Muscle Tissue and Organization Flashcards Preview

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Flashcards in Muscle Tissue and Organization Deck (100):
1

Why are muscles considered organs?

they are composed of muscle, epithelial, connective, and nervous tissue

2

What do muscles convert?

chemical energy into physical energy

3

Types of muscle tissue

skeletal, smooth, and cardiac

4

typically voluntary muscle tissue

skeletal

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typically involuntary muscle tissue

smooth and cardiac

6

Is essential for propelling materials through our internal tubes (i.e. peristalsis)

smooth muscle

7

is essential for the pumping of blood (found only in the walls of the heart)

cardiac muscle

8

specific characteristics ALL muscle cells exhibits

Excitability, Contractility, Elasticity, and Extensibility

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another name for muscle cells

muscle fibers

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muscle fiber property which means it responds to electrical stimuli

Excitability

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muscle fiber property which means it contracts to move bones or propel materials inside the body

Contractility

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muscle fiber property which means the muscle cell will recoil to its resting length when the applied tension is removed

Elasticity

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muscle fiber property which means a muscle cell is capable of extending in length in response to the contraction of opposing muscle cells

Extensibility

14

length of a single muscle fiber

as long as the muscle itself

15

hypertrophy

increase in muscle fiber size (not number)

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often follows regular exercise

hypertrophy

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Functions of skeletal muscle tissue

1. Body Movement (using bones as levers)
2. Maintenance of Posture (stabilize joints for upright position)
3. Temperature Regulation
4. Storage and Movement of Materials (sphincters vs. orifices)
5. Support by Stabilizing the Body Walls (prevent displacement of internal structures)

18

When a student falls asleep in lecture hall, muscular control of the bones and joints is lost, allowing the head to droop forward and the temporomandibular joint to become depressed. Which function of skeletal muscle tissue is absent in this situation?

Maintenance of Posture

19

Gross anatomy of skeletal muscle includes:

muscle attachments, blood vessels, and nerves

20

At the ends of a muscle the connective tissue layers merge to form a fibrous cordlike ______, which typically attaches to bone.

tendon

21

Sometimes the tendon forms a thin, flattened sheet, called an _______. (Greek for "from sinew")

aponeurosis

22

which characteristic does a tendon share with a muscle cell?

tendons have some elasticity

23

the less moveable attachment of a muscle. where does it typically lie?

the origin, which typically lies proximal to the insertion

24

the more moveable attachment of a muscle. where does it typically lie?

the insertion, which typically lies distal to its origin

25

Why are skeletal muscles classified as voluntary?

they are controlled by the Somatic (voluntary) Nervous System

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the neurons (nerve fibers) that stimulate muscle contraction and innervate muscle fibers within the muscle

motor neurons

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neurons that travel away from the center of activity (which is the CNS). another term for motor neurons

efferent neurons

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muscle fibers will do this if they are not periodically stimulated to contract by motor neurons

atrophy (waste away)

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atrophy

to waste away muscle fibers

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the long extension of each motor neuron that transmits a nerve impulse to a muscle fiber

axon

31

where does the axon travel through?

the fibrous coverings of the muscle

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sends impulses to the brain and spinal cord about the activity of the muscles

sensory neurons

33

neurons that travel towards the CNS. another term for sensory neurons

afferent neurons

34

bundles of muscle fibers lie parallel to each other within each muscle and are termed _____.

fascicles

35

The organization of fascicles in different muscles varies in these four different patterns.

1. Circular muscles
2. Parallel muscles
3. Convergent muscles
4. Pennate muscles

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pattern where fascicles are are concentrically arranged around an opening or recess

Circular muscles

37

Why is a circular muscle also called a sphincter?

because the contraction of the muscle closes off an opening (orifice)

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another name for circular muscles

sphincters

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an example of a sphincter that is found within the lips and surrounds the opening of the mouth. Why is this so special?

the orbicularis oris muscle, which is the first sphincter of the digestive tract

40

pattern where fascicles run parallel to its long axis.

parallel muscles

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the central body of a parallel muscle

a "belly"

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what happens to the body (belly) of parallel muscle when it shortens (contracts)?

it increases in diameter (bulges)

43

2 examples of parallel muscles that bulge when they contract

biceps brachii and the rectus abdominis (which forms the "six-pack")

44

pattern of widespread fascicles (bundle of muscle fibers) that converge on a common attachment site. these are often triangular shaped, resembling a broad fan with a tendon at the tip. (ex. Deltoid)

Convergent muscles

45

a convergent muscle on the anterior of the chest that inserts onto the proximal end of the humerus

pectoralis major

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have one or more tendons extending through their body, and the fascicles are arranged at an oblique angle to the tendon. Latin for "looks like a feather"

Pennate muscles

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unipennate muscle

all muscle fibers are on the SAME SIDE of the tendon

48

bipennate muscle

most common arrangement. muscle fibers are on BOTH SIDES of the tendon

49

multipennate muscle

tendon branches within the muscle. example: deltoid muscle

50

biomechanics

the practice of applying mechanical principles to biology.

