Types of Muscle and Properties
Define what Atrophy is. (1 mark)
Atrophy is the loss of size or mass of muscle tissue.
Define what a motor neuron is. (1 mark)
A motor neuron transmits impulses from the central nervous system (brain, spinal cord) to the muscles.
Outline the process of Reciprocal Inhibition (1mark)
A process that inhibits the stretch reflex in antagonistic muscle pairs. When one muscle contracts, it sends an inhibitory nerve impulse to its opposing muscle, causing it to relax.
Outline the parts of a lever and what they are in the body (1 mark)
Levers have a fulcrum, effort and a load. In the body, the fulcrum is the joint, the effort is the muscle, and the load is the weight/resistance.
Define Innervate. (1 mark)
To supply an organ or body part with nerves.
Compare the shape of smooth and cardiac muscles. (2 marks)
The shape of smooth muscle is narrow tapered rod-shaped cells but on the other hand the shape of cardiac muscle is tubular, branched and contains un-inucleated fibers.
Outline the function and structure of Cell body in a motor neuron. (2 marks)
The function of a cell body is to transmit information from the dendrites to the axon, the structure contains the nucleus.
Distinguish between concentric and eccentric muscle Contractions. (2 marks)
Concentric shortens muscles while as Eccentric lengths muscles, Concentric goes against gravity while Eccentric goes with gravity.
State the equation for how to calculate the mechanical advantage of a lever (2 marks)
Length of effort moment arm/length of load moment arm = the Mechanical Advantage
State 2 properties of muscle tissue (2 marks )
Contractility
Extensibility
Elasticity
Hypertrophy
Atrophy
State 3 types of muscles. (3 marks)
Cardiac, Smooth and Skeletal Muscle.
Distinguish between the 3 types of motor units (3 marks)
Type I (Slow Twitch) - Fatigue resistant, can maintain contractions for extended periods of time, and has small muscular forces.
Type IIa (Fast Twitch) - has big muscular forces, stronger contraction forces, and is more prone to fatigue.
Type IIx (Fast Twitch) - Fastest and strongest contractions and forces, very prone to fatigue, and cannot maintain contractions for long periods of time.
List 3 antagonistic pairs that are found in the arms and trunk of the body (3 marks)
Biceps and Triceps, Pectoralis Major and Latissimus Dorsi, and Abdominals and Erector Spinae.
Discuss the lever functions based on limb lengths. (3marks)
There is long levers and short levers, the short levers result in greater speed at the end of the limb, and short levers can be moved with less force and at a greater speed.
Compare the 3 motor units by structural characteristics (3 marks)
Type l has a small fiber diameter, high mitochondria, and high capillary density.
Type ll has moderate fiber diameter, mitochondria, and capillary density
Type llx has a large fiber diameter, low mitochondria and low capillary density
Discuss the 4 main functions of muscle. (4 marks)
There are 4 main functions of muscle, the 1st being joint movement this occurs when Skeletal muscles contract that exert force on tendons which then pulls on bones to cause joint movement. The 2nd being substance movement throughout the body this is could be how cardiac muscle helps pump blood through the body. The 3rd being how muscle stabilizes and maintains posture by contracting postural muscles for body positions like sitting and standing. Lastly the 4th being producing body heat, this contracts voluntary and involuntary that generates 85% of body heat.
Using a sports example, explain how type I motor units could be beneficial to an athlete. (4marks)
Type l motor units are slow-twitch fibers that have Slow nerve transmission speeds and are fatigue resistant. These motor units could be beneficial to a track runner who does long distance running, this is because the fatigue resistant can allow them to run longer without getting tired easily.
Describe the reciprocal inhibition process of a bicep curl (4 marks)
During a bicep curl, as the bicep brachii shortens, it contracts, this is the agonist. As for the antagonist, the tricep brachii was sent an inhibitory signal from the bicep brachii to relax, allowing the movement of the bicep curl to take action.
Find and explain a 1st class lever found in the body. (4marks)
A 1st class lever is when the fulcrum is in the middle and has the load and effort at the ends. When you extend or flex your neck, this is a 1st class lever, the head being the load, the trapezius being the effort, and the fulcrum being the vertebrae.
Explain how skeletal muscle works (4marks)
Motor neurons carry information from the CNS (brain and spinal cord) to the muscle that signals muscles to contract or relax. Adenosine Triphosphate (ATP) provides the energy for muscle contraction