muscle response a level biology

What are the three types of muscle found in mammals?

Skeletal muscle, Smooth muscle, Cardiac muscle.

What is another name for skeletal muscle?

Striated muscle or voluntary muscle.

What is the primary function of skeletal muscles?

To move the rigid skeleton of mammals.

What unique structures do muscle fibres contain?

Organised arrangement of contractile proteins, many nuclei, and are surrounded by a sarcolemma.

What is the cytoplasm of a muscle fibre called?

Sarcoplasm.

What is the function of mitochondria in muscle fibres?

To carry out aerobic respiration to generate ATP required for muscle contraction.

What are the two types of protein filaments found in myofibrils?

Thick filaments made of myosin and thin filaments made of actin.

What are sarcomeres?

The contractile units of myofibrils.

How does smooth muscle differ from skeletal muscle in terms of appearance?

Smooth muscle does not have any banding or striation.

What characterizes cardiac muscle?

It is myogenic, does not tire, and contracts continuously.

What are intercalated discs?

Specialized connections between cardiac muscle fibres.

What are the key components of an optical microscope?

Eyepiece lens, objective lenses, stage, light source, coarse and fine focus.

What is the purpose of adding a drop of water to a specimen on a slide?

To prevent dehydration of the thin layer of material.

What is a graticule?

A small disc with an engraved ruler used for measuring cells under a microscope.

What is a limitation of optical microscopes?

They do not have the same magnification power as other types of microscopes.

What is the appearance of skeletal muscle fibres under an optical microscope?

They show banding, giving them a characteristic striped appearance.

Why is it important to start with the low power objective lens when using a microscope?

It is easier to find what you are looking for and prevents damage to the lens or coverslip.

What is cardiac muscle?

Cardiac muscle is a type of involuntary striated muscle found only in the heart, responsible for pumping blood throughout the body.

What are the characteristics of cardiac muscle cells?

Cardiac muscle cells are branched, striated, and interconnected, allowing for synchronized contractions. They have a single central nucleus and are rich in mitochondria.

How does cardiac muscle differ from skeletal muscle?

Cardiac muscle is involuntary and striated, while skeletal muscle is voluntary and also striated. Cardiac muscle cells are connected by intercalated discs which enable rapid electrical impulses.

What role does the pacemaker play in cardiac muscle?

The pacemaker, or sinoatrial node, generates electrical impulses that initiate the heartbeat, ensuring the heart contracts in a coordinated and rhythmic manner.

What is the significance of intercalated discs in cardiac muscle?

Intercalated discs allow for electrical communication and mechanical coupling between cardiac muscle cells, enabling synchronized contractions essential for effective heart function.

What is the function of cardiac muscle tissue?

The primary function of cardiac muscle tissue is to contract and relax in a rhythmic manner to pump blood to the lungs and the rest of the body