Histology - 514-8

Question 1

What is the connective tissue component that surround a muscle cell?

Answer 1

Endomysium

Question 2

What is the specialized plasma membrane of muscle cells called?

Answer 2

Sarcolemma

Question 3

What is the cytoplasm of a muscle cell called?

Answer 3

Sarcoplasm

Question 4

What is the specialized series of interconnected tubules throughout the sarcoplasm connected to storage sacs of Calcium called?

Answer 4

Sarcoplasmic Reticulum

Question 5

Myofibrils are made up of…

Answer 5

myofilaments

Question 6

Myofilaments are made of…

Answer 6

Actin and Myosin

Question 7

What protein anchors myofibrils inside a muscle cell?

Answer 7

Dystrophin

Question 8

What is a disease caused by abnormalities in dystrophin?

Answer 8

Muscular Dystrophy

Question 9

What are T-tubules?

Answer 9

Perpendicular invaginations of the sarcolemma.

Question 10

What connective tissue fibers surround the sarcolemma and connect muscle cells together?

Answer 10

Endomysium

Question 11

What type of CT is continuous with the ends of a muscle cell to tendon?

Answer 11

Dense Regular

Question 12

What type of cells are found between the Endomysium and Sarcolemma?

Answer 12

Satellite Cells.

Question 13

A resting muscle cell membrane is______ and has a ______ charge

Answer 13

Polarized

Net postitive outside the cell

Question 14

What defines a sarcomere?

Answer 14

Z- lines

Question 15

Where does depolarization of a cell occur after it leaves the NMJ?

Answer 15

Sarcolemma and T-tubules

Question 16

What are A bands?

Answer 16

The entire length of Myosin

Question 17

What is the H band?

Answer 17

Myosin without actin overlap

Question 18

What is the I band

Answer 18

Only actin with no myosin overlap

Question 19

At rest, what covers the active site on the actin filaments?

Answer 19

Tropomyosin

Question 20

What begins at the ACh receptors at the terminal button?

Answer 20

Depolarization

Question 21

Upon depolarization, what do T-tubules induce the sarcoplasmic reticulum to release?

Answer 21

Calcium through channels.

Question 22

What does Calcium bind to release tropomyosin from the actin filament?

Answer 22

Troponin

Question 23

What is the key process of anabolic steroid use?

Answer 23

Stimulation of satellite cells. (Incorporation in fibers)

Question 24

What is the functional unit of a muscle?

Answer 24

Sarcomere

Question 25

Where is the calcium reservoir in sarcoplasmic reticulum?

Answer 25

Terminal Cisternae

Question 26

Where are terminal cisternae positioned?

Answer 26

Over actin/myosin overlap

Question 27

What structure is located between two terminal cisternae?

Answer 27

T-tubule

Question 28

What does the t-tubule combined with lateral cisternal structures comprise?

Answer 28

Triad

Question 29

Where are triads found in an transmission electron micrograph?

Answer 29

On border of myosin/actin, often next to mitochondria

Question 30

What are the two regulatory proteins on Actin?

Answer 30

Tropomyosin (big) | Troponin (small - Ca binding site)

Question 31

How many heads does one myosin contain?

Answer 31

Two

Question 32

How many actin subunits make up an actin filament?

Answer 32

6 or 7

Question 33

What is the elastic component in a sarcomere?

Answer 33

Titin - aka connectin

Question 34

Where is Titin found?

Answer 34

Z-disk to M-line

Question 35

How many muscle fibers can a small motor unit innervate? | Large motor unit?

Answer 35

3-6 fibers per nerve | 1000 fibers per nerve

Question 36

What is the synapse between a nerve fiber and muscle cell called?

Answer 36

NMJ

Question 37

What is the folded and specialized region of sarcolemma under the terminal bouton called?

Answer 37

Motor End Plate

Question 38

What enzyme breaks down ACh in the synaptic cleft?

Answer 38

Acetylcholinesterase

Question 39

What is a cell membrane potential?

Answer 39

0.06 volts / 60 millivolts

Question 40

What main ion is outside the cell? | Inside the cell?

Answer 40

Na | K

Question 41

What helps create negative charge inside the cell?

Answer 41

Anionic proteins

Question 42

What ion enters the synaptic bulb (bouton)

Answer 42

Calcium

Question 43

What does entry of Calcium trigger?

Answer 43

ACh release

Question 44

What moves more in depolarization, Na or K?

Answer 44

Na

Question 45

Is the motor end plate ligand gated or voltage gated?

Answer 45

Ligand (ACh)

Question 46

What do ACh receptors allow?

Answer 46

binding of ACh, opening of channel, which allows Na to rush into the cell

Question 47

What does Calcium bind? | What does this do?

Answer 47

Troponin | Exposes Actin active site

Question 48

What breaks the cross-bridge between actin and myosin?

Answer 48

ATP

Question 49

What removes calcium from the sarcoplasmic reticulum?

Answer 49

Active transport pumps (use ATP)

Question 50

What causes rigor mortis?

Answer 50

Sarcoplasmic reticulum breaks down - releases Calcium Ca activated actin/myosin cross bridging No ATP to remove myosin heads

Question 51

How does botox work?

Answer 51

blocks ACh release

Question 52

How does curare work?

Answer 52

blocks ACh receptors

Question 53

How does tetrodotoxin work?

Answer 53

blocks Na movement in nerves

Question 54

How does Black Widow venom work?

Answer 54

causes mass release ACh

Question 55

How does Tetanus work?

Answer 55

blocks glycine (inhibitor preventing overstimulation)

Question 56

How do many pesticides work?

Answer 56

By inhibiting acetylcholinesterase

Question 57

What is Myasthenia Gravis and how does it work?

Answer 57

Autoimmune | Degrades ACh receptors - muscles no longer work

Question 58

What are 2 ways to regenerate ATP from ADP?

Answer 58

Myokinase | Creatine kinase

Question 59

What type of muscle fiber is fast twitch?

Answer 59

White | IIb

Question 60

What is the main difference between cardiac and skeletal muscle?

Answer 60

Intercalated disks | also gap junctions and desmosomes

Question 61

Is smooth muscle multi-nucleated?

Answer 61

No

Question 62

What are the neurotransmitters for smooth muscle?

Answer 62

Norepinepherine and ACh

Question 63

What to dense bodies do in smooth muscle?

Answer 63

create triangulation contraction between thin and thick filaments.

Question 64

How are calcium channels often stimulated in smooth muscle?

Answer 64

Mechanically

Question 65

What is a primary regulatory protein in smooth muscle?

Answer 65

Calmodulin

Question 66

What does Calmodulin activate?

Answer 66

MLCK

Question 67

Why is smooth muscle contraction slow?

Answer 67

ATPase act slowly | Ca pumps also slow