Unit 11: Muscular System

Question 1

What is a group of muscle fibres called?

Answer 1

A fascicle

Question 2

Fascia is the CT that surrounds muscles or other organs. What are the 3 main types of fascia?

Answer 2

Epimysium: surrounds entire muscle
Perimysium: surrounds fascicles within muscle
Endomysium: surrounds each muscle fibre (cell) within muscle

Question 3

What are tendons and aponeuroses and what function do they have?

Answer 3

They are extensions of the fascia of a muscle which anchor it to bones and cartilage

Question 4

What is the difference between a tendon and an aponeuroses?

Answer 4

Tendon: rope-like bundle of dense regular CT (e.g. Achilles tendon)
Aponeuroses: flat sheet of dense regular CT (e.g. epicranial aponeuroses (scalp))

Question 5

What is the name for the cell membrane of a muscle fibre?

Answer 5

Sarcolemma

Question 6

What are T-tubules?

Answer 6

Continuations of the sarcolemma that extend deep into the fibre

Question 7

What is sarcoplasmic reticulum?

Answer 7

Smooth ER. A triad is formed from 2 enlarged areas of the SR (terminal cisternae), and a T-tubule that runs in between them

Question 8

What makes up the thin filaments in the sarcomere?

Answer 8

Actin (structure)
Tropomyosin (blocks binding site with myosin to prevent contraction)
Troponin (sits on tropomyosin and controls its blocking ability)