muscles

Question 1

4 types of muscle

Answer 1

• visceral (smooth)
• skeletal (striated)
• cardiac
• myoepithelium cells/ myoid cells

Question 2

visceral (smooth) muscle

Answer 2

• contracts spontaneously/ autonomic nerves
• usually involuntary
• internal organs

Question 3

skeletal (striated) muscle

Answer 3

• nervous stimulation, usually voluntary
• usually in partly contracted state (tone)
• produce most of body heat in body

Question 4

cardiac muscle

Answer 4

intermediate, continuous contraction

Question 5

myoepithelium

Answer 5

cells found in mammary glands; squeeze out milk

Question 6

myoid cells

Answer 6

found in testes; move semen around

Question 7

functions of muscle

Answer 7

• produce movement
• restrain movement
• support joints
• produce heat (significant only in endothermic animals)

Question 8

muscle fibers can be

Answer 8

slow twitch (type 1) or
fast twitch (type 2)

based on contraction time to peak tension

Question 9

slow twitch muscles/ fibers

Answer 9

• high nedurance
• aerobic; rich blood supply, many mitochondria, much myoglobin “red meat”; use ocygen constantly to remain tone
• comparatively small and weak
• postural +/- propulsive

Question 10

high twitch muscles/ fibers

Answer 10

• sporadic; low endurance (1-30mins)
• anaerobic ; use intrinsic glycogen store, build up lactic acid and oxygen debt
• used infrequently; rapid burst of activity
• comparatively large and strong
• mainly propulsive
• types IIa, IIx and IIb

Question 11

muscles names according to

Answer 11

function, position, direction of fiber, shape and form

Question 12

fascia

Answer 12

connective tissue associated with muscle; tough fibrous tissue

Question 13

muscles are separated by

Answer 13

fascia; connective tissue

Question 14

deep fascia

Answer 14

immediately around muscles, continues as tendons at ends of muscle

Question 15

superficial fascia

Answer 15

loose, under the skin (fascia binds skin to muscle underneath)

Question 16

deep fascia (aka epimysium) continue at end of muscle to form

Answer 16

tendons

Question 17

tendons are usually _____ than muscles

Answer 17

thinner

Question 18

tendons attach to

Answer 18

bone (ex tuberosities and tubercles)

Question 19

aponeurosis

Answer 19

a broad flat tendon

Question 20

do tendons have elasticity

Answer 20

some; stores energy for locomotion

Question 21

____ are stronger than bone

Answer 21

tendons

v strong!!!!

Question 22

tendons may be associated with

Answer 22

bursae, tendon sheaths or sesamoid bones

Question 23

bursae

Answer 23

synovial structure between tendon and bone, reduce friction

Question 24

tendon sheath

Answer 24

an extension of bursae that wrap completely around tendon

Question 25

sesamoid bones;

Answer 25

bones developed in tendons

Question 26

origin of muscles

Answer 26

least movement; usually proximal

Question 27

insertion of muscles

Answer 27

most movement, usually distal

Question 28

muscles exert force by

Answer 28

contraction of individual muscle fibers

Question 29

total force of muscle =

Answer 29

sum of indiivudal fibers = cross-sectional area of muscle

Question 30

more muscle fibers=

Answer 30

greater muscle strength

Question 31

does length of muscle correlate with strength

Answer 31

no

Question 32

bigger the muscle fibers =

Answer 32

greater the muscle strength

Question 33

if muscle A’s diameter is twice the diameter of muscle B, then the cross sectional area of muscle A will be 4x greater than that of muscle B and so

Answer 33

muscle A is 4x stronger than muscle B (even if they are the same length)

Question 34

long fibers

Answer 34

Greater length (but not necessarily strength) of contraction (muscles can contract about half their size ex if fibers are 30cm than muscle can contract about 15cm further)

Question 35

short fibers

Answer 35

Shorter length
Lighter, no point being longer if not needed

Question 36

fusiform muscle

Answer 36

• Fibers concierge on tendon
• Muscle is spindle-shaped thin-round-thin
• Length for length has greatest contractile

Question 37

Pennate muscle

Answer 37

• Long tendon attachment at an angle
• Powerful due x section but less range of movement
• Cross section is slightly at an angle too (in pic its the solid black line)
• Less contractile length but more strength
• Uni-, bi- multi-pennate

Question 38

____ may divide muscles

Answer 38

tendons

example clavicular tendon divides brachiocephalic muscle into 3 parts

Question 39

tendinous inscriptions example

Answer 39

• rectus abdominis (abs) tendinous inscriptions give the 6 pack look
• Muscle fibers run up and down and the tendinous inscription cut across middle (horizontal) (when you exercise muscle get bigger but tendons don’t)

Question 40

muscle growth and repair

Answer 40

• New fibers not normally formed post-natal;
• Increase in muscle size: increase in size of fibers but not the number of fibers
• After damage, new muscle fibers can form BUT usually connective tissue invades first

Question 41

how many arteries per muscle

Answer 41

Usually 2+ arteries to a muscle but anastomoses usually incomplete (arteries don’t join together, so if you damage one, you do need to worry about blood supply in that area because one artery one supply blood to whole muscle)

Question 42

tendons blood supply

Answer 42

poor supply; no hemorrhage if cut but slow healing

Question 43

nerves usually follow

Answer 43

blood vessels (veins/ arteries)

• Motor, pain, proprioception, stretch, etc
• No motor nerves to tendons