Topic 33 - Muscular Tissue: Cardiac Muscle

Question 1

How are cardiac myofibers organized?

Answer 1

• Cardiac myofibers are organized for pumping the blood in the circulatory system.
• Formed by individual cells that branch and anasotomose (forbindelser).

Question 2

Cardiac muscle function?

Answer 2

•Quick contractions without fatigue. Involuntary impulses generated by cardiac muscle. Found in the heart

Question 3

Morphology

Answer 3

• Y-shaped fibre-derived cells.
• Central located nucleus.
• Densely vascularized.
• Cell borders: Eberth’s line

Question 4

Difference bw. smaller and larger fibers?

Answer 4

•Smaller fibres engage in contraction, larger fibres (more sarcoplasm) generate impulse. Systole (atrial) occurs, with delay before diastole, impulse carried by Purkinje fibres.

Question 5

What is cardiac myocytes?

Answer 5

Purkinje fibres or discus intercalis (desmosomes and gap junctions)