Interview part 6 Flashcards
(21 cards)
What is the function of the skeletal muscle?
those which attach to bones and have the main function of contracting to facilitate movement of our skeletons
Contractions can vary to produce powerful, fast movements or small precision actions. Skeletal muscles also have the ability to stretch or contract and still return to their original shape.
Describe the function of the smooth muscle
Smooth muscle is also sometimes known as involuntary muscle due to our inability to control its movements, or unstriated as it does not have the stripy appearance of Skeletal muscle. Smooth muscle is found in the walls of hollow organs such as the Stomach, Oesophagus, Bronchi and in the walls of blood vessels. This muscle type is stimulated by involuntary neurogenic impulses and has slow, rhythmical contractions used in controlling internal organs, for example, moving food along the Oesophagus or contricting blood vessels during Vasoconstriction.
What is the function of the cardiac muscle?
This type of muscle is found solely in the walls of the heart (the contraction of the heart). It has similarities with skeletal muscles in that it is striated and with smooth muscles in that its contractions are not under conscious control.
Under which control is the cardiac muscle?
Autonomic nervous system
What happens at the motor end plate after the action potential is conveyed to a motor end plate on each muscle fiber?
the action potential causes the release of packets or quanta of acetylcholine into the synaptic clefts on the surface of the muscle fiber.
What happens after the release of Ca++ by the sacroplastic reticulum?
The calcium ions result in movement of troponin and tropomyosin on their thin filaments, and this enables the myosin molecule heads to “grab and swivel” their way along the thin filament. This is the driving force of muscle contraction.
Sacrolemma
Plasma membrane of a muscle fiber that forms T tubules
Sacroplasm
Cytoplasm of a muscle fiber that contains organelles, including mitochondria
What is the function of glycogen in muscle contraction?
A polysaccharide present in sarcoplasm that stores energy for muscle contraction
Myoglobin
A red pigment present in sarcoplasm that stores oxygen for muscle contraction
T tuble
Extension of the sarcolemma that extends into the muscle fiber and conveys impulses that causes Calcium to be released from the sarcoplasmic reticulum
Sacroplasmic reticulum
The smooth endoplasmic reticulum (ER) of a muscle fiber that stores calcium
Myofibril
A bundle of myofilaments that contract
Myofilament
Actin and myosin filaments whose structure and functions account muscle striations and contractions
What has to be available for muscle contraction to occure?
ATP
Where can you find ATP for muscle contraction?
Within the muscle fiber In the stored glucose In glucose and fatty acids Creatine phosphate During cellular respiration: glycolisis -> anaerobic cell respiration
What is the advantage of anaerobic cell respiration in muscle contraction?
Anaerobic respiration is relatively rapid, and it does not require oxygen.
What are the disadvantages of anaerobic cell respiration?
Anaerobic respiration generates only two ATPs and produces lactic acid. Most lactic acid diffuses out of the cell and into the bloodstream and is subsequently absorbed by the liver. Some of the lactic acid remains in the muscle fibers, where it contributes to muscle fatigue. During strenuous exercise, a lot of ATP needs to be produced. Since a person is exercising faster than they are bringing in oxygen, the body tries to make ATP using the anaerobic pathway. This results in the production of ATP and lots of lactic acid. After exercise, the liver and muscles need to convert the lactic acid back to pyruvic acid. In order to do that, a lot of the oxygen the body is now taking in does the conversion instead of being used elsewhere. This is known as “repaying the debt,” hence the term “oxygen debt.”
How many ATP molecules are produced in aerobic cell repiration?
36 ATP molecules (including the two from glycolysis)
What are the advantages of aerobic cell respiration?
Aerobic respiration generates a large amount of ATP
What are the disadvantages of aerobic cell respiration?
Aerobic respiration is relatively slow and requires oxygen.
