muscular physiology
TRANSCRIPT
Choose a category. You will be given the answer.
You must give the correct question. Click to begin.
Click here for Final Jeopardy
Category B Category D Category E
10 Point
20 Points
30 Points
40 Points
50 Points
10 Point 10 Point 10 Point 10 Point
20 Points 20 Points 20 Points 20 Points
30 Points
40 Points
50 Points
30 Points 30 Points 30 Points
40 Points 40 Points 40 Points
50 Points 50 Points 50 Points
Category CCategory A
Explain how skeletal muscles provide
movement, heat, and posture. Are all of these
functions unique to muscles? Explain your
answer
The nervous system senses changes in body position and degrees of movement-
permitting integration of feedback loops that ultimately regulate the muscular contractions hat maintain posture and
produce movement. They are because the cardiovascular system maintains blood flow
in the muscles and the urinary and respiratory systems get rid of the body
waste produced in the muscles
(2)
The characteristics of excitability is shared by
what other system? Relate contractility and
Extensibility to the concept of agonist and antagonist discussed in chapter 10.
Digestive System, Lymphatic System, Muscular System and the Nervous System
are some examples of characteristic of excitability within the systems. Antagonist
and contractility are both about contracting or shorting a muscle to create movement while agonist and extensibility are similar but different agonist is like the perform a
specific movement and extensibility is being able to stretch out a muscle and being able
to be back in its normal stage. (2)
What structures are unique to skeletal muscle
fibers? Which of the structures involved
primarily in contractility and which are in involved
in excitability?
made of myofilaments, which are organized into sarcomeres, the functional unit of
contraction. myosin and the thin filaments are made up the three proteins, troponin,
tropomyosin and actin. It is the cyclic binding between myosin heads of the thick
filament and actin of the thin filaments, crossbridge formation, that allows of force
production or muscle shortening. (2)
Explain how the structure of the myofilaments is related to their
function.
Myofilament is the chains of primarily actin and myosin that pack a muscle fiber. These
are the force generating structures.
(2)
Explain how the sliding filament
theory allows for the shortening of a muscle fiber.
During contraction, myosin cross bridges pull the thin filaments toward the center of each sarcomere, thus shortening the myofibril and the entire muscle fiber.
Definition of sliding filament theory- model of muscle contraction in which sliding of thin filaments toward the
center of each sarcomere quickly shortens the muscle fiber and thereby the entire muscles
(2)
Compare and contrast the role of Ca++ in
excitation, contraction, and relaxation of a
muscle cell.
Muscle contraction begins with an electrical "go" signal from your brain. The signal stimulates the SR to open its calcium gates, flooding the myofilaments with calcium.
The sudden increase in calcium concentration sets off an energy-consuming chain reaction that causes the myofilaments to change shape and shorten. The
simultaneous shortening of thousands of microscopic myofilaments leads to muscle contraction. When the "go"
signal stops, the SR calcium gates close and calcium pumps quickly return the mineral from the myofilaments
to the interior of the SR. As the calcium concentration around the myofilaments falls, your muscle returns to a
relaxed state. (2)
People who exercise seiously are sometimes told to work a muscle until they "feel the burn". In terms of how
muscle is able to release energy, explain what is going on in the muscle early in
the exercise and when the muscle is "burning."
The burning feeling is the something we call micro tear. Micro tear is when you feel the
burn the micro fibers are tearing to get larger or smaller so they can contract the
muscle to shape the muscle. (2)
Describe the anatomical
arrangement of a motor unit. Contrast fine and gross motor
units.
Motor unit: The axon of an anterior horn cell, or the motor fiber of a cranial nerve, together with the striated muscle fibers innervated by its terminal branches.
Contrast: motor unit consist of one somatic motor neuron and the muscle fibers
supplied by its branches. (2)
Using fiber types, design a muscle for a marathon runner. and a different muscle for a 100-yard-dash Sprinter. Explain
our choice.
How can one person beat everyone in a marathon, but be left in the dust in a sprint? Strength, power and endurance may be due, in
part, to the distribution of the two different types of muscle fiber in a person’s muscles. Muscles are a mixture of two basic types of
fibers – fast twitch and slow twitch.
Fast twitch fibers can:
•develop greater forces
•contract faster
•contract without needing oxygen (anaerobic)
Slow twitch fibers:
•develop force slowly
•maintain contractions longer
•have greater aerobic capacity (with oxygen) (4)
Using fiber types, design a muscle for a marathon runner. and a different
muscle for a 100-yard-dash Sprinter. Explain our
choice.
4B CONTINUED…..
Different types of exercise use mostly different types of muscle fibers. Aerobic exercise (for example, running a
marathon) involves low levels of exertion over a long period of time. All the muscles are being used at well
below their maximal contraction strength, but for long periods of time.
On the other hand, anaerobic exercise (like weightlifting or sprinting) involves short bursts of higher intensity
contractions at a much greater percentage of their maximum contraction strength. (4)
Explain the meaning of a "unit of combined cells" as it relates to cardiac Muscle.
How does the structure arrangement affect its
function?
A unit of combined cells is a big group of incomplete cells that branch into each other to form a big continuous mass
of cytoplasm ( a syncytium). That all relates to Cardiac muscle and the structure arrangement affecting its
function, due to it special features of intercalated discs and branching which creates a continuous sarcolemma
(2)
Describe Rigor Mortis.
Rigor Mortis is literally the “stiffness of death”; the permanent contraction of muscle tissue after death caused by the depletion of
ATP during the actin-myosin reaction, preventing myosin releasing actin to allow
relaxation of the muscle.
(2)
Describe in detail the 4 factors that influence the strength of muscle
contractions
Motor Unit Activation
-A motor unit consists of an alpha-motor neuron and the muscle fibers it innervates.
Stimulation Frequency
-A single stimulus of the muscle fiber from the nervous system will produce a small amount of muscle force
Muscle Fiber Length
-our muscles have thin and thick filaments, which are organized into contractile units called sarcomeres. Within each sarcomere, thick filament proteins slide and bind to proteins in the thin filament during muscle contraction.
Contraction Speed
-Muscle contraction speed determines the force-producing capacity of your muscle. (3)
What are the phases of a twitch contraction?
What molecular events occur during each of
these phases.
Phase 1: latent period
- The impulse initiated by the stimulation triggers the release of calcium ions into the sarcoplasm
Phase 2: contraction phase
- Calcium binds to troponin and the sliding of the myofilaments begins
Phase 3: relaxation phase
-all of the myosin- actin reactions in all the fibers have ceased
(2)
How does the treppe effect relate to the
warm-up exercises of athletes?
The treppe phenomenon is defined as the gradual increase in strength of contraction that can be observed in a series of twitch contractions that occur about one second apart. This is why athletes must warm up, because a muscle can contract more forcefully after having been contracted a
few times.
(2)