CLS 224: Lecture 4 - Blood Basics

Questions and Answers

What is the primary function of neutrophils in the body?

Produce antibodies

Act as phagocytes at sites of infection (correct)

Fight chronic infections

Stimulate clotting during injury

Which type of white blood cell is primarily responsible for producing antibodies?

B lymphocytes (correct)

T lymphocytes

Neutrophils

Monocytes

Leukocytosis is characterized by which of the following?

Excessive production of lymphocytes

Abnormal low leukocyte levels

WBC count below 11,000 leukocytes/mm3

WBC count above 11,000 leukocytes/mm3 (correct)

What is the lifespan of platelets in the bloodstream?

9 to 12 days Signup and view all the answers

What role does the hemocytoblast play in blood cell formation?

It derives all blood cells from a common stem cell Signup and view all the answers

Which type of leukocyte is the largest and often has a kidney-shaped nucleus?

Monocytes Signup and view all the answers

What is the main function of erythrocytes?

To carry oxygen Signup and view all the answers

Leukopenia is typically caused by which of the following?

Certain drugs such as corticosteroids Signup and view all the answers

What is the normal range for platelet count in the blood?

150,000 to 400,000 per cubic millimeter Signup and view all the answers

What is a defining characteristic of erythrocytes?

Have no organelles Signup and view all the answers

How many hemoglobin molecules are typically found in one erythrocyte?

250 million Signup and view all the answers

Which of the following conditions is characterized by a decrease in the oxygen-carrying ability of the blood?

Anemia Signup and view all the answers

What is the normal range of leukocytes found per cubic millimeter of blood?

4,800 to 10,800 Signup and view all the answers

Which type of leukocyte is involved primarily in targeting parasitic infections?

Eosinophils Signup and view all the answers

What is a key feature of agranulocytes compared to granulocytes?

Lack visible cytoplasmic granules Signup and view all the answers

What mnemonic helps to remember the order of leukocyte abundance?

Never Let Monkeys Eat Bananas Signup and view all the answers

What substance stimulates the production of platelets?

Thrombopoietin Signup and view all the answers

What is the first step in the blood-clotting process?

Exposure of collagen fibers Signup and view all the answers

Which blood type can receive blood from all blood types?

Type AB Signup and view all the answers

What is the result of mixing Rh+ blood into a body with Rh– blood?

Potential antibodies formation Signup and view all the answers

What is a potential consequence of a blood loss over 30%?

Shock, which can be fatal Signup and view all the answers

Which type of blood can a person with Type A blood safely receive?

Type A Signup and view all the answers

Which antibodies would be present in the plasma of a Type O individual?

Anti-A and Anti-B Signup and view all the answers

What can happen during a second pregnancy if the mother is Rh- and the child is Rh+?

Formation of anti-Rh+ antibodies Signup and view all the answers

What is the role of colony stimulating factors (CSFs)?

Signal bone marrow to produce leukocytes Signup and view all the answers

What mechanism is responsible for attracting more platelets during clot formation?

Sticky nature of platelets Signup and view all the answers

What is the primary component of blood plasma?

Water Signup and view all the answers

Which of the following describes the hematocrit?

The percentage of erythrocytes in blood Signup and view all the answers

What regulates osmotic pressure in blood plasma?

Albumin Signup and view all the answers

Which type of blood cell is primarily responsible for immune response?

Leukocytes Signup and view all the answers

What happens to blood pH during acidosis?

It becomes more acidic Signup and view all the answers

Which statement about blood temperature is accurate?

It is slightly higher than body temperature Signup and view all the answers

What percentage of body weight does blood typically make up?

8 percent Signup and view all the answers

What type of cell fragment is found in the formed elements of blood?

Platelets Signup and view all the answers

Study Notes

Composition and Functions of Blood

Blood is the only fluid tissue in the human body and classified as connective tissue.
Whole blood consists of formed elements (living cells) and plasma (non-living matrix).
Blood volume in a healthy adult is approximately 5–6 liters, constituting about 8% of body weight.
Blood has a pH range of 7.35–7.45 and is slightly warmer than body temperature at 38°C (100.4°F).
Centrifuged blood reveals erythrocytes at the bottom (45%, hematocrit), a buffy coat of leukocytes and platelets (<1%), and plasma at the top (55%).

Blood Plasma

Plasma is about 90% water and contains various dissolved substances, including nutrients, electrolytes, hormones, and waste products.
Plasma proteins are the most abundant solutes; they include:
- Albumin: regulates osmotic pressure.
- Clotting proteins: prevent excessive blood loss.
- Antibodies: protect against pathogens.
Acidosis occurs when blood acidity increases; alkalosis occurs when blood becomes too basic, with the respiratory system and kidneys acting to restore pH balance.

Formed Elements

Formed elements of blood include:
- Erythrocytes (red blood cells): Main function is oxygen transport, contain hemoglobin which binds to oxygen.
- Leukocytes (white blood cells): Essential for immune defense.
- Platelets: Cell fragments crucial for clotting.
Erythrocytes are biconcave, anucleate, and contain approximately 5 million cells per mm³ of blood, with a lifespan of about 120 days.
Normal hemoglobin levels range from 12–18 g per 100 mL of blood.

Hematopoiesis

Hematopoiesis, or blood cell formation, occurs in the red bone marrow.
All blood cells are derived from hemocytoblasts (stem cells), differentiating into lymphoid stem cells (lymphocytes) and myeloid stem cells (other formed elements).
Erythrocytes are removed by phagocytes in the spleen or liver after their lifespan, with new cells produced by hemocytoblasts.

Hemostasis

Hemostasis involves the formation of a platelet plug upon blood vessel injury:
- Exposed collagen fibers attract platelets, which become sticky and release chemicals to recruit more platelets.
- Blood typically clots within 3 to 6 minutes, allowing for tissue repair afterward.

Blood Groups and Transfusions

Blood transfusions are necessary after significant blood loss (15-30% causes weakness; over 30% can lead to shock).
Blood types are determined by specific antigens present on the red blood cells:
- ABO blood groups are defined by the presence/absence of type A and B antigens.
- Blood types are categorized as A, B, AB (universal recipient), and O (universal donor).
Rh factor presence can cause complications if Rh-negative individuals receive Rh-positive blood, particularly in pregnancy.

Rh Factors and Pregnancy

Rh incompatibility arises when an Rh-negative mother carries an Rh-positive baby. This can sensitize the mother's immune system, leading to hemolytic disease in subsequent pregnancies.
RhoGAM can be administered to prevent antibody buildup against Rh-positive blood during pregnancy.

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Description

This quiz covers the essentials of blood, including its composition, functions, and importance in the human body. You'll explore developmental aspects of blood, hemostasis, and the critical topic of blood groups and transfusions. Perfect for students studying basic anatomy and physiology.