Structure And Function Of The Muscular, Nervous And Skeletal Systems

1. What is the function of the endomysium?

A carbohydrate found in fruits and vegetables.

Surrounding the individual muscle fiber and thus separating the fibers from one another. A layer of connective tissue.

A neurotransmitter responsible for muscle contraction.

A type of hormone released during stress.

Endomysium is a layer of connective tissue that surrounds individual muscle fibers, separating them from one another.

Explanation

Endomysium is a layer of connective tissue that surrounds individual muscle fibers, separating them from one another.

2. What is the Sarcoplasmic Reticulum responsible for in muscle cells?

Producing glucose for energy

Removing waste products from muscle cells

A highly specialized complex that stores calcium ions. The function of this system is described in the theory of muscle contraction.

Transporting oxygen to muscle cells

The Sarcoplasmic Reticulum plays a crucial role in regulating calcium ion levels, which are essential for muscle contraction.

Explanation

The Sarcoplasmic Reticulum plays a crucial role in regulating calcium ion levels, which are essential for muscle contraction.

3. What proteins are attached to actin to help with its function in muscle contraction?

Tropomyosin and myoglobin

Attached are tropomyosin and troponin, which help with actin's function in muscle contraction. Tropomyosin is a long, rope-like protein that spirals around the actin double helix, blocks the binding sites for actin-myosin interaction or coupling. Troponin is a globular molecule that attaches at regular intervals to the tropomyosin.

Myosin and troponin

Actin and myosin

Tropomyosin and troponin are the proteins attached to actin that help with muscle contraction. Tropomyosin blocks the binding sites for actin-myosin interaction, while troponin attaches at regular intervals to the tropomyosin.

Explanation

Tropomyosin and troponin are the proteins attached to actin that help with muscle contraction. Tropomyosin blocks the binding sites for actin-myosin interaction, while troponin attaches at regular intervals to the tropomyosin.

4. What is the role of myosin in muscle contraction?

Myosin is a type of neurotransmitter that stimulates muscle contractions.

Myosin is responsible for triggering the release of calcium ions in muscle cells.

Myosin acts as a structural support for muscle cells.

The molecule has two globular heads, called myosin heads. The change of sarcomere length occur when the myosin cross-bridges bind to sites on the actin and then rotate, causing the filament sliding.

Myosin is a protein that plays a crucial role in muscle contraction by interacting with actin filaments to generate the force necessary for muscle movement. The correct answer explains the mechanism by which myosin heads bind to actin and cause filament sliding, leading to muscle contraction.

Explanation

Myosin is a protein that plays a crucial role in muscle contraction by interacting with actin filaments to generate the force necessary for muscle movement. The correct answer explains the mechanism by which myosin heads bind to actin and cause filament sliding, leading to muscle contraction.

5. Type 1 fibers.

Contain a large amount of mitochondria. These are your red, slow-twitch muscle fibers. Have a less developed sarcoplasmic reticulum, which leads to a slower calcium ion-handling capability. The large capacity of mitochondrial enzymes enhances their aerobic metabolism capacity.

Type 1 fibers are white muscle fibers with low mitochondria content.

Type 1 fibers have a highly developed sarcoplasmic reticulum for rapid calcium ion-handling.

Type 1 fibers are fast-twitch muscle fibers with high anaerobic capacity.

Type 1 muscle fibers, also known as slow-twitch fibers, are characterized by their high mitochondria content and strong reliance on aerobic metabolism. They are red in color due to their high myoglobin content. These fibers have a less developed sarcoplasmic reticulum compared to fast-twitch fibers, leading to slower calcium ion-handling capabilities, which is beneficial for endurance activities.

Explanation

Type 1 muscle fibers, also known as slow-twitch fibers, are characterized by their high mitochondria content and strong reliance on aerobic metabolism. They are red in color due to their high myoglobin content. These fibers have a less developed sarcoplasmic reticulum compared to fast-twitch fibers, leading to slower calcium ion-handling capabilities, which is beneficial for endurance activities.

6. What are the characteristics of Type 2 Fibers?

Have a slow rate of shortening and force development compared to slow-twitch fibers.

Have a highly developed sarcoplasmic reticulum. Ability to generate powerful, rapid muscle contractions. Called fast-twich muscle fibers. The speed of shortening and force development is three to five times faster than that of slow-twitch fibers.

Have a small sarcoplasmic reticulum with limited ability to generate muscle contractions.

Called slow-twich muscle fibers with the ability to generate powerful, rapid muscle contractions.

Type 2 fibers are known for their fast-twitch characteristics, including highly developed sarcoplasmic reticulum, fast muscle contractions, and rapid force development. These fibers are distinct from Type 1 fibers, which are slow-twitch and have different characteristics.

Explanation

Type 2 fibers are known for their fast-twitch characteristics, including highly developed sarcoplasmic reticulum, fast muscle contractions, and rapid force development. These fibers are distinct from Type 1 fibers, which are slow-twitch and have different characteristics.

7. What is a motor unit?

A neurotransmitter released at the neuromuscular junction.

A type of protein essential for muscle contraction.

Consists of the motor nerve and the muscle fibers it innervates. Each motor nerve innervates several muscle fibers. Slower movements, like the eye, may contain only 10 muscle fibers per motor neuron.

A group of tendons responsible for connecting muscles to bones.

A motor unit consists of the motor nerve and the muscle fibers it innervates, allowing for the coordination of muscle movements.

Explanation

A motor unit consists of the motor nerve and the muscle fibers it innervates, allowing for the coordination of muscle movements.

