Animal Circulation. Cellular Respiration One very important process that takes place most of your cells is cellular respiration.

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1 Animal Circulation The Cardiovascular System Coordinated activities such as growth and homeostasis depend on: transfer of ions, waste products, signaling molecules, transport proteins, and other substances within the body The circulatory system is a internal transport system consisting of: blood vessels, a muscular heart, and fluids Cellular Respiration One very important process that takes place most of your cells is cellular respiration. How all of your cells get energy from food How do all of our cells get O 2 and glucose to them? What about getting rid of CO 2? Respiratory and Circulatory systems! Blood Contains Many Different Cell Types Blood plasma is the fluid portion of blood and is 92 percent water; it contains dissolved gases, ions, and molecules Red blood cells contain oxygen binding proteins called hemoglobin for transporting oxygen throughout the body White blood cells are involved with fighting foreign substances Blood Contains Many Different Cell Types Platelets are fragments of larger cells that clump together to help stop the loss of blood if a vessel is damaged Iron containing protein that transports O 2 and CO 2. Makes up approximately 97% of the red blood cells' dry content in mammals Hemoglobin Iron containing hemegroups are in green 1

2 Other blood pigments: Hemocyanin Other animals use metals such as copper, manganese, and vanadium Horseshoe crabs use hemocyanin, blue when oxygenated and clear when not! We collect horseshoe crab blood for testing the presence of some bacteria Other Oxygen Binding Proteins Myoglobin: muscle tissue of many vertebrates, including humans, gives muscle tissue a distinct red or dark gray color. It is very similar to hemoglobin. It is used to store oxygen rather than transport it. Other colors of oxygen transporting fluid: Some marine invertebrates: pink/violet when oxygenated, clear when not. Iron. Some annelids: green when deoxygenated and red when oxygenated. Iron. Bivalve mollusk Pinna squamosa: Brown, Manganese. Diversity of the Heart Closed verses Open Circuit Circulatory Systems Open circuit Fish Amphibians and Reptiles Mammals Closed circuit Pumps Blood to the Body through Two Circuits The pulmonary circuit flows between the heart and the lungs deo 2 to lungs to pick up oxygen and unload CO 2 The systemic circuit flows between the heart and the body O 2 rich blood to all body cells and removes wastes The human heart is divided into four chambers that create two physically independent pumping units 2

3 The chambers on the right and left sides of the heart are separated by a thick wall of tissue called the septum The upper chambers: atria The lower, larger chambers are called the ventricles The chambers on the left side of the heart: receive oxygenated blood returning from the lungs pump oxygenated blood through the systemic circuit The two chambers on the right side of the heart: receive blood returning from the systemic circuit that is low in oxygen and rich with CO 2 pump that blood through the pulmonary circuit The atria contract simultaneously and move blood to the ventricles The ventricles have large, muscular walls, which are required for moving blood out of the heart The atria and ventricles are separated by valves that allow blood to flow in only one direction Measuring the Heart The heart rate is the number of times the heart beat per minute and can be measured as the pulse rate Blood pressure measures the pressure in the arteries leading to the body from the left ventricle The beating of the heart is part of the cardiac cycle, which is made up of a relaxation phase and a contraction phase 3

4 The cardiac cycle is made up of a relaxation phase and a contraction phase Diastole: relaxation phase of the cardiac cycle Systole is the pumping phase, during which blood is pumped first from the atria to the ventricles then from the ventricles to the lungs or the rest of the body The signal to contract is delivered to the heart muscle by a group of specialized cells in a region of the heart called the sinoatrial (SA) node The signals from the SA node are relayed to the atrioventricular (AV) node If the SA node is not working correctly an artificial pacemaker is sometimes implanted Written as a ratio of systolic to diastolic pressure for example: 120/80 mmhg Systolic pressure represents the higher value in a blood pressure reading and diastolic pressure is the lower value Blood Pressure Blood Pressure 4

5 Arteries branch many times to form a network of arterioles that carry blood from the heart for distribution to the body and control the flow of blood to the capillaries Arteries have highly elastic walls that enable them to stretch when a heart contraction increases the blood pressure All blood flowing away from the heart is in arteries Capillaries allow the exchange of materials between the blood and the surrounding interstitial fluid and cells Capillary bed of the thyroid gland Capillaries have extremely thin, porous walls across which materials diffuse easily The large surface area of capillaries ensures efficient exchange of gases, nutrients, and other materials with the surrounding interstitial fluid, and in turn with respiring cells Veins bring blood back to the heart via a network of increasingly larger vessels All blood flowing towards the heart is in venules or veins Veins have specialized oneway valves to keep blood flowing toward the heart against gravity Yes, exercising keeps your blood flowing!! More on the Cardiovascular System and Homeostasis The heart can be influenced by the nervous system and signaling molecules Norepinephrine is a neurotransmitter that causes the cells of the SA node to signal the heart to beat faster and more forcefully under stressful situations Changes in body temperature and exercise can also affect the heart rate of an individual 5

6 The Cardiovascular System and Homeostasis Flow Charts! 6