Bio 102 Lab 03 Hematology And Circulation
Bio 102 Lab 03 Hematology And Circulation
Animals too large to accomplish internal transport by diffusion are equipped with a system of branching vessels filled with blood, which is usually propelled through the system by the muscular contractions of the heart. Vertebrates have a closed circulatory system—a circuit of continuous vessels. Other animals, such as arthropods and annelids, have an open circulatory system: blood flows from vessels to open spaces in the tissues and then to vessels again.
A pump is used to move the blood throughout the vessels of the circulatory system. Many organisms couple the circulatory system with a respiratory surface such as lungs or gills, where gases can be exchanged between the blood and the environment. In vertebrates other than birds and mammals, a serial circuit delivers blood directly from the respiratory surface to the tissues. The parallel circuitry (pulmonary and systemic systems) present in birds and mammals is more efficient. Blood traveling in the circulatory system is made up of a fluid matrix called plasma, which carries cells, oxygen, nutrients, wastes, and other materials from one region of the body to another.
Blood often contains special respiratory pigments that deliver the oxygen throughout the body. The rate at which the blood is pumped by the heart can be measured as one’s pulse. Blood pressure is a measure of the force exerted by blood against the walls of the blood vessels. Both pulse and blood pressure can be influenced by a variety of factors, including diet, exercise, hormones, age, smoking, alcohol intake, and a number of other environmental factors. During this laboratory, you will investigate the properties of blood cells, learn the path taken by blood through the heart and lungs, take your pulse, and learn what blood lab values mean.
Section A – Hematology
Part 1 – Hematology - Blood cells
Blood contains white cells (leukocytes) and red cells (erythrocytes). Mature mammalian erythrocytes are biconcave disks that lack a nucleus and contain hemoglobin for the transport of oxygen. Leukocytes are nucleated cells. Granulocytes and monocytes, types of leukocytes, transform into macrophages that migrate to infected areas, where they perform a clean-up function. Lymphocytes, another type of leukocyte, are responsible for immune reactions.
Many infections are characterized by an increase in the white blood cell count. 1. Observe the photograph of a prepared slide of human blood. Use Figure below to help identify cell types. Human Blood Slide © Carolina Biological
- On this slide, which type(s) of blood cells lack(s) nuclei?
- On your slide, which cell type is most abundant?
- Which type of white blood cell (leukocyte) is most abundant?
- Granulocytes are characterized by nuclei of many different shapes and by the granules in their cytoplasm. What color are these granules? Why do the granules have this color?
2. Examine the slide of blood from a carrier of sickle-cell anemia in low-oxygen crisis.
- a. Make a sketch of several abnormal red blood cells.
- b. Healthy red blood cells are round. Are all the red blood cells on your slide round?
- c. How do you think the abnormal shape of some of the red blood cell would interfere with circulation?
The hemoglobin of an individual who carries the recessive sickle-cell allele in the heterozygous condition is less soluble than normal hemoglobin. When the oxygen supply is inadequate or when the carbon dioxide concentration increases, sickle-cell hemoglobin molecules tend to crystallize to form hair-like rods that pile up and transform the cell into a sickle shape. The cells then clump and clog the blood vessels and cannot carry out their function of transporting oxygen. To determine whether a person is a carrier of the sickle-cell allele, blood is subjected to a low-oxygen atmosphere and examined with a microscope.
In an individual who is homozygous for the sickle-cell allele (that is, has sickle-cell anemia), hemoglobin is abnormal even at normal oxygen and carbon dioxide concentrations.
3. Mononucleosis is a disease characterized by fever, headache, scratchy throat, easy fatigue after minimal exertion, and enlargement of the lymph glands. Examine the blood slide from a person with mononucleosis. Do some of the white blood cells look abnormal? How?
4. Examine a prepared slide of frog blood. B How do frog erythrocytes differ from those of humans?
Part 2 - HEMATOLOGY – Analysis of Complete blood counts
WHAT ELSE CAN YOUR BLOOD TELL YOU ABOUT YOUR HEALTH? Blood has many compounds and enzymes that provide a window into a person’s health.
As part of a full checkup a complete blood count (CBC) is often conducted. Typical tests included in a CBC are shown below in the chart from the National Heart, Lung, and Blood Institute (a part of the National Institutes of Health in Bethesda, Maryland). In addition to these standards, additional tests may be carried out depending upon your risk factors or symptoms. A second blood test may be ordered to further investigate abnormal results of an initial blood test.
| Test | Normal Range | Results* |
|---|---|---|
| Red blood cell (varies with altitude) | Male: 5 to 6 million cells/mcL Female: 4 to 5 million cells/mcL | |
| White blood cell | 4,500 to 10,000 cells/mcL | |
| Platelets | 140,000 to 450,000 cells/mcL | |
| Hemoglobin (varies with altitude) | Male: 14 to 17 gm/dL Female: 12 to 15 gm/dL | |
| Hematocrit (varies with altitude) | Male: 41% to 50% Female: 36% to 44% | |
| Mean corpuscular volume | 80 to 95 femtoliter |
Blood Glucose: This table shows the ranges for blood glucose levels after 8 to 12 hours of fasting (not eating). It shows the normal range and the abnormal ranges that are a sign of prediabetes or diabetes.
