Module 5.3 - Animal responses Flashcards
What are the three types of muscle?
Skeletal, cardiac and smooth.
Describe skeletal muscle?
> Cylindrical bundles of muscle fibres.
Multinucleate cells
Obvious striations
Describe cardiac muscle?
> Striated and branched.
Has intercalated discs (discs that connect the cells to help it work as a single functional organ).
Gap junctions (tunnels between cells)
Myogenic, meaning contractions are produced spontaneously, without requiring stimulation from nerve cells.
Describe smooth muscle?
> Cells have a tapered/spindle shape (not in fibres).
Two layers: inner layer arranged in a circular fashion to allow segmentation. Outer layer is longitudinal, producing waves of movement.
What is the plasma membrane of a muscle fibre called?
Sarcolemma
What is the cytoplasm of a muscle fibre called?
Sarcoplasm.
What are myofibrils?
Any of the elongated contractile threads found in striated muscle cells.
What is a sarcomere?
The basic unit of striated muscle tissue: the repeating unit between two Z lines/discs.
What are gap functions and what are they for?
Small tunnels that connect cells, facilitating the passing of molecules, ions and electrical impulses between cells.
Name the thick and thin filaments in muscle fibres?
Thin = actin Thick = myosin.
What is the neuromuscular junction?
Point of contact between a motor neuron and a muscle cell.
What does a motor unit refer to?
All of the muscle fibres innervated by a single motor neuron.
What is the sarcoplasmic reticulum?
Muscle cell’s endoplasmic reticulum, used to store calcium ions.
Describe the location of the Z discs, M line, I band and A band?
Z discs - between sarcomeres.
M line - Middle of sarcomere.
I band - From end of myosin on one sarcomere, to the end of myosin on the next one.
A band - spans the length of the myosin within one sarcomere.
Describe what the peripheral system splits into?
Peripheral system -> Somatic nervous system
->Autonomic nervous system -> Sympathetic or parasympathetic.
What does the somatic nervous system control?
Controls conscious activities.
What does the autonomic nervous system control?
Controls unconscious activities (e.g. digestion).
What is the sympathetic nervous system’s function?
Gets the body ready for action, it’s the ‘fight or flight’ system. Sympathetic neurons release the neurotransmitter noradrenaline