Chapter 10 - Muscles & Muscle Tissue Flashcards Preview

A&P 1 - Chap 5 - Chap 12 (2nd test) > Chapter 10 - Muscles & Muscle Tissue > Flashcards

Flashcards in Chapter 10 - Muscles & Muscle Tissue Deck (43)
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1
Q

Skeletal muscle

A

voluntary, striated muscle attached to & covering skeleton; most abundant type; function: to move bones; length of muscle = length of cell; involved in reflexes–fastest contraction & w/greatest force; downside-gets tired easily;
cells = long, thick, straight cells; striped

2
Q

Cardiac muscle

A

involuntary, striated muscle in the heart wall; not as long as skeletal; interconnected & branched; can contract by itself–only tissue that does this; steady rate of contraction–rhythmic

3
Q

Smooth muscle

A

involuntary, nonstriated muscle in the hollow visceral organs (except heart & blood vessels); not as long as skeletal muscle tissue; (ex. stomach, intestines, bladder, uterus, blood vessels); slowest rate of contraction–doesn’t tire out

4
Q

4 Characteristics of Muscle tissue

A
  1. Excitability or Irritability
  2. Contractility
  3. Extensibility
  4. Elasticity
5
Q

Excitability or Irritability

A

ability to receive & respond to a stimulus

6
Q

Contractility

A

ability to shorten

7
Q

Extensibility

A

ability to be extended or stretched

8
Q

Elasticity

A

can recoil after being stretched & return to original resting length

9
Q

Muscle fiber

A

muscle cells

10
Q

Fascicles

A

bundles of muscle fibers

11
Q

Gross anatomy of a muscle (3 CT coverings)

A

consists of many skeletal fibers; continuous; connected to each other @ the ends

  1. Endomysium
  2. Perimysium
  3. Epimysium
12
Q

Endomysium

A

CT sheath which surrounds each muscle fiber

13
Q

Perimysium

A

CT sheath which covers each fascicle

14
Q

Epimysium

A

CT sheath which surrounds the entire muscle

15
Q

Insertion

A

site of attachment of muscle to a movable bone

16
Q

Origin

A

site of attachment of muscle to an immovable or less movable bone; always proximal to insertion

17
Q

2 Main types of muscle attachment

A
  1. Tendons - rope-like attachments to bone; most common attachment of muscle to bone; dense regular CT; collagen fibers
  2. Aponeuroses - flat sheet-like attachments of muscle to other muscle or to bone; dense regular CT; abdominal muscles
18
Q

Muscle Actions

A

usually work together to from opposite movements;

  1. Flexor - muscle which decreases the angle of the joint
  2. Extensor - muscle which increases the angle of the joint
19
Q

Sarcolemma

A

plasma membrane of muscle fibers; can carry electrical signals

20
Q

Sarcoplasm

A

cytoplasm of muscle fibers; includes cytosol, organelles & inclusions

21
Q

Myoglobin

A

muscle protein that binds oxygen

22
Q

Myofibrils

A

organelles in the sarcoplasm which contain contractile elements; structures that shorten (contract); consists of thick filaments & thin filaments;

23
Q

Sarcomeres

A

smallest contractile units in muscle fibers; length of a sarcomere is from Z disc to the next Z disc; repeating unit making up myofibril

24
Q

Thick filament

A

made of the structural protein myosin; darker region

25
Q

Thin filament

A

made of the structural protein actin, and 2 regulatory proteins (not actively involved in muscle contraction): tropomyosin & troponin; lighter region

26
Q

Sarcoplasmic reticulum

A

smooth ER of muscle fibers, stores Ca++ ions

27
Q

Terminal cisterns

A

end regions of the sarcoplasmic reticulum

28
Q

T tubule

A

sarcolemma which penetrates muscle cell interior; found between neighboring sarcoplasmic reticulum; made of same material as sarcolemma; electrical signals can go inside cell

29
Q

Triad

A

consists of a T tubule between 2 terminal cistern; 3 structures–terminal cisterns on either side & t-tubule

30
Q

Functions of Muscles

A

-Produces movement - of bones, blood, food digestion; applies to all 3 types of muscle tissue
The below 3 apply to Skeletal muscle tissue only:
-Maintains posture
-Stabilizes joints
-Generates heat - transforms chem energy (ATP) to mechanical energy & releases heat

31
Q

Skeletal muscles are organs

A

700 muscles; richly vascularized; have all 4 tissue types (CT, muscle tissue, epitheleal & smooth muscle tissue, nervous tissue); plus very specific function

32
Q

“myo”, “mys” & “sarco”

A

“muscle”

33
Q

Example of Flexor muscle

A
  1. biceps - decreases elbow joint

2. hamstrings (knee) - bends knee

34
Q

Example of Extensor muscle

A
  1. Triceps

2. Quadriceps - can’t bend knee; can only extend

35
Q

Microscopic anatomy of skeletal muscle fibers

A

long, thick cells; many, many nuclei (100s or 1,000s); 2nd longest cells in body–some over 1 foot long; nerve cells are the longest cells

36
Q

Embryonic development

A

100s of myoblasts line up to form one long skeletal muscle (cell): fusion of many myoblasts

37
Q

Special names given to structures inside cell

A

bc unusual

38
Q

Inclusions (in sarcoplasm)

A

stockpile of carbs & O2 built in & can quickly make ATP;

-glycogen granules & myoglobin

39
Q

Glycogen granules (inclusions)

A

polysaccharide (carb); stored nutrients right inside cell; allow it to have carbs right there; so not entirely dependable upon blood

40
Q

Interaction between thick & thin filaments

A

allows myofibrils to shorten; arrangements of thick & thin filaments give cell striated look

41
Q

Myosin

A

fibrous protein w/2 globular regions (myosin heads) @ end; q protein made of amino acids (myosin tail)–thin part

42
Q

Muscle contraction occurs when

A

myosin interacts w/actin

43
Q

Regulatory proteins (in thin filament)

A

block contraction or release muscle so it can contract;

  • Troponin - binds calcium (trigger for muscle contraction)
  • Tropomyosin - blocks binding sites on actin