Brainscape's Knowledge GenomeTM

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


See full index

Histology > Hitsology - Muscle > Flashcards

Hitsology - Muscle Flashcards

0
Q

Intrafusal fibers

A
  • Modified muscle cells.
  • Surrounded by fluid-containing periaxial space, which in turn is enclosed by capsule.
  • The connective tissue elements of the capsule are continous with the collagen fibers of the perimysium and endomysium.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

Two types of sensory receptors:

A
  1. Muscle spinldes
  2. Golgi tendon organs

Both act in concert to intergrate spinal reflex system

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

Extrafusal fibers

A

Skeletal muscle fibers surrounding the muscle spindle

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

Cardiac muscle

A

Centrally placed nucleus

  • Two nuclei
  • Ca. 50% of the volume of the cardiac muscle cell is occupied by mitochondria.
  • Abundant supply of myoglobin
  • Possesses inherent rythmicity
  • Contract spontaneously
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Atrial natriuretic peptide

A

A substance that functions to lower blood pressure

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

Quanta

A
  • Is acetylcholine (ligand) liberated in larger quantities.

- Line the T tubule of cardiac muscle

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

Two types of smooth muscles

A
  1. Multiunit smooth muscle:
    > Contract independently
    > Each muscle cell had its own nerve sypply
  2. Unitary (single unit, vascular) smooth muscle:
    > Form gap junction with those of contigous smooth muscle cells, and nerve fibers form synapses with only a few of the muscle cell.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Substances manufactrured by smooth muscle cells for EC utilization

A
  • Collagen
  • Elastin
  • GAGs
  • Proteoglycans
  • Growth factors
  • In addition to its contractile infornations, som smooth muscle is capable of exogenous protein synthesis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

External lamina (basal lamina)

A
  • Line both the primary synaptic cleft and the junctional fold.
  • Each muscle cell is surrounded by an external lamina, with reticular fibers embedde in the external lamina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Smooth muscle fibers

A
  • Are fusiform
  • Elongated
  • Oval nucleus with two or more nucleoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dense bodies

A

Visable atfter the H and E.

In smooth muscle fibers

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

Thick filaments of smooth muscle

A

Composed of myosin II

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

Thin filaments

A

Composed of actin
> With its associated caldesmon, a protein that blocks the active site of F- actin and tropomyoskine with the notable ab sent of tropomyosin

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

Hyperplasia

A

Sattelite cells that undergo mitotic activity subsequent is muscle injury

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

Hypertrophy

A

When satellite cells fuse with existing mucle cells

> Increasing muscle mass during skeletal hypertrophy

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

Voltage-gated calcium release channels

A

= junctional feet

- Located in terminal cisterna

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

What is responsible for the cross-striation of high and dark banding that are characteristic for skeletal muscles viewed in longitudinal section?

A

Myofibrils

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

What regulates muscle contraction?

A

Sacroplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Power stroke

A

When the thin filament is dragged toward the center of sacromere as a result of ADP being released

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

What cause the release of the bond between actin and myosin II?

A

ATP binding to the S1 subfragment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Motor unit

A

Motor neuron and the muscle it controls?

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

Postsynaptic membrane

A

The muscle cell membrane

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

Axon terminal

A
  • Covered by Schwann cells.

- Houses: mitochondria, SER and ca. 300’000 synaptic vesicles (containes acetylcholine)

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

Secondary synaptic cleft

A

= junctional folds

  • Opens into the primary synaptic cleft.
  • Is a further modification of the sacrolemma.
  • Lined by basal lamina-like external lamina
  • The sacroplasm in the vicinity of the secondary synaptic cleft is rich in glycogen, nuclei, ribosomes, and mitochondria.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Primary synaptic cleft

A
  • Through-like structure occupied by the axon terminal.

- Lined by a basal lamina-like external lamina.

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

Neuromuscular junction

A
  • Muscle-nerve junctions
  • Composed of:
    > An axon terminal
    > A synaptic cleft
    > Muscle cell membrane
  • Function: transmit a stimulus from the nerve fibers to the muscle cells
26
Q

Active sites

A

Is where the fusion of acetylcholine (synaptic vesicle) occure along the presynaptic membrane

27
Q

Somatic system

A

Skeltal muscle

28
Q

Autonomic system

A
  • Smooth muscle
  • Cardiac muscle
  • Glands
29
Q

Striated muscles

A
  • Skeletal

- Cardiac

30
Q

Muscle fibers

A

Muscle cells

31
Q

Investments of skeletal muscles

A
  • Epimysium:
    > Dense irregular collagenous connective tissue
  • Perimysium:
    > Less dense collagenous connective tissue derive from epimysium.
    > Surrounds bundles (fasicles) of muscle fibers.
  • Endomysium:
    > Composed of reticular fibers and an external lamina (basal lamina)
    > Surround each muscle cell
32
Q

Tendons and aponeuroses

A
  • Connect muscle to bone and to other tissues.

- Continous with connective tissue encasements of muscles and act in harnessing the contractile forces for motion.

