Muscle Tissue 1

Question 1

What is myoglobin?

Answer 1

A protein only found in striated muscle. When striated muscle dies or is damaged, myoglobin is released into the bloodstream and can cause renal damage.

Question 2

Muscle cell component terminology

Answer 2

Sarcolemma: the outer membrane of a muscle cell, Sarcoplasm: the cytoplasm of a muscle cell, Sarcosome: the mitochondrion, Sarcomere: contraction unit in striated muscle, Sarcoplasmic Reticulum: the SER of a muscle cell.

Question 3

Describe muscle contraction speeds.

Answer 3

There are three types: slow, intermediate and fast. Each fascicles has at least one of each.

Question 4

What are ways in which tissues can increase in size?

Answer 4

Hypertrophy: enlargement of their individual cells. Hyperplasia: multiplication of their cells.

Question 5

What are the colours of muscle fibre types?

Answer 5

Slow- red, Intermediate- red to pink, Fast- white

Question 6

What does continued muscle contraction depend on?

Answer 6

Depends on Ca2+ ions and also the amounts of ATP.

Question 7

Describe the appearance of cardiac muscle fibres in LS.

Answer 7

Striations, centrally positioned nuclei, intercalated discs and branching.

Question 8

Where are ANP & BNP released?

Answer 8

ANP is released by atria whereas BNP is released by ventricles, they’re released by the heart during heart failure.

Question 9

How can you reduce arterial pressure?

Answer 9

By decreasing the blood volume and systemic vascular resistance.

Question 10

What are purkinje fibres?

Answer 10

Large cells with abundant glycogen, sparse myofibrils and extensive gap junction sites

Question 11

Describe smooth muscle cell structure.

Answer 11

Spindle-shaped with a central large nucleus. Not striated, no sacromeres and no T tubules. They’re capable of being stretched substantially.