Intro to Muscular System/Axial Musculature

Question 1

How are muscles like Russian dolls?

Answer 1

Muscles are made up of fascicles, which are made up of fibres. The fibers are inside of the fascicles, which are inside of the muscles.

Question 2

What is the epimysium?

Answer 2

The muscle’s epithelial layer

Question 3

What is the perimysium?

Answer 3

The fascicle’s epithelial layer

Question 4

What is the endomysium?

Answer 4

The fiber’s epithelial layer

Question 5

What makes up a fibre?

Answer 5

Myofibrils (like spaghetti strands)

Question 6

What does the sarcoplasmic reticulum do?

Answer 6

Stores Ca2+ for muscle contraction

Question 7

What is a sarcomere?

Answer 7

The basic unit of muscle contraction

Question 8

What are the boundaries of a sarcomere?

Answer 8

The Z-lines

Question 9

What is the centre of a sarcomere?

Answer 9

The M-line

Question 10

What are myocin and actin and what do they do?

Answer 10

Myocin is a thick filament and actin is a thin filament. They interdigitate (go in between one another).

Question 11

What does the H-band contain?

Answer 11

Myocin only (thick filaments) – think: H-band is MYocin

Question 12

What does the I-band contain?

Answer 12

Actin only (thin filaments) – think: “I” is a thin letter

Question 13

What does the A-band contain?

Answer 13

Both myocin (thick) and actin (thin) filaments.

Question 14

During contraction, the H-band _______, the I-band ______ and the A-band _______. (increases/stays the same/decreases)

Answer 14

H-band decreases
I-band decreases
A-band stays the same

Question 15

Which line do the myocin heads tilt toward?

Answer 15

The M-line

Question 16

What is the importance of motor units?

Answer 16

They control the intensity of nerve stimulation and muscle tension

Question 17

What color are slow fibers? What color are fast fibers?

Answer 17

Slow are red, fast are white.

Question 18

Are slow or fast fibers more powerful?

Answer 18

Fast

Question 19

Which type of fibers (slow or fast) uses aerobic metabolism to generate ATP?

Answer 19

Slow

Question 20

Which type of fibers (slow or fast) uses anaerobic glycosis to generate ATP?

Answer 20

Fast

Question 21

Does aerobic metabolism or anaerobic glycosis require oxygen?

Answer 21

Aerobic metabolism

Question 22

If a runner had an enlarged soleus muscle in their leg, would they be a long distance runner or a sprinter? Would they have more slow or fast fibers?

Answer 22

They would be a long distance runner. They would have more slow fibers.

Question 23

If a runner had an enlarged gastrocnemius muscle in their leg, would they be a long distance runner or a sprinter? Would they have more slow or fast fibers?

Answer 23

They would be a sprinter. They would have more fast fibers.

Question 24

Do slow or fast fibers fatigue more rapidly?

Answer 24

Fast

Question 25

What is the most common muscle type?

Answer 25

Parallel muscles

Question 26

During the contraction of parallel spindle muscles, the muscle gets ______ and the belly gets ______.

Answer 26

Shorter, wider.

Question 27

Do parallel or convergent muscles exert more force?

Answer 27

Parallel

Question 28

What is the name of the fan-shaped muscle type?

Answer 28

Convergent muscles

Question 29

Where would you find a circular muscle?

Answer 29

Around an opening, aka. any sphincter.

Question 30

What is the name of the muscle type shaped like a bird feather?

Answer 30

Pennate muscles

Question 31

What do the fascicles in a pennate muscle strike at an oblique angle?

Answer 31

A tendon

Question 32

What is the benefit of pennate muscles?

Answer 32

It packs more fibers into a small space than parallel muscles, creating more force.

Question 33

What is the difference between a unipennate, bipennate and multipennate muscle?

