Lecture 15-19: Muscle Physiology and Blood Circulation

These flashcards cover essential concepts related to muscle physiology, blood composition, functions of blood, and respiratory physiology.

What are the four unique characteristics of muscle tissue?

Excitability, Contractility, Extensibility, Elasticity.

What are the functions of skeletal muscle?

Body movement, maintenance of posture, temperature regulation, storage and movement of materials, protection/support.

What distinguishes skeletal muscle fibers?

They are long, cylindrical, multinucleate, striated, and under voluntary control.

What are the characteristics of cardiac muscle fibers?

Striated, one or two nuclei, Y-shaped, autorhythmic, under involuntary control.

What characterizes smooth muscle fibers?

Nonstriated, tapered ends, one nucleus, involuntary control.

What are the two functional categories of smooth muscle?

Single-unit smooth muscles and multi-unit smooth muscles.

What is the difference between isotonic and isometric contractions?

Isotonic contractions change muscle length while isometric contractions do not.

What is the role of calcium ions in muscle contraction?

Calcium ions bind to troponin, exposing binding sites for myosin on actin myofilaments.

What are the phases of a muscle twitch?

Latent phase, Contraction phase, and Relaxation phase.

What is a cross-bridge cycle?

It refers to the cycle of myosin binding to actin and pulling it during muscle contraction.

What happens during excitation-contraction coupling?

An action potential triggers calcium release from the sarcoplasmic reticulum, leading to muscle contraction.

What is oxygen debt?

The amount of oxygen required to restore the body to its pre-exercise state.

What are the primary functions of blood?

Transportation of oxygen and carbon dioxide, regulation of temperature, pH and fluid volume, and protection through immune response.

What are the three fractions of blood composition?

Plasma (55%), Erythrocytes (44%), and Buffy coat (1%).

What is the main function of erythrocytes?

To transport oxygen and carbon dioxide.

What is the difference between type A and type B blood?

Type A has A antigens and anti-B antibodies, while type B has B antigens and anti-A antibodies.

What is the universal donor and universal recipient in blood types?

Universal donor is O negative, and universal recipient is AB positive.

What initiates the hemostatic process?

Exposure of collagen when a blood vessel is injured.

What are the components of the coagulation cascade?

Intrinsic pathway, extrinsic pathway, and the common pathway.

What are the factors affecting stroke volume?

Preload, contractility, and afterload.

What regulates heart rate?

The autonomic nervous system and chemical agents like hormones.

What are the primary respiratory functions?

Ventilation, gas exchange, and oxygen utilization.

How is gas exchange facilitated in the lungs?

Through the partial pressure differences of gases across the alveolar and capillary membranes.