| Plasma Glucose Results (mg/dL)* | Diagnosis |
|---|---|
| 70 to 99 | Normal |
| 100 to 125 | Prediabetes |
| 126 and above | Diabetes |
LDL (bad cholesterol) and HDL (good cholesterol) levels after 9 to 12 hours of fasting are also used for health assessments.
| Total Cholesterol Level | Category |
|---|---|
| Less than 200 mg/dL | Desirable |
| 200–239 mg/dL | Borderline high |
| 240 mg/dL and above | High |
| LDL Cholesterol Level | Category |
|---|---|
| Less than 100 mg/dL | Optimal |
| 100–129 mg/dL | Near optimal/above optimal |
| 130–159 mg/dL | Borderline high |
| 160–189 mg/dL | High |
| 190 mg/dL and above | Very high |
HDL Cholesterol Level
| HDL Cholesterol Level | Category |
|---|---|
| Less than 40 mg/dL | A major risk factor for heart disease |
| 40–59 mg/dL | The higher, the better |
| 60 mg/dL and above | Considered protective against heart disease |
Questions & Analysis:
- Why do you think hemoglobin levels vary with altitude?
- High levels of what substance found in the blood can determine diabetes and prediabetes?
- High cholesterol and triglycerides may indicate cardiovascular disease. What happens when cholesterol and other lipids are deposited in artery walls? When this happens, what is the process called?
Part 1 - Evolutionary Circulation
The circulatory system is responsible for the movement of nutrients within the bodies of many animals. It takes many forms across the animal kingdom, but most contain at least one heart, which pumps the fluid keeping it moving.
The first big distinction is an open versus a closed system. In an open circulatory system, the blood or hemolymph is not contained in vessels but bathes the organs & the heart's job is just to keep it moving, preventing “dead spaces” from occurring where the fluid sits in one place too long becoming nutrient depleted resulting in local tissue death. Many animals with open circulatory systems also have multiple hearts and most don't use their hemolymph to transport oxygen or carbon dioxide. Many invertebrates have open circulatory systems, including insects, crustaceans, & arachnids. In a closed circulatory system, the fluid is contained inside of blood vessels at all times.
The heart is used to pump the fluid in a distinct pathway. Closed systems have 3 distinct vessel types: arteries, veins, and capillaries. Arteries take blood away from the heart, veins return blood, and capillaries facilitate exchange. Animals with closed systems include birds, mammals, fish, cephalopods, amphibians, reptiles, and annelids.
Within vertebrates, there are variations in heart structure that affect efficiency. Reptiles and amphibians have three-chambered hearts with some mixing of oxygenated and deoxygenated blood. Fish have a two-chambered heart and face challenges in oxygen delivery due to low pressure. Birds and mammals have four-chambered hearts, with complete separation of oxygenated and deoxygenated blood, enabling efficient circulation.
Exercise 1 – Identifying the structures of the human heart
Using the diagram provided, identify structures of the human heart, including atria, ventricles, valves, and major arteries and veins, referencing your textbook or online sources for accurate orientation.
Exercise 2 – Changes in heart rate
Measure your pulse before and after various activities—lying down, sitting, standing, and after exercise. Record your results and analyze how position and exertion influence your heart rate. Additionally, explore the electrical activity of the heart via ECG/EKG, explaining what occurs at each peak and interval in your own words.
Exercise 3 – The Electrocardiogram (ECG or EKG)
Review the ECG diagram and describe the significance of the P-wave, QRS complex, T wave, and intervals, noting how they relate to the cardiac cycle and heart function.
Exercise 4 – Blood vessels of the human body
Compare the structure and function of arteries and veins, explaining how their differences support their roles in circulation. Identify which artery transports deoxygenated blood and trace its path to and from the heart.
References
- Guyton, A. C., & Hall, J. E. (2016). Textbook of Medical Physiology (13th ed.). Elsevier.
- Marieb, E. N., & Hoehn, K. (2018). Human Anatomy & Physiology (11th ed.). Pearson.
- Levi, M., et al. (2019). Hemostasis and thrombosis. Blood, 134(7), 547–559.
- National Heart, Lung, and Blood Institute. (2020). Complete Blood Count - CBC. NIH Publication.
- Mattson, G. (2021). Circulatory system evolution in vertebrates. Journal of Comparative Physiology.
- Smith, L. D. (2017). The physiology of blood flow and the heart. Physiology Journal, 32(2), 101-115.
- Harrison's Principles of Internal Medicine (20th Ed.), Kasper et al., 2018.
- Niles, R. M., et al. (2020). Cholesterol and cardiovascular disease risk. Journal of Lipid Research.
- Yamamoto, K. et al. (2019). The impact of altitude on hemoglobin concentration and circulation. High Altitude Medicine & Biology.
- Reich, P., et al. (2018). Hematology in veterinary medicine. Veterinary Clinics of North America: Small Animal Practice.