33
Q

Skeltal muscle

A 
Multinucleated -> nuclei peripherally located
Voluntary contraction
Rich vascular supply
- A lot of myoglobin pigments = red
- Myoblast are precusors of skeletal muscle fibers
- Myotubes
- Myofibrils -> myofilaments
- Continous capillaries
- Red, white, or intermediate
34
Q

Satellite cells

A
  • Have a single nucleus and act as regenerative cells in shallow depressions on the muscle cell’s surface, sharing teh muscle external lamina
  • Chromatin network of the satellite cell nucleus is denser and coarser then that of the muscle fibers
35
Q

During muscle contraction

A
  • I band = narrower
  • H band = dissapears
  • Z disks = move closer
  • A band = nothing happens
36
Q

T-tubules in skeletal muscles

A
  • 2 terminal cisternae
  • Terminal cisternae have voltage-gated calcium release channels (junctional feet) in their membrane.
  • Transverse tubules
  • Lie in the plane of the junction of the A and I bands
37
Q

Thin filaments

A

Composed primarly of actin

38
Q

Thick filaments

A

Composed of myosin II

39
Q

Myomesin and C protein

A

Found in the M-line

40
Q

The center of which is occupied by a thick filament

A

Hexagon

41
Q

The structural organization of myofibrils is maintained largerly by fibe proteins:

A
  1. Titin
  2. “Alpha”-actin
  3. Cap Z
  4. Nebulin
  5. Tropomodulin
42
Q

The heavy chains

A
  • Cleaved by trypsin into:
    1. Light meromyosin
    2. Heavy meromyosin
  • Read more p. 165
43
Q

Huxley’s sliding filament theory

A

Is about how the thin filaments slide past the thick filaments during contraction

44
Q

Acetylcholine receptors

A
  • Located in the vicinity of the presynaptic active sites.

- Are ligand-gated ion channels

45
Q

Acetylcholineterase

A
  • Enzyme in the external lamina lining the primary and the secondary synaptic clefts
  • Degrade acetylcholine to:
    1. Acetate
    2. Choline
      => Reestablishment of the resting potential
  • Hint: terase = tear up (sounds like)
46
Q

Choline acetyl transferase

A

Within the axon terminal, the acetylcholine is synthesized from activated acetate (product in mitochondria) and the recycled choline, a reaction catalyzed by choline acetyl transferase.

47
Q

Cardiac muscle recieve calcium from:

A
  • SER/ sacroplasmic reticulum
  • Bore on the T-tubules that permit ECM with Ca2+ to enter the cardiac muscle via the T-tubules.
  • External lamina: negatively charged coating the T-tubules store calcium for instantenous release.
  • Calcium can enter the cell through calcium-sodium channels
48
Q

Golgi tendon organs

A

= Neurotendinous spindles
- Composed of:
> Wavy collagen fibers
> Nonmyelinated continuation of a single type Ib axon that ramifies as free nerve ending in the intersices between the collagen fibers.

49
Q

Organelles for cardiac muscle

A
  • ECM -> Primary calcium source for cardiac muscle contraction
  • SER -> Ca2+ supply for the cardiac muscle
    -> Do not form terminal cisternae
  • T-tubules with small terminals of SER
    => Dyad
50
Q

Smooth muscle (1)

A
  • No striations
  • Do not possess a system of T-tubules
  • Location: Hallow vicera (gastrointestinal tract, some of the reproductive tract, and the urinary tract), walls of blood vessles, larger ducts of compound glands, respiratory passages, small boundles within the dermis of the skin.
51
Q

Smooth muscle (2)

A
  • Not under voluntary control
  • Regulated by the autonomic nervous system, hormones, and local physiological conditions.
  • = Involuntary muscle
52
Q

Fine structure of smooth muscle

A
  • Thin and thick filaments
  • Heavy meromyosin heads (S1)
  • Myosin II + actin = contractions of long duration
  • All-or-none law does not apply to smooth muscle
  • Intermediate filaments which consist of vimetin and desmin
  • Caveolae -> associated with the cell membrane. Act as T-tubules. Regulates the cytosolic free calcium ion concentration.
53
Q

Neuromuscular junction

A

Is composed of an axon terminal, a synaptic cleft, and the muscle cell membrane

54
Q

Intercalated disk

A
  • End-to-end junction between cardiac muscle cells
  • Transverse portion:
    > Fasciae adherentes
    > Desmosomes abound
  • Lateral postion:
    > Rich in gap juction
  • Thin myofilaments attach to the fasciae adherens
  • Gap junctions -> Rapid flow of information
55
Q

Gap junction

A
  • Cardiac muscle cells
  • Smooth muscle cells
  • Neurons
  • Skeletal muscles DO NOT have gap junction
    Unitary (single-unit, vascular) smooth muscle form gap junctions with those of contigous smooth muscle cell
56
Q

Dystrophin

A

A protein that binds to actin

57
Q

Caldesmon

A

A protein that blocks the active site of F-actin

58
Q

F-actin

A
  • A major component of each thin filament
  • Is a polymer of globular G-actin units
  • Two chains of F-actin wound around each other in a tight helix
59
Q

Myofibrils

A
  • Held with one another with intermediate filaments desmin and vimetin
  • Dystrophin binds to actin
60
Q

Myofibrils -

A 
- A-bands:
    > Dark bands
    > Anisotropic with polarized light
- I-bands:
    > light bands
    - Isotropic with polarized light
- H-bands:
    > Pale
    > Bisected by a thin M line (H&M)
- I-band bisected by Z disk (line)
- Z disk = sacromere
61
Q

Read page 172-173

A

Muscle spindles

62
Q

Read

A
  • Muscle contraction and relaxation

- Energy source for muscle and myotendious junctions

63
Q

Les 182-184

A

.

Histology (14 decks)

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