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”
What does muscle tissue do?
Utilises energy from hydrolysis of ATP to generate force
Contractions produce body movements, maintains posture and generates heat
Define striation
Dark and light bands in muscle fibres. Caused by thin and thick filaments
Define sarcoplasm
The cytoplasm of striated muscle cells
What does the prefix myo- mean?
Of or relating to muscles
What are intercalated discs?
Structures unique to cardiac muscle, comprises of desmosomes and gap junctions
