1.2 AND 1.3

"Describe the role of connective tissues in the body."

"Connective tissues bind together, support, strengthen other body tissues, protect internal organs, permit movement, and increase stability."

"Define bone and its functions in the body."

"Bone is a rigid connective tissue that provides structure, protection, and acts as levers for movement."

"Explain the function of ligaments in the skeletal system."

"Ligaments connect bone to bone and provide stability to joints."

"How does cartilage contribute to joint function?"

"Cartilage provides smooth, flexible connections that reduce friction and absorb shock in joints."

"What is fascia and its role in the body?"

"Fascia is sheets of connective tissue that surround and separate muscles and organs."

"Describe the function of tendons in the muscular system."

"Tendons connect muscles to bones and transmit force from muscle contraction to produce movement."

"Define articulations in the context of the skeletal system."

"Articulations, or joints, are the points where two or more bones meet."

"Explain the characteristics of fibrous joints."

"Fibrous joints are connected by dense connective tissue and allow little to no movement."

"What are cartilaginous joints and their function?"

"Cartilaginous joints are connected by cartilage and allow limited movement."

"Describe synovial joints and their unique feature."

"Synovial joints are characterized by a synovial cavity filled with fluid, allowing for a wide range of motion."

"List the types of synovial joints and their movements."

"Types of synovial joints include ball and socket (multidirectional movement), gliding (sliding movements), pivot (rotation around one axis), saddle (movements in two planes), hinge (flexion and extension), and condyloid (movement in two planes without rotation)."

"Explain the concept of a motor unit in muscle contractions."

"A motor unit consists of a motor neuron and all the muscle fibers it controls."

"What is the All or None principle in muscle contraction?"

"The All or None principle states that when a motor unit is stimulated, all its fibers contract fully or not at all."

"Identify the energy source used for muscle contraction."

"The energy source used for muscle contraction is ATP (adenosine triphosphate)."

"Describe the role of acetylcholine in muscle contraction."

"Acetylcholine is a neurotransmitter that triggers skeletal muscle contraction by transmitting signals from nerve endings to muscle fibers."

"Explain the process of motor unit recruitment."

"Motor unit recruitment is the process of activating more motor units to increase muscle force during contraction."

"Define the principle of orderly recruitment in muscle contractions."

"The principle of orderly recruitment states that muscle fibers are recruited in a specific order based on the force required for the movement."

"What is muscle atrophy and what causes it?"

"Muscle atrophy is a decrease in muscle size due to inactivity or injury."

"How does reciprocal inhibition work in muscle movement?"

"Reciprocal inhibition occurs when one muscle (the agonist) contracts while the opposing muscle (the antagonist) relaxes, allowing for smooth movement."

"Identify the main function of the agonist muscle."

"The agonist, or prime mover, is the main muscle responsible for producing a specific movement."

"What is the role of the antagonist muscle?"

"The antagonist muscle opposes the action of the agonist, helping to control and stabilize movement."

"Describe the function of synergist muscles."

"Synergist muscles assist the agonist in performing a movement, providing additional force or stability."

"Explain the role of fixator muscles during movement."

"Fixator muscles stabilize the origin of the agonist during movement, ensuring proper alignment and function."

"Differentiate between isometric and isotonic muscle contractions."

"Isometric contractions occur without changing muscle length, while isotonic contractions involve changes in muscle length, which can be concentric (muscle shortens) or eccentric (muscle lengthens)."

"Describe the sliding filament theory in muscle contraction."

"The sliding filament theory explains that muscle contraction occurs when actin filaments slide over myosin filaments, resulting in the shortening of the muscle fiber."

"Explain the role of actin in muscle contraction."

"Actin is a thin filament that interacts with myosin during muscle contraction, forming cross bridges that enable the sliding motion."

"Define tropomyosin and its function in muscle fibers."

"Tropomyosin is a protein that blocks the binding sites on actin when the muscle is relaxed, preventing contraction."

"How does calcium contribute to muscle contraction?"

"Calcium is released from the sarcoplasmic reticulum and binds to troponin, causing tropomyosin to move away from actin's binding sites, allowing contraction to occur."

"What initiates the process of muscle contraction?"

"The process of muscle contraction is initiated when a nerve sends a message using acetylcholine to the muscle."

"Describe the steps involved in cross bridge cycling during muscle contraction."

"Cross bridge cycling involves attachment of myosin to actin, pulling the actin filament, and then releasing, which is repeated as long as calcium is present."

"Explain the significance of acetylcholine in muscle contraction."

"Acetylcholine is a neurotransmitter that transmits the signal from the nerve to the muscle, triggering the contraction process."

"What happens to tropomyosin when calcium binds to troponin?"

"When calcium binds to troponin, it causes tropomyosin to shift, exposing the binding sites on actin for myosin attachment."

"Define the term 'cross bridge' in the context of muscle contraction."

"A cross bridge refers to the connection formed between the myosin head and the actin filament during muscle contraction."

"How does the sarcoplasmic reticulum contribute to muscle contraction?"

"The sarcoplasmic reticulum stores calcium and releases it into the muscle cell in response to a nerve signal, facilitating muscle contraction."

"Describe the role of ATP in the power stroke of muscle contraction."

"ATP binds to myosin, causing it to detach from actin, and then is broken down into ADP and Pi, providing energy for myosin to reset and prepare for the next contraction."

"Explain the process that occurs when calcium is present during muscle contraction."

"As long as calcium and ATP are present, myosin can continue to bind to actin and perform power strokes, leading to muscle contraction."

"Define the relaxation phase in muscle contraction."

"Relaxation occurs when the nerve signal stops, calcium is reabsorbed into the sarcoplasmic reticulum, binding sites on actin close, and the muscle relaxes."

"How does myosin reset after a power stroke?"

"Myosin resets by breaking down ATP into energy, which allows it to cock back into position to grab actin again."

"What happens to calcium ions when the nerve signal ceases?"

"When the nerve signal stops, calcium ions are pumped back into the sarcoplasmic reticulum, leading to muscle relaxation."

"Explain the significance of calcium in muscle contraction."

"Calcium ions are crucial for muscle contraction as they bind to sites on actin, allowing myosin to attach and perform power strokes."

"Describe the cycle of myosin and actin interaction during muscle contraction."

"Myosin attaches to actin, performs a power stroke, detaches when ATP binds, resets using energy from ATP breakdown, and repeats as long as calcium and ATP are available."