Questions and Answers
What is the primary function of erythropoietin?
The majority of blood plasma is composed of proteins.
False
What hormone is responsible for stimulating erythropoiesis?
Erythropoietin
Excessive red blood cells can lead to increased blood ______.
Signup and view all the answers
Match the following blood disorders with their causes:
Signup and view all the answers
Which of the following is NOT a type of white blood cell?
Signup and view all the answers
Red blood cells contain a nucleus and organelles.
Signup and view all the answers
What is the lifespan of a red blood cell?
Signup and view all the answers
The main component of hemoglobin that binds to oxygen is called ______.
Signup and view all the answers
Which type of cell is primarily responsible for immune response?
Signup and view all the answers
Study Notes
Functions of Blood
- Distributes oxygen, nutrients, hormones, and removes carbon dioxide from body tissues.
- Regulates body temperature through heat absorption and distribution; maintains pH and fluid volume.
- Protects against blood loss by forming clots and combats infections via antibodies and white blood cells.
Composition of Blood
- Blood is a fluid connective tissue: 55% plasma and 45% formed elements.
- Formed elements include erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.
- Blood pH ranges from 7.35 to 7.45, indicating a slightly basic nature.
Blood Separation
- Centrifugation separates blood components: erythrocytes settle at the bottom, leukocytes in the middle, and plasma on top.
- Hematopoiesis, or blood cell formation, occurs in the red bone marrow, particularly in the shoulder and pelvic girdles and the epiphyses of the humerus and femur.
Erythropoiesis (Red Blood Cell Production)
- Hemocytoblasts are hematopoietic stem cells responsible for forming blood cells.
- Erythropoiesis takes around 15 days from hemocytoblast to mature erythrocyte.
- Cells transition from blue (ribosomes) to pink (hemoglobin) during development.
- Involves ribosome synthesis, hemoglobin accumulation, and ejection of the nucleus.
Impacts of Erythrocyte Levels
- Insufficient red blood cells can cause tissue hypoxia, leading to tissue death due to inadequate oxygen supply.
- Excess red blood cells increase blood viscosity, raising risks for heart attack and stroke.
Hormonal Regulation of Erythropoiesis
- Erythropoietin (EPO) is a hormone released by kidneys in response to hypoxia, stimulating red blood cell production.
- Testosterone enhances EPO production, increasing red blood cell counts, potentially beneficial in blood doping contexts.
Negative Feedback Mechanism
- Hypoxia prompts the kidneys to release erythropoietin, stimulating increased red blood cell production.
- Higher red blood cell counts improve the oxygen-carrying capacity of blood.
White Blood Cell Production
- Leukopoiesis is the process of white blood cell production, often heightened during illness.
- All leukocytes originate from hemocytoblasts under chemical signals from the bone marrow and mature leukocytes.
- Five types of white blood cells: monocytes, lymphocytes, neutrophils, basophils, and eosinophils, arise from lymphoid and myeloid stem cells.
Blood Plasma Composition
- Plasma constitutes about 90% water and contains proteins, nitrogenous by-products, nutrients, electrolytes, gases, and hormones.
- Red blood cells are primarily involved in respiratory gas transport, lacking nuclei and organelles.
Red Blood Cells (Erythrocytes) Characteristics
- Biconcave discs designed for maximum surface area for gas exchange.
- Hemoglobin binds oxygen reversibly; one hemoglobin molecule can transport four oxygen molecules.
- Each red blood cell contains approximately 250 million hemoglobin molecules.
Lifespan and Recycling of Red Blood Cells
- Red blood cells mature in about 15 days and have a lifespan of around 120 days.
- They are destroyed by macrophages in the spleen; hemoglobin is broken down, with parts recycled or excreted.
Erythrocyte Disorders
- Anemia is characterized by low oxygen-carrying capacity due to blood loss, insufficient production, or abnormal red blood cells.
- Causes include hemorrhagic anemia (blood loss), pernicious anemia (vitamin B12 deficiency), and aplastic anemia (bone marrow destruction).
- Conditions like hemolytic anemia, thalassemias, and sickle cell anemia are linked to abnormal red blood cells or hemoglobin.
- Polycythemia results from an excess of red blood cells, increasing blood viscosity.
- Causes include bone marrow cancer, secondary polycythemia linked to reduced oxygen availability, and blood doping.
Oxygen Transport Mechanics
- Oxygen binds to iron atoms in hemoglobin, enhancing its transport capacity via the biconcave shape of red blood cells.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the critical functions of blood in the human body with this quiz. Learn about how blood distributes oxygen and nutrients, regulates body temperature, and protects against blood loss and infections. Test your understanding of blood composition and its essential role as a connective tissue.
