BIOL125 Lecture Notes - Lecture 19: Semimembranosus Muscle, Myoglobin, Blood Sugar
Muscular System
• 4.11. Muscle tissue
o Muscle cell = muscle fibre - contractile proteins known as filaments
o Tend to have prefix "sarco" e.g. sarcolemma = plasma/cell membrane
o 4.11.1. cells and associated tissues/structures
• A skeletal muscle contains muscle tissue, connective tissues, blood vessel and
nerves
o 4.11.2. functions and properties
• Has excitability/irritability due to polarised membrane - ability to
contract/shorten and relax/lengthen to produce movement
• All muscle cells contain protein myofilaments actin and myosin that interact to
produce contraction and relaxation
• 4.12 and 4.16 The three types of muscle tissue and key histological features of the three
types of muscle tissue
o 4.12.1. skeletal, smooth and cardiac
• 4.12.1.1. functions
• 4.12.1.2. locations
• 4.12.1.3. regenerative ability
o 4.16.1 movement
• 4.16.1.1 muscle tone
• 4.16.1.2 definition of types of movement
• 4.16.1.3 control of movement)
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• 4.13. Skeletal muscle
o 4.13.1. structure: histology and gross
• 3 layers to muscle, each having a collagen-rich connective tissue later
▪ Endomysium - inside
• Areolar/loose CT
• Surrounds individual muscle cells
• Not that much collagen
• Neurons and blood vessels down to muscle fibres
• Contains capillaries, myosatellite cells, and nerve fibres that
control muscle cells
▪ Perimysium - around
• dense irregular CT
• Surrounds bundles of wrapped muscle cells (fascicles)
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• Lots of collagen fibres
• Protective layer
• Contains blood vessels and nerves that branch to each fascicle
▪ Epimysium - outer
• Dense irregular CT
• Very protective
• Keep all fascicles together in the right alignment
▪ Surrounds entire muscle (bundles of fascicles, blood vessels and nerves)
• Collagen fibres from all 3 CT layers join together -> tendons or sheets -> extend
into bone matrix -> attach muscle to bone
o 4.13.2. names and locations of key muscles
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