Muscles

Question 1

Muscle function (1)

Answer 1

Exert force (movement, maintain posture)

Question 2

Muscle function (2)

Answer 2

Stabilize joints

Question 3

Muscle function (3)

Answer 3

Produce heat

Question 4

Muscle function (4)

Answer 4

Protect internal organs

Question 5

Special feature (1)

Answer 5

Contractile (exerts force by contracting/shortening and pulling things together)

Question 6

Special feature (2)

Answer 6

Electrically excitable = allows rapid stimulation of whole cell

Question 7

Skeletal muscle tissue

Answer 7

Voluntary (typically) except reflexes

Question 8

Cardiac muscle tissue

Answer 8

In heart

Question 9

Smooth muscle tissue

Answer 9

In walls of other hollow organs

Question 10

What are skeletal muscles main function?

Answer 10

To move bones

Question 11

Skeletal muscle origin attachment

Answer 11

The less moveable attachment (proximal)

Question 12

Skeletal muscle insertion attachment

Answer 12

The more moveable attachment (distal)

Question 13

Skeletal muscles must cross a _____ to act on that _____

Answer 13

Joint, joint

Question 14

What does skeletal muscle action depend on?

Answer 14

Side of bone the attachment is on

Question 15

Muscles do work by ____________ NOT __________

Answer 15

Shortening, lengthening

Question 16

Antagonist

Answer 16

Another muscle undoing an action for another muscle’s action

Question 17

Agonist (prime mover)

Answer 17

A muscle that has major responsibility for a particular action

Question 18

Synergist

Answer 18

A muscle that helps the agonist

Question 19

Sheaths of connective tissue organize what?

Answer 19

Muscle fibers

Question 20

Endomysium

Answer 20

Surrounds muscle fiber (delicate white network)

Question 21

Perimysium

Answer 21

Surrounds each fascicle (bundle of muscle fibers wrapped around)

Question 22

Epimysium

Answer 22

Surrounds entire muscle (thickest and wraps around entire muscle)

Question 23

Tendon

Answer 23

Extension of the sheaths (connects muscle to bone)

Question 24

Fascia

Answer 24

Surrounds groups of muscles

Question 25

Muscle fiber (cell) is normally as long as what/

Answer 25

The whole muscle

Question 26

Myofibrils

Answer 26

Long organelles made of actin and myosin filaments

Question 27

Multinucleate

Answer 27

Has many nuclei

Question 28

In muscle cells, actin and myosin are organized into myofilaments which is a type of what?

Answer 28

Microfilament

Question 29

Striations indicate what?

Answer 29

Repeating groups of protein filaments (actin, myosin, etc.)

Question 30

What is each section of myofibril called?

Answer 30

Sarcomere

Question 31

Sarcomere

Answer 31

Basic functional unit of skeletal muscle contraction

Question 32

Can muscle fiber cells divide after birth?

Answer 32

NO!

Question 33

Strength training

Answer 33

Each muscle fiber thickens by adding more protein filaments

Question 34

Strength is proportional to _____________________

Answer 34

Total cross-sectional area of fibers attached to tendon

Question 35

Which muscles are stronger? Pennate or parallel?

Answer 35

Pennate are stronger, but parallel are more flexible/able to contract

Question 36

Satellite cells

Answer 36

Undifferentiated cells between muscle fibers

Question 37

Do satellite cells continue dividing?

Answer 37

Yes when needed

Question 38

What happens when muscles grow, strengthen, or there is muscle damage?

Answer 38

Satellite cells merge with muscle fibers (adds nucelus)

Question 39

Nerve cells

Answer 39

Direct nervous stimulation is the ONLY cause of contraction

Question 40

Motor neuron

Answer 40

Nerve cell that controls muscle fibers

Question 41

Motor unit

Answer 41

Motor neuron + all muscle fibers it innervates

Question 42

Neuromuscular junction

Answer 42

Region where motor neuron contacts muscle fibers

Question 43

What does botox do in the neuromuscular junction?

Answer 43

Botox blocks neurons from getting to the muscles (paralyzes face essentially removing wrinkles)

Question 44

What is the sliding filament mechanism?

Answer 44

Myosin and actin filaments slide past one another (myosin head crawls along actin)

Question 45

What happens while actin and myosin are sliding against each other in the sliding filament mechanism?

Answer 45

The sarcomere shortens by increasing overlap between actin and myosin = FILAMENTS DO NOT SHORTEN

Question 46

Where is cardiac muscle found and is it voluntary?

Answer 46

Walls of heart, no

Question 47

What do chains of short branching cells allow for in cardiac muscle?

Answer 47

Stacked end-to-end cells allows for coordinating activities

Question 48

How many nuclei are there per cell in cardiac muscle?

Answer 48

1 or 2 nuclei per cell

Question 49

Can cardiac muscle cells divide after birth?

Answer 49

NO! Stuck with the heart you are born with essentially

Question 50

Intercalated discs

Answer 50

Junctions between cells

Question 51

Gap junctions

Answer 51

Passageway for communication (ions carry signal between cells)

Question 52

Fasciae adherens

Answer 52

Function is resisting tension (hold adjoining cells together)

Question 53

Is cardiac muscle striated?

Answer 53

Yes, zig-zag shaped in orderly structure

Question 54

Are sarcomeres present in cardiac muscle?

Answer 54

Yes, along with actin and myosin

Question 55

Causes of contraction in cardiac muscle (1)

Answer 55

Spontaneously generated signal! (on a timer)

Question 56

Causes of contraction in cardiac muscle (2)

Answer 56

Via gap junctions from other cardiac muscle cells (got signal from something)

Question 57

The _____ of spontaneous contraction is/is not affected by nervous input

Answer 57

Rate, is

Question 58

Where does smooth muscle form?

Answer 58

Walls of hollow organs (other than heart)

Question 59

Are smooth muscle contractions voluntary?

Answer 59

No!

Question 60

How many nucleuses per fusiform cell in smooth muscle?

Answer 60

1 (uninucleate)

Question 61

Can cells divide after birth in smooth muscle?

Answer 61

Yes! They can easily regrow and regenerate better than other tissues

Question 62

Does smooth muscle have striations or sarcomeres?

Answer 62

No! Instead, has network of actin and myosin

Question 63

What do all the gap junctions in smooth muscle allow for?

Answer 63

Coordinating contractions

Question 64

What is the loose organization of actin and myosin good for?

Answer 64

Allows smooth muscle cells to generate force even when greatly stretched (DIG system stretching when there's food present)

Question 65

What happens when smooth muscle contracts in circular layers?

Answer 65

The tube narrows

Question 66

What happens when smooth muscle contracts in longitudinal layers?

Answer 66

The tube shortens

Question 67

Smooth muscle contraction cause (1)

Answer 67

By direct nervous control (but involuntary)

Question 68

Smooth muscle contraction cause (2)

Answer 68

Other chemical signals (ex: hormones/during pregnancy)

Question 69

Smooth muscle contraction cause (3)

Answer 69

Stretching

Question 70

Smooth muscle contraction cause (4)

Answer 70

Via gap junctions from other smooth muscles

Question 71

Smooth muscle contraction cause (5)

Answer 71

Spontaneously generated