Week 5: Muscular System

Question 1

What are the 3 types of muscle tissue?

Answer 1

• Skeletal
• Cardiac
• Smooth muscle (walls of hollow or visceral organs)

Question 2

What is skeletal muscle?

Answer 2

Skeletal muscle is the type of muscle tissue attached to bones via tendons, enabling voluntary movements such as walking, lifting, running, and also maintains posture, and produces heat. It has a striated appearance due to repeating sarcomere structure.

Question 3

What is cardiac muscle?

Answer 3

Cardiac muscle is the specialised muscle found in the heart. It has a striated appearance and intercalated discs that allow for synchronised contractions. It is responsible for involuntary contractions that pump blood throughout the circulatory system.

Question 4

What is smooth muscle?

Answer 4

Smooth muscle is a type of non-striated muscle tissue found in the walls of internal organs. It has a smooth, spindle-shaped appearance, and controls involuntary functions such as digestive tract peristalsis and blood vessel and respiratory passages constriction.

Question 5

What are the functions of skeletal muscle tissue?

Answer 5

• Producing body movement
• Stability of body position
• Storing and moving substances
• Generating heat

Question 6

What are the functions of cardiac muscle tissue?

Answer 6

• Generates involuntary rhythmic contractions that pump blood through the circulatory system, facilitating the circulation of oxygen and nutrients to body tissues and organs.

Question 7

What are the functions of smooth muscle?

Answer 7

Moving substances within the body, such as through persitalsis in the GI tract, or facilitating blood flow through blood vessels.

Question 8

How does skeletal muscle generate heat?

Answer 8

The metabolic processes of muscle contraction produce heat.

Question 9

Which of the 3 muscle types undergo the most significant stretching?

Answer 9

Smooth muscle

Question 10

What 2 muscle types are regulated by the autonomic nervous system?

Answer 10

• Cardiac muscle: specifically regulated by the cardiac conduction system.
• Smooth muscle: regulated by the ANS and local factors such as hormones and stretches.

Question 11

How is the skeletal muscle system controlled?

Answer 11

It is controlled by the Somatic Nervous System, and can be voluntarily moved/controlled.

Question 12

Which 4 properties does muscular tissue possess?

Answer 12

• Contractility
• Excitability
• Extensibility
• Elasticity

Question 13

What is the electrical excitability property of muscle tissue?

Answer 13

Muscular tissue can generate electrical signals, primarily in response to chemical stimuli. These electrical events play a vital role in muscle contraction.

Question 14

What is the contractility property of muscle tissue?

Answer 14

When stimulated by an electrical event, it can contract. This contraction results in the shortening of muscle fibres, leading to various movements and functions within the body.

Question 15

What is the extensibility property of muscle tissue?

Answer 15

Muscular tissue can undergo extending (stretching) within the limits imposed by its connective tissue. This property allows muscles to stretch without causing damage, enabling flexibility in movement.

Question 16

What is the elasticity property of muscle tissue?

Answer 16

After being stretched, muscle tissue has the capacity to return to its original length and shape. This elasticity is crucial for maintaining muscle function and stability, as it ensures that muscles can recover their initial state after contraction or stretching.

Question 17

What are tendons?

Answer 17

Connective tissue that joins muscle tissue to bone.

Question 18

What is fascia?

Answer 18

Fascia is a dense sheet or broad band of irregular connective tissue that lines the body wall and limbs and supports and surrounds muscles and other organs of the body.

Question 19

What is the hierarchial organisation of skeletal muscle components?

Answer 19

• Epimysium - outermost layer, a protective sheath.
• Perimysium - surrounds and provides structural support for the bundles of fascicles (muscle fibre bundles).
• Endomysium - internal layer. Surrounds individual muscle fibres within a fascicle. Contains blood vessels and nerves.

Question 20

What is a sarcolemma?

Answer 20

A muscle cell membrane.

Question 21

Is skeletal muscle single or multi-nucleated?

Answer 21

Multi-nucleated.

Question 22

What is sarcoplasm?

Answer 22

the cytoplasm of a muscle cell.

Question 23

What are mitochondria?

Answer 23

Organelles within the sarcoplasm that generate energy in the form of ATP.

Question 24

What is the sarcoplasmic reticulum?

Answer 24

An organelle within the sarcoplasm that stores and releases calcium ions.

Question 25

What are myofibrils?

Answer 25

Cylindrical structures within the muscle cell responsible for muscle contraction. They are composed of repeating units called sarcomeres.

Question 26

What are sarcomeres?

Answer 26

The functional units of myofibrils. Contractile units of muscle responsible for generating force.

Question 27

What are the 2 types of sarcomeres?

Answer 27

• Thick filaments (myosin)
• Thin filaments (actin, troponin, tropomyosin)

Question 28

What are transverse tubules?

Answer 28

Invaginations of the sarcolemma that penetrate the muscle cell’s interior. They are crucial in transmitting action potentials deep into the muscle fibre.

Question 29

Label the components in the diagram

Answer 29