Muscle Tissue Flashcards
What are the 2 ways muscles are classified by?
- Morphological classification - striated (sacromeres) or non striated/smooth
- Functional classification - voluntary or involuntary
What is the 3 types of muscle in the body?
-Skeletal muscle which is striated and voluntary
-Cardiac muscle which is striated and involuntary
-Smooth muscle which is non striated and involuntary
What is human locomotion mediated by?
Skeletal muscle
What is the function of skeletal muscle?
-Produce skeletal movement
-Maintain posture
-Support viscera
-Guard entrances and exits of body
-Maintain body temp
-Store nutrients
What is skeletal muscle?
-Muscular system composed of specialised cells called muscle fibres that contract
-Under voluntary control by CNS
-Muscle fibres are striated
Features of muscle fibres?
-Elongated
-Cylindrical
-Multinucleate (nuclei peripherally located beneath cell membrane)
-Contractile
What bands can be seen under light microscopy of muscle fibres?
-dark bands - A bands (anisotropic w polarised light)
-light bands I bands (isotropic w polarised light)
-Centre of A band - pale area called H band
-H band bisected by a thin dark line - Z-disc / Z-line
What are the 3 layers of connective tissue each skeletal muscle has?
-Epimysium
-Perimysium
-Endomysium
What is the epimysium?
-Outer layer that surrounds each muscle
-Dense irregular connective tissue
-Maintains tructural integrity and allows contraction and for independent movement
-Projects inwards and divides muscle into compartments of muscle fibre bundles called fasciculi
What is the perimysium?
-Surrounds each fasciculi
-Fascicular organisation common in muscles of the limbs
What is the endomysium?
-Encases each muscle fibre within a fascicle
-Connective tissue layer of collagen and reticular fibres
-contains ECF and nutrients to support the muscle fibre
What does the size of the fasciculi reflect?
The function of the muscle
What is a myocyte?
A muscle cell
What is the sarcolemma?
plasma membrane
What is the sarcoplasm?
Cytoplasm
What is the sarcoplasmic reticulum?
Smooth ER
What is the sarcosome?
Mitochondria
What is the sacromere?
Functional unit of muscle
-contains contractile myofilaments
-thin filament- actin
-thick filament- myosin
What is the sacromere made of?
Myofilaments (actin and myosin) and regulatory proteins (troponin and tropomyosin)
FINISH MUSCLE - HAVENT FINISHED FIRST
