Bio Human Body Systems Answer Key

ANSWER KEY Biology – Unit #9b: Human Body Systems – Circulatory & Respiratory Systems Study Guide 1. List at least 4 components of your plasma? What percentage of your blood is plasma? How would a high level of salt in your plasma affect your blood volume? Plasma makes up 55% of blood. It is mostly water (90%) and contains glucose, hormones and other chemical nutrients needed by your cells. A high level of salt in your plasma would cause cells to shrink due to osmosis. This would increase the overall volume of water in the plasma itself as water leaves the cells and enters the plasma. 2. Compare and contrast Red Blood Cells, White Blood Cells and Platelets, in terms of normal percent of blood and function. RBCs (45%) – transport oxygen molecules WBCs (<1%) – fight off pathogens Platelets (<1%) – clot the blood Plasma (55%) – carries nutrients, water, proteins and hormones 3. What is the roll of hemoglobin? How does this relate to anemia? What nutrient in the diet do most people with anemia need? Oxygen is transported throughout the body bound to the hemoglobin molecules inside of red blood cells. Hemoglobin contains atoms of iron, which attract oxygen molecules. Anemia results from a lack of enough iron, which affects hemoglobin’s ability to transport oxygen in the blood. 4. What is the difference between an Artery, Vein and Capillary? Explain the purpose of each. Artery – carries blood away from the heart Vein – carries blood in to the heart Capillary – tiny blood vessels that surround the body’s cells and the alveoli; diffusion of gases occurs across the capillaries in or out of the blood 5. Explain how O2 and CO2 diffuse from the alveoli into the capillaries. Oxygen is acquired from the atmosphere during external respiration, when air enters the lungs filling up the alveoli. The concentration of O2 is higher in the alveoli than in the capillaries, so it moves down the concentration gradient into the capillaries. The blood traveling through the capillaries from the heart has a high concentration of CO2. The CO2 diffuses out of the capillaries into the lungs to be exhaled. 6. Explain how O2 and CO2 diffuse from the capillaries to the body cells. The concentration of O2 is higher in the capillaries than in the body cells, so it moves down the concentration gradient into the body cells to be used for cellular respiration. A byproduct of cellular respiration is CO2. As the concentration of CO2 builds up, it becomes higher in the body cells than in the capillaries. The CO2 moves down the concentration gradient into the capillaries to be carried by the blood back to the lungs. 7. Explain the difference between Diastolic and Systolic blood pressure. What is a normal blood pressure? What are 3 health problems associated with high blood pressure? Diastolic pressure is the pressure of the blood against the artery walls while the heart is relaxed. Systolic pressure is the pressure of the blood against the artery walls when the heart contracts. Normal blood pressure is approximately 120/80 mmHg (systolic/diastolic). Some factors that may increase blood pressure are high cholesterol, obesity, unhealthy diet, lack of exercise, stress, and smoking. 8. What are the roles of the left and the right side of the heart? What do the atria do and what do the ventricles do? The left side of the heart receives oxygenated blood from the lungs and pumps it to the body. The right side of the heart receives oxygen-poor blood from the body and pumps it to the lungs. 9. Describe the path that blood takes through the heart. From the body  in through the vena cava (vein)  right atrium  right ventricle  out the pulmonary arteries  to the lungs From the Lungs  in through the pulmonary veins  left atrium  left ventricle  out the aorta (artery)  to the body 10. During the Heart Rate lab, why did your heart rate and breathing rate increase? As you exercise, your muscle cells increase their rate of cellular respiration, using up more oxygen and releasing CO2 at a faster rate. This causes your breathing rate to increase to keep up with oxygen demand and get rid of CO2. It also causes your heart rate to increase so the blood can transport O2 & CO2 more rapidly.