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Flashcards in Physiology Deck (11):
1

Types of muscle

Skeletal, smooth and cardiac

2

Striated muscles

Cardiac and skeletal

3

One motor unit consists of:

A single motor neuron and all its connecting muscle fibres (muscle fibres are muscle cells).

4

The more muscle fibres to a motor unit the..

Less refined the action will be.

5

The fewer muscle fibres to a motor unit the..

More precise an action will be e.g. muscles in the eye, hand movements etc

6

What are muscle cells made up of? What is the functional unit within them?

Myofibrils- the functional units with muscle cells are sacromeres.

7

What do sacromeres contain?

Actin (thin) and myocin (thick) filaments.

8

How is muscle contraction brought about?

Calcium is released from lateral sacs of the sacroplasmic reticulum when an action potential passes. The AP passes down T tubules. The calcium then binds to troponin creating tropomyosin which causes cross bridge formation of actin and myocin.

9

In sacromeres, describe the H zone

Thin filaments don't reach

10

In sacromeres describe the M line

Extends vertically down the middle of the A band in the centre of the H zone.

11

In sacromeres describe the A band?

Thick and thin filaments overlap at both ends of the filament.