Muscles - from Lab Flashcards
4 main muscle fiber patterns - features, examples
- Circular: Fibres arranged concentrically around an opening - functions as sphincter to close passageway or opening -e.g. orbicularis oris 2. Parallel: Fascicles parallel to long axis of muscle - body of muscle increases in diameter w/ contraction. -high endurance, not very strong -e.g. rectus abdominis 3. Convergent: Triangular muscles w/ common attachment site - direction of pull can be changed Does not pull as hard as equal-sized muscle. -e.g. pectoralis major 4. Pennate (uni-, bi-, multi-): muscle body has 1 or more tendons, fasciles at oblique angle to tendon, pulls harder than a parallel muscle of equal size. unipennate: all muscle fibres same side (extensor digitorum) bipennate: muscle fibres on both sides (Rectus femoris) multipennate: tendon branches w/ muscle (Deltoid)
Muscle terminology;- Brevis Capitis Endo- epi- gastro- inter- magnus oblique peri- rectus
Brevis - short Capitis - head Endo- - within epi- - upon gastro- -stomach inter- -between magnus -large oblique -at an angle peri- -around rectus -straight
Define; - -Origin -Insertion
Origin: The less mobile attachment of a muscle that doesn’t move as much during contraction Insertion: The more mobile attachment of a muscle that moves during contraction (comes closer to the origin when muscle contracts)
What does triceps brachii move?
-Extends forearm
What does biceps branchii move?
Flexes elbow joint
What does pectoralis major move?
Glenohumeral joint (shoulder joint)
What does Latissimus dorsi move?
Abduction of arm/arm extension
What does gluteus maximus move?
Extension of hip
What does biceps femoris move?
Flexion of knee
Muscle functions;- Flexors Extensors Abductors Adductors Rotators
Flexors - muscles that bend the limb Extensors - muscles that straighten the limb Abductors - Muscles that move the limb away from the midline Adductors - muscles that move the limb towards the midline Rotators - muscles that rotate a bone around its own long axis
Muscles involved in flexing the elbow joint (3)
-Biceps branchii -Brachialis -Brachioradialis (insertion near humerous)
Muscle that extends the fingers to open the hand
-Extensor digitorum
Muscles that make up quadriceps (4)
-Vastus lateralis -Rectus femoris (crosses hip and knee joint) -Vastus medialis -sartorius
Muscles that make up hamstring (3)
-Semimembranosus -Semitendinosus -Biceps femoris (has 2 heads/muscle bellies)
Muscles that make up “calf muscle” (2) -Tendon both insert
-gastrocnemius -soleus *both insert into calcaneous tendon (AKA achilles)
4 main muscles of mastication
-Masseter -temporalis -Pterygoids (medial and lateral) -Buccinator
3 muscles of facial expression
-orbicularis oris -obricularis oculi -mentalis
3 muscles of facial expression
-orbicularis oris (kissing) -obricularis oculi (blinking & squinting) -mentalis
Muscles involved in inhalation (1) & exhalation (2) -role of scalene muscles
Inhalation: External intercostal (elevate ribs) Exhalation: Internal intercostal mucles (depress ribs) & Transvrsus thoracis (depresses ribs) -Scalene muscles allows more air in during forced inspiration (i.e. during exercise)
Diaphragm movement during inhalation and exhalation
Inhalation: Diaphragm moves inferiorly during contraction Exhalation: Diaphragm moves superiorly as it relaxes
Muscles involved in jaw closure
Masseter & Temporalis - also slightly the medial pterygoid (elevates mandible)
Muscls involved in side-to-side grinding of mandible
Medial & lateral pterygoid
Muscles of arm;-
- triceps branchii
- biceps branchii
- branchialis
- brancioradialis
- extensor digitorum
More muscles of the arm;-
- flexor carpi radius
- palmaris longus
- flexor carpi ulnaris
Muscles of lower leg;-
- Soleus
- gastrocnemius
- calcaneus
- calcaneal tendon
- tibialis anterior
Muscles of the upper leg;-
- Gracilis
- sartorius
- vastus lateralis & medialis
- rectus femoris
- biceps femoris
- semitendinosus
- semimembranosus
- gluteus maximus
- adductor magnus
Muscles of the back/shoulder;-
- Trapezius
- deltoid
- latissimus dorsi
- infraspinatus
- tres major
Muscles of abdominal cavity;-
- rectus abdominis
- transverse abdominis
- internal obliques
- external obliques
Actions of muscles;-
- Gluteus minimus
- gluteus maximus
- Biceps femoris
- Gluteus minimus: hip abductor - internal roation of hip
- Gluteus maximus: hip extension & external rotation of hip
- Biceps femoris: Flexion of knee, hip extension, lateral rotation of hip when knee flexed
Actions of muscles;-
- Biceps brachii
- triceps brachii
- deltoid (3)
- Biceps brachii: flexion of elbow
- Triceps brachii: Extension of elbow
- Deltoid: anterior portion: shoulder flextion & external roation
- Posterior portion: shoulder extension & external roation
- all fibres: shoulder abduction
Actions of muscles;-
- Pectorialis major
- Adductor longus
- Rectus femoris
- Gastrocnemius
- Pectorialis major: Shoulder flexion, internal rotation, adduction
- adductor longus: hip adduction, hip flexion
- Rectus femoris: Flexion of hip, extension of knee
- gastrocnemius: plantar flexion
