Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histology > Muscle > Flashcards

Muscle Flashcards

1
Q

What is found in the muscle tissue…

A
  • muscle cells (myocytes, myofibers)
  • stem cells (satellite cells)
  • nerve supply
  • somatic motor (for voluntary muscles)
  • visceral motor (for involuntary muscles)
  • sensory
  • excitable plasma membranes
  • connective tissue
  • blood vessels, lymphatics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is found in non-muscle contractile tissue…

A
  • myoepithelial cells
  • glandular tissues
  • myofibroblasts
  • wound healing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Classification of muscles

A

1) Skeletal (striated)

  • voluntary muscles associated with skeletal movement
    • biceps brachii, trapezius, deltoid etc.

1a) Visceral (striated)

  • voluntary visceral muscles
    • upper esophagus, pharynx, tongue, etc.

2) Cardiac (striated)

  • under autonomic (sympathetic/
    • parasympathetic) control

3) Smooth (non-striated)

  • wide distribution
    • gut, bronchioles, blood vessels, ureter, gall bladder, etc.
  • under autonomic (sympathetic/parasympathetic) control
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

myo…, sarco…, …mysium

A

…mysium (flesh)

Muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sarcolemma

A

plasma membrane + external lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Sarcoplasma

A

cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Sarcoplamic Reticulum

A

smooth ER

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

myofiber

A

AKA myocyte = muscle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Skeletal Muscle Characteristics

A
  • striated
  • voluntary*
  • long unbranched muscle fibers
  • continuous external lamina
  • no cell-cell gap junctions
  • rich CT investments:
    • surrounding entire muscle
    • surrounding muscle fascicles
    • surrounding muscle fibers
  • multinucleated (true syncytium)

*atypical muscles (usually involuntary, but otherwise is voluntary:

  • lower pharynx
  • diaphragm, etc

The labeled …mysiums are all continuous with tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Skeletal muscle fibers - describe the cells

A

multinucleated, giant cells

(range from ~1mm (stapedius) to >1m (sartorius)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

ID the tissue

A

skeletal muscle

longitudinal section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

ID the tissue

A

skeletal muscle

cross section

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

myofibrils

A

cytoplasmic collection of sarcomeric units surrounded by the sarcoplasmic reticulum and other organelles; the sarcomere’s A and I bands in adjacent myofibril are in register, thus giving the muscle its characteristic striated appearance

packed with myofilaments; myofilaments consist of repeating sarcomeres

Muscle cells are packed with myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

endomysium

A

between lateral cell boundaries

delicate layer (made from Type III collagen) that surrounds each individual myofiber and contains reticular fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Myofilaments

A

myofibrils are composed of myofilaments which consist of actin and myosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

During muscle contraction, what happens to the different bands

A
  • sarcomere shortens (Z-lines
    • move together)
  • neither thin (actin) nor thick
    • (myosin) filaments shorten
  • A band width does not change
  • I band narrows
  • H band narrows

I band - Isotropic

A band - Anisotropic

H band - Ger. Heller (“bright”)

M line - Ger. Mittel (“center”)

Z line- Ger. Zwishen (“between” the I bands)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Excitation-contraction coupling: Skeletal muscle

A

Regulated by Ca2+

  • two sarcomere/t-tubule triads
  • continuous, enlarged SER cisterna
  • propagate depolarization into cell
  • stimulate calcium release from SR
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

dystrophin complex

A

Contractile proteins are linked to the ECM via the dystrophin complex

Dystrophin connects actin to plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Muscular dystrophy

A

dystrophin deficiency:

  • mechanical failure
  • hypercalcemia leading to increased osmosis, mitochondrial rupture
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Skeletal muscle fiber types

A

red: (slow-twitch) many mitochondria, myoglobin & oxidative enzymes (aerobic)

(these can contract for long periods without fatigue)

white: (fast-twitch) fewer mitochondria & oxidative enzymes (anaerobic)

(these are quick to fatigue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

motor unit density

A

The ratio of neuro-muscular junctions will change depending on the function of the tissue

coarse control, neuron:muscle fibers = 1:1000’s

fine control, neuron:muscle fiber = ~1:3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Sensory perception

A

provide proprioceptive information and mediate stretch reflex

a. muscle spindle
b. golgi tendon organs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Muscle spindle

A

one type of sensory fiber

provide proprioceptive information and mediates stretch reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

golgi tendon organ

A

one of the sensory fibers

proprioception and inhibition reflex (protection from overstretching)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Cardiac muscle characteristics

A
  • involuntary
    • (sympathetic/parasympathetic)
  • striated
  • long branched muscle fibers:
    • formed by end to end cell fusion via specialized cell-cell junctions
  • discontinuous external lamina
  • many gap junctions
  • cells often binucleate
  • has intrinsic capability to beat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

ID tissue type

A

Cardiac muscle, longitudinal view

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Cartoon diagram of cardiac muscle (no question)

A
28
Q

ID tissue type

A

Cardiac muscle, cross section view

  • note stippling in cytoplasm (myofibrils)
  • note central location of nucleus (when visible)
29
Q

intercalated discs

A

Cardiac cell-cell junctions

Made up of end-to-end juctions (uses fascia adherens and desmosomes) and lateral cell-cell junctions (uses gap junctions and desmosomes and is discontinuous basal lamina)