51

when analyzing muscle contraction, an anatomist often uses this practice to compare it to a lever

biomechanics

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A "__1__" is an elongated, rigid object that rotates around a fixed point called the "__2___".

1: lever
2: fulcrum

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The part of a lever from the fulcrum to the point of effort.

the "effort arm"

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The part of a lever from the fulcrum to the point of resistance.

the "resistance arm"

55

In the body, what acts as the lever that moves the resistance (R)? the fulcrum (F)? generates the effort (E)?

a long bone acts as the lever that move the R, a joint serves as the F, and a muscle attached to the bone generates the E.

56

When thinking about a muscle providing the effort (E), what must you realize?

That the effort is NOT where the body of the muscle is located, but rather where the muscle attaches (inserts) to the bone.

57

Types of Lever Systems

"F R E 1 2 3"
first class (1)=fulcrum (F) in middle
second class (2)=resistance (R) in middle
third class (3)=effort (E) in middle

58

A lever system similar to a seesaw, in which the fulcrum (F) is between the effort (E) and the resistance (R).

First Class Lever System

59

One example of a first class lever is the ______ joint of the neck, where the muscle on the posterior side of the neck pull inferiorly on the nuchal lines of the occipital bone and oppose the tendency of the head to tip anteriorly.

atlanto-occipital

60

One example of a first class lever is the pulling of the _______ muscle on the ______ to extend the elbow. (In this instance, the effort arm is very short and the resistance arm is very long.)

pulling of the "triceps brachii muscle" on the "olecranon process"

61

A lever system similar to lifting the handles of wheelbarrow, in which the resistance (R) is between the fulcrum (F) and the effort (E).

Second Class Lever System

62

Contracting the calf muscle to elevate the body onto the distal ends of metatarsals (ball of foot) is an example of what type of lever?

Second Class Lever

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A lever system similar to a drawbridge, in which the effort (E) is between the resistance (R) and the fulcrum (F).

Third Class Lever System

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The most common type of lever system in the body

Third Class Levers

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The flexion of the elbow and elevation of the mandible to bite off a piece of food is demonstrating what types of levers?

both are Third Class Levers

66

What is important to remember about the actions of skeletal muscles?

they do NOT work in isolation; rather they work together to produce movements

67

Muscles are grouped according to their primary actions into these 3 types.

Agonist, Antagonist, and Synergist

68

An "____" (also called a "____") is a muscle that contracts to produce a particular movement, such as the triceps brachii muscle causing extension of the forearm.

agonist (also called a prime mover)

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An "_____" is a muscle whose actions oppose those of the agonist, such as the biceps brachii muscle causing flexion of the forearm.

antagonist

70

The opposing force of an antagonist muscle enables us to do what?

control the speed of the agonist to allow smooth movements

71

A "____" is a muscle that assists the prime mover in performing its action, such as the teres major muscle assisting the latissimus dorsi in moving the arm.

synergist

72

Skeletal muscles are named according to what 7 criteria?

1. Muscle action
2. Specific body regions
3. Muscle attachments
4. Orientation of muscle fibers
5. Muscle shape and size
6. Muscle heads/tendons of origin
7. Relative position

73

adductor, flexor, extensor, pronator, and levator (lifter) are examples of which criteria used in naming skeletal muscles?

muscle action

74

pectoralis, intercostal, and brachii are examples of which criteria used in naming skeletal muscles? What do each of those mean?

Specific body regions
Pectoralis=the chest, or "pectus"
Intercostal=between the ribs
Brachii=on upper arm

75

zygomaticus and sternocleidomastoid are examples of which criteria used in naming skeletal muscles? What do each of those mean?

Muscle attachments
Zygomaticus=zygomatic bone
Sternocleidomastoid=sternum, clavicle, and mastoid process of skull

76

rectus, transverse, and oblique are examples of which criteria used in naming skeletal muscles? What do each of those mean?

