Module One: Introduction to the Cardiovascular System

These flashcards cover major concepts from the lecture notes on the cardiovascular system, including its components, blood composition, transport roles, fetal circulation, hemorrhage responses, energy mobilization, and temperature regulation.

What are the three main components of the cardiovascular system?

The heart, blood, and blood vessels.

What is the primary overall function of the cardiovascular system?

Transport of substances throughout the body.

Besides transport, what protective role does the cardiovascular system perform?

Protection against foreign substances via white blood cells (WBCs).

In which direction do arteries carry blood?

From the chambers of the heart to the tissues of the body.

In which direction do veins carry blood?

From body tissues back to the chambers of the heart.

What are the two major circulatory cycles in the body?

Pulmonary cycle and systemic cycle.

Where does blood travel during the pulmonary cycle?

From the heart to the lungs and back to the heart.

Where does blood travel during the systemic cycle?

From the heart to the rest of the body and back to the heart.

What gas is obtained through external respiration in the lungs and delivered to body cells for ATP production?

Oxygen.

Which cardiovascular cargo consists of products of the digestive system delivered to cells for metabolism?

Nutrients.

Name two waste products that blood removes from body cells.

Carbon dioxide (CO₂) and nitrogenous wastes.

What substances produced by endocrine glands are transported by the cardiovascular system to target organs?

Hormones.

What is the fluid vehicle for transport in the cardiovascular system?

Blood plasma (a water-based medium).

Give an example of a conduit that carries blood.

Blood vessels (arteries, veins, capillaries).

Which fluid transport systems are considered more prominent besides the cardiovascular system?

Lymphatic and cerebrospinal fluid systems.

Why does the fetus bypass the pulmonary cycle?

Because fetal lungs do not take in air; oxygen exchange occurs at the placenta.

What percentage of total blood volume is made up of plasma?

Approximately 55%.

List three major plasma proteins.

Albumin, globulins, and fibrinogen.

Which plasma protein is critical for blood clotting?

Fibrinogen.

What is the typical percentage of formed elements (cells) in blood?

About 40–45%.

What is another name for red blood cells (RBCs)?

Erythrocytes.

What molecule inside RBCs has a high affinity for oxygen due to its iron atoms?

Hemoglobin.

Describe the normal mature shape of an RBC and its functional advantage.

A biconcave disc, which increases surface area for gas exchange.

How long is the average life span of an RBC?

Approximately 120 days.

Which organs remove worn-out RBCs and recycle their iron?

The spleen removes old RBCs; the liver salvages iron.

What general term refers to white blood cells?

Leukocytes.

Which WBCs actively engulf foreign substances by phagocytosis?

Neutrophils, monocytes, and other phagocytic WBCs.

Accumulated dead WBCs can form a yellow-white fluid known as __.

Pus.

Which type of leukocyte is chiefly responsible for antibody production?

Lymphocytes.

What are platelets and from which precursor cells do they originate?

They are cell fragments crucial for clotting, originating from megakaryocytes.

During oxygen transport, what is the main element that carries most of the O₂?

Red blood cells via hemoglobin.

Most carbon dioxide in the blood is converted to what ion within RBCs?

Bicarbonate (HCO₃⁻).

What hormone delivered by the cardiovascular system increases metabolic rate during ‘fight-or-flight’?

Epinephrine (adrenaline).

Which circulatory system initially transports the end products of lipid digestion?

The lymphatic circulatory system.

What color fat in infants rapidly releases energy when needed?

Brown fat.

Define hemorrhage.

Escape of blood from damaged blood vessels.

What immediate vessel reaction reduces blood loss after injury?

Vascular contraction (spasm).

What blood component forms an initial plug at small vessel injuries?

Platelets (platelet clumping).

During coagulation, fibrinogen is converted into sticky strands of __.

Fibrin.

Name two organs that act as blood reservoirs.

Spleen and liver (large abdominal veins also function as reservoirs).

When is transfusion of whole blood necessary versus plasma alone?

Whole blood is needed after loss of both fluid and cells (hemorrhage); plasma or substitutes are used when only fluid is lost (e.g., burns).

How do superficial capillary beds aid in eliminating excess heat?

By increasing blood flow to the skin, allowing heat loss and sweat secretion.

Which brain region continuously monitors core blood temperature?

The hypothalamus.

Explain the counter-current heat exchange mechanism in the limbs.

Adjacent arteries warm cooler returning veins, conserving core body heat.

Why do organs like the brain and liver require special cooling of their blood supply?

They have high metabolic rates that generate excess heat.

How is incoming air warmed before reaching the lungs?

Blood flowing through the arteries of the nasal mucoperiosteum warms the air.

What does erythema (redness) of the skin usually indicate?

Increased local blood flow and heat in the area.