Introduction to muscular system

Question 1

What are the four functions of the skeletal muscle?

Answer 1

Movement
posture
protection
thermogenesis

Question 2

What type of skeletal muscle is this?
_________-contraction pulls on insertions where a tendon attaches to a bone or
other tissue.

Answer 2

Movement

Question 3

What type of skeletal muscle is this?
_________-producing muscle tone with continuous contractions to stabilize
joints.

Answer 3

Posture

Question 4

What type of skeletal muscle is this?
_________-muscles support the walls of the abdominopelvic cavity and protect
the visceral organs ex: rectus abdominis and transverse abdominis protect the intestines.

Answer 4

Protection

Question 5

What type of skeletal muscle is this?
_________-Metabolism can be regulated to produce heat and warm the body
temperature.

Answer 5

Thermogenesis

Question 6

What are the two general functional properties of muscle tissue?

Answer 6

Excitability and

contractility

Question 7

What type of general functional property of muscle tissue is this?
_______- muscles respond to stimuli. In the case of skeletal muscles, we will
see that the stimulus comes from a motor neuron.

Answer 7

Excitability

Question 8

What type of general functional property of muscle tissue is this?
_______-muscles can shorten when stimulated.

Answer 8

Contractility

Question 9

Structure/Location Cardiac Muscle: Found in the muscular wall of the heart (myocardium).
Branching striated cells called 7)______ have a central round nucleus and form cell
junctions called 8)___________ disks that contain desmosomes and gap junctions.
9)_____________- alternating light and dark bands (stripes)

Answer 9

7) cardiomyocytes
8) Intercalated discs
9) Striations

Question 10

Functional Properties of Cardiac Muscle:
• Contraction is 10) _______
o Stimulated by an internal pacemaker of the heart.
o Regulated by the autonomic nervous system and endocrine system.

Answer 10

10) involuntary

Question 11

Structure/Location of Smooth Muscle: Spindle shaped (fusiform) cells with a central nucleus
and no striations. Found in the walls of hollow organs.
Functional Properties of Smooth Muscle:
• 11) ______
o Regulated by the autonomic nervous system and endocrine system.

Answer 11

11) involuntary

Question 12

Structure/Location of Skeletal Muscle: Long, striated cells called 12)_________ that
contain multiple nuclei.

Answer 12

12) fibers

Question 13

13)_________- a bundle of skeletal muscle fibers
The Skeletal Muscle Organs are connected to bones through tendons (dense regular CT)
• Aponeurosis- tendon that forms a thick flattened sheet.

Answer 13

Fascicle

Question 14

14)_________- location where a tendon attaches to a bone that remains stationary during
the action produced by contraction of that skeletal muscle.

Answer 14

Origin

Question 15

15)________- attachment that moves during the action produced by contraction.

Answer 15

Insertion

Question 16

Connective Tissue layers of skeletal muscle.

*In order

Answer 16

Epimysium
perimysium
endomysium
sarcolemma
myofibril
Sarcoplasmic
Transverse (T) Tubules 
Terminal citernae.

Question 17

What connective tissue layer of skeletal muscle is this?
16)_________- superficial covering of fibrous CT that encloses the skeletal muscle
organ and connects to the tendons

Answer 17

Epimysium

Question 18

What connective tissue layer of skeletal muscle is this?

______-fibrous CT covering bundles of muscle fibers called fascicles

Answer 18

Perimysium

Question 19

What connective tissue layer of skeletal muscle is this?

______-areolar CT covering individual fibers within a fascicle.

Answer 19

Endomysium

Question 20

What connective tissue layer of skeletal muscle is this?

_______-plasma membrane of a muscle fiber

Answer 20

Sarcolemma

Question 21

What connective tissue layer of skeletal muscle is this?
_______-non-membranous organelles within muscle fibers made of repeating
structural and functional units called Sarcomeres containing overlapping myofilaments.

Answer 21

Myofibril

Question 22

What connective tissue layer of skeletal muscle is this?
______-membranous organelles similar to the smooth endoplasmic
reticulum surrounding myofibrils its primary function is storage and release of calcium.

Answer 22

Sarcoplasmic Reticulum

Question 23

What connective tissue layer of skeletal muscle is this?
______-deep indentations in the sarcolemmal surface forming a
network of narrow spaces filled with extracellular fluid. The sarcolemma here contains channels
that allow facilitated diffusion of sodium ion from the extracellular fluid into the cytoplasm
surrounding the sarcoplasmic reticulum

Answer 23

Transverse (T) tubules

Question 24

What connective tissue layer of skeletal muscle is this?
_____-expanded chambers of sarcoplasmic reticulum adjacent to
T-tubules.

Answer 24

Terminal cisternae

Question 25

________: structural and functional unit of skeletal muscle cells contains overlapping thick and thin myofilaments

Answer 25

Structure of Sarcomere

Question 26

What type of Structure of Sarcomere is this: 24)_______: fibrous proteins within myofibrils that produce contraction o Thick filaments contain the motor protein called 25)________ ATPase o Thin filaments contain actin, tropomyosin, and troponin § ____- cytoskeletal protein supports shape of the cell and contains binding sites for myosin. § _____- calcium sensor protein § _____- fibrous protein covers myosin binding sites of actin

Answer 26

24) Myofilament 25) Myosin ATpase * Actin * Troponin * Tropomyosin

Question 27

What type of Structure of Sarcomere is this: | ______-ends of sarcomere contain proteins that anchor thin filaments in place.

