Lecture 7 - Muscular System Flashcards
What are fascicles and how do they affect muscles
- > they’re skeletal muscle fibres arranged in a muscle in bundles.
- > they give the muscle its shape and therefore its function
Origin vs insertion
Origin: end of the muscle that is attached to an immovable bone
Insertion: end of the muscle which attaches to the movable bone
What are the different muscle groups/ muscle actions, explain.
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
Motion executed by occipitofontalis
raise eyebrows and wrinkle forehead
motion executed by corrugator supercilii
draws eyebrows down and medially
motion executed by orbicularis oculi
serves to close the eye
motion executed by levator palpebrae superioris
responsible for elevating upper eyelid; bugeyes
motion executed by nasalis
flares the nostrils
motion executed by levator labii superioris
elevates upper lip
motion executed by orbiculairs oris
pucker lips/ duck lip
motion executed by zygomaticus major and minor
draws angle of mouth up and out, allows smiles
motion executed by platysma
draws lower lip down and out, flex neck
list all muscle involved in mastication
- > masseter
- > temporalis
- > pterygoids (medial and lateral)
motion executed by the masseter
elevates and retracts mandible
motion executed by the temporalis
elevates and retracts mandible
motion executed by the pterygoids
lateral and medial pterygoids allow mandible to lower and move side to side (cow thing)
motion executed by the buccinator
compress cheeks when blowing air, trumpet mouth, suck milkshake
name all extrinsic eye muscles
- > 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)
name the muscles of the neck and what they do
- > sternocleidomastoid (moves head down and to the sides)
- > trapezius (synergist to sterno….)
name all the muscles involved in breathing and what each one does
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
name all the muscles of the abdominal wall and their function
- > rectus abdominis (abdominal flexor)
- > external obliques (superficial; rotates and flex spine)
- > internal oblique (deep; rotates and flex spine)
- > transverse abdominis (increases abdominal pressure)
3 muscles groups that move the spine
- Iliocostalis thoracic
- Longissimus thoracic
- Spinalis thoracic
(extend vertebral column; I long for spinach)
muscles which stabilize the pectoral girdle
- > serratus anterior (pull scapula anteriorly and around the rib cage)
- > trapezius (extend neck, elevate the shoulder, adduct the scapula; fibres run in 3 directions)
motion executed by the pectoralis major
flexes and adducts hummerus
motion executed by the latissimus dorsi
powerful arm extender, adductor, medial rotator
motion executed by the deltoid
flex, abduct, extend the arm
muscle of the rotator cuff
(SITS)
- > Supraspinatus
- > Infraspinatus
- > Teres minor
- > Subscapularis
- more stable on superior aspect, why people dislocate arms*
major flexors of the forearm
- > biceps brachii (superficial, helps with supination)
- > brachialis (deep, more powerful)
extensor of the forearm
- > triceps brachii
- > anconeus (synergist extensor)
list all muscles of the anterior forearm
- > brachioradialis (synergist pronator supinator)
- > Pronator teres
- > pronator quadratus
- > supinator
muscles which extend and abduct the thighs
- > gluteus maximus
- > gluteus medius
- > gluteus minimus
muscles which flex the thigh
Illiopsoas (Illiacus + psoas major)
Name all adductor muscles of the medial thigh
- > adductor longus
- > adductor brevis
- > adductor magnus
what are the four muscles of the quadricep femoris
- > rectus femoris
- > vastus lateralis
- > vastus medialis
- > vastus intermedius
sartorius
- > allows you to sit cross legged
- > flexes, abducts, laterally rotates the thigh
- > flexes and medially rotates the leg
name all hamstring muscles
- > semimembranosus (most medial)
- > semitendinosus
- > bicep femoris
(extend hip and flex knee)
muscles of the leg
- > tibialis anterior
- > fibularis brevis & longus
- > gastrocnemius
- > soleus
types of interossei
Dorsal interossei -> abduct the fingers NAILS
Plantar interossei -> adduct the fingers NO
fibularis brevis & longus fuctions
responsible for eversion of the foot
function of popliteus
pops knee out of locked position ,hamstrings do the rest
what is the tricep surae
gastrocnemius + soleus muscle
Gastrocnemius and soleus’s involvement in plantar flexion
Gastrocnemius - > prime mover
soleus - > synergist (its under gastro…)
