Myology Flashcards
composed of contractile units of varied morphologic characteristics, activated by voluntary or involuntary nerve impulses or by humoral substances.
Muscular System
provide forces for many functions, including locomotion or posture, respiration, alimentation, and circulation.
Muscles
What is the latin word for muscle
little mouse
Other term for muscle fiber/muscle cell?
Myofiber, Myocyte
- functional cellular unit
- with organelles and inclusions
Myofiber/Myocyte
Cell membrane = ____________
Sarcolemma
Cytoplasm = _______________
sarcoplasm
Muscle is the primary tissue in the?
- Heart (Cardiac MT)
- Walls of hollow organs (Smooth MT)
- Skeletal Muscle
Functions of the muscle tissue
- Movement
- Maintenance of posture
- Joint Stabilization
- Heat Generation
- Contractility
- Excitability
- Extensibility & Elasticity
Electrical nerve impulse stimulates the muscle cell to contract
Excitability
Can be stretched back to its original
length by contraction of an opposing muscle
Extensibility & Elasticity
Long cells shorten and generate pulling force
Contractility
•Muscle contractions produce heat
•Helps maintain normal body temperature
Heat Generation
enables the body to remain sitting or standing
Maintenance of Posture
–Moves body by moving the bone
Skeletal Muscle
– squeezes fluids and other substances through hollow organs
Smooth Muscle
- efficient pumping blood
Cardiac Muscle
What are the types of muscle tissue
- Smooth / Unstriated Involuntary MT
- Skeletal / Striated Voluntary MT
- Cardiac / Striated Involuntary MT
•Visceral muscle
•Smooth myofibers with a single central nucleus
•Walls of hollow organs: blood vessels, eyeball, dermis,
Smooth Muscles
•Packaged into skeletal muscles
•Makes up 40% of body weight
•Cells are striated
Skeletal Muscle
Basic Features of a Skeletal mm.
• Connective tissue and fascicles
– Connective tissue sheaths bind a skeletal muscle and its fibers together
Types of Skeletal Muscles
- Epimysium
- Perimysium
- Endomysium
a fine sheath of connective tissue wrapping each muscle cell.
Endomysium
surrounds each fascicle (group of muscle fibers)
Perimysium
dense regular connective tissue surrounding entire muscle
Epimysium
In *Sliding Filament Theory**, myosin head attach to _________ in the ____________.
actin, thin filaments
Basic unit of contraction in a skeletal mm.
Sarcomere
the point where nerve ending and muscle fiber meet
Neuromuscular junction
Motor neurons innervate _______________
skeletal muscle tissue
Occurs in the walls of the heart
Cardiac Muscle
2 types of cardiac muscle
- Ordinary Cardiac Muscle Tissue
- Special Cardiac Muscle Tissue
Example of special cardiac MT?
Purkinje fibers
impulse- conducting cells which conduct impulses from the AV node through the interventricular septum of the ventricles
Purkinje fibers
- highly vascular
- fibers are branched
- presents intercalated disk
Ordinary Cardiac MT
Ordinary Cardiac MT presents _________ disk.
Intercalated disk
> serve to coordinate the contraction of the atria and ventricles.
> larger than the ordinary cardiac cells, with lighter sarcoplasm containing fewer myofibrils located at the periphery of the cell
Cardiac Muscle
What are the muscle attachments?
- Origin
- Insertion
- Belly
- Tendinous Attachment
- Aponeurotic Attachment
- Intrinsic Muscle
- Extrinsic Muscle
• Prime movers or agonists
• Antagonist
the more movable, in the limbs, it is the more distal attachment
Insertion
the less movable; in the limbs, it is the more proximal attachment
origin
thick fleshy central part of the muscle tissue
belly
the dense connective tissue connecting the
spindle shape or pennate muscle to bone
Tendinous attachment
lie completely within one region of the body where they have their origin and insertion. They act on the bones in that part only
Intrinsic muscle
the flat, tendinous sheet associated with flat muscles such as those of the abdominal wall
Aponeurotic attachment
run from one region of the body to another and alter the position of the whole part
Extrinsic muscle
the characteristic movement of a joint is
produced by a muscle/s
Prime movers or agonists
the muscles responsible for the opposite action
Antagonist
In the elbow joint, what muscles are the prime mover and antagonist?
flexion- biceps brachii m (prime mover)
extension- triceps brachii m (antagonist)
_______________- is a disease that interrupts the way nerves communicate with muscles.
Canine Myasthenia Gravis
rapidly progressive motor paralysis caused by a toxin in the tick’s saliva that attacks the nervous system.
Tick paralysis
_____________ - the wasting or thinning of muscle mass. It can be caused by disuse of your muscles or neurogenic conditions.
Muscle atrophy
