Ch. 6 - The Cardiovascular System

Ch. 6 - The Cardiovascular System

Ch. 6 - Part 8 - Vocabulary Terms to Know (for vocab foldable):

• formed elements

• plasma

• red blood cells

• white blood cells

• platelets

Open Ended

Why do you think the cardiovascular system is important?

The Cardiovascular System

• The cardiovascular system's main responsibility is to circulate, or move blood throughout the body so that the blood can deliver oxygen & nutrients to the body's cells & remove waste materials like carbon dioxide.

• The blood also transports hormones secreted by the endocrine system

The heart, arteries, and veins are the main organs of this system

Because of the cardiovascular system's important, life sustaining role, cardiovascular diseases & disorders are often serious & even life threatening.

Multiple Choice

The leading cause of death in the United States is _______.

• Cancer

• Coronavirus

• Heart disease

• Lung disease

Some common diseases & disorders of the cardiovascular system include:

• myocardial infarction (heart attack)

• aneurysm (burst blood vessel)

• atherosclerosis

• heart murmurs

• hypertension

• endocarditis

The Heart

A normal heart rate when you're not being active is between 60 - 100 beats per minute. The heart is about the size of a clenched fist.

The heart has four chambers

• The upper chambers, or atria (plural for atrium) & the lower chambers, or ventricles

• The upper chambers receive blood coming into the heart

• The lower chambers pump blood out of the heart

The septum divides the heart vertically into right & left halves.

The interatrial septum seperates the right & left atria.

The thick interventricular septum divides the 2 ventricles.

The walls of the septum prevent oxygen-rich blood from mixing with oxygen-poor blood.

The heart consists of three layers:

• Outer layer, called the pericardium is a double-layered sac

• Middle layer, the myocardium, is the muscle of the heart

• Innermost layer, endocardium lines the heart chambers & valves

Valves of the Heart

• The heart has 4 valves, which ensure that blood flows in only one direction

• The 2 atrioventricular valves (AV valves) are located between the atria & the ventricles

• When the AV valves open, they allow blood flow to travel from the atria into the ventricles

• If closed, the AV valves prevent blood from flowing backward into the atria as the ventricles contract

Valves of the Heart

• The AV valve on the right side of the heart is called the tricuspid valve.

• The AV valve on the left side of the heart is called the mitral valve, or bicuspid valve.

Valves of the Heart

• The 2 valves that separate the ventricles from the lungs & rest of the body are called the semilunar valves.

• The pulmonary valve, located at the opening of the pulmonary artery is on the right side of the heart

• The aortic valve, located at the opening of the aorta is on the left side of the heart

Multiple Choice

How many valves does the heart have?

• 2

• 4

Multiple Select

The 2 atrioventricular (AV) valves that are located between the atria and ventricles are the _____ and ______.

• pulmonary valve

• tricuspid valve

• aortic valve

• mitral valve

Blood Flow through the Heart

To fully understand how the heart performs its critical function, you should understand the step-by-step flow of blood through the heart. This process is happening on both sides of the heart at the same time.

Blood Vessels

The heart pumps blood through the blood vessels to all parts of the body.

Blood Vessels

There are 3 types of blood vessels that transport blood throughout the cardiovascular system: arteries, capillaries, & veins.

Arteries

• With the exception of the pulmonary arteries (which carry oxygen-poor blood to the lungs), all arteries in the body carry oxygen-rich blood away from the heart.

• Arterial blood is bright red in color bc of the O2 it carries.

• Arterial walls are thick bc they have to withstand the pumping force of the heart.

• Arteries branch into arterioles, connecting arteries to capillaries

Arteries

• The aorta is the largest artery in the body

• Coronary arteries branch off the aorta to supply blood to the walls of the heart

• Blockage of a coronary artery may result in coronary artery disease (CAD) and a heart attack

Veins

• Veins are vessels that carry oxygen-poor blood from the capillaries back to the heart.

• Smaller veins, called venules, carry blood from the capillaries to the veins; at that stage the blood is called venous blood.

• Venous blood is a darker red color than arterial blood.

Veins

• Veins have thinner walls than arteries & valves that help prevent backward flow of blood.

• These valves keep venous blood moving forward to the heart.

Capillaries

• Capillaries are microscopic, thin-walled blood vessels.

• Nutrients pass from the bloodstream to the cells of the body via the capillaries.

• The body's cells take in oxygen & nutrients from the blood through the thin capillary walls & transfer waste & carbon dioxide to the blood cells in the capillaries

Multiple Choice

True or False. With the exception of the pulmonary arteries, all arteries in the body carry oxygen-rich blood away from the heart.

• True

• False

Multiple Choice

There are 3 types of blood vessels that transport blood throughout the cardiovascular system. This vessel allows nutrients to pass from the bloodstream to the cells of the body. The body's cells take in oxygen & nutrients from the blood through this vessel's walls. Which vessel is this?

• artery

• vein

• capillary

• arteriole

Components of the Blood

• The average adult body contains between 4 & 6 quarts of blood.

• Blood contains many different types of solid cells (known collectively as the formed elements), which are suspended in the plasma, or liquid portion of blood.

• Formed elements - the solid components of blood, including red blood cells, white blood cells, & platelets.

• Plasma - the liquid component of blood.

• Plasma is about 90% water w/ the remaining 10% comprised of proteins, electrolytes, nutrients, ions, gases, waste products, & hormones.

• About 55% of blood is made up of plasma & the other 45% is the formed elements.

Components of the Blood - RBCs

• Red blood cells (also called erythrocytes) are produced in the bone marrow

• Red Blood Cells - part of the formed elements; contain hemoglobin, which carries oxygen & carbon dioxide to & from the body's cells; also called erythrocytes

• RBCs live for about 120 days before being broken down by the liver & spleen

• Immature RBCs are rarely seen outside of the bone marrow, but mature RBCs are appear by the millions in one drop of blood.

• RBCs contain hemoglobin, a protein that carries oxygen to the body's cells & picks up carbon dioxide from the cells

• Hemoglobin contains iron, which is neccessary for body survival

Components of the Blood - WBCs

• White blood cells, or leukocytes, are not as numerous as red blood cells & live for about 3-9 days

• WBCs are part of the immune system; main function is to fight infection

• There are 5 types of WBCs: neutrophils, lymphocytes, monocytes, eosinophils, & basophils

• White Blood Cells - part of the formed elements; fight infection in the body; also called leukocytes

Components of the Blood - Platelets

• Platelets (thrombocytes) are actually fragments of specialized bone marrow cells.

• Platelets - part of the formed elements; play an important role in blood clotting.

• Platelets are essential for the formation of blood clots, which stop bleeding.

• When a cut occurs in the body, platelets form a plug at the site of the cut, beginning the clotting process.

Multiple Choice

The solid components of the blood make up the formed elements. Which of the following is not a formed element?

• red blood cells

• plasma

• white blood cells

• platelets

Electrical Activity of the Heart

The conductions system of the heart is responsible for controlling the rate, rhythm, & strength of heart beats, or contractions.

Electrical Activity of the Heart

The conductions system conveys electrical impulses that facilitate proper heart function

Open Ended

What's the difference between an artery and a vein?