Quiz #3: Muscle Flashcards

1
Q

What are the three types of muscle tissue? Name the types of contractions and where they are located.

A
  1. Skeletal: Voluntary Movements, anything you can move
  2. Cardiac: Involuntary/Strong, found in the heart
  3. Smooth: Involuntary/Weak, found in hollow tubes (respiratory tract, digestive tract, Fallopian tubes, vas deferens…)
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2
Q

What is the basic function of muscle?

A

-Contactility
-Achieved due to actin protein filament with Myosin

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3
Q

All cells have actin and myosin (True/False)

A

-True
-Although concentrations are higher around muscles, all cells have actin and myosin.

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4
Q

Myosin is a motor protein that has a similar function to _________

A

Kinesin

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5
Q

The contraction of muscle is important for numerous functions including:

A

-Locomotion
-General body movements
-Blood circulation
-Peristalis
-Involuntary functions of the body:
(Transport of sperm/ovum, heart pumping, maintenence of blood pressure and function of sphincters)

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6
Q

What is the difference between G-actin and F-actin?

A

G-Actin: Single strand
F-Actin: Two strands wrapping around each other to form a micro filament
(Each actin filament has two strands)

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7
Q

Why are myosin and actin important in cytokinesis (end of meiosis)?

A

Formation of the contractile ring

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8
Q

What are some differences between rER and sER?

A

-Prescence of ribosomes: sER has none
-Structure: sER is more tubular/saccular

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9
Q

What is the function of sER in muscle?

A

Storage and release of calcium ions
(activate the contractile mechanism)

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10
Q

Name the cellular organelles of a muscle cell and their definitions

A

-Sarcoplasm: Cytoplasm of a muscle cell
-Sarcoplasmic Reticulum: Smooth ER
-Sarcolemma: Plasma membrane of the muscle cell

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11
Q

Actin and Myosin play a time in forming the contractile ring when the 2 daughter cells separate at the end of cell division (True or False)

A

True

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12
Q

Functions of Muscle Cells

A

-Storage and release of calcium ions
-Activate the contractile mechanism

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13
Q

Cellular Organelles of a muscle cell

A

-Sarcoplasm: Cytoplasm of a muscle cell
-Sarcoplasmic Reticulum: Smooth ER
-Sarcolemma: Plasma membrane of the muscle cell

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14
Q

Characteristics of Skeletal Muscle

A

-Multinucleated (Located Peripherally below the sarcolemma)
-Striated (Very evident)
-1 multinucleated cell
-Voluntary (all or none)
-Contraction is quite strong
-Cylindrical Shape

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15
Q

What is the regeneration capacity of skeletal muscle and how does it regenerate?

A

Limited; Regeneration done through Satellite Cells

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16
Q

Where is skeletal muscle found in the body?

A

Skeletal muscle, tongue, eyes, diaphragm

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17
Q

Characteristics of Cardiac Muscle

A

-Cylindrical (Branched)
-Mononucleated (surrounded by glycogen inclusion bodies)
-Strong Involuntary contractions
-Glycogen used for energy
-Cell connections made via intercalated discs (making cells striated)
-Many mononucleated cells attached end to end
-Automomous innervation (All or None)

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18
Q

What is the regeneration capacity of cardiac muscle?

19
Q

Where is cardiac muscle found?

A

Heart only

20
Q

Characteristics of Smooth Muscle

A

-Spindled (fusiform) shaped
-Lack Striations
-Not to strong, involuntary contractions (partial)
-Many spindle cells bound to one another via cell junctions

21
Q

What is the capacity of smooth muscle to regenerate?

A

Greatest capacity to regenerate (Mitosis of muscle cells)

22
Q

Where does skeletal muscle originate and what do they differentiate into?

A

Embryonic mesenchyme; First differentiate into myoblasts

23
Q

How does skeletal muscle form one multinucleated cell?

A

Many myoblasts fuse with each other then later develops into a striated muscle fiber

24
Q

Where are satellite cells found and what is their function?

A

-“left out” cells found attached to muscle cells outside the sarcolemma
-Muscle Repair (Cell division/forming new cells)

25
Characteristics of Epimysium
-Dense layer of CT that covers the whole muscle -Present just under the deep fascia -Connects bone to muscle
26
Characteristics of the Perimysium
-Dense layer of connective tissue that covers fascicles -Thinner than Epimysium but still dense CT
27
Characteristics of Endomysium
-Covers each muscle fiber -Both endomysium layers contain collage type 1, collagen type 3 and fibroblasts
28
What kind of nucleus does a fibroblast have?
Pachychromaric nucleus (dormant cell)
29
What kind of nucleus does a skeletal muscle have?
Leptochromatic nucleus (Active cell)
30
What is the A-Band made of?
Myosin protein
31
What is the I-Band made of?
Actin
32
What is each myofiber made up of?
5-6 myofibrils
33
What is the contractile unit of a muscle fiber?
Sarcomere
34
Where does a sarcomere span?
From z-disc to z-disc
35
What is a thick filament?
Myosin
36
What is a thin filament?
Actin
37
What two regulatory proteins are associated with F-actin?
Troponin and Tropomyosin
38
What three things combine together to make the thin filament?
F-actin + tropomyosin + troponin
39
What is Tropomyosin and what is it’s purpose?
-Wraps around the twisted F-actin/lies in the groove between 2 f-actin fibers -keeps the myosin binding sites of actin covered when not in action
40
What is the structure of Troponin and what does it do?
-1 protein and 3 subunits -Binds to Tropomyosin
41
What are the three subunits of Troponin and what is their purpose?
-TnT: Binds to Tropomyosin -TnC: Binds to Ca++ -TnI: Actin and Myosin interactions
42
What is the structure of myosin?
Made of 2 tails twisted around each other and 2 globular heads
43
What does ATP break down in order to make a contraction
ADP + Pi