Circulation Maintains homeostasis by transporting materials like food (nutrients), oxygen, water, wastes, heat throughout an animals body.

1) OPEN circulatory system Blood is only partially contained in blood vessels One or more hearts pump blood, which collects in sinuses (open areas where blood is in contact with all body cells). Arthropods:

2) Closed Circulatory System Blood is always contained in blood vessels as it travels throughout the body. Single –loop system because blood only travels in one direction Look: 5 hearts

Find & Highlight the heart & blood vessels (arteries) in the animals here

Vertebrates (Closed Circulatory System) 1.Single Loop System Found in animals with gills Blood flows in a “single-loop” HEART  GILLS  BODY  HEART Blood gets oxygen here (oxygenated) Body uses the oxygen; blood becomes deoxygenated

Single Loop Circulatory System 2) Trace the path of blood 1) Complete the fish’s circulatory system 3) Where does the blood exchange O 2 and CO 2 ?

2. Double-Loop System Found in animals with LUNGS First loop =lungs/heart Oxygen-poor blood from body  right atrium Oxygen-rich blood from lungs  left atrium Blood flows in a “double- loop” Second loop = heart/body Oxygen-rich blood from left atrium  Oxygen-poor blood from right atrium  lungs body

Circulatory Systems Count the number of atria and ventricles in each circulatory system. Highlight them. Trace the path of blood flow. Single loop system Atrium: Ventricles: 1 1 FISH

Circulatory Systems Count the number of atria and ventricles in each circulatory system. Highlight them. Trace the path of blood flow. Double loop system Atrium: Ventricles: 2 1 FROGS, TURTLES, ETC.

Circulatory Systems Count the number of atria and ventricles in each circulatory system. Highlight them. Trace the path of blood flow. Double loop system Atrium: Ventricles: 2 2 MAMMALS

Can you see the difference between single-loop and double-loop?

So, what is the purpose of the heart chambers? Purpose = separate oxygen (O 2 )-rich blood from the oxygen–poor blood – Most efficient heart is one with 4 chambers. A heart with 3 chambers (compared to one with 4 chambers) –has lower pressure and gets less O 2 from the lungs. – Animals with 3 chambers can NOT move as fast as those with 4 chambers.

Which animal moves faster? Why? Look at the two pictures in your notes. Read the comments around the heart. Answer: The bird moves faster Because it has 4 chambers in its heart, not 3. Complete the chart and directions for the rest of the page…

Human circulation Components: 1.Heart 2.Blood vessels 3.blood Function: Pump blood through body to keep it moving. Double loop system with 4 chambers: Right atriumleft atrium Right ventricleleft ventricle

Pathway of blood flow: (deoxygenated) blood from body carried by Superior & inferior vena cava  Right atrium  Tricuspid valve  Right ventricle  Pulmonary valve  Through pulmonary artery  Lungs (where the blood is oxygenated)… lungs

Pathway of blood flow: (oxygenated) blood from lungs… Through pulmonary veins  Left atrium  mitral valve  Left ventricle  Aortic valve  Through aorta  To body to deliver the oxygen Lungs To the body

Notice the ventricles have thicker, more muscular walls than the atria This is because… They have to pump blood a much farther distance Right Ventricle  lungs Left ventricle  rest of the body

Blood Vessels How many different kinds do you see?

Arteries Carry oxygenated blood away form the heart. Thick walls to withstand high blood pressure Largest artery in the body = aorta Arteries that surround the heart muscle are called coronary arteries

Capillaries Connect arteries and veins Surround ALL cells in the body Extremely thin walls for diffusion Ex. Oxygen and carbon dioxide  remember the respiratory system

Veins Carry deoxygenated blood to the heart Have valves to prevent backflow of blood Largest veins in body: superior and inferior vena cava

Pathway of Blood The list below is scrambled. Put them in the correct order. Arteries Heart Capillaries Veins Arterioles Venules Heart

Pathway of Blood Here is the correct order… Heart Arteries Arterioles Capillaries Venules Veins Heart How did you do?

What’s in your blood?

PLASMA Fluid made mostly of water Also contains: Gases (O 2 & CO 2 ) Salts (electrolytes) Nutrients Proteins Enzymes Hormones Wastes

PLASMA Responsible for: 1.Transporting substances (nutrients, gasses, antibodies, wastes, etc.) 2.Regulating blood volume (amount of H 2 O in blood) 3.Fighting infections 4.Clotting when necessary (cuts, etc.)

JOB: Transport O 2 to all body cells Iron is part of the hemoglobin molecule 1) Red Blood Cells (RBC’s) Made in bone marrow Requires iron (for holding O 2 ) which can be found in foods like: meat, beans, seeds, spinach Carbon monoxide (CO) poisoning: CO binds more readily to hemoglobin than O 2 does, so your cells don’t get oxygen and die. How many oxygen molecules can ONE hemoglobin carry?

2) White blood cells (WBC’s) JOB: fight infections Also called leukocytes Usually engulf & digest pathogens (bacteria, etc)

3) Platelets Made of cell fragments

Platelets JOB: clotting see all the fibers connecting together?