Chapter 10 Circulation

Section 1 The Body’s Transport System

The Cardiovascular System The cardiovascular system, or circulatory system, consists of the heart, blood vessels, and blood. The system is carries needed substances to cells and carries waste products from cells. – The cells in blood also helps to fight disease and infecto

The Circulatory System Substances in the body are carried by the blood. – Oxygen from your lungs – Glucose for energy Waste is also eliminated by cells in the body. – Carbon dioxide from glucose Certain cells in the blood also fight infection and disease.

The Red is oxygen rich blood Blue is oxygen poor blood Lungs Heart

The Heart The heart is a hollow, muscular organ that pumps blood throughout your body – About the size of your fist, located in the center of your chest, right behind your sternum Each time your heart beats, it pushes blood through the blood vessels of the cardiovascular system – Heart is made out of cardiac muscle

The

The Heart The right side of the heart is completely separated form the left side by tissue called the septum. Each side has 2 compartments, or chambers, an upper and lower chamber. Each upper chamber is called an atrium – The atrium is the chamber that recieves blood that comes into the heart

The Heart The lower chamber is called a ventricle. – The ventricle pumps blood out of the heart The atrium and ventricle are separated by valves. – A valve is a flap of tissue that prevents blood from flowing backwards.

The Heart How the heart works – In the first phase the heart relaxes and fills the heart with blood. – In the 2 nd phase the heart contracts to pump blood forward.

Two Loops After leaving the heart blood travels in blood vessels through the body. Arteries are blood vessels that carry blood away from the heart. Narrow vessels are called capillaries. – In capillaries substances are exchanged between blood and cells. Veins are what carry blood back to the heart.

Two Loops In the 1 st loop blood travels from the heart to the lungs and then back to the heart. In the 2 nd loop blood is pumped from the heart throughout the body and then back to the heart

The Heart

Two Loops Blood that flows to the lungs and back, the blood is a dark red, which is oxygen poor. Blood flows from the right atrium into the right ventricle. The ventricle pumps the blood to the lungs The large vessels of blood become thinner, into tiny capillaries The blood then absorbs oxygen and pumps back to the heart.

Two Loops In the 2 nd loop, the left atrium recieves the blood and then moves to the left ventricle. The blood then moves through the aorta, the largest vein in the body. The blood then pumps through the veins throughout the body into capillaries and then flows back to the heart to start the cycle again.

Section 2 A Closer Look at Blood Vessels

Arteries If all the veins, arteries and capillaries in your body were connected, they would be 100,000 kilometers long. When blood leaves the heart, it travels through the arteries. The first branches of arteries are called coronary arteries. – Other branches carry blood to the brain, intestines and other organs.

Arteries The walls of the arteries are thick. The walls consist of 3 layers – First layer is epithelial tissue The smooth surface allows for the blood to flow freely – Second layer is muscle tissue – Outer layer is a flexible connective tissue This layered effect gives arteries great strength and flexibility

Arteries Your pulse is caused by the alternating expansion and relaxation of the artery wall. The layer of muscle tissue acts as a control gate of blood flow – So when you eat, your stomach and intestines need more blood – The arteries leading to these organs relax allowing for greater blood flow

Capillaries In the capillaries, materials are exchanged between the blood and the body’s cells. – Materials such as glucose and oxygen pass from the blood to the cells. Capillary walls are only one cell thick Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration.

Veins After the blood moves through the capillaries it enters large vessels called veins which carry blood back to the heart. The walls of the veins are like the artery, the have 3 layers, which muscle in the middle

Veins

Blood Pressure Blood pressure is like water flowing out of a hose – More water, greater pressure, less water less pressure Blood exerts a force called blood pressure against the walls of blood vessels Blood pressure is caused by the force with which the ventricles contract

Section 3 Blood and Lymph

Blood Blood is a complex tissue that has several parts. Blood is made up of 4 components – Plasma – Red blood cells – White blood cells – Platelets

Blood Most of the materials transported in the blood is plasma Plasma is the liquid part of the blood – Water makes up 90% of plasma – Other 10% is dissolved materials Plasma carries glucose, fats, vitamins and minerals Protein gives plasma its yellow color

Blood Red blood cells take up oxygen in the lungs and deliver it to cells elsewhere in the body Red blood cells are made mostly of hemoglobin, which is an iron containing protein that binds to oxygen molecules – When combined with oxygen its turns bright red – Carbon dioxide is carried mostly by the plasma Red blood cells contain no nuclei, and live only 120 days and there are 2 million red blood cell

Blood White blood cells are the body’s disease fighters These cells either fight disease or tell the brain they need help – Some fight by eating, other fight by releasing chemicals – White blood cells are also larger than red blood cells

Blood Platelets are cell fragments that help to form clots This series of reactions produce a protein called fibrin Fibrin weaves a net of fibers across the cut in the skin

Blood

Blood Types Sometimes when a person loose a lot of blood, a blood transfusion is necessary. There are 4 blood types – A, B, AB and O A means there is an A marker, B means a B marker, AB means there is an A and B marker. O has neither A or B

Blood Types The markers molecules on your red bloods cells determine your blood type and the type of blood you can receive for a transfusion.

Blood Types

Lymphatic System The lymphatic system is your body’s drainage system. The lymphatic system is a network of veinlike vessels that returns the fluid to the bloodstream – It acts like rain gutters carrying excess fluid away Once the fluid is in the lymphatic system it is called a lymph. – Consists of water and dissolved materials

Lymphatic System As the fluid flows through lymphatic system it passes through knobs called lymph nodes. Lymph nodes filter lymph, trapping bacteria and other disease causing microorganisms in the fluid. When the body is fighting disease the nodes become enlarged. – This is called swollen glands.

Section 4 Intergrading Health: Cardiovascular Health

Cardiovascular Diseases Diseases of the cardiovascular system include artherosclerosis and hypertension Artherosclerosis is a condition in which an artery wall thickens as a result of fatty buildup. – One substance is cholesterol A heart attack occurs when blood flow to part of the heart is blocked – Cells die during an attack, so there is permanent damage

Cardiovascular Disease Hypertension, or high blood pressure, is the blood pressure is higher than normal. – This makes the heart work harder than it has to Hypertension and artherosclerosis are closely related diseases.

Keeping Healthy To stay healthy people should: – Exercise and diet – Avoid smoking – Eat a balanced diet low in saturated fats, trans fats, cholesterol, and sodium.