Lecture 10- Muscle

Question 1

Skeletal muscle

Answer 1

connected to bones, voluntary control, striated, and multi-nucleated with nuclei often found in the periphery of the cells

Question 2

Cardiac muscle

Answer 2

involuntary control, striated, centrally located mono-nucleated, branching, lots of mitochondria

Question 3

Smooth muscle

Answer 3

in hollow organs, involuntary control, spindle shaped, non-striated, and mono-nucleated

Question 4

Muscle tissues develops from what?

Answer 4

myoblasts. It is the fusion of mononucleated embryonic myoblasts

Question 5

Purpose of satellite cells in skeletal muscle

Answer 5

help with regeneration.

Question 6

Skeletal growth plasticity

Answer 6

atrophy and hypertrophy

Question 7

Plasticity

Answer 7

ability to change in size but not number

Question 8

Sacromere

Answer 8

the basic unit of a striated muscle tissue. Between two Z lines

Question 9

When calcium is present in a muscle

Answer 9

Myosin is able to bind to actin when the binding sites on actin are exposed because of calcium binding

Question 10

Z line

Answer 10

Where actin molecules (think filaments) are anchored. Found in the I band.

Question 11

I band

Answer 11

zone of thin filaments only (actin)

Question 12

A band

Answer 12

contains the entire length of a single thick filament

Question 13

H zone

Answer 13

Within the A band. Only thick filaments (myosin)

Question 14

M line

Answer 14

within the H one. Where the myosin is anchored.

Question 15

3 CT layers of skeletal muscle

Answer 15

Epimysium, perimysium, and endomysium

Question 16

Dystrophin

Answer 16

establishes contact with actin, transmembrane glycoproteins, and lamins of the extracellular matrix.

Question 17

Titins

Answer 17

act as springs to help reshape after muscles are stretched.

Question 18

T tubules

Answer 18

invaginations of the sarcolemma.

Question 19

Triad

Answer 19

at the I-A junction. When cisterane (SR) sandwiches the T tubules.

Question 20

Importance of triad

Answer 20

nerve induced muscle impulse causes calcium from SR into the sarcoplasm causing contraction of the myofilaments.

Question 21

Number of actin to myosin in the A band

Answer 21

6 actin per myosin.

Question 22

Tropomyosin

Answer 22

filamentous type of protein

Question 23

Troponin’s 3 subunits

Answer 23

TnT: binds tropomyosin
TnC: binds calcium and causes a conformational change
TnI: inhibits the binding of all the proteins around

Question 24

ATP’s role in muscle contraction

Answer 24

ATP binds to troponin but only is productive when calcium is present. ATPase hydrolyzes allowing for the binding of myosin and actin.

Question 25

T or F: a neuron may innervate more than one fiber

Answer 25

True

Question 26

Neurotransmitter found in neuromusclar junction and enzyme to break down

Answer 26

acetylcholine and cholinesterase

Question 27

What causes relaxation of muscle?

Answer 27

ATP attached to the myosin head.

Question 28

White muscle fibers

Answer 28

Type II, fast muscle fibers (ATP pool, phosphocreatine, glycogen). Little myoglobin, glycolytic respiration, abundant glycogen

Question 29

Red muscle fibers

Answer 29

Type I, slow muscle fibers.(oxidative phosphorylation). Lots of myoglobin, mitochondria, small diameter

Question 30

Propioceptors

Answer 30

relaying info to the brain to keep it informed.

Question 31

Muscle spindle

Answer 31

relaying info to the CNS about the condition of the muscle via pseudounipolar neurons. contain intrafusal fivers. (example of golgi tendon organ)

Question 32

Intrafusal vs extrafusal fibers

Answer 32

Intrafusal: sensory feedback (nuclear chain and bag fibers) Extrafusal: majority, provides force (Type I&II, intermediate fibers)

Question 33

Can cardiac muscle regrow?

Answer 33

No.

Question 34

Layer of the heart that cardiac muscle is seen in?

Answer 34

Myocardium

Question 35

Intercalated disks

Answer 35

disks seen between cardiac muscle cells

Question 36

Natriuretic peptides

Answer 36

ANP and BNP. decreases blood pressure

Question 37

3 ways BP is decreased from natriuretic peptides

Answer 37

promote kidney diuresis and natriuresis; cause vasodilation; inhibit central sympathetic outflow

Question 38

Dense bodies in smooth muscle

Answer 38

distributed along the sarcolemma and are the actin and intermediate filament anchoring sites

Question 39

Caveolae

Answer 39

tiny caves on smooth muscle cell surface that may be involved in sequestering calcium

Question 40

Multi-unit smooth muscle

Answer 40

richly innervated for rapid, precise, graded contractions

Question 41

Visceral smooth muscle

Answer 41

poorly innervated with slow contractions; excitations are transmitted from cell to cell by numerous gap junctions

Question 42

Varicosities in muscles

Answer 42

accumulate neurotransmitters and will release the signal

Question 43

Dense bodies that are phosphorylated

Answer 43

in the active state

Question 44

Diad in cardiac muscle

Answer 44

Found at the Z line of cardiac muscle. No triads are present in cardiac muscles.