Lecture 4: Skeletal Muscle and Nerve Tissue Flashcards Preview

04. MSK Exam 2 Final > Lecture 4: Skeletal Muscle and Nerve Tissue > Flashcards

Flashcards in Lecture 4: Skeletal Muscle and Nerve Tissue Deck (53)
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1

Simply put, how does contraction occur?

Actin (thin filaments) and myosin (thick filaments) slide past each other in myofibrils in the cytoplasm 

2

What is actin made of?

G-Actin Monomers

(globular protiens)

3

What two chains does Myosin have?

Heavy chain with a globular head

Light chain

4

How can you differentiate between skeletal, cardiac, and smooth muscle?

Skeletal: Striated and Voluntary

Cardiac: Striated and Involuntary 

Smooth: Non-striated and Involuntary

5

From smallest unit to largest, what are the divisions of a muscle?

Sarcomere -> Myofibrils -> Myocyte (Myofiber) -> Fascicle -> Muscle

6

What connective tissue separates myofibers?

Endomysium

7

What connective tissue separates fascicles?

Perimysium

8

What fascial covering surrounds the entire muscle itself?

Epimysium

9

What features can be used to identify Skeletal Muscle, especially in a histological slide?

Peripheral nucleii and Striations

Myofibers: Multinculeaded cylinders in the periphery of cell

Myofibrils: In the cytoplasm 

10

What is a sarcomere?

Basic structure of myofibril

11

What serves as the defined border of a sarcomere?

Z disks

12

What is the Sarcoplasm?

Cytoplasm of a Muscle Cell

13

What is Sarcoplasmic Reticulum?

What is stored in there?

Tubular system which acts like smooth ER

-Calcium is stored

14

What is the Sarcolemma?

The membrane around myocytes that penetrates the muscle cell as T tubules

15

What are Transverse (T) Tubules?

Invaginations of sarcolemma

16

What connects the Transverse Tubule to the Terminal Cisternae?

 

What do they do?

"End Feet"

 

Allow for calcium release

17

What does the Terminal Cisternae do?

Dilated ends of Sarcoplasmic Reticulum that releases Calcium to trigger muscle contraction

 

 

18

What is marked here as 1?

What does it contain?

I Band

-only actin thin filaments

19

What is marked here as 2?

What is found here?

A Band

-Overlap of actin and myosin and H zone

 

20

What is marked here as 3?

What is found here?

H Zone

-only myosin thick filaments

21

What is marked here as 4?

What is found here?

M Line

-anchor site for myosin thick filaments

22

What is marked here as 5?

What is found here?

Z Line

Anchor site for actin thin filaments

23

What attaches to the Z disk?

Actin and Titin (which in turn holds myosin)

24

What holds the Myosin to the Z disk, thus holding Myosin in place?

Titin protiens

25

What all is contained within the H Zone?

Myosin fibers and the M line

26

What is contained within the I band?

Actin

The Z Disk

(straddles sarcomeres)

27

What is defined as the A band?

Distance from end to end of myosin within one sarcomere.

28

Does the A Band shorten during contraction?

No. Only the H Zone and the I band shorten

29

Where are myosin going one direction attached to the myosin going the other direction?

M line / M disc

30

What two regions of a Myofibril shorten during muscle contraction?

The H Zone and the I Band