Answer 27

Z-lines

Question 28

What type of Structure of Sarcomere is this: | ____-entire length of the thick filaments

Answer 28

A- band

Question 29

What type of Structure of Sarcomere is this: | ____-only thin filaments with no overlap of thick filaments

Answer 29

I-Band

Question 30

What type of Structure of Sarcomere is this: | ____-central region of thick filaments with no overlap of thin filaments

Answer 30

H-band

Question 31

What type of Structure of Sarcomere is this: | _____-center of H band

Answer 31

M-line

Question 32

Functional Properties of Skeletal Muscle: Contraction is under 26) _______control by the somatic nervous system. Somatic motor neurons excite contraction of muscle fibers.

Answer 32

26) Voluntary

Question 33

Nueromuscular: ____-end of motor neuron that releases neurotransmitters to excite muscle fiber

Answer 33

Axon Terminal

Question 34

Nueromuscular: _____-sarcolemmal surface adjacent to axon terminal that has receptors that detect neurotransmitters

Answer 34

Motor end

Question 35

Nueromuscular: | _____-small space between the axon terminal and motor end plate

Answer 35

Synaptic cleft

Question 36

Nueromuscular: | ____-a motor neuron and all of the muscle fibers it excites

Answer 36

Motor Unit

Question 37

Mechanism of excitation contraction coupling: _____-At the NMJ, the axon terminal releases acetylcholine (ACh). The motor end-plate is the location of the ACh-receptors in the muscle fiber sarcolemma. When Ach molecules are released, they diffuse across a minute space called the synaptic cleft and bind to the receptors that stimulate an action potential (brief reversal of the membrane potential)

Answer 37

Excitation

Question 38

Mechanism of excitation contraction coupling: _____-An action potential stimulates the release of calcium ions from the sarcoplasmic reticulum into flood the sarcoplasm. Calcium is the mediator of excitation contraction coupling that binds to troponin exposing the binding sites on actin to allow crossbridge formation. A cross-bridge forms between actin and the myosin heads triggering contraction. As long as Ca++ ions remain in the sarcoplasm to bind to troponin, and as long as ATP is available, the muscle fiber will continue to shorten.

Answer 38

Contraction

Question 39

What are fascicle arrangement: there are 5

Answer 39

* Parallel (non fusiform) * Fusiform * Convergent * Circular * Pennate

Question 40

What type of fascicle arrangement is this? _____-fibers run straight from origin to insertion o Ex: Sartorius

Answer 40

Parallel (non-fusiform)

Question 41

What type of fascicle arrangement is this? ____-spindle shaped large belly tapers at ends o Ex: Biceps brachi

Answer 41

Fusiform

Question 42

What type of fascicle arrangement is this? ____-spread out broadly at the origin but come together to a narrow tendon for the insertion. o Ex: Pectoralis major

Answer 42

Convergent

Question 43

What type of fascicle arrangement is this? _____-fascicles form concentric rings that surround an opening o Ex: Orbuclaris oris

Answer 43

Circular

Question 44

What type of fascicle arrangement is this? _____-“feather like” fibers arranged at an oblique angle to a tendon. Allows the muscle to produce a large force at the expense of producing less movement. * Unipennate *Bipennate *Multipennate

Answer 44

Pennate

Question 45

What are three different from of pennate one of the fascicle arrangement.

Answer 45

Unipennate Bipennate Multipennate

Question 46

What type of pennate is this? ____-all muscle fibers on same side of the tendon. § Ex: Extensor digitorum

Answer 46

Unipennate

Question 47

What type of pennate is this? _____-fibers on both sides of the tendon. § Ex: Rectus femoris

Answer 47

Bipennate

Question 48

What type of pennate is this? ____-tendon branches within the muscle. § Ex: Deltoid

Answer 48

Multipennate

Question 49

Muscle Nomenclature: 7 criteria commonly used to name muscles Shape- ex: 40)______________=triangular Origin/Insertion- ex: 41)_________________= O- manubrium and clavicle I- mastoid Fiber direction: rectus abdominis, external and internal abdominal oblique # of origins: 42)______________ (2 heads) brachii, 43)___________ (3 heads) brachii Location: ex: biceps brachii (arm), biceps femoris (thigh), temporalis (covers temporal bone) Size: ex: extensor carpi radialis brevis (short) and longus (long), adductor magnus (largest) Action: ex: extensor carpi radialis, flexor carpi radialis, adductor magnus, supinator, pronator

Answer 49

``` 40) Deltoid 41) stermocleidomastoid 42) Biceps 43) Triceps ```

Question 50

What type of Muscle Terminology: Example of Elbow Flexion: _____-main muscle responsible for the action. • Ex: Biceps brachii

Answer 50

Prime mover

Question 51

What type of Muscle Terminology: Example of Elbow Flexion: ____-muscle that stretches and stabilizes in support of the action of the agonist. • Ex: Triceps brachii o O: long head infraglenoid tubercle, lateral head proximal lateral humerus, medial head posterior humerus o I: Olecranon process of ulna o A: Extension as prime mover but as antagonist slows and stabilizes elbow flexion.

Answer 51

Antigonist

Question 52

What type of Muscle Terminology: Example of Elbow Flexion: ____-muscles assist by adding additional force for movement or stability. • Ex: Brachialis and Brachioradialis assist with flexion of the elbow

Answer 52

Synergist

Question 53

What are the three types of Muscle Terminology: Example of Elbow Flexion?

Answer 53

Prime mover Antigonist Synergist