Lecture 12 Flashcards
Which muscle type is striated and voluntary?
Skeletal mm
Skeletal mm fibers develop enbryologically from what?
myoblasts: mononucleated cells that fuse into long fibers which become peripheral and multinucleated.
Which muscle type is visceral or involuntary?
Smooth mm.
Which muscle type is smooth and not striated?
smooth mm… duh!
What muscle types are multinucleated ?
smooth mm.
What muscle types are mononucleated AND striated?
cardiac mm.
Branchiomeric mm is associated with ….
pharyngeal arches
describe branchiomeric mm
associated with pharyngeal arches
somewhat of a transition between smooth and striated
innervated by cranial nerves
what innervates the branchiomeric muscles?
cranial nerves
Voluntary muscle:
- muscle whose action is normally controlled by an individual’s will;
- mainly skeletal muscle, composed of parallel bundles of striated, multinucleate fibers.
Involunary muscle:
• a muscle that contracts without conscious control and found in walls of internal organs such as stomach and intestine and bladder and blood vessels (excluding the heart)
Origin (proximal attachment:)
usually proximal, may be fixed with regard to movement
Insertion (distal attachment)
usually distal, Usually more moveable
Tendons:
attachments between muscle fibers and bone
what are tendons made from?
dense collagenous connective tissue
Tendons are surrounded by…
peritendineum
Tendons are poorly/richly vascularized.
POORLY! Think about how long it takes to heal a sprained ankle!
Aponeuroses:
flat, fan shaped tendons, typically giving rise to other tendons
- Describe the gross hierarchical organization of a skeletal muscle, including the connective tissue partitions that subdivide the muscle.
Myofilament, myofibril, myofiber, Fascicle, Muscle
What are the two types of myofilament:
myosin and actin
which are the thick filaments
myosin
which are the thin filaments:
actin
Myofilaments are organized into
sarcomeres
What is a myofibril?
chain of sarcomeres