30
Q

Excitation-contraction coupling: Cardiac Muscle

A

Regulated by Ca2+

  • one T-tubule/sarcomere: Diad rather than triad
  • discontinuous, anastomosing cisterna
  • T-tubules situated at Z-bands
  • SER does not encircle myofibrils

therefore, less efficient than skeletal muscle but cell-autonomous contractility and a functional syncytium (gap junctions) compensate

31
Q

Specialized myocardial cells

A

Endocrine cells

Purkinjee fibers (specialized conducting cells)

32
Q

Endocrine cells

A

type of specialized myocardial cell

  • ANF (Atrial Natriuretic Factor) – vasodilator
  • released in response to high BP, high Na+, angiotensin II
  • predominantly in atria
33
Q

Purkinjee Fibers

A

Specialized conducting cells

  • rich in glycogen
  • conduct impulses
34
Q

Smooth muscle characteristics

A
  • non-striated
  • involuntary
  • unfused, spindle-shaped cells (20-500mM)
  • central nucleus
  • discontinuous external lamina
  • many gap junctions
  • widely distributed:
    • hollow organs (GI tract, blood vessels, bladder etc.), skin (arrector pili)
  • no true sarcomeres
35
Q

ID tissue type

A

Smooth muscle

36
Q

Excitation-contraction coupling: Smooth Muscle

A

1) electrical, via gated Ca2+ channels

  • atypical neuromuscular junction:
    • neurotransmitters released at 10-200m from muscle = slow excitation

2) mechanical
* stretching stimulates mechano-sensitive ion channels (“myogenic” response)
3) hormonal
* e.g. oxytocin stimulates uterine contractions

Doesn’t have t-tubules; caveolae replace T tubule system because deep penetration not needed

37
Q

caveolae

A

replace T tubule system in smooth muscle

38
Q

Skeletal Muscle Repair

A

Satellite cell activation

  • disease (e.g. muscular dystrophies)
  • damage (e.g. excessive weight training)

(although most increased muscle mass during normal training is due to hypertrophy not hyperplasia)

39
Q

Cardiac Muscle Repair

A

Some satellite cell activation????

  • limited mitosis is possible
  • most repair is fibrotic (scar tissue)
40
Q

Smooth Muscle Repair

A

Actively proliferates in response to:

  • damage
  • physiological needs (e.g. uterine expansion during pregnancy)
41
Q

Skeletal muscle examples

A

biceps brachii, trapezius, deltoid etc.

Visceral muscle: upper esophagus, pharynx, tongue, etc.

42
Q

Cardiac muscle examples

A

main tissue in the walls of the heart

43
Q

Smooth muscle examples

A

gut, bronchioles, blood vessels, ureter, gall bladder, etc.

44
Q

Epimysium

A

outermost CT capsule that contains the bundles of myofibrils arranged into fascicles

dense connective tissue sheath (made from type I collagen) on the external surface of the muscle, which is continuous with the tendons that attach the muscle to bones. The epimysium is synonymous with deep fascia in gross anatomy and will frequently be named according to the muscle it covers, such as brachial and crural fascia for the arm and leg muscles, respectively

45
Q

Perimysium

A

(Made from type I collagen) surrounds groups of fibers and

organizes them into fascicles

46
Q

Sarcomere

A

Sliding filament mechanism for muscle contraction

  • sarcomere shortens (Z-discs move together)
  • neither thin (actin) nor thick (myosin) filaments shorten
  • A band width does not change
  • I band narrows
  • H band narrows
47
Q

ID the tissue

A

Cardiac Muscle

48
Q

ID the tissue

A

Cardiac muscle cross section

  • note stippling in cytoplasm (myofibrils)
  • note central location of nucleus (when visible)
49
Q

ID the tissue

A

cardiac muscle, longitudinal view

Note: intercalated disc

50
Q

ID the tissue

A

Purkinje fibers

  • rich in glycogen, which is what gives them the pale appearance
  • conduct impulses
  • contractile, but not thought of that way

Endocardium is at the top of the picture

Cardiac muscle below

51
Q

Dense bodies

A

Dense bodies are the z-disc (line) equivalent in smooth muscles

52
Q

ID the tissue

A

Smooth muscle

note the dense bodies

53
Q

T-Tubules

A

perpendicular invaginations of the sarcolemma

Once depolarized, impulses travel from the sarcolemma into the musclefiber through T tubules

Not found in all muscles; they are found in large cells in order to propegate action potential

Not needed in smooth muscle; caveolae replace T tubule system in smooth muscle

54
Q

ID the tissue

A

Smooth muscle cross-section

Note gap junctions (arrows) – in these locations the external lamina is absent

55
Q

ID the tissue

A

Skeletal and smooth muscle

56
Q

Leiomyomas

A

Fibroids - smooth muscle tumors almost exclusively found in the uterus

57
Q

ID the tissue

A

skeletal muscle - longitudinal section

58
Q

ID the tissue

A

skeletal muscle - cross section

59
Q

ID the tissue

A

Skeletal

60
Q

ID the tissue

A

Cardiac

61
Q

ID the tissue

A

Smooth

62
Q

ID the tissue

A

Skeletal - cross section

63
Q

ID the tissue

A

Smooth muscle - cross section

64
Q

ID the tissue

A

Cardiac - cross section

65
Q

Comparison of muscles (no question)

A
66
Q

Smooth muscle vs. dense, regular CT of a tendon

A

Histology (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions