The Muscular System Flashcards
What is the function of muscle?
Movement, Respiration function, Sphincter, Heat Production, Electrical signals
What does the muscle types depend on?
Color (Red, white)
Location (Skeletal, somatic, visceral)
Control (Voluntary or involuntary)
Microscopic (Straited, Cardiac and Smooth)
Define Skeletal Muscle
Most common type
Tissues composed of syncytia
* refer tothe diagram
Define Cardiac Muscle
unique type of stiated muscle
- differs in that: branching monoucleate syncytia of cells separated by intercalated disks
- capable of contracting without neural stimulaution - Refer to diagram
What are the two typesof smooth muscle
Single unit
Multi Unit
Define Smooth Muscle
- consists of elongate, spindle-shaped cellshaving a single nucleus
- actin and myosin fibers not regularly arranged
What is single unity smooth muscle
- contraction is myogenic
- digestive tract, uterus, urinary ducts, etc.
What are the multi unit smooth muscles
- Contraction is neurogenic
- blood vessels, iris, sperm ducts, etc.
How is smooth muscle often found ?
In two bands or layers
- e.g along the wall of the intestine
- refer to diagram
What is the Microanatomy of Muscle Fibres
Thin (actin) and Thick (myosin) filaments
What is the sliding filament mechanism?
Myosin binds to actin, uses ATP to “rachet” onces and releases “unrachets” and binds to the next actin
- myosin pulls actin chai along in one direction
Sarcomeres and Whole Fibres Shortens
What are tendons
- collagenous bundles continuous with those found in muscle sheath
(epimysium) and periosteum - Tendons allow muscles to be located in one area while acting on bones located some distance away
- can also store energy
- minimal energetic requirements but long healing time