Orientation of muscle fibers
Rectus=straight
Transverse=across
Oblique=at an angle

77

deltoid, trapezius, longus, brevis, teres, maximus, and minimus are examples of which criteria used in naming skeletal muscles? What do each of those mean?

Muscle shape and size
Deltoid=shaped like triangle
Trapezius=shaped like trapezoid
Longus=long
Brevis=short
Teres=both long and round
Maximus=large
Minimus=small

78

biceps, triceps, and quadriceps are examples of which criteria used in naming skeletal muscles? What do each of those mean?

Muscle heads/tendons of origin
Biceps=2 heads/tendons of origin
Triceps=3 heads/tendons of origin
Quadriceps=4 heads/tendons of origin

79

This begins as a direct result of increasing inactivity, typically in a person's mid-30s.

a slow progressive loss of skeletal muscle mass

80

What components of all muscle tissues decreases with inactivity? What often replaces the lost muscle mass?

size and power decreases. mass replaced by adipose tissue or fibrous connective tissue.

81

Aging affects the muscular system by decreasing the number of contractile filaments within muscle cells, which then causes what?

muscle cells (muscle fibers) to diminish in size (atrophy)

82

Overall, as an individual ages, what muscle functions are impaired that result in a tendency to fatigue easily?

muscle strength and endurance

83

This often accompanies aging, and leads to poorer delivery of oxygen and nutrients to muscle cells.

decreased cardiovascular performance

84

Tolerance for this decreases with age and rapid fatigue occurs

exercise

85

This has a reduced capacity to recover from disease or injury with age.

muscle tissue

86

As a person ages, increasing amounts of dense regular connective tissue causes a decrease in muscle elasticity. What process does this describe?

fibrosis

87

How can the adverse affects aging has on the muscular system be delayed?

Through regular, moderate exercise coupled with good nutrition

88

What is the common name and scientific name for a "bifid Zygomaticus Major" muscle deformity? What medical condition (much more serious) is this similar to?

dimple, or gelasin. This is similar to an inward hernia

89

inflammation of either a tendon or a synovial sheath surround the tendon. typically from overuse. may be caused by absent "glide-path"

tendonitis

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syndrome of chronic severe pain involving both muscles and skeleton. most commonly affects neck or lower back. treated through self-care measures, and NSAIDS

fibromyalgia

91

collective terms for several hereditary diseases where skeletal muscle degenerates

muscular dystophy

92

most common neuromuscular disease. expression of sex-linked recessive allele. exclusively affects males. posture abnormalties (scoliosis). rarely live past 30 and die of resp or heart complications. possible treatment by altered virus carring gene for dystrophin (essential protein for muscle function missing in these patients)

Duchenne muscular dystrophy DMD

93

common disorder associated with excessive use of postural muscles. "trigger point" stimulation of pain. bands of muscle fibers tighten and twitch after skin is toughed. can also produce autonomic nervous system changes (flushed skin, sweating, goose bumps)

myofascial pain syndrome MPS

94

unilateral paralysis of muscles of facial expression. nerve is inflamed and compressed within narrow stylomastoid foramen. may use prednisone to reduce inflammation and swelling of nerve, or acyclovir (antiviral) if herpes simplex is suspected.

facial nerve (CN VII) paralysis, Bell Palsy

95

eyes are improperly aligned, not working synchronously to transmit stereoscopic view. brain ignores eye and becomes lazy eye. 2 types, external vs. internal that are caused by oculomotor cranial nerve (CN III) or abducens cranial nerve (CN VI)

strabismus

96

when lazy eye loses visual acuity

strabismic amblyopia

97

toxin prevents release of ACh at NMJ and leads to muscular paralysis. commonly caused my improperly canned foods, and infants ingesting unpasteurized honey.

Botulism

98

known as wryneck, shortened and tightened sternocleidomastoid muscle.hematoma and fibrosing of muscle tissue. extended periods of time in infant seats. plagiocephaly (flattening of head) often accompanies. treatment with botox, stretching, surgery.

congenital muscular torticollis CMT

99

extracapsular femur fracture, typically from trauma

intertrochanteric fracture

100

intracapsular femoral fracture. often in those with osteoporosis. results in tearing of retinacular fibers and retinacular arteris. head and neck of femur lose blood supply causing death of bone tissue due to lack of blood (avascular necrosis)

subcapital fractures