Muscle

Question 1

What are the striated muscles?

Answer 1

skeletal and cardiac

Question 2

Which muscles are voluntary and what are involuntary?

Answer 2

• voluntary: skeletal
• involuntary: smooth and cardiac

Question 3

What are the connective tissue layers (outside to in)?

Answer 3

muscles> fascicle> fiber> muscle cell> myofibril

Question 4

What does the endomysium surround?

Answer 4

each single muscle cell

Question 5

What does the perimysium surround?

Answer 5

each fasicle

Question 6

What does the epimysium surround?

Answer 6

the entire muscle

Question 7

What are the 3 connective tissue layers of muscle (outside to in)?

Answer 7

epimysium> perimysium> endomysium

Question 8

Which connective tissue layers are made from dense irregular tissue?

Answer 8

epimysium and perimysium

Question 9

Which connective tissue layers are made from reticular connective tissue?

Answer 9

endomysium

Question 10

What band stays consistent with its length during a contraction?

Answer 10

A band (actin + myosin)

Question 11

Which bands get smaller during a contraction?

Answer 11

I (actin) and H (myosin) bands

Question 12

What makes up the triad?

Answer 12

sarcoplasmic reticulum + t tubule + sarcoplasmic reticulum

Question 13

What is needed to have the muscle relax after each stroke?

Answer 13

ATP

Question 14

Where are the nuclei located in skeletal muscle?

Answer 14

on both sides of the fiber

Question 15

What is myomesin?

Answer 15

cross-links thick filaments that are next to each other at M line

Question 16

What is titin?

Answer 16

forms elastic lattice that anchors thick filaments to Z disks

Question 17

What is troponin?

Answer 17

• binds Ca
• binds to tropomyosin
• binds to actin

Question 18

What is tropomyosin?

Answer 18

occupies grooves of the thin filaments

Question 19

What is C protein?

Answer 19

binds thick filaments at the M line

Question 20

What are the 2 types of muscle?

Answer 20

red and white muscle

Question 21

What is a muscle spindle?

Answer 21

sense what the contraction level is of a muscle

Question 22

What occurs during Ca depolarization?

Answer 22

1. membrane depolarizes
2. L-type Ca channel located in transverse tubule changes conformation
3. ryanodine-sensitive Ca channel becomes present in sarcoplasmic reticulum to open and release Ca
4. ryanodine channel releases Ca into sarcomere
5. released Ca binds to troponin C and initiates contraction

Question 23

What is rigor mortis?

Answer 23

continued contraction of muscle due to lack of ATP

Question 24

What is the process of a contraction?

Answer 24

1. need ATP for muscle contraction
2. ATP broken down to ADP
3. release of phosphate group
4. release ADP to bind ATP for muscle relaxation

Question 25

What is a powerstroke in regards to a contraction?

Answer 25

conformation change leads to the release of ADP

Question 26

What is the vascularization of red and white muscle fibers?

Answer 26

* red: rich vascular supply * white: poor vascular supply

Question 27

What is the contractiontion of red and white muscle fibers?

Answer 27

* red: slow but repetitive; NOT easily fatigued; weaker contraction * white: fast but easily fatigued; stronger contraction

Question 28

What is the mitochondria composition in red and white muscle fibers?

Answer 28

* red: numerous * white: few

Question 29

What is the myoglobin composition of red and white muscle fibers?

Answer 29

* red: rich * white: poor

Question 30

What is the relationship between intrafusal and extrafusal fibers?

Answer 30

when intrafusal contracts, extrafusal relaxes

Question 31

What is needed to stimulate a skeletal muscle contraction?

Answer 31

Ach

Question 32

What is myasthenia gravis?

Answer 32

autoimmune disease where antibodies are produced against Ach receptors

Question 33

Where are intercalated disks located?

Answer 33

between cardiac muscle cells

Question 34

What are the components of the intercalated disk?

Answer 34

fascia adherens, desmosomes, and gap junctions

Question 35

What type of muscle has the least amount of sarcoplasmic reticulum?

Answer 35

smooth muscle

Question 36

What regulates the smooth muscle contraction?

Answer 36

Ca/calmodulin

Question 37

What is the smooth muscle contraction system bound to?

Answer 37

the membrane and dense bodies made of alpha-actinin

Question 38

What are the 2 things unique to smooth muscle for a contraction?

Answer 38

1. myosin lightchain kinase (MLCK) 2. calmodulin

Question 39

What is the purpose of the calveola?

Answer 39

brings in Ca via pinocytosis to initiate contraction

Question 40

What are the 3 layers of smooth muscles?

Answer 40

1. muscularis mucosa 2. muscularis externa inner circular 3. muscularis externa outer longitudinal