Muscular & Skeletal System

Question 1

what is the characteristic of skeletal muscles?

Answer 1

• you can control it –> voluntary - its purpose is to body movement –> attached to bones - motor units – consists of groups of muscle cells –> multinucleate - microscopic appearance –> striated (because of the actin and myosin/ Sarcomere

Question 2

What are the layers of a muscle?

Answer 2

a whole muscle (bundle of fascicle) Fascicle (bundle of muscle cells) Muscle cell (bundle of Microfibril) - Myofiber Mycofibril (surrounded by cell plasma, wrapped by sarcoplasmic reticulum) Sarcomere Actin & Myosin

Question 3

what wraps around the microfibril – What is it for? what is a microfibril?

Answer 3

• storage of Ca which is vital for contraction

Question 4

what does the “T” in the T-tubule stand for?

Answer 4

transverse tubule - connected to the cell membrane that allows the propagation of action potential

Question 5

Where does the striation of muscle come from?

Dark and light bands? What are the structural differences that cause the difference in lighting absorption?

Question 6

What are the four steps in the sliding filament theory? in which step does the “sliding” occur? Does that step require power/energy/ATP? Which steps require ATP?

Question 7

in which step of the sliding filament theory is myosin at its highest energy state? what is its high energy conformation? how does it obtain this high energy state?

Question 8

Why do we need Ca for muscle contraction?

Question 9

When does “cross-bridge formation” happen?

Question 10

What does the binding of ATP do to the “cross bridge formation” ?

Question 11

Can muscles contract in the absence of ATP? can a power stroke occur in the absence of ATP? aren’t these the same questions? why not?

Question 12

does “cross-bridge formation” occur uniformly across the microfibril?

If your team is trying to pull a stone uphill, what happens when y’all let go (detach from the actin) simultaneously?

Thus, myosin head groups must operate … ?

Answer 12

asynchronously

Question 13

What are the other two proteins involved with actin?

Answer 13

Troponin and tropomyosin

• Actin is series of small units binding together into a helix. Tropomyosin is a two-stranded alpha-helical coiled-coil protein that surrounds the actin. Troponin is a small molecule binding tropomyosin.
• When Ca binds to troponin, tropomyosin changes its conformation revealing the myosin binding site.

Question 14

Calcium binds to what on the actin?

Answer 14

troponin

Question 15

where are the myosin binding sites?

Answer 15

tropomyosin changes its conformation revealing the binding site on actin.

Question 16

what happens when Ca is not being removed from the muscle cells?

Answer 16

The muscle won’t be able to relax and cannot contract.

Question 17

What are two possible ways that prevent the muscle from relaxing thus leading to the inability to contract?

Question 18

What does a motor unit consist of?

Answer 18

a neuron connected to muscle cells

Question 19

what does the size of a motor unit depend on?

does fine movement require small or large motor units? and how many? (a lot or a few)

What is the relationship between the number of motor units and the size of units?

Answer 19

the number of muscle cells connected to the neuron.

fine movement requires a large number of small motor units. this is because fine movement requires precision and not force.

larger motor units will be activated when the body requires more strength. often time when the size of units goes up, the number of motor units go down. Make sense if you think out it… you want a large group of muscles to behave in the same manner (lifting something)

Question 20

what does the amount of force generated depend on?

Answer 20

number of motor units activated

Question 21

What are the energy sources that muscle cells can use? There are three to be exact. one is faster than the other. Each source is used depending on the type of activity

Answer 21

• The fastest form of energy is actually drawn from creatine-P. Creatine-P donates its P converting ADP into ATP. But this is only short term energy and not sustainable.
• The other source is anaerobic preparation – Glycolysis (2 ATP)
• Aerobic respiration (oxidative phosphorylation) yield 30 ATP, CO2 and more.

Question 22

so you know that hemoglobin is the protein that carries oxygen in the blood, correct?

What is the protein that carries oxygen for muscle cells? what is the prefix that is used very often in naming things related to muscle?

Question 23

why is lactic acid produced and accumulated in muscle during exercise?

