Lab Final PPT. Quizzes Flashcards
Which type of muscle tissue is highly branched, possess intercalated discs and is comprised of cells having a single nucleus?
smooth
Which cellular component/feature do skeletal, cardiac, and smooth muscle share?
large number of mitochondria
Which type of muscle tissue is comprised of multinucleated, striated cells that are under voluntary control?
skeletal
Why do skeletal muscle cells contain high numbers of mitochondria?
to supply the ATP needed for skeletal muscle function
Which type of muscle tissue is comprised of cells that lack striations?
smooth
What transport process is used when acetylcholine (ACh) is released into the synaptic cleft?
exocytosis
Acetylcholine is a(n) __________, which is a type of chemical released by neurons that changes the plasma membrane permeability or other properties of another cell.
neurotransmitter
What are two ways that ACh is removed from the synaptic cleft?
diffusion and break down by acetylcholinesterase
During contraction, the entire skeletal muscle shortens and produces a pull on the tendons on either end of the muscle. This is called
tension
When an action potential travels along the sarcolemma, it triggers the release of calcium ions by the sarcoplasmic reticulum (SR). What part of the SR releases calcium?
terminal cisternae
Interactions between thin and thick myofilaments of the sarcomere are responsible for ________.
muscle contraction
_______ covers the active sites of actin prior to calcium binding to troponin.
tropomyosin
“Cocking” the myosin head requires energy. What molecule acts as an ATPase to break down ATP for the energy needed to cock the myosin head?
myosin
An action potential in the axon terminal of a motor neuron opens what type of ion channels?
voltage-gated calcium channels
Binding of neurotransmitter to the receptors on the motor end plate opens what type of ion channels?
chemically-gated channels
Once an action potential is propagated down the t-tubules, the terminal cisternae release ___________.
calcium ions
During events in the cross bridge cycle, which molecule has a binding site for calcium ions?
troponin
During events in the cross bridge cycle, which molecule covers the actin binding site?
tropomyosin
During events in the cross bridge cycle, which molecule has a binding site for myosin heads?
actin
What molecule must bind to the myosin head in order for it to disconnect with actin?
ATP
Hydrolysis of ATP returns the myosin molecule to the _________________________ conformation
high energy
Latin words have been used to assign descriptive names to skeletal muscles. When naming muscles, magnus means __________.
large