Musculo-Skeletal System (VSAQs)

Zoology-2 | Unit-3A: Musculo-Skeletal System – VSAQs:
Welcome to VSAQs in Unit-3A: Musculo-Skeletal System. This page includes the most important FAQs from previous exams. Each answer is presented in the exam format to help you prepare effectively and aim for top marks in your final exams.


VSAQ-1: What is the Triad System?

Think of the triad system in muscle cells as a team of helpers that make your muscles work. Inside each muscle fiber, there are T-tubules, which are like electrical wires that carry signals deep into the muscle. Next to these T-tubules are the terminal cisternae, which are like storage tanks filled with calcium. When the signal travels through the T-tubules, these tanks release calcium, causing the muscle to contract and move. So, the triad system is key for making sure your muscles respond quickly when you need them to.


VSAQ-2: Write the Difference Between Actin and Myosin

Imagine actin and myosin as two teammates in a tug-of-war game. Actin is like the thin rope, spread out across the muscle fiber. Myosin is the thicker rope that pulls on the actin rope. When your muscles contract, the myosin rope pulls on the actin rope, making the muscle shorten and create movement. So, actin and myosin work together, with actin as the thin filaments and myosin as the thick ones that help your muscles move.


VSAQ-3: Distinguish Between Red Muscle Fibers and White Muscle Fibers

Think of red muscle fibers as marathon runners. They are good for long-lasting activities because they have lots of oxygen and energy. White muscle fibers are like sprinters. They are better for quick, intense actions but get tired faster. Red fibers help you with activities like jogging, while white fibers help you with short bursts of energy, like sprinting.


VSAQ-4: What is a ‘Motor Unit’ with Reference to Muscle and Nerve?

A motor unit is like a team made up of a motor neuron and the muscle fibers it controls. The motor neuron sends signals telling the muscle fibers when to contract. Think of it as a coach giving instructions to a group of players. The size of the team changes depending on the job: for precise tasks like writing, the team is small; for big movements like jumping, the team is larger. This helps your muscles work properly for different actions.


VSAQ-5: Name the Ear Ossicles and Their Evolutionary Origin in Human Beings

In your ear, there are three tiny bones called ossicles that help you hear. The malleus (or hammer) evolved from a bone in early vertebrates, the incus (or anvil) came from a bone in ancient reptiles, and the stapes (or stirrup) started as a bone in early fish. These bones have changed over time to help transmit sound from the outer ear to the inner ear, so you can hear properly.


VSAQ-6: Name Two Cranial Sutures and Their Locations

The coronal suture is a line that goes across your forehead, separating the frontal bone from the top of your head. The lambdoid suture is found at the back of your head, connecting the top of your skull to the bottom part. These sutures are like the seams in a baseball, joining the different parts of your skull together.


VSAQ-7: Name the Keystone Bone of the Cranium. Where Is It Located?

The sphenoid bone is the keystone of the cranium because it sits in the middle of your skull, connecting with all other cranial bones. It’s like the central piece in a puzzle that holds everything together. This bone is important for keeping the structure of your skull stable and well-supported.