Take this Exam: Anatomy and Physiology | Zestly

Question 1

During muscle contraction, what changes occur within the sarcomere?

Accepted Answer

The H-zone becomes smaller.

Question 2

What happens to the thick filaments during muscle contraction?

Accepted Answer

They stay in place.

Question 3

What is a myoblast, as described in the document?

Accepted Answer

A muscle stem cell

Question 4

Which of the following organelles are specialised to support contraction and high levels of activity in muscle cells?

Answer

Mitochondria

Answer

Sarcoplasmic reticulum

Answer

Ribosomes

Answer

Myofibrils

Question 5

What is the role of nebulin in actin (thin) filaments?

Answer

It binds g-actin molecules into a long twisted strand.

Answer

It blocks myosin binding sites.

Answer

It binds calcium ions.

Answer

It attaches myosin to the Z-line.

Question 6

Which of the following are characteristics of myosin (thick) filaments?

Answer

Heads contain ATP binding site.

Answer

They are composed of g-actin molecules.

Answer

Heads bind to actin during contraction.

Answer

They are attached to the Z-line by nebulin.

Question 7

What is the definition of a 'Triad' in muscle cells?

Answer

A T-tubule flanked by two terminal cisternae

Answer

Three myofibrils bundled together

Answer

A group of three muscle fibers

Answer

The three binding proteins of troponin

Question 8

Which of the following statements about muscle fibers (myofibers) are correct?

Answer

They are long cylindrical cells.

Answer

They are multinucleated myotubes.

Answer

They are muscle stem cells.

Answer

They are responsible for muscle repair and maintenance.

Question 9

What is the term for the bundles of muscle fibers within a skeletal muscle?

Answer

Myofibrils

Answer

Fascicles

Answer

Sarcomeres

Answer

Myofilaments

Question 10

Which of the following are binding proteins found within troponin?

Answer

Actin binding site (TnI)

Answer

Tropomyosin binding site (TnT)

Answer

Calcium binding site (TnC)

Answer

Myosin binding site

Question 11

What type of connective tissue surrounds fascicles?

Answer

Dense irregular CT

Answer

Areolar CT

Answer

Elastic CT

Answer

Reticular CT

Question 12

What is the effect of decreasing calcium levels in a muscle?

Answer

Stronger contractions

Answer

Weaker contractions

Answer

Increased ATP production

Answer

Faster nerve impulse conduction

Question 13

Which of the following muscle types are described as having a 'striped appearance' or 'striations'?

Answer

Skeletal muscle

Answer

Cardiac muscle

Answer

Smooth muscle

Answer

Epithelial muscle

Question 14

What is the primary function of the DHPR (Dihydropuridine Receptor) protein on T-tubules?

Answer

It is voltage gated and electrically connects sarcolemma to SR.

Answer

It releases calcium from the sarcoplasmic reticulum.

Answer

It binds to actin during contraction.

Answer

It provides structural support to the sarcomere.

Question 15

What is the definition of 'Extensible' as a functional property of skeletal muscle tissue?

Answer

Can stretch beyond resting length when relaxed

Answer

Can recoil to original resting length

Answer

Can shorten when stimulated

Answer

Can respond to nerve stimulus

Question 16

Which of the following are components of a muscle fiber (cell)?

Answer

Sarcolemma

Answer

Nucleus

Answer

Mitochondrion

Answer

Epimysium

Question 17

What is the primary role of the RYR1 (Ryanodine protein)?

Answer

It is involved in calcium release from the sarcoplasmic reticulum.

Answer

It is a voltage-gated protein on T-tubules.

Answer

It links adjacent myosin proteins at the M-line.

Answer

It forms the twisted strand of g-actin molecules.

Question 18

What is the term for the microscopic units of contractile proteins in the myofibril?

Answer

Myofilaments

Answer

Sarcomeres

Answer

Fascicles

Answer

Myofibers

Question 19

Which of the following statements about muscle cells are correct?

Answer

They have organelles specialised to support contraction.

Answer

They contain myofibrils, which are contractile organelles.

Answer

They are always single-nucleated.

Answer

They are primarily responsible for storing nutrients.

Question 20

What is the main characteristic of the A band (dark) in a sarcomere?

Answer

It contains thick and thin filaments overlapping.

Answer

It contains only thin filaments.

Answer

It is the center line, linking adjacent myosin.

Answer

It forms the boundaries of a sarcomere.

Question 21

What is the term for the plasma membrane surrounding a muscle fiber?

Answer

Sarcolemma

Answer

Sarcoplasm

Answer

Endomysium

Answer

Myofibril

Question 22

Which of the following are types of muscle tissue?

Answer

Skeletal

Answer

Smooth

Answer

Cardiac

Answer

Nervous

Question 23

What is the primary function of the H band in a sarcomere?

Answer

It is the center, containing only thick filaments.

Answer

It contains only thin filaments.

Answer

It forms the boundaries of a sarcomere.

Answer

It links adjacent myosin proteins.

Question 24

What is the definition of 'Elastic' as a functional property of skeletal muscle tissue?

Answer

Can recoil/rebound to original resting length after contraction or stretching

Answer

Can stretch beyond resting length when relaxed

Answer

Can shorten when stimulated

Answer

Can respond to nerve stimulus

Question 25

What is the primary role of muscle stem cells (myoblasts or satellite cells)?

Answer

To repair and maintain existing myofibers or become nascent myofibers.

Answer

To produce ATP for muscle contraction.

Answer

To conduct electrical impulses throughout the muscle.

Answer

To store calcium for muscle contraction.

Question 26

Which of the following are components of actin (thin) filaments?

Answer

G-actin molecules

Answer

Tropomyosin

Answer

Troponin

Answer

Myosin heads

Question 27

What is the definition of 'Excitable' as a functional property of skeletal muscle tissue?

Answer

Respond to nerve stimulus

Answer

Shorten when stimulated

Answer

Stretch beyond resting length

Answer

Recoil to original resting length

Question 28

What is the significance of Z-line streaming, as mentioned in the document?

Answer

It is a result of marathon running or HRST.

Answer

It indicates muscle relaxation.

Answer

It is a normal part of muscle contraction.

Answer

It is caused by an excess of calcium.