Answer 33

``` Unipennate = fibers only on one side of the tendon Bipennate = fibers on both sides of the tendon Multipennate = tendon branches within the muscle ```

Question 34

During an action, what is the agonist muscle?

Answer 34

The prime mover, whose contraction produces movement.

Question 35

During an action, what is the synergist muscle?

Answer 35

It assists the prime mover (agonist) in performing the movement.

Question 36

During an action, what is the antagonist muscle?

Answer 36

It opposes the movement of the prime mover (agonist) in order to counterbalance its movement.

Question 37

What is a class 1 lever and what are the benefits and drawbacks?

Answer 37

The fulcrum is in between the weight and the force, increasing range and speed. The drawback is that it requires an immense amount of force.

Question 38

What is a class 2 lever and what are the benefits and drawbacks?

Answer 38

The weight is in between the fulcrum and the force, which produces a lot of force. The drawback is that the range is small and slow.

Question 39

What is a class 3 lever and what are the benefits and drawbacks?

Answer 39

The force is in between the fulcrum and the weight, giving it a high range and speed. The drawback is that the higher the range and speed, the smaller the force.

Question 40

What is the most common class of lever in the body?

Answer 40

Class 3

Question 41

What is an example in the body of a class 1 lever?

Answer 41

The neck is the fulcrum, the head is the weight and the neck muscles are the force.

Question 42

Which cranial nerves are the extraocular muscles innervated by?

Answer 42

3, 4 and 6 | CN III, IV and VI - Oculomotor, Trochlear and Abducens

Question 43

Which cranial nerve is the mastication muscles innervated by?

Answer 43

5-3. | CN V3 - Trigeminal

Question 44

Which cranial nerve is the facial expression muscles innervated by?

Answer 44

7 | CN VII - Facial

Question 45

Which cranial nerve is the pharyngeal muscles innervated by?

Answer 45

10 | CN X - Vagus

Question 46

Which cranial nerve is the tongue muscles innervated by?

Answer 46

12 | CN XII - Hypoglossal

Question 47

Which cranial nerve is the neck muscles innervated by?

Answer 47

Neck muscles are innervated by the cervical nerves

Question 48

Which extraocular muscles are NOT innervated by CN III? Which CNs are they innervated by?

Answer 48

The lateral rectus - VI (6) | The superior oblique - IV (4)

Question 49

When looking up, which 2 muscles do you use?

Answer 49

Superior rectus and inferior oblique

Question 50

When looking down, which 2 muscles do you use?

Answer 50

Inferior rectus and superior oblique

Question 51

How would you determine if a patient had a CN VI or CN IV palsy?

Answer 51

You would ask them to look left an right, and if they had difficulty looking right it would be damage in the lateral rectus, making it a CN VI palsy. If they had difficulty looking left it would be damage in the superior oblique, making it a CN IV palsy.

Question 52

What do the temporalis and masseter muscles do?

Answer 52

They open and close the mouth (for chewing)

Question 53

What do the lateral and medial pterygoid muscles in the jaw do?

Answer 53

Lateral: depresses the mandible and grinds food Medial: elevates the mandible to chew

Question 54

What does the orbicularis oculi muscle of the face do?

Answer 54

It closes the eyes

Question 55

What does the orbicularis oris muscle of the face do?

Answer 55

It purses the lips

Question 56

What does the platysma muscle of the face do?

Answer 56

It tenses the skin of the neck

Question 57

What does the frontaris muscle of the face do?

Answer 57

It wrinkles the forehead and raises the eyebrows

Question 58

What does the buccinator muscle of the face do?

Answer 58

It tenses the cheeks for sucking

Question 59

How do you get Bell's palsy?

Answer 59

By damaging the facial nerve (CN VII)

Question 60

What do the tensor & levator veli palatini muscles of the throat do?

Answer 60

They tense and elevate the soft palate

Question 61

What does the superior, middle and inferior constrictors of the throat do?

Answer 61

They constrict different sections of the pharynx

Question 62

What are the four muscles of the tongue?

Answer 62

Palatoglossus Styloglossus Hyoglossus Genioglossus

Question 63

What does the hyoid bone do?

Answer 63

It supports the tongue

Question 64

What does the mylohyoid muscle in the throat do?

Answer 64

It tenses the floor of the mouth for swallowing

Question 65

What does the digastric muscle in the throat do?

Answer 65

It depresses the mandible to open the mouth wide

Question 66

What is the correct order of these events during swallowing? 1. Contraction of tensor and levator veli palatini muscles 2. Contraction of mylohyoid and tongue muscles 3. Sequential contraction from the top of constrictor muscles 4. Elevation of larynx by many muscles

Answer 66

2, 1, 4, 3

Question 67

What does the sternocleidomastoid muscle in the throat do?

Answer 67

It turns the head in the opposite direction of contraction

Question 68

What do the infrahyoid muscles in the throat do?

Answer 68

They pull down the hyoid bone

Question 69

What do the longus capitis and longus colli muscles do?

Answer 69

They flex the neck

Question 70

What do the scalene muscles do?

Answer 70

They flex the neck and head, and elevate the ribs.

Question 71

What does the transversospinal group of muscles do?

Answer 71

It allows vertebrae to flex & extend and does fine movement adjustments

Question 72

If you sprain the zygapophyseal joints in your back, what might happen?

Answer 72

You might have acute back pain

Question 73

What 3 muscles make up the erector spinae and what do they do?

Answer 73

Longissimus, Spinalus and Iliocostalis | They extend the back

Question 74

What do the intercostal muscles do?

Answer 74

They contract to elevate the ribs during inhalation

Question 75

What do the rectus abdominis muscles do?

Answer 75

They are trunk flexors

Question 76

How many layers of abdominal muscles are there? What are they?

Answer 76

3 - External abdominal oblique, internal abdominal oblique and transverse abdominis

Question 77

What is the inferior vena cava?

Answer 77

A vessel that carries blood

Question 78

What is the largest artery that carries blood to the lower body?

Answer 78

The aorta

Question 79

What are the right and left crura?

Answer 79

The tendinous structures that come up from the legs

Question 80

What is innervated by the phrenic nerve? Which nerves make up the phrenic nerve?

Answer 80

The diaphragm. C3, C4 and C5

Question 81

Does the diaphragm contract during inhalation or exhalation?

Answer 81

Inhalation

Question 82

Where are the coccygeus and levator ani muscles?

Answer 82

In the pelvic floor

Question 83

Is the external urethral sphincter larger in males or females? Why?

Answer 83

It's larger in males to accommodate for ejaculate

Question 84

What are the Ischiocavernosus and Bulbospongiosus | muscles and what happens when they contract?

Answer 84

They are perineal muscles. Contraction increases blood flow into the erectile tissues of the genitalia.