Muscle Tissue Flashcards
List the 3 types of muscle tissue
- Skeletal
- Cardiac
- Smooth
What is the location, structure, control and function of skeletal muscle?
Location: attached to bones via tendons
Structure: long cells, striated, multinucleated, cylindrical cells
Control: voluntary
Function: motion, posture, heat, protection
What surrounds skeletal muscle?
Protective connective tissue
List the levels of organisation in skeletal muscles
Muscle fibres ->fascicles -> specific anatomical muscles
What are striations composed of?
Highly organised arrangement of myofibrils
What is a myofibril?
Contractile units of muscle fibres, fill sarcoplasm and extend entire length of cell
Name the two types of myofibrils
Thin - actin
Thick - myosin
Do myofilaments extend the entire length of the muscle fibre?
No, they form compartments called sarcomeres
What is a sarcomere?
The basic functional unit of a myofibril, extends between two Z discs
What does an A band contain?
All thick filaments
What does the I band contain?
Only thin filaments
What does the H zone contain?
Only thick filaments
What is the M line?
The middle of the sarcomere: holds thick filaments together
What is the function of a Z disc?
The Z disc passes through the centre of a band and separates sarcomeres from one another
List the 4 principle connective tissue groupings associated with skeletal muscle
- Tendons
- Epimysium
- Perimysium
- Endomysium
What kind of connective tissue are tendons made of, and where can a tendon be found?
Dense regular; attaches to bone
What type of connective tissue comprises the epimysium? Where is the epimysium found?
Dense irregular; surrounds anatomical muscle
What type of connective tissue comprises the perimysium? Where is the perimysium found?
Dense irregular; surrounds muscle bundles/fascicles
What type of connective tissue comprises the endomysium? Where can the endomysium be found?
Areolar; surrounds each muscle fibre
What is the location, structure, control and function of cardiac muscle?
Location: heart
Structure: striated, branched, single nucleus, intercalated discs
Control: involuntary
Function: coordinated contractions pumps blood
What is an intercalated disc comprised of?
Desmosomes: bind intermediate filaments - adhesion in contraction
Gap junctions: communication - coordinated, rapid conduction of the contraction stimulus
What is the location, structure, control and function of smooth muscle?
Location: walls of hollow internal structures (e.g blood vessels, intestines, uterus)
Structure: non-striated, short, single nucleus
Control: involuntary
Function: contractions to push
What do thin filaments attach to in smooth muscle tissue?
Dense bodies (function similarly to Z discs)
What also connects to dense bodies alongside thin filaments in smooth muscle tissue?
Intermediate filaments (non-contractile) - tension transmitted to intermediate filaments cause cell “twisting”
