BIO 1170

Coronary Circulation

The system of blood vessels that supply blood to the heart muscle.

Arteries

Blood vessels that carry blood away from the heart, usually under high pressure.

Veins

Blood vessels that return blood to the heart, generally operating at lower pressure.

Tunica Intima

The innermost layer of a blood vessel, in direct contact with blood.

Tunica Media

The middle layer of a blood vessel, composed of smooth muscle and elastic fibers.

Tunica Externa

The outer layer of a blood vessel, providing structural support and containing nerves.

Atria

The two upper chambers of the heart that receive blood from the veins.

Ventricles

The two lower chambers of the heart that pump blood into the arteries.

Arterial Anastomoses

Connections between branches of arteries that provide alternate routes for blood flow.

Cardiac Veins

The vessels that drain blood from the heart muscle into the coronary sinus.

Capillaries

Small blood vessels where exchange of gases, nutrients, and waste occurs.

Aorta

The largest artery in the body, carrying oxygenated blood away from the heart.

Pulmonary Circulation

The part of the circulatory system that carries deoxygenated blood from the heart to the lungs.

Systemic Circulation

The part of the circulatory system that carries oxygenated blood from the heart to the rest of the body.

Coronary Sinus

A large vein that collects deoxygenated blood from the heart muscle.

Great Cardiac Vein

The vein that drains blood from the anterior heart and empties into the coronary sinus.

Middle Cardiac Vein

The vein that runs alongside the posterior interventricular artery and drains into the coronary sinus.

Small Cardiac Vein

The vein that collects blood from the right side of the heart and drains into the coronary sinus.

Endothelium

A thin layer of cells lining the blood vessels.

Lumen

The inside space of a tubular structure, such as a blood vessel.

Elastic Tissue

Connective tissue that allows blood vessels to stretch and recoil.

Smooth Muscle

Involuntary muscle found in the walls of blood vessels that regulates diameter.

What primary function does skeletal muscle serve?

Skeletal muscle mainly facilitates voluntary body movements.

What primary function does cardiac muscle serve?

Cardiac muscle is essential for pumping blood throughout the heart and into the circulatory system.

Skeletal muscle primarily utilizes anaerobic metabolism for quick energy bursts, while cardiac muscle predominantly depends on aerobic metabolism for sustained energy needs.

Do skeletal and cardiac muscles rely on the same energy sources?

How does the composition of the tunica media differ between arteries and veins?

The tunica media in arteries is thicker and composed of more smooth muscle and elastic fibers, allowing for high pressure and elasticity. In contrast, veins have a thinner tunica media with less smooth muscle, providing less structural support.

What is the significance of the tunica intima in arteries compared to veins?

The tunica intima in arteries is typically more prominent and smooth to reduce friction, facilitating blood flow under high pressure. In veins, the tunica intima is thinner and may have valves to prevent backflow of blood under lower pressure.

How does the tunica externa differ in structure between arteries and veins?

The tunica externa in arteries is thicker and provides support and protection due to higher pressure, while in veins it is comparatively thinner but may contain more connective tissues and structures like valves.

What role do elastic fibers play in the tunica media of arteries?

Elastic fibers in the tunica media of arteries allow them to stretch and recoil with each heartbeat, maintaining blood pressure and facilitating continuous blood flow.

In terms of blood pressure, how does the structure of veins accommodate their function?

Veins have a thinner tunica media and larger lumen, enabling them to accommodate a larger volume of blood at lower pressure, while the valves prevent backflow and assist in returning blood to the heart.

Cardiovascular System

A system that transports blood and its constituents around the body, delivering oxygen and nutrients to cells and removing waste.

Dual Circulation

A circulatory system in which the output of one circulation serves as the input for the other, consisting of pulmonary and systemic circuits.

Chambers of the Heart

The four compartments of the heart: right atrium, left atrium, right ventricle, left ventricle.

Arteries

Vessels that carry oxygenated blood away from the heart under high pressure.

Veins

Vessels that carry deoxygenated blood toward the heart under low pressure.

Mediastinum

The central compartment of the thoracic cavity, where the heart is located between the two lungs.

Pericardium

The protective sac surrounding the heart, consisting of layers: fibrous pericardium and serous pericardium.

Cardiac Cycle

The sequence of events in one complete heartbeat, including contraction (systole) and relaxation (diastole) phases.

Thermoregulation

The process by which the cardiovascular system helps to maintain body temperature by transporting heat.

Blood Composition

Blood comprises approximately 55% plasma (liquid) and 45% formed elements (cells) such as erythrocytes, leukocytes, and platelets.

What percentage of blood is comprised of plasma?

About 55% of blood consists of plasma.

What is the primary function of dual circulation in the cardiovascular system?

The primary function of dual circulation is to separate oxygenated and deoxygenated blood, allowing for more efficient oxygen delivery to tissues and organs.

How do the pulmonary and systemic circuits function together in dual circulation?

In dual circulation, the pulmonary circuit carries deoxygenated blood from the right ventricle to the lungs for oxygenation, while the systemic circuit carries oxygenated blood from the left ventricle to the rest of the body.

What are the advantages of dual circulation over a single circulatory system?

Dual circulation allows for higher blood pressure in the systemic circuit, enhancing the delivery of oxygen and nutrients and enabling more efficient removal of waste products.

How does the heart accommodate dual circulation?

The heart has four chambers (two atria and two ventricles) that separate the oxygenated and deoxygenated blood, facilitating dual circulation.

What role do valves play in the dual circulation system?

Valves in the heart and blood vessels ensure unidirectional flow of blood, preventing backflow and maintaining efficient circulation.

Homeostasis

The ability of the body to maintain a stable internal environment despite changes in external conditions.

ATP (Adenosine triphosphate)

The primary energy carrier in all living organisms.

ICF (Intracellular Fluid)

Fluid contained within cells, making up a major component of total body water.

ECF (Extracellular Fluid)

Fluid found outside of cells, including interstitial fluid and plasma.

Diffusion

The net movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Tonicity

The ability of a solution to affect the fluid volume and pressure in a cell.

Negative Feedback

A process whereby a system responds to a change by initiating mechanisms that reverse that change.

Positive Feedback

A process that enhances or amplifies changes; it moves a system away from equilibrium.

Feedforward Mechanisms

Anticipatory responses that prepare the body for changes in the environment.

Plasma Membrane

A selectively permeable barrier that separates the cytoplasm from the extracellular fluid.

Selective Permeability

The ability of the plasma membrane to allow certain substances to pass while restricting others.

Carrier Proteins

Proteins that transport specific substances across a cell membrane.

Ion Pumps

Proteins that move ions against their concentration gradient, requiring energy.

Homeostatic Regulation

The process of maintaining stability in an organism's internal environment through feedback systems with regulations.