Intro to Muscular System Flashcards
(43 cards)
Where is smooth muscle found?
Walls of hollow organs
Muscle cells are also called ____
Myocytes
Contractions of smooth muscle are ___ movements triggered by ___
involuntary movements triggered by impulses from autonomic nervous system
What cells make up cardiac muscle?
Cardiomyocytes
What property of cardiac muscle facilitates coordinated contraction?
Branched cells allow for connections to form a network
Groups of Skeletal muscle fibers are organized into:
Fascicles
Skeletal muscle is innervated by:
motor neurons
Endomysium
CT surrounding muscle fiber
Perimysium
CT surrounding a fascicle
Epimysium
thin CT that wraps around whole muscle
Skeletal muscle origin
Attachment site where bone remains immobile during action
Skeletal muscle insertion
Attachment site where the bone moves during an action
Antagonist pairs consist of…
an agonist muscle and an antagonist muscle
Agonist
muscle that is performing an action
Antagonist
muscle that performs opposite action to agonist relaxing
Circular muscles
Circular in shape
ex. mouth, eye, sphincters of bowels and bladder
Convergent muscle structure and function
Origin is wider than insertion; triangular
Fiber arrangement allows for maximum force production
ex. pectoralis
Parallel muscles structure and function
Parallel fibers
Long muscles, large movements
Lower strength, higher endurance
ex. sartorius
Fusiform muscles structure
Muscle belly is wider than origin and insertion
ex. biceps brachii
Pennate muscles structure and function
Large number of muscle fibers insert on a tendon (instead of bone), high strength
Unipennate muscles structure
Fibers arranged to insert in diagonal direction onto the tendon
ex. lumbricals, extensor digitorum longus
Bipennate muscles structure and function
Two rows of muscle fibers, facing in opposite diagonal directions
Central tendon, like a feather
Greater power, less range of motion
ex. rectus femoris (of quads)
Multipennate muscles structure
Multiple rows of diagonal fibers
Central tendon that branches
ex. deltoid
Hypaxial back muscles are innervated by:
Ventral rami