Musculature I (lecture)

Question 1

what are the functions of the musculature system?

Answer 1

movement, resist opposing forces, movement within body organ systems (digestion, respiration, circulation, reproduction excretion), body posture, support weight, generate heat, protection, general physique

Question 2

What are the three stypes of muscle tissue in vertebrates?

Answer 2

skeletal, cardiac, smooth

Question 3

what are the characteristics of skeletal muscle? Is it associated with voluntary or involuntary movement?

Answer 3

striated, bulk of muscle tissue, attached to skeletal system
voluntary movement

Question 4

what are the characteristics of smooth muscle? is it voluntary or involuntary movement?

Answer 4

walls of hollow organs, changes diameter of lumen
involuntary movement (pupillary dilators for example)

Question 5

what are the characteristics of cardiac muscle? is it voluntary or involuntary?

Answer 5

wall of heart, pumping action
involuntary

Question 6

what forms muscle fibers?

Answer 6

fusion of plasma membranes of multiple mononucleate cells

Question 7

what is a syncytium?

Answer 7

fusion of mononucleate cells

Question 8

what is a myocyte?

Answer 8

a syncytium consisting of repeating sarcomeres

Question 9

what are sarcomeres composed of?

Answer 9

long fibrous proteins: actin and myosin

Question 10

what is the fucntion of actin and myosin in sarcomeres?

Answer 10

long fibrous proteins that slide past each other when muscles contract and relax

Question 11

What causes striation in muscles?

Answer 11

sections of sarcomeres where myosin and actin overlap or don’t overlap

Question 12

what are myofibrils?

Answer 12

chains of sarcomeres

Question 13

Skeletal mucles move joints through _______

Answer 13

contraction

Question 14

what is a gaster?

Answer 14

muscle belly, fleshy portion containing contractile muscle fibers (actin and myosin)

Question 15

what is a tendon?

Answer 15

collagenous dense regular connective tissue that attaches muscle to bone

Question 16

what is the enthesis?

Answer 16

point at which tendon inserts into the bone

Question 17

tendons transmit force produced by ________ tissue

Answer 17

contractile

Question 18

T/F: tendons can transmit force from a distant point, permitting delicate control

Answer 18

true

Question 19

what is fascia?

Answer 19

a layer of connective tissue that surrounds muscles, groups of muscles, internal organs, blood vessels, nerves etc..

Question 20

What is the function of fascia?

Answer 20

binds structures, permits muscles to slide smoothly over eachother

Question 21

what are some examples of fascia in the body?

Answer 21

the rectus sheath, thoracolumbar fascia

Question 22

Why is the evolutionary history of muscles so complex?

Answer 22

lots of fusion and splitting, expansion and reduction

Question 23

T/F: information on muscle history is gained through muscle scars

Answer 23

true, muscles most often don’t leave a fossil record

Question 24

What is muscle classification based on?

Answer 24

attachment similarity, functional similarity, nervous innervation, embryonic origin

Question 25

what is a myotome?

Answer 25

undifferentiated embryonic muscle cells

Question 26

what does the myotome form?

Answer 26

skeletal musculature associated with the notochord and vertebral column, ribs, and body wall
eventually forms segmented myomeres

Question 27

T/f: myotomes give rise to muscles?

Answer 27

true

Question 28

myomeres are separated by connective tissue called ______

Answer 28

myosepta

Question 29

T/F: each myomere/myotome has its own nerve supply

Answer 29

true

Question 30

where do spinal nerves originate?

Answer 30

the spinal cord

Question 31

what is the function of spinal nerves?

Answer 31

transmit motor (voluntary and involuntary) and sensory between the spinal cord and the body

Question 32

what does the dorsal rami innervate?

Answer 32

epaxial musculature, dorsal skin

Question 33

what does the ventral rami innervate?

Answer 33

hypaxial musculature and ventral skin

Question 34

Which nerve causes the diaphragm to contract

Answer 34

Phrenic nerve

Question 35

Hypobranchial muscles are an extension of the ____________ muscles that migrate under the _________ arches, thus are innervated by the __________ of a spinal nerve

Answer 35

hypaxial muscles, branchial, ventral ramus

Question 36

extrinsic appendicular muscles (dorsal or ventral) originate on ________ skeleton and insert on ________

Answer 36

axial skeleton, girdle/limb

Question 37

intrinsic appendicular muscles (dorsal or ventral) originate on _________ girdle/limb and insert on _______ limb

Answer 37

proximal, distal

Question 38

dorsal muscles _____ fins

Answer 38

abduct

Question 39

ventral muscles ________ fins

Answer 39

adduct

Question 40

T/F? anything to do with the mandibular arch or palatoquadrate are modifications of the 1st pharyngeal arch

Answer 40

true

Question 41

What is the function of muscles of mastication? some specific muscles?

Answer 41

used for chewing, temporalis, masseter, pterygoideus

Question 42

Branchiomeric muscles are associated with the ___________ and innervated by __________ nerves

Answer 42

pharyngeal, cranial