Biology: Muscle Physiology and Nervous System

Muscle Anatomy and Nervous System

• Origin: The starting point of a muscle's attachment to a bone.

Muscle Physiology

• Insertion: The point of attachment of a muscle to a bone that moves when the muscle contracts.
• Prime Mover: A muscle that produces the primary movement in a joint.
• Antagonist: A muscle that opposes the action of another muscle.
• Synergist: A muscle that assists the movement produced by a prime mover.
• Fixator: A muscle that stabilizes a joint, allowing other muscles to produce movement.

Muscle Contraction

• Sarcomere: The functional unit of muscle contraction, consisting of actin and myosin filaments.
• Threshold: The minimum intensity of a stimulus required to generate an action potential.
• Action Potential: A rapid change in the electrical potential of a muscle cell membrane that triggers muscle contraction.
• Cross-bridge: The temporary bonds formed between actin and myosin filaments during muscle contraction, generating force.
• Power Stroke: The movement of the myosin head along the actin filament, producing force.

Nervous System

• Neuromuscular Junction: The site where a motor neuron terminates and releases neurotransmitters to stimulate muscle contraction.
• Neurotransmitter: A chemical messenger released by a neuron to transmit signals to other neurons or muscle cells.
• Myoglobin: A protein in muscle cells that stores oxygen for energy production.
• Neuron: A nerve cell that receives and transmits information.
• Neuroglia: Non-neuronal cells that provide support and maintenance functions for neurons.

Nervous System Organization

• Central Nervous System (CNS): The brain and spinal cord, responsible for integrating and processing information.
• Peripheral Nervous System (PNS): Nerves that connect the CNS to the rest of the body, dividing into somatic and autonomic systems.
• Autonomic Nervous System (ANS): A branch of the PNS controlling involuntary functions, such as heart rate and digestion, divided into sympathetic and parasympathetic divisions.
• Somatic Nervous System: A branch of the PNS controlling voluntary movements.
• Sympathetic Division: The "fight or flight" response system, stimulating "energy-expending" activities.
• Parasympathetic Division: The "rest and digest" response system, promoting relaxation and reduced energy expenditure.

Neural Pathways

• Sensory (Afferent) Pathway: A neural pathway transmitting information from sensory receptors to the CNS.
• Motor (Efferent) Pathway: A neural pathway transmitting information from the CNS to muscles or glands, producing a response.
• Reflex: An automatic, involuntary response to a stimulus, often involving a sensory receptor, CNS integration, and motor response.

Test your knowledge of muscle physiology and the nervous system, including concepts like muscle fibers, neurons, and neural pathways.