Answer 23

when you exercise for a prolonged period of time, you deplete stored oxygen. Without oxygen creb cycle and oxidative phosphorylation cannot run because they run out of electron carried NAD and FAD.

Glycolysis needs NAD to run. NADH is reduced converting pyruvate into lactic acid in the fermentation pathway. In other words, fermentation pathways results in the reduction of NADH into NAD allowing for the continuation of glycolysis.

Question 24

What happens to our oxygen level after exercise?

Answer 24

we depleted the oxygen stored in myoglobin. We need to increase myoglobin level of saturation and to oxidize lactin acid. we can have excess lactin acid sitting around in the body.

Question 25

how do we pay for the oxygen debt? hint: affinity level of hemoglobin

Answer 25

bohr condition decrease the oxygen affinity of myoglobin thus dropping more oxygen into the tissue for myoglobin to absorb

Question 26

what are bohr conditions?

Question 27

what is the difference between dark and white meat? red and white chicken meat?

Question 28

What is the difference between cardiac muscle and smooth muscle in its function (voluntary vs involuntary), location (Where in the body), nuclei (Uni vs multi) & microscopic appearance (uni vs multinucleated) ?

Question 29

How is connective tissue different from other tissue types?

Answer 29

Other tissue types have a lot of cells. Connective tissue has a lot of extracellular material and only a few cells

Question 30

What are different types of cells in the connective tissue? What are the endings that signify the maturity of connective tissue cells?

Answer 30

--- blast: immature cell still divide and produce matrix --- cyte: mature cells (stop dividing) and maintain the matrix.

Question 31

what is the difference between -cyte and -blast in connective tissue?

Question 32

what are different fibers in the matrix? Structure gives rise to function. if you know the function, we can deduce the structure. What are some of the properties of the matrix? What are examples of some connective tissues? cartilage and fat. these tissues are .... can they hold tention? can they be stretched? What are components within the matrix that allows for these properties?

Answer 32

- Elasticity from Elastic and strength from collagen.

Question 33

what are the two main components that made up the matrix? You need something to provide function and structure. You need something to hold everything together.

Answer 33

- fibers to provide functions and structure. - The glop (ground substance) to hold everything together. This ground substance can range from liquid to solid.

Question 34

what kind of tissue is bond?

Question 35

What are the functions of the bone/ skeletal system? Think .... What happens when you break your bone or have an accident that causes misalignment? you can't move .. hurts your body. Where do blood cell formation and maturation occur? what protects the brain, the spinal cord, the heart, and the lungs? What happen when you don't have enough Ca in your diet?

Answer 35

- support and movement. - protection - blood cell formation - mineral storage

Question 36

what do you call the shalf and the ends of a long bone? what is a long bone anyway? Does long bone mean they are long? What is the name of the bone defined by?

Question 37

What are two types of bone tissues? What type of bone tissue makes up the diaphysis, the epiphysis, and the inter-core of the epiphysis?

Question 38

what are the two functions of the respiratory system?

Question 39

What is the difference between ventilation and respiration?

Answer 39

Ventilation = moving air into/out of the system Respiration = gas exchange

Question 40

why do you need to breath?

Question 41

what is two systems that controls the pH level of your blood? which one is faster and which one is slower?

Question 42

What the are the main places that respiration (gas exchange) occur?

Answer 42

lung and the bloodstream bloodstream and cells

Question 43

What are conduction zones and where are they?

Answer 43

Conduction zones are where ventilation occurs.

Question 44

What are the conduction zones and what happen there?

Answer 44

nose, pharynx, larynx, trachea, (lung) bronchi, bronchioles, and terminal bronchioles. Air is filtered, humidified, and transported.

Question 45

what is the anatomy of the trachea and how does that affect its function?

Answer 45

the trachea is made up of mostly cartilage rings with connective tissue in between. The cartilage is rigid allowing for the trachea to hold its shape. The connective tissue allows for contraction, narrowing down of the airway resulting in an increase in air flow.

Question 46

What are the structures that air needs to travels through between reaching the brochioles?

Answer 46

nose, pharynx, larynx, trachea, primary bronchi (2), secondary bronchi, tertiary bronchi, and the bronchioles.