3 types of muscle tissue
- Skeletal
- Cardiac
- Smooth
Characteristics of Muscle Tissue
- Excitability
- Contractality
- Extensibility
- Elasticity
Excitability is also known as what? Function.
- responsiveness
- ability to receive and respond to stimuli
Contractility’s function is:
ability to shorten forcibly when stimulated
Extensibility’s function is:
ability to be stretched
Elasticity’s function is:
ability to recoil to resting length
Skeletal Muscles
- attached to bone and skin
- single, long, cylindrical, multinucleate cells, striated
- voluntary
Cardiac Muscles
- walls of the heart
- branch chain of cells, uni/binucleate, striated
- involuntary
Smooth Muscles
- walls of hollow organs: stomach, urinary bladder, airway
- single, uninucleate,non striated
-involuntary
Muscle Functions
- Movement of bones or fluids
- Maintaining posture and body positon
- Stabilize joints
- Heat generation
*Bonus functions: protect organs, forms valves, controls pupil size, causes goosebumps
Where do skeletal muscles attach?
insertion: movable bone
origin: immovable/ less movable bone
Attachments may be ____ or ____.
direct
indirect
Connective tissue sheaths of skeletal muscles:
- Epimysium
- Perimysium
- Endomysium
Epimysium
surrounding the entire muscle
Perimysium
surrounding groups of muscle fibers (fascicles)
Endomysium
surround each muscle fiber
What does the sarcolemma consist of/contain?
- plasma membrane
- glycosomes
What doe the sarcoplasm contain or consist of?
cytoplasm
Myofibrils
- packed rodlike elements
- exhibits striations
Myofibrils contain sarcomeres which are:
the smallest contractile unit of muscle fiber
Different types of striations:
- H zone
- M line
- Z disc
- Thick/thin filaments
- Sarcomere
Sarcoplasmic Reticulum
- a network of smooth endoplasmic reticulum surrounding each myofibril
- functions in regulation of intracellular calcium levels:
- stores and release Ca2+
