Chapter 12 The Circulatory System

The Circulatory system, also known as the Cardiovascular system, consist of the heart, blood vessels, and blood. The Circulatory system, also known as the Cardiovascular system, consist of the heart, blood vessels, and blood. Cardio – means heart Cardio – means heart Vascular – means blood vessels Vascular – means blood vessels

The blood vessels of the cardiovascular system reach throughout the entire body. Blood flows through these vessels to every organ in the body. The blood vessels of the cardiovascular system reach throughout the entire body. Blood flows through these vessels to every organ in the body.

Functions of the Circulatory System Carries needed materials to the cells Carries needed materials to the cells Oxygen from the lungs Oxygen from the lungs Glucose (from food) to produce energy Glucose (from food) to produce energy Carries waste products away from the cells Carries waste products away from the cells Carbon dioxide Carbon dioxide Transports cells that fight disease Transports cells that fight disease

The Heart The Heart The heart is made up of two sides with an upper and lower chamber on both sides. The heart is made up of two sides with an upper and lower chamber on both sides. The heart works with the lungs to provide oxygen to the body. The heart works with the lungs to provide oxygen to the body.

Atrium – the two upper chambers of the heart. Receive blood coming into the heart. Atrium – the two upper chambers of the heart. Receive blood coming into the heart. Ventricle – the two lower chambers of the heart. Pumps blood out of the heart. Ventricle – the two lower chambers of the heart. Pumps blood out of the heart. Valve – a flap of tissue that prevents blood from flowing backward. Located between each chamber and in the large blood vessels. Valve – a flap of tissue that prevents blood from flowing backward. Located between each chamber and in the large blood vessels.

How the Heart Works The heart muscle relaxes and the atria fill with blood. The heart muscle relaxes and the atria fill with blood. The atria contracts and fill the ventricles with blood. The atria contracts and fill the ventricles with blood. The ventricle contracts to pump the blood out of the heart and into the arteries. The ventricle contracts to pump the blood out of the heart and into the arteries.

The Heart Beat The heart makes a lub-dub sound. The heart makes a lub-dub sound. The lub sound is the valve between the atrium and the ventricle shutting. The lub sound is the valve between the atrium and the ventricle shutting. The dub sound is the valve between the ventricle and the arteries. The dub sound is the valve between the ventricle and the arteries.

Two Loops In the first loop blood travels from the heart to the lungs and back to the heart. In the first loop blood travels from the heart to the lungs and back to the heart. In the second loop blood travels from the heart to the body and back to the heart. In the second loop blood travels from the heart to the body and back to the heart. lungs

First Loop Blood from the body enters the right atrium Blood from the body enters the right atrium Blood passes from the right atrium to the right ventricle Blood passes from the right atrium to the right ventricle Blood is pumped out of the right ventricle into the large artery going to the lungs where it picks up oxygen Blood is pumped out of the right ventricle into the large artery going to the lungs where it picks up oxygen

Second Loop Oxygenated blood from the lungs flows into the left atrium Oxygenated blood from the lungs flows into the left atrium Blood passes from the left atrium into the left ventricle Blood passes from the left atrium into the left ventricle The left ventricle contracts squeezing the blood into the Aorta that carries blood throughout the body. The left ventricle contracts squeezing the blood into the Aorta that carries blood throughout the body.

Three kinds of Blood Vessels Arteries – blood vessels that carry blood away from the heart Arteries – blood vessels that carry blood away from the heart Veins – blood vessels that carry blood back to the heart Veins – blood vessels that carry blood back to the heart Capillaries – tiny blood vessels capable of exchanging substances between the blood and body cells Capillaries – tiny blood vessels capable of exchanging substances between the blood and body cells

Three kinds of Blood Vessels

Regulation of Heartbeat The pacemaker regulates the heart beat. The pacemaker regulates the heart beat. A group of cells located in the right atrium A group of cells located in the right atrium Sends signals that make the heart contract Sends signals that make the heart contract Constantly receives internal stimuli about the body’s oxygen needs. Constantly receives internal stimuli about the body’s oxygen needs.