Muscles - from Lab

Question 1

4 main muscle fiber patterns - features, examples

Answer 1

1. 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)

Question 2

Muscle terminology;- Brevis Capitis Endo- epi- gastro- inter- magnus oblique peri- rectus

Answer 2

Brevis - short Capitis - head Endo- - within epi- - upon gastro- -stomach inter- -between magnus -large oblique -at an angle peri- -around rectus -straight

Question 3

Define; - -Origin -Insertion

Answer 3

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)

Question 4

What does triceps brachii move?

Answer 4

-Extends forearm

Question 5

What does biceps branchii move?

Answer 5

Flexes elbow joint

Question 6

What does pectoralis major move?

Answer 6

Glenohumeral joint (shoulder joint)

Question 7

What does Latissimus dorsi move?

Answer 7

Abduction of arm/arm extension

Question 8

What does gluteus maximus move?

Answer 8

Extension of hip

Question 9

What does biceps femoris move?

Answer 9

Flexion of knee

Question 10

Muscle functions;- Flexors Extensors Abductors Adductors Rotators

Answer 10

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

Question 11

Muscles involved in flexing the elbow joint (3)

Answer 11

-Biceps branchii -Brachialis -Brachioradialis (insertion near humerous)

Question 12

Muscle that extends the fingers to open the hand

Answer 12

-Extensor digitorum

Question 13

Muscles that make up quadriceps (4)

Answer 13

-Vastus lateralis -Rectus femoris (crosses hip and knee joint) -Vastus medialis -sartorius

Question 14

Muscles that make up hamstring (3)

Answer 14

-Semimembranosus -Semitendinosus -Biceps femoris (has 2 heads/muscle bellies)

Question 15

Muscles that make up “calf muscle” (2) -Tendon both insert

Answer 15

-gastrocnemius -soleus *both insert into calcaneous tendon (AKA achilles)

Question 16

4 main muscles of mastication

Answer 16

-Masseter -temporalis -Pterygoids (medial and lateral) -Buccinator

Question 17

3 muscles of facial expression

Answer 17

-orbicularis oris -obricularis oculi -mentalis

Question 18

3 muscles of facial expression

Answer 18

-orbicularis oris (kissing) -obricularis oculi (blinking & squinting) -mentalis

Question 19

Muscles involved in inhalation (1) & exhalation (2) -role of scalene muscles

Answer 19

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)

Question 20

Diaphragm movement during inhalation and exhalation

Answer 20

Inhalation: Diaphragm moves inferiorly during contraction Exhalation: Diaphragm moves superiorly as it relaxes

Question 21

Muscles involved in jaw closure

Answer 21

Masseter & Temporalis - also slightly the medial pterygoid (elevates mandible)

Question 22

Muscls involved in side-to-side grinding of mandible

Answer 22

Medial & lateral pterygoid

Question 23

Muscles of arm;-

• triceps branchii
• biceps branchii
• branchialis
• brancioradialis
• extensor digitorum

Answer 23

Question 24

More muscles of the arm;-

• flexor carpi radius
• palmaris longus
• flexor carpi ulnaris

Answer 24

Question 25

Muscles of lower leg;-

• Soleus
• gastrocnemius
• calcaneus
• calcaneal tendon
• tibialis anterior

Answer 25

Question 26

Muscles of the upper leg;-

• Gracilis
• sartorius
• vastus lateralis & medialis
• rectus femoris
• biceps femoris
• semitendinosus
• semimembranosus
• gluteus maximus
• adductor magnus

Answer 26

Question 27

Muscles of the back/shoulder;-

• Trapezius
• deltoid
• latissimus dorsi
• infraspinatus
• tres major

Answer 27

Question 28

Muscles of abdominal cavity;-

• rectus abdominis
• transverse abdominis
• internal obliques
• external obliques

Answer 28

Question 29

Actions of muscles;-

• Gluteus minimus
• gluteus maximus
• Biceps femoris

Answer 29

• 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

Question 30

Actions of muscles;-

• Biceps brachii
• triceps brachii
• deltoid (3)

Answer 30

• 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

Question 31

Actions of muscles;-

• Pectorialis major
• Adductor longus
• Rectus femoris
• Gastrocnemius

Answer 31

• Pectorialis major: Shoulder flexion, internal rotation, adduction
• adductor longus: hip adduction, hip flexion
• Rectus femoris: Flexion of hip, extension of knee
• gastrocnemius: plantar flexion