20 Questions
What characterizes the latch bridge mechanism in smooth muscle contraction?
Leaves myosin head bound to actin without Pi
In the smooth muscle contraction cycle, what causes muscle relaxation?
Removal of calcium and phosphate by phosphatase
What is the function of the latch bridge cycle in smooth muscle contraction?
Reduces energy consumption by maintaining tension
How does the latch bridge mechanism contribute to tonic contraction in smooth muscle?
Maintains myosin head binding to actin without phosphate
What is the primary role of phosphatase in the smooth muscle contraction cycle?
Remove phosphate from myosin
What is the term for the swelling of a neuron where neurotransmitter is stored?
Varicosity
Which neurotransmitters are released by autonomic nerves?
Norepinephrine and acetylcholine
In smooth muscles, which type of system is associated with norepinephrine?
Sympathetic
Which type of smooth muscle can contract in response to stretch?
Multi-unit smooth muscle
What is the purpose of having gap junctions in single-unit smooth muscles?
To enable coordinated contraction as a unit
What is the role of dense bodies in smooth muscles?
Anchor actin and connect to the extracellular matrix
How are neurons connected to smooth muscles?
Not directly connected
What is a key characteristic of autonomic neurons at the junction of smooth muscles?
Connection to smooth muscles without neuromuscular junctions
Where are smooth muscles mainly located in vessels?
Tunica media
How do contractions of smooth muscles compare to skeletal muscles?
Skeletal muscles contract more slowly but sustain tension better than smooth muscles
What are the two types of cholinergic receptors?
Muscarinic and adrenergic
Where are alpha 2 receptors primarily found?
Presynaptic side
What is the primary action of alpha 1 receptors?
Vasoconstriction
Which neurotransmitters do beta 2 receptors respond to mainly?
Epinephrine and norepinephrine
What is the mechanism of action for removing acetylcholine from a synaptic cleft?
Degraded by acetylcholinesterase
Test your knowledge about varicosities, neurotransmitters released by autonomic nerves, the association of norepinephrine and acetylcholine with specific systems, smooth muscle properties, and the arrangement of smooth muscle in viscera.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
