Muscle Anatomy & Function

Question 1

How are skeletal muscles attached to bones?

Answer 1

They are attached by tendons, which are extensions of the epimysium that connect the ends of skeletal muscles to bone or fascia.

Question 2

What are tendons made of?

Answer 2

Very tightly packed bundles of collagen fibers with rows of fibrocytes between the bundles.

Question 3

What type of connective tissue makes up tendons?

Answer 3

Dense regular connective tissue with densely packed collagen fibers, minimal ground substance, and few blood vessels, designed to resist linear mechanical stress.

Question 4

How do connective tissue layers relate to tendon attachment?

Answer 4

Endomysium, perimysium, and epimysium surround muscle fibers and fascicles and are continuous with tendons, allowing muscles to anchor to bone.

Question 5

What are aponeuroses?

Answer 5

Sheets of fibrous connective tissue that connect muscles to bones or to other muscles, functioning similarly to tendons.

Question 6

What is the basic structure of skeletal muscle?

Answer 6

Skeletal muscle consists of large multinucleated cells with peripheral nuclei, numerous mitochondria, myoglobin, and glycogen.

It contains connective tissue layers (endomysium, perimysium, epimysium) that hold components together and are continuous with tendons.

Question 7

What are the connective tissue layers of skeletal muscle?

Answer 7

• Endomysium surrounds each muscle fiber
• Perimysium surrounds bundles of fibers (fascicles)
• Epimysium surrounds groups of fascicles and is continuous with tendons

Question 8

What is the structure of a muscle fiber?

Answer 8

A muscle fiber is a muscle cell containing a sarcolemma, sarcoplasm, sarcoplasmic reticulum, myofibrils, and sarcomeres (the contractile units).

Question 9

What is the function of skeletal muscle?

Answer 9

• Locomotion
• Maintaining posture
• Regulating body temperature
• Protecting internal organs
• Enabling breathing and swallowing
• Nutrient storage

Question 10

What type of connective tissue forms tendons?

Answer 10

Dense regular connective tissue with densely packed collagen fibers, minimal ground substance, few blood vessels, and resistance to linear mechanical stress.

Question 11

What is the microscopic structure of tendons?

Answer 11

Very tightly packed bundles of collagen fibers with rows of fibrocytes between the bundles.

Question 12

What is the function of tendons?

Answer 12

Tendons connect the ends of skeletal muscles to bone or fascia, transmitting the force of muscle contraction to produce movement.

Question 13

How do tendons relate structurally to muscle?

Answer 13

Tendons are continuous with the muscle’s connective tissue layers, especially the epimysium, allowing force transfer from muscle to bone.

Question 14

What are skeletal muscle cells like?

Answer 14

Large multinucleated cells with peripheral nuclei.

Question 15

What organelles are abundant in skeletal muscle cells?

Answer 15

Numerous mitochondria.

Question 16

What molecules are stored in skeletal muscle for oxygen and energy?

Answer 16

Myoglobin (oxygen carrier) and glycogen (energy source).

Question 17

What is the endomysium?

Answer 17

Connective tissue that surrounds each muscle fiber and contains stem cells for regeneration.

Question 18

What is a fascicle?

Answer 18

A group of skeletal muscle fibers.

Question 19

What is the perimysium?

Answer 19

Connective tissue surrounding bundles of muscle fibers (fascicles) that generally work together.

Question 20

What is the epimysium?

Answer 20

A fibrous layer of tough collagen fibers that surrounds groups of fascicles and is continuous with tendons.

Question 21

How do muscle connective tissue layers contribute to attachment?

Answer 21

They hold muscle components together and become continuous with tendons or aponeuroses that attach muscle to bone.

Question 22

What is the sarcolemma?

Answer 22

The cell membrane of a muscle fiber.

Question 23

What is the sarcoplasm?

Answer 23

The cytoplasm of the muscle cell.

Question 24

What is the sarcoplasmic reticulum?

Answer 24

The endoplasmic reticulum of muscle.

Question 25

What are myofibrils?

Answer 25

Cylinders containing stacked sarcomeres. ## Footnote This is a rod-like organelle within the muscle fiber's cytoplasm (sarcoplasm)

Question 26

What is a sarcomere?

Answer 26

The contractile unit of muscle.

Question 27

What type of connective tissue forms tendons?

Answer 27

Dense regular connective tissue.

Question 28

What characterizes the ECM of tendons?

Answer 28

Densely packed collagen fibers, minimal ground substance, and few blood vessels.

Question 29

What mechanical property do tendons resist?

Answer 29

Linear mechanical stress.

Question 30

What is the microscopic structure of tendons?

Answer 30

Very tightly packed bundles of collagen fibers with rows of fibrocytes between bundles.

Question 31

What do tendons connect?

Answer 31

The end of skeletal muscles to bone or fascia.

Question 32

What is the function of tendons?

Answer 32

They transmit the force of muscle contraction to produce movement.

Question 33

How do connective tissue layers relate to overall muscle structure?

Answer 33

They surround muscle fibers and fascicles and continue outward to form tendons or aponeuroses.

Question 34

What is the overall organizational hierarchy of skeletal muscle?

Answer 34

Muscle → fascicles → muscle fibers → myofibrils → sarcomeres

Question 35

What type of connective tissue do tendons and ligaments consist of?

Answer 35

Dense regular connective tissue.

Question 36

What is the ECM of tendons and ligaments like?

Answer 36

It contains densely packed collagen fibers, minimal ground substance, and few blood vessels, resisting linear mechanical stress.

Question 37

What do tendons and aponeuroses connect?

Answer 37

They connect the end of skeletal muscles to bone or fascia.

Question 38

What is the microscopic structure of tendons?

Answer 38

Very tightly packed bundles of collagen fibers with rows of fibrocytes between the bundles.

Question 39

What do ligaments (and retinacula) connect?

Answer 39

Ligaments connect bone to bone.

Question 40

How does the fiber packing of ligaments compare to tendons?

Answer 40

Ligament fibers are less tightly packed than those in tendons.

Question 41

What additional fibers may ligaments contain?

Answer 41

Ligaments may contain elastic fibers.

Question 42

Muscle origin

Answer 42

The more stable of a muscle’s attachment sites, usually the proximal attachment.

Question 43

Muscle insertion

Answer 43

The attachment site that undergoes most of the movement when a muscle contracts, usually the distal attachment.

Question 44

What is an agonist (prime mover)?

Answer 44

A muscle or muscle group that directly produces a desired movement.

Question 45

What is an antagonist?

Answer 45

A muscle or muscle group that opposes the action of a prime mover.

Question 46

Example that illustrates agonist vs. antagonist?

Answer 46

Biceps brachii flexes the elbow (agonist) and triceps brachii extends the elbow (antagonist).

Question 47

Tendons and ligaments have ___ blood vessels.

Answer 47

few

Question 48

How is the blood supply to muscle described in the slides?

Answer 48

Connective tissue components contain the blood vessels and nerve fibers that supply the muscle fibers.

Question 49

Tendons & ligaments to muscle: which tissue has better healing potential?

Answer 49

Muscle, because it has a richer blood supply than tendons or ligaments.

Question 50

Muscle fiber is equivalent of?

Answer 50

**Individual muscle cell**. The two terms are interchangable.

Question 51

What are synovial bursae?

Answer 51

Little bags of synovial fluid inserted between tendons and bones, to cushion the tendons as they pass over hard surfaces.

Question 52

What is the function of synovial bursae?

Answer 52

To cushion tendons as they pass over bones.

Question 53

How are tendon sheaths related to bursae?

Answer 53

Tendon sheaths are essentially bursae that wrap around the tendons.