15CHAPTER 10: MUSCLES

Question 1

Where is deep fascia found?

Answer 1

found between adjacent muscles

Question 2

Where would you find superficial fascia (hypodermis)?

Answer 2

adipose between skin and muscles

Question 3

What are the 2 ways muscle attaches to bone?

Answer 3

Direct and indirect attachment.

Question 4

What is the difference between direct and indirect attachment?

Answer 4

Direct attachment: epimysium is continuous with periosteum; e.g. intercostals

Indirect attachment: epimysium continues as tendon that merges into periosteum; e.g. biceps brachii

Question 5

What does muscle attach to other than bone?

Answer 5

The dermis and aponeurosis.

Question 6

How does muscle attach to the dermis (superficial fascia)?

Answer 6

epimysium attaches to collagen fibers of the dermis e.g. muscles of facial expression

Question 7

What are aponeurosis?

Answer 7

sheet like tendon; e.g. abdominal muscles

Question 8

During contraction, bone at one end is stationary (______) and bone at other end moves (_____).

Answer 8

Origin, Insertion

Question 9

`What does origin mean?

Answer 9

attachment to least mobile bone

Question 10

What does insertion mean?

Answer 10

attachment to most mobile bone

Question 11

What is the belly of a muscle?

Answer 11

thicker, middle region of muscle

Question 12

Strength of a muscle and its direction of action are determined primarily by what?

Answer 12

orientation of its fascicles

Question 13

What are the 4 types of muscles?

Answer 13

1. Prime mover (agonist)
2. Synergist
3. Antagonist
4. Fixator

Question 14

What is the function of a prime mover and give an example?

Answer 14

Produces most of the force -e.g. brachialis – flexion of the elbow

Question 15

What is the function of a synergist and give an example?

Answer 15

Aids the prime mover -e.g. biceps brachii refines movement when elbow is flexed

Question 16

What is the function of an antagonist and give an example?

Answer 16

Opposes the prime mover -e.g. triceps brachii opposes biceps brachii and visa versa (antagonist pair)

Question 17

What is the function of a fxator and give an example?

Answer 17

Prevents a bone from moving, while a muscle attached to that bone contracts
e.g. fixators (rhomboids) hold scapula in place when biceps brachii contracts

Question 18

What are intrinsic muscles?

Answer 18

contained within a region – origin and insertion are within the region e.g., the hand

Question 19

What are extrinsic muscles?

Answer 19

Muscles that act on a region but origins are outside the region e.g., move the fingers but found in the forearm

Question 20

What is muscle innervation?

Answer 20

Nerve supply to a muscle

Question 21

What do cranial nerves (arising from the brain) and Spinal nerves (arising from the spinal cord) supply muscles with?

Answer 21

Impulses

Question 22

Anterior muscles are what kind of muscles?

Answer 22

Flexors (main exception is the knee)

Question 23

Posterior muscles are what kind of muscles?

Answer 23

Extensors

Question 24

What is the origin and insertion and action of the orbicularis oculi?

Answer 24

O= orbit, I= eyelid, A= closes eye

Question 25

What is the origin and insertion and action of the orbicularis oris?

Answer 25

O= muscle fibers around mouth, I= Lips, A= closes lips; kissing

Question 26

What is the origin and insertion and action of the temporalis?

Answer 26

O= parietal bone- temporal lines, I= mandible- coronoid process A= elevates mandible

Question 27

What is the origin and insertion and action of the masseter?

Answer 27

O= zygomatic arch, I= mandible-angle, A=elevates mandible

Question 28

What is the origin and insertion and action of the sternocleidomastoid?

Answer 28

O= clavicle, sternum, I= mastoid process of temporal bone, A= flexion of head

Question 29

What is the origin and insertion and action of the trapezius?

Answer 29

O= nuchal lines of occipital bone, C7-T12, I= clavicle, scapula, A= extension of neck

Question 30

What is the origin and insertion and action of the diaphragm?

Answer 30

O= xiphoid process, costal cartilages, ribs 10-12, I= central tendon, A= inspiration and increases volume of thoracic cage.

Question 31

What is the origin and insertion and action of the external intercostals?

Answer 31

O= inferior margins of rib 1-11, I= superior margins of ribs 1-11, A= inspiration

Question 32

What is the origin and insertion and action of the internal intercostals?

Answer 32

O= superior margins of ribs 2-12, I= inferior margins of ribs 1-11, A= forced expiration and smooths inspiration

Question 33

What is the origin and insertion and action of the rectus abdominis?

Answer 33

O= pubis, I= xiphoid process, costal cartilages 5-7, A= flexes waist

Question 34

What is the origin and insertion and action of the external oblique?

Answer 34

O= ribs 5-12, I= xiphoid process, linea alba, A= flexes and rotates waist.

Question 35

What is the origin and insertion and action of the internal oblique?

Answer 35

O= ilium, I= xiphoid process, linea alba, A= flexed and rotates waist.

Question 36

What is the origin and insertion and action of the transverse abdominal?

Answer 36

O= ilium, costal cartilages 7-12, I= xiphoid process, linea alba, A= flexes waist, compresses abdomen; especially during defecation and childbirth.

Question 37

What is the origin and insertion and action of the erector spinae group?

Answer 37

O= sacrum, vertebrae, angles of ribs, I= vertebrae superior to origin, A= extension of waist, lateral flexion of vertebral column

Question 38

What is the origin and insertion and action of the external anal sphincter?

Answer 38

No origin or insertion, A= inhibits defecation

Question 39

What is the origin and insertion and action of the levator ani?

Answer 39

O= os coxae, I= coccyx, anal canal, A= allows defecation, supports viscera

Question 40

What is the origin and insertion and action of external urethral sphincter?

Answer 40

No origin or insertion, A= inhibits urination

Question 41

What are the 3 layers of muscles that make up the pelvic floor?

Answer 41

1. Superficial layer
2. Middle layer – contains external urethral sphincter and external anal sphincter
3. Deep layer – contains levator ani