Muscular System and Metabolism

Muscular System

• A sarcomere contains two main types of myofilaments: thick filaments (myosin) and thin filaments (actin)
• Three essential ions and minerals for muscle contraction are: calcium, sodium, and potassium
• Acetylcholine is the neurotransmitter released in a neuromuscular junction

Anaerobic Metabolism

• Glycolysis is the breakdown of glucose into pyruvate, producing ATP and NADH
• Glycolysis takes place in the cell's cytoplasm
• Glycolysis often starts with glucose, a six-carbon carbohydrate
• The final product of glycolysis is pyruvate, which is then converted into lactic acid or used in the citric acid cycle
• 2 ATP are produced once the final product is completed

Aerobic Metabolism

• Aerobic metabolism is the process of generating ATP from glucose, fatty acids, and other energy sources in the presence of oxygen
• The two metabolic pathways used for ATP production are: citric acid cycle (Krebs cycle) and oxidative phosphorylation
• Aerobic metabolism takes place in the mitochondria
• Oxidative phosphorylation produces the most ATP

Nervous System

Divisions of the Nervous System

• The nervous system is divided into: Central Nervous System (CNS) and Peripheral Nervous System (PNS)
• The CNS is responsible for homeostasis and integrates sensory information
• The Somatic Nervous System (SNS) stimulates skeletal muscles and is responsible for the "Fight or Flight" response
• The Autonomic Nervous System (ANS) stimulates smooth and cardiac muscle, cells of glands, and adipose tissue, and is responsible for the "Rest and Digest" response
• The direction of nerve stimulation in the sensory pathway is towards the CNS, while in the motor pathway it is away from the CNS

Action Potential and Neurotransmitter Release

• Three ions that help with the movement of an action potential and release of the neurotransmitter are: sodium, potassium, and calcium

Reflex

• A reflex is an automatic, involuntary response to a stimulus, often involving a sensory receptor, a neuron, and an effector organ

Neuroglia

• In the CNS, the four types of neuroglia are: astrocytes, oligodendrocytes, ependymal cells, and microglia
• In the PNS, the two types of neuroglia are: Schwann cells and satellite cells