T1L5 - Muscle systems

Question 1

Locomotion [2]

Answer 1

Requires contraction of muscle fibres (cells) 
Contractile proteins (myofilaments) arranged as myofibrils

Question 2

Skeletal muscle [6]

Answer 2

Elongated and multinucleated
Peripheral nuclei
CT: Epimysium, Perimysium and endomysium
Bundles = fascicles
Epimysium surrounds entire muscle, Perimysium surrounds fascicles
Regenerate - satellite cells

Question 3

Movement

Answer 3

Shortening between origin and insertion

Question 4

Myocardium function [4]

Answer 4

Function: continuous rhythmic contractions to pump blood from the heart

Continuous into adjacent portions of the great vessels

Intrinsically generated contractions modified by the autonomic nervous system (ANS)

Parasympathetic (via Vagus nerve) decreases HR

Question 5

Myocardium [2]

Answer 5

Central nuclei + Branching pattern + Cells connected by intercalated discs
Myofibrils less defined and no defined connective tissue layer

Question 6

Intercalated discs contain [2]

Answer 6

Fascia adhesions (Desmosomes allow coordination of contraction)

Gap junctions (allow fast conduction and dissemination of Action Potential)

Question 7

Viscera (Smooth muscle) [7]

Answer 7

Spindle shaped
Single central nuclei
Branching pattern
Contractile proteins not arranged as myofibrils/sacromeres
Proteins criss-cross and anchor to focal densities
Cells run parallel to force of contraction
Has a supporting network of connective tissue

Question 8

Muscular dystrophies

Answer 8

group of genetic diseases causing progressive muscle weakness

Question 9

Cardiomyopathies

Answer 9

Deterioration in heart muscle function – range of reasons