Human Anatomy and Physiology - Muscles and Muscle Tissue

These flashcards cover key concepts related to muscle contraction, motor units, muscle twitches, energy sources, and fatigue as outlined in the Human Anatomy and Physiology lecture notes.

What is the difference between isometric and isotonic contraction?

Isometric contraction involves no shortening while muscle tension increases; isotonic contraction involves muscle shortening when tension exceeds load.

What does a motor unit consist of?

A motor unit consists of one motor neuron and all the muscle fibers it innervates.

What are the three phases of a muscle twitch?

The three phases of a muscle twitch are the latent period, period of contraction, and period of relaxation.

What is temporal summation in muscle contraction?

Temporal summation occurs when two stimuli are received by a muscle in rapid succession, leading to increased force in contractions.

What is the role of creatine phosphate in muscle contraction?

Creatine phosphate donates a phosphate to ADP to instantly form ATP, providing energy for muscle contraction.

What is the difference between anaerobic and aerobic respiration?

Anaerobic respiration does not require oxygen and produces lactic acid, whereas aerobic respiration requires oxygen and produces a larger amount of ATP.

What causes muscle fatigue?

Muscle fatigue can result from ionic imbalances, increased inorganic phosphate, decreased ATP, increased magnesium, and decreased glycogen.

What is excess postexercise oxygen consumption (EPOC)?

EPOC refers to the extra oxygen needed to restore the muscle to its pre-exercise state, replenishing reserves and removing lactic acid.

What are isotonic contractions and provide examples?

Isotonic contractions involve muscle length change while moving a load. Concentric contractions shorten the muscle, e.g., lifting a book; eccentric contractions lengthen it, e.g., laying a book down.

What determines the strength of muscle contraction?

The strength of muscle contraction is graded by changing the frequency of stimulation and the strength of the stimulation.