Lecture Review: Anatomy and Physiology of Muscles and Neurons

A set of flashcards to review key concepts, definitions, and physiological processes from the lecture on muscles and neurons.

What are the three main components of bone composition?

67 percent inorganic components, 33 percent organic components (primarily collagen), and 99 percent of the body’s calcium.

What hormone is secreted from the parathyroid glands to increase blood calcium levels?

Parathyroid hormone (PTH).

How do osteoclasts contribute to calcium regulation in the body?

Osteoclasts erode the bone matrix, releasing stored calcium into the bloodstream.

What is the role of calcitonin?

Calcitonin inhibits osteoclast activity and decreases blood calcium levels.

What is the primary function of skeletal muscle tissue?

To produce skeletal movements by pulling on bones.

What are the layers of connective tissue surrounding skeletal muscle fibers?

Epimysium, perimysium, and endomysium.

What is the sliding filament theory?

It states that during muscle contraction, thin filaments slide past thick filaments, shortening the sarcomeres.

What initiates the contraction cycle in muscle fibers?

The binding of calcium ions to troponin.

What happens at the neuromuscular junction (NMJ)?

The motor neuron releases acetylcholine (ACh) that binds to muscle fiber receptors, leading to muscle contraction.

What is muscle tone?

The continuous and passive partial contraction of the muscles, regulated at a subconscious level.

What are the three sources of ATP for muscle fibers?

Glycolysis, aerobic metabolism, and creatine phosphate (CP).

What is hypertrophy?

The increase in muscle size due to an increase in myofilaments and myofibril size.

How does the muscle fiber respond to a decrease in pH during fatigue?

Decreased calcium/troponin binding, leading to decreased muscle performance.

What are the two types of synaptic potentials?

Excitatory postsynaptic potential (EPSP) and inhibitory postsynaptic potential (IPSP).

How does summation contribute to action potentials in neurons?

It refers to the integration of multiple postsynaptic potentials to reach the threshold for firing an action potential.

What is unique about unipolar neurons?

Dendrites and axon are continuous, with the cell body located off to one side.

What are neuroglia?

Cells in the nervous system that support and protect neurons.

What triggers action potentials in neurons?

A stimulus that causes the neuron to depolarize, reaching a threshold.

What type of ions contribute to hyperpolarization of a neuron?

Potassium ions (K+) leaving the cell.

What is the role of the sodium-potassium pump?

To actively transport sodium ions out of the cell and potassium ions into the cell, maintaining resting membrane potential.