Quiz 1 Flashcards
What is the term used to refer to the cytoplasm of a muscle fiber?
sarcoplasm
Are the amounts of sarcoplasm in each muscle fiber the same?
no, they will vary from fiber to fiber
What is the difference between dark and light muscle fibers?
the amount of sarcoplasm within the majority of the fibers
Are type I fibers dark?
yes
Are type II fibers dark?
no
Are type I fibers light?
no
Are type II fibers light?
yes
What type of muscle fibers are found in muscles where long, sustained or continuous contraction are required (i.e. posture maintenance, ocular, respiratory, and masticatory muscles)?
Type I
What type of muscle fibers are associated with endurance activities?
Type I
What type of muscle fibers are associated with relatively higher levels of continuous metabolic activity (aerobic metabolism)?
Type I
What type of muscle fibers are used for quick, more powerful activities and thus related to speed and strength (i.e. sprinting, weight lifting, etc.)?
Type II
What type of muscle fibers are associated with anaerobic metabolism?
Type II
What type of muscle fibers have large amounts of sarcoplasm and myoglobin?
Type I
What type of muscle fibers have lesser amounts of sarcoplasm and myoglobin?
Type II
What type of muscle fibers have extensive capillary beds?
Type I
What type of muscle fibers have fewer capillary beds?
Type II
What type of muscle fibers are slow twitch?
Type I
What type of muscle fibers are fast twitch?
Type II
Which type of muscle fibers are fatigue resistant?
Type I
Which type of muscle fibers fatigue easily?
Type II
What type of muscle fibers have numerous mitochondria?
Type I
What type of muscle fibers have more fatty acids and less glycogen?
Type I
What type of muscle fibers have more glycogen and less fatty acids?
Type II
What type of muscle fibers atrophy with immobilization?
Type I
What type of muscle fibers atrophy with age?
Type II
What type of muscle fibers exhibit characteristics which are somewhere between type I and type II fibers?
Intermediate
Intermediate fibers contract faster than type __ but slower than type __.
I;II
What type of muscle fibers do intermediate fibers histologically resemble?
Type II
What is the muscle fiber’s cell membrane?
Sarcolemma
What is an elaborate, tubular network which functions to store and transport calcium ions to the myofibrils?
sarcoplasmic reticulum
What is a tubular invagination of the sarcolemma that allows electrical (nerve) impulses to enter the muscle fiber and make their way to the myofibrils?
Transverse Tubules
What do the transverse tubules (T-System) allow for the release of?
calcium in the sarcoplasmic reticulum
What is a red protein pigment found in the sarcoplasm of a muscle fiber?
Myoglobin
What protein gives color to muscle?
Myoglobin
What protein stores oxygen for metabolism in muscle fibers?
Myoglobin
What is the contractile apparatus of the muscle fibers?
Myofibril
Does snake venom cause an action potential?
No
What do snake venom’s neurotoxins prevent?
prevent ACH from binding to ACH receptor sites
What are the two type of toxins that snake venom contain?
cytotoxins and neurotoxins
What is the difference between nicotine and ACH’s action potentials?
nicotine’s are much more prolonged (because it is not broken down by ACHe)
What is an example of a drug that is able to compete with ACH molecules in binding to the ACH receptor sites?
nicotine
What is the condition where a pregnant women suffering from Myasthenia Gravis has about a 25% chance of having her infant born with the condition?
transitional neonatal myasthenia gravis
What is a common condition associated with Myasthenia Gravis?
Hyperplasia of the thymus gland
What are the first muscles affected by Myasthenia Gravis?
muscles supplied by the cranial nerves (muscles of the eyes and face) and in many cases will progress to muscles of the extremities
With an autoimmune disorder like Myasthenia Gravis, the body’s immune system produces abnormal __________, which damage and destroy the ___ ________ sites on the __________ of the muscle fibers.
antibodies; ACH receptor; sarcolemma
What is the most common neuromuscular junction disorder?
myasthenia gravis
What does ACHe break down ACH into?
acetate and choline
What is the enzyme that breaks down ACH?
acetycholinesterase (ACHe)