L23. Muscle Tissue Flashcards
Name the 3 types of muscle specialised for contraction.
Skeletal
Cardiac
Smooth
Outline a flowchart for somatic muscle.
Somatic (voluntary) -> striated -> skeletal muscle
Outline 2 flowcharts for autonomic muscle.
Autonomic (involuntary) -> striated -> cardiac
-> non-striated -> smooth
Describe the appearance of skeletal muscles cells and how they are bundled.
Elongated cylindrical cells.
Multinucleated on periphery
Fascicle wrapped in perimysium is made of many muscle fibres wrapped in endomysium.
Describe the make-up of myofibrils.
Each muscle cell has many myofibrils to give the striated appearance.
Myofibrils are made for repeating units called myofilaments.
Describe the make-up of myofilaments.
They have dark bands of myosin (a bands) and light bands of actin (I bands). Light bands are bisected by Z lines which divide the myofibril into contractile units called sarcomeres.
How do sarcomeres move?
Sliding filament mechanism.
What kind of neurons innervate skeletal muscle?
somatic motor neurons.
What is a motor unit made of?
Motor neuron + its muscle fibres = motor unit
How are T tubules created?
The sarcolemma folds inwards to create T tubules.
What is the sarcoplasmic reticulum?
A modified version of the endoplasmic reticulum.
Describe the role and appearance of cardiac muscle.
Only found in the heart for autonomous contraction.
Elongated, striated, branched cylinder cells with 1 or 2 central nuclei.
Give a name for cardiac muscle.
Myocardium.
Name and describe the 3 layers of cardiac wall.
Endocardium (single layer of endothelial cells)
Myocardium (cardiac muscle)
Pericardium (outer supporting tissue layer)
Describe a similarity between cardiac muscle and skeletal muscle.
Same arrangement of sarcomeres.
Contains T tubules and sarcoplasmic reticulum.
