question 23

muscles which stabilize the pectoral girdle

Answer 23

• > serratus anterior (pull scapula anteriorly and around the rib cage)
• > trapezius (extend neck, elevate the shoulder, adduct the scapula; fibres run in 3 directions)

Question 24

motion executed by the pectoralis major

Answer 24

flexes and adducts hummerus

Question 25

motion executed by the latissimus dorsi

Answer 25

powerful arm extender, adductor, medial rotator

Question 26

motion executed by the deltoid

Answer 26

flex, abduct, extend the arm

Question 27

muscle of the rotator cuff

Answer 27

(SITS) - > Supraspinatus - > Infraspinatus - > Teres minor - > Subscapularis * more stable on superior aspect, why people dislocate arms*

Question 28

major flexors of the forearm

Answer 28

- > biceps brachii (superficial, helps with supination) | - > brachialis (deep, more powerful)

Question 29

extensor of the forearm

Answer 29

- > triceps brachii | - > anconeus (synergist extensor)

Question 30

list all muscles of the anterior forearm

Answer 30

- > brachioradialis (synergist pronator supinator) - > Pronator teres - > pronator quadratus - > supinator

Question 31

muscles which extend and abduct the thighs

Answer 31

- > gluteus maximus - > gluteus medius - > gluteus minimus

Question 32

muscles which flex the thigh

Answer 32

Illiopsoas (Illiacus + psoas major)

Question 33

Name all adductor muscles of the medial thigh

Answer 33

- > adductor longus - > adductor brevis - > adductor magnus

Question 34

what are the four muscles of the quadricep femoris

Answer 34

- > rectus femoris - > vastus lateralis - > vastus medialis - > vastus intermedius

Question 35

sartorius

Answer 35

- > allows you to sit cross legged - > flexes, abducts, laterally rotates the thigh - > flexes and medially rotates the leg

Question 36

name all hamstring muscles

Answer 36

- > semimembranosus (most medial) - > semitendinosus - > bicep femoris (extend hip and flex knee)

Question 37

muscles of the leg

Answer 37

- > tibialis anterior - > fibularis brevis & longus - > gastrocnemius - > soleus

Question 38

types of interossei

Answer 38

Dorsal interossei -> abduct the fingers NAILS | Plantar interossei -> adduct the fingers NO

Question 39

fibularis brevis & longus fuctions

Answer 39

responsible for eversion of the foot

Question 40

function of popliteus

Answer 40

pops knee out of locked position ,hamstrings do the rest

Question 41

what is the tricep surae

Answer 41

gastrocnemius + soleus muscle

Question 42

Gastrocnemius and soleus's involvement in plantar flexion

Answer 42

Gastrocnemius - > prime mover | soleus - > synergist (its under gastro...)