The Heart
The Heart Made up of 3 different tissue: cardiac muscle tissue, nerve tissue, and connective tissue. Your heart pumps with a regular beat (Heart Rate) Your heart rate can change depending on your activity, stress, temperature, and general health.
Heart The heart is about the size of your fist and is located in the middle of your chest. It is protected by the sternum and the rib cage. The heart has four chambers, two on each side. ➊
Heart Atria are small chambers on the top of the heart that receive blood and pump it to the ventricles. Ventricles are larger chambers found at the bottom of the heart. The right ventricle pumps blood to the lungs. The left ventricle pumps blood to the rest of the body. ➌ ➊ ➋ ➍ Right Left Fig. 2 pg 257 Nelson Biology 11
The Circulatory System
Blood Flow through the Heart atria contract blood flows from atria to ventricles ventricles contract blood flows from right ventricle to lungs blood flows from left ventricle to aorta (body) Fig. 1 pg 261 Nelson Biology 11
Blood Flow through the Heart Contraction of the atria, fills the ventricles. Contraction of the ventricles, sends blood out of the heart. http://www.medmovie.com/2002demos/chmc_00_normalbeat.html
The Heart A Four chambered muscular organ that pumps blood around your body. The heart is lined by endocardium inside chambers of the heart and reduces friction as blood flows. The muscular tissue of the heart is called myocardium and give it the ability to contract.
1. The Septum Separates the right and left sides of the heart. It prevents the oxygenated and deoxygenated blood from mixing.
2. Tricuspid Valve Located between the right atrium and ventricle. Prevents back flow of blood to right atrium from right ventricle.
3. Bicuspid Valve Located between the left atrium and ventricles. Prevent back flow of blood to left atrium from left ventricle.
4. Pulmonary Semilunar Valve Controls passage of blood from the right ventricle. Prevents back flow of blood to pulmonary arteries from right ventricle.
5. Aortic Semilunar Valve Controls passage of blood from the left ventricle to the aorta.
6. Superior Vena Cava Used to transport deoxygenated blood from the upper part of the body to the right side of heart. Largest vein in the upper body
7. Inferior Vena Cava Used to transport deoxygenated blood from the lower half of the body to the right side of heart. Largest vein in the lower body.
8. Pulmonary Artery Used to transport deoxygenated blood from right side of heart and travel to the lungs. Blood at lungs will pick up oxygen
9. Pulmonary vein Now oxygenated blood (coming from lungs) will reenter heart in pulmonary vein. Brings blood into the Left Atria
10. Aorta Artery that carries blood away from the left side of the heart to body tissues.
Superior Vena Cava Aorta Pulmonary Artery Pulmonary Vein Pulmonary Semilunar Valve Right Atria Tricuspid Valve Left Atria Aortic Semilunar Valve Bicuspid Valve Septum Inferior Vena Cava Left Ventricle Right Ventricle
Heart Sounds we hear a LUB & DUB sound from the heart caused by the closing of the heart valves and refilling of the heart chambers. Diastole: the relaxation of the heart, during which the cavities of the heart fill with blood Systole: contraction of the heart, during which blood is pushed out of the heart.
irregular heartbeats is referred to as Arrhythmia.
Temperature Regulation! Circulatory system is able to control heat loss by changing the volume of blood flowing near the body surface!2 ways:!1.vasodilation - the widening or dilating of the blood vessels to increase blood flow!2.vasoconstriction - the narrowing of the blood vessels to decrease blood flow 32
Controlled by Factors!Blood pressure - if it s high, vasodilation will reduce it. If low, vasoconstriction will increase it!increased metabolic activity. Ex. exercise (increase blood flow to tissues)!foreign substances or chemicals. Ex. alcohol and nicotine 33