Muscles Flashcards
What are 4 functions of muscles?
- Movement
- Maintain posture
- Stabilise joints
- Generate heat
What are the 3 muscle types/
- Skeletal
- Cardiac
- Smooth
What is hypertrophy?
Enlargement
What are 3 main histological features of skeletal muscle?
- Myofibres have cross striations
- Myofibres are long, unbranched and multinucleated
- Nuclei occur at periphery of fibre
What is the hierarchy of skeletal muscle in descending order?
- Muscle
- Muscle fascicle
- Muscle fibre
- Myofibril
- Myofilaments
Name 2 myofilaments
- Actin
2. Myosin
Name 3 types of CT of skeletal muscles
- Epimysium
- Perimysium
- Endomysium
What is epimysium?
Connective tissue which surrounds the outside of an entire muscle
What is perimysium?
Connective tissue which surrounds the outside of a muscle fascicle
What is endomysium?
Connective tissue which surrounds the outside of a muscle fibre
What is the I band?
Composed of actin myofilaments anchored to the Z-line
What is the A band?
Overlap of actin anchored to the Z-line and myosin anchored to the M-line
What is a sarcomere?
Distance between two Z-lines
What is the only band that remains the same length when a muscle contracts?
A band
What is the sarcolemma?
Plasma membrane of a muscle fibre
What are transverse tubules?
Tubular invaginations of the sarcolemma
What is the function of transverse tubules?
Carry a wave of depolarisation into the muscle fibre
What is the sarcoplasm?
Cytoplasm of muscle fibre
Name 4 structures found in the sarcoplasm
- Myofibrils
- Mitochondria
- Sarcoplasmic reticulum
- Myoglobin
Where is cardiac muscle found?
The heart
Name 3 histological features of cardiac muscle
- Striated
- Branched cells joined by intercalated discs
- Nucleus positioned centrally in the fibre
What are intercalated discs?
Adhesion specialisations comprising fascia adherens and nexus
Where is smooth muscle found?
Tubular organs
Name 3 histological features of smooth muscle
- Non-striated
- Spindle shaped cells
- Corkscrew shaped nucleus
