The Circulatory System Quiz

The Circulatory System

• The circulatory system is the organ system responsible for transporting substances throughout the body.
• The circulatory system comprises blood, the heart, and blood vessels.
• The circulatory system contains four types of tissue: connective, epithelial, cardiac muscle and nerve tissue.
• Blood is a type of connective tissue that circulates throughout the body.
• Blood transports oxygen, nutrients, heat energy, carbon dioxide, hormones, and waste.

Blood

• Blood is 45% red blood cells.
• Red blood cells (erythrocytes) contain hemoglobin, which has four sites where oxygen and carbon dioxide can attach.
• Oxygen is transported from the lungs to tissues in the blood.
• Carbon dioxide is transported from tissues to the lungs in the blood.
• Blood is also 1% white blood cells (leukocytes).
• Macrophages ("eat" infections) are a type of white blood cell.
• Lymphocytes form antibodies that attach to and destroy infections.
• Platelets make up less than 1% of blood and are responsible for blood clotting.
• Plasma is 55% of blood and is the liquid part.
• Plasma is rich in protein, controls blood volume and blood pressure, and carries dissolved minerals, nutrients, and wastes.

The Heart

• The heart contains three types of tissue: cardiac muscle, nerve, and connective tissue.
• The heart is divided into four chambers.
• Blood flows from the body to the heart, to the lungs, and back to the body.
• The heart's chambers are the right atrium, right ventricle, left atrium, and left ventricle.

Blood Vessels

• There are three types of blood vessels: arteries, veins, and capillaries.
• Arteries carry blood away from the heart with high pressure.
• Artery walls are thick and muscular to withstand the pressure.
• Veins carry blood toward the heart.
• Capillaries are small blood vessels with very thin walls (one cell thick).
• Blood cells pass through capillaries one at a time, and materials (like oxygen and carbon dioxide) are exchanged.
• All blood vessels have an endothelium layer, a smooth muscle layer, and a connective tissue layer.