Lecture 9 - Muscle Physiology

Question 1

Why is muscle unique to other tissues?

Answer 1

Due to the ability to convert chemical energy to force generation and movement

Question 2

What are the defining characteristics of skeletal muscle cells?

Answer 2

Multi-nucleated
many mitochondria
T-tubules
contains myofibrils and sarcomeres

Question 3

What are the functions of skeletal muscle?

Answer 3

Locomotion, stability, communication, control of body openings, heat production, store glucose

Question 4

What makes up a single muscle fibre?

Answer 4

Cylindrical bundles called myofibrils

Question 5

What makes up Myofibrils?

Answer 5

Sacromeres

Question 6

What makes up thick and thin filaments?

Answer 6

Thick = myosin
Thin = actin + troponin + tropomyosin

Question 7

What is the globular head?

Answer 7

The combination of heavy and light chains
- forms cross bridges with thin filaments to generate force

Question 8

What are the two binding sites on the globular head?

Answer 8

One site for ATP
One site for thin filament

Question 9

What are all the sarcomere Features?(hint - think zones)

Answer 9

A Band - area of the thick filaments
I band - where the thin filaments don’t overlap the thick filaments
H Zone - space between opposing thin filaments
M disk - proteins that link thick filaments
Z line - length of one sarcomere

Question 10

What are the two membranes essential for skeletal muscle contraction

Answer 10

Sarcoplasmic Reticulum
Transverse Tubules

Question 11

What is the Sarcoplasmic Reticulum? What two structures does it involve?

Answer 11

Forms the sleeves around each myofibril
Contains Terminal Cisternae - enlarged regions at the end of each sarcoplasmic reticulum segment
Also contains calsequestrin that allows for Ca storage