8. What is the function of Muscle Spindles?

D. Assist in maintaining muscle tone and posture.

Lie parallel to muscle fibers, provide sensory feedback concerning the length change and speed of length change in muscle fibers.

A. Responsible for muscle contraction and relaxation.

B. Facilitate the exchange of nutrients and waste products between blood and muscle cells.

C. Help in the storage of glycogen for energy.

Muscle spindles are specialized stretch receptors located within muscle tissue that provide sensory feedback about changes in muscle length and the speed of these changes. They do not directly control muscle contraction or relaxation, facilitate nutrient exchange, store glycogen, or help maintain muscle tone and posture.

Explanation

Muscle spindles are specialized stretch receptors located within muscle tissue that provide sensory feedback about changes in muscle length and the speed of these changes. They do not directly control muscle contraction or relaxation, facilitate nutrient exchange, store glycogen, or help maintain muscle tone and posture.

9. What is the purpose of the stretch reflex?

The stretch reflex helps muscles relax after they have been contracted.

The muscle spindle protects the muscle from extreme ranges of stretch or from stretches that are performed too fast.

The stretch reflex enhances muscle strength and endurance.

The stretch reflex is responsible for initiating voluntary muscle movements.

The correct answer explains how the stretch reflex functions to protect the muscle from potential harm during stretching.

Explanation

The correct answer explains how the stretch reflex functions to protect the muscle from potential harm during stretching.

10. What is the function of Golgi Tendon Organs?

Lie within the tendons of the musculotendinous region and recognize changes in tension in the muscle. In response to this muscle tension, the central nervous system may reflexively send a message to suppress the muscular force.

Found in the bones and help in regulating calcium levels in the blood

Located within the muscle cells and are responsible for muscle contraction

Situated in the brain and control decision-making processes

Golgi Tendon Organs are specialized receptors found within the tendons that help in determining the tension in muscles and regulating muscular force.

Explanation

Golgi Tendon Organs are specialized receptors found within the tendons that help in determining the tension in muscles and regulating muscular force.

11. What is included in the axial skeleton?

The clavicle

The appendicular skeleton

Or central skeleton, consists of the skull, vetebral column, sternum, and ribs.

The pelvic girdle

The axial skeleton is composed of the bones that form the central axis of the body, while the appendicular skeleton includes the bones of the limbs. The pelvic girdle and clavicle are both parts of the appendicular skeleton, not the axial skeleton.

Explanation

The axial skeleton is composed of the bones that form the central axis of the body, while the appendicular skeleton includes the bones of the limbs. The pelvic girdle and clavicle are both parts of the appendicular skeleton, not the axial skeleton.

12. What is included in the appendicular skeleton?

Consists of the pelvis and sacrum.

Consists of the shoulder girdles, arms, legs, and hips.

Consists of the skull and vertebrae.

Consists of the rib cage and sternum.

The appendicular skeleton is composed of the bones of the limbs and their supporting elements. It includes the shoulder girdles, arms, legs, and hips, which are essential for movement and support.

Explanation

The appendicular skeleton is composed of the bones of the limbs and their supporting elements. It includes the shoulder girdles, arms, legs, and hips, which are essential for movement and support.

13. What are proprioceptors?

Specialized receptors in muscles, joints, and tendons. Proprioceptors help maintain posture and balance when performing a movement.

Structures in the eyes that detect light and color.

Endocrine glands that secrete hormones into the bloodstream.

Nerve cells in the brain responsible for memory retention.

Proprioceptors are specialized receptors located in muscles, joints, and tendons that provide information to the brain about body position and movement. They play a crucial role in maintaining posture and balance during various activities.

Explanation

Proprioceptors are specialized receptors located in muscles, joints, and tendons that provide information to the brain about body position and movement. They play a crucial role in maintaining posture and balance during various activities.

14. What factors contribute to force production by muscle tissue?

Intake of vitamin C

Frequency of muscle stretching

Time of day when exercise is performed

-Number of muscle fibers in a motor unit.-Size of fibers in a motor unit.-Number of motor units activated. -Rate coding.-Fatigability of muscle fibers.-Motor unit recruitment order.

Force production by muscle tissue is influenced by factors such as the number of muscle fibers in a motor unit, the size of fibers in a motor unit, the number of motor units activated, rate coding, the fatigability of muscle fibers, and the motor unit recruitment order. Factors like the frequency of muscle stretching, vitamin C intake, or the time of day when exercise is performed do not directly impact force production by muscle tissue.

Explanation

Force production by muscle tissue is influenced by factors such as the number of muscle fibers in a motor unit, the size of fibers in a motor unit, the number of motor units activated, rate coding, the fatigability of muscle fibers, and the motor unit recruitment order. Factors like the frequency of muscle stretching, vitamin C intake, or the time of day when exercise is performed do not directly impact force production by muscle tissue.

15. What is Rate Coding?

Rate coding determines the color of the muscle fibers.

A signal to the muscle telling it how much force it should produce. more action potentials = more twitches. leads to more contraction and force.

Rate coding is an instruction for the muscle to contract rapidly.

Rate coding refers to the speed at which muscles fatigue.

Rate coding is a neural mechanism that controls the force output of muscles by regulating the frequency of action potentials sent to the muscle fibers. This directly impacts the amount of force a muscle can generate during contraction.

Explanation

Rate coding is a neural mechanism that controls the force output of muscles by regulating the frequency of action potentials sent to the muscle fibers. This directly impacts the amount of force a muscle can generate during contraction.