Muscle Tissue

Question 1

Slow Twitch Muscle

Answer 1

Type 1 Oxidative, Slow ATP
Hi Mito
Hi Myoglobin
Aerobic
Take Hold and Hold, relax slowly, shows up darker
Myoglobin stores O2 in muscles
In back, hips, costal, posture muscles

Question 2

Intermediate Muscle

Answer 2

Type 2A Oxidative
Fast ATP, Hi Mito
Aerobic/Anaerobic 
ATPase burns faster
In legs and arms

Question 3

Fast Muscle

Answer 3

Type 2B Glycolytic
Fast ATP
Anaerobic
Limited range

Question 4

Motor Endplate

Answer 4

Where muscle meets neuron

Very specialized tissue found only where neuron is

Question 5

Myasthenia Gravis

Answer 5

Motor endplate receptors disappear (switch broken)

Question 6

Smooth muscle calcium source

Answer 6

Extracellular, no SR calcium

Question 7

Tonic flextion

Answer 7

Always flexed, ex holding mouth shut

Question 8

What are the three kinds of muscle tissue?

Answer 8

Skeletal
Smooth
Cardiac

Question 9

What make muscle cells different then others?

Answer 9

They are elongated and specialized for contraction and to exert force

Question 10

What are the functions of muscle tissue?

Answer 10

Movement
Digestion, waste
Breathing, speech
Blood circulation

Question 11

Explain skeletal muscle

Answer 11

Long unbrunched muscle fibers that are striated. It is voluntary controlled. Muscle fibers have multiple nuculi that are found at the edges of the cells. Muscle fibers are myofiber and they attach to the bone or skin

Question 12

Explain cardiac muscle

Answer 12

It is only found in the heart and is striated. It is involuntary control with short branded cells. They have a central nuclei within each cell and they are cardiomyocytes.

Question 13

Explain smooth muscle

Answer 13

It is found in blood vessels and hollow organs. It is unstriated with involuntary movement. They only have one nuclei per cell and the cell type is a myocyte.

Question 14

What are the functions of muscle?

Answer 14

Movement
Stability
Control of bodies opening and passages
Heat generation
Glycemic control

Question 15

What are the universal properties of muscles (skeletal)?

Answer 15

Excitability - responsiveness because of sodium potassium pumps. These send electrical charges across plasma membranes.
Conductivity - local electrical excitation initiates wave that travels along the muscle fiber, this leads to contraction
Contractility - shortens when stimulated, movement
Extensibility - capable of being straightened between contractions
Elasticity - return to its original rest length after being stretched.

Question 16

Explain the construction or gross anatomy of muscle tissue. Deep to superficial.

Answer 16

Myofilaments that is made of think myosin and thin actin. These are what makes up the muscle fibers. Muscle fibers are wrapped in the endomysium. Muscle fibers are the actual muscle cells. Muscle fibers are then bundles together to make up the muscle focicle. Focicles are wrapped in perimysium. Many bundles of muscle focicles are the muscle. Muscle tissue is wrapped in epimysium.

Question 17

Explain the importance of the muscle-nerve relationship.

Answer 17

Skeletal muscle never contracts unless stimulated by a nerve. If there is no nerve connection the muscle is paralyzed.

Question 18

What does somatic mean?

Answer 18

Somatic is in relation to the muscle. So a somatic nerve is a nerve that stimulates skeletal muscles.

Question 19

What is a motor unit?

Answer 19

Nerves and muscles that are all connected and work together. Some units are very strong and some are small that are used for fine motor skills.

Question 20

What are the steps to muscle contraction?

Answer 20

Excitation
Excitation- contraction coupling
Contraction
Relaxation

Question 21

What are the steps to muscle excitation?

Answer 21

A nerve signal goes to axon terminal
Synaptic vesicles release ACh which then defuses across the synaptic cleft and binds with receptors on the sarcolemma of the muscle fiber. This opens ion gates in the sarcolemma resulting in the sodium potassium movement through the membrane that electrically excite the muscle fibers.
Wave is made of excitation spreads down the length of the fiber and into the T tubule and into the cell.

Question 22

What are the steps of excitation - contraction coupling?

Answer 22

Electrical events in the T tubule leads to the opening o calcium gates in the sarcolemic reticulum. The SR releases a flood of calcium ions into the cytosol.
Calcium ions bind to troponin molecules in the myofilaments.
Myosin was in the waiting position (like a bent elbow) with ATP bound to it. Energy is created by the breaking apart of ATP into ADP which straightens the myosin

Question 23

What are the steps to contraction?

Answer 23

Myosin forms a link with an action binding site and released the ADP.
Myosin flexes and pulls the thin myofilament.
Contraction will continue to do these steps until the muscle is relaxed.

Question 24

What are the steps to relaxation?

Answer 24

The motor neuron that started the excitation needs to stop firing. This will stop the release of ACh which will stop the electrical excitation.
The SR reabsorbs the calcium ions and stores them which then stops the binding of the troponin to the myofilaments.

Question 25

What is found in the sliding filaments and what do they do when muscle contraction occurs?

Answer 25

The sarcomere shortens
Z disc move closer together
A band do not shorten
I band narrow 
Think filaments slide toward the M line 
H band shortens or disappears