L2 physiology

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Questions and Answers

What is the primary cellular component of blood when decreased in number is called anemia?

White blood cells

Red blood cells (correct)

Platelets

Plasma proteins

Which plasma protein is most abundant and plays a major role in maintaining osmotic pressure?

Globulin

Alpha protein

Fibrinogen

Albumin (correct)

What is the average range of red blood corpuscles (RBCs) in mm3?

100000-400000

4000-11000

1 million

5 million (correct)

What represents the liquid component of blood?

Plasma Signup and view all the answers

When the number of white blood cells decreases, which condition does this indicate?

Leukopenia Signup and view all the answers

Which of the following electrolytes is NOT typically found in plasma?

Vitamin B12 Signup and view all the answers

What is the main function of fibrinogen in the blood?

Blood clotting Signup and view all the answers

How does serum differ from plasma?

Plasma lacks clotting factors Signup and view all the answers

What is the primary function of the biconcave shape of red blood cells?

To provide the largest possible surface area for gas exchange Signup and view all the answers

In which organ does erythropoiesis occur during intrauterine life between 2-7 months?

Spleen Signup and view all the answers

Which blood type has the A and B agglutinogens present?

Type AB Signup and view all the answers

Why is knowing a person's blood group important in blood transfusions?

To avoid incompatibility reactions Signup and view all the answers

Which of the following describes the blood donation type of an individual with no A or B agglutinogen?

Type O Signup and view all the answers

Where does erythropoiesis primarily occur in adults?

In the axial skeleton and proximal ends of long bones Signup and view all the answers

What type of antigen presence classifies blood as Rh positive?

Presence of D antigen Signup and view all the answers

In what circumstance can blood grouping tests be useful in legal matters?

To exclude paternity Signup and view all the answers

Which plasma proteins are synthesized outside the liver?

У globulins Signup and view all the answers

What is the main component of the cytoplasm in red blood cells (RBCs)?

Hemoglobin Signup and view all the answers

What is a specific consequence of the biconcave shape of RBCs?

Increased deformability through capillaries Signup and view all the answers

What hormonal difference contributes to variations in RBC counts between males and females?

Androgens Signup and view all the answers

Which enzyme in RBCs catalyzes the formation of carbonic acid from CO2 and water?

Carbonic anhydrase Signup and view all the answers

What is the lifespan of red blood cells (RBCs)?

120 days Signup and view all the answers

Which of the following statements about RBCs is true?

RBCs transport respiratory gases. Signup and view all the answers

What role does hemoglobin play in blood besides gas transport?

Buffering acids in the blood Signup and view all the answers

What is the primary role of erythropoietin in erythropoiesis?

It stimulates erythropoiesis in response to decreased blood oxygen tension. Signup and view all the answers

Which component is essential for the formation of hemoglobin in the liver?

Globin Signup and view all the answers

What condition results from a decrease in red blood cell count?

Anemia Signup and view all the answers

Which factor is NOT typically involved in the dietary requirements for erythropoiesis?

Excessive fats Signup and view all the answers

How long is the average lifespan of red blood cells in the bloodstream?

120 days Signup and view all the answers

What type of anemia is characterized by decreased production of RBCs due to bone marrow aplasia?

Aplastic anemia Signup and view all the answers

Which type of anemia is characterized by blood loss?

Hemorrhagic anemia Signup and view all the answers

What happens to old red blood cells in the bloodstream?

They become rigid and are engulfed by macrophages. Signup and view all the answers

Which of the following conditions can lead to excessive hemolysis of RBCs?

Autoimmune hemolytic anemia Signup and view all the answers

What morphological classification describes anemia with normal MCV but decreased RBC count?

Normocytic normochromic anemia Signup and view all the answers

Which of the following characterizes hereditary spherocytosis?

RBCs are spherocytic and hemolyze readily in hypotonic solutions. Signup and view all the answers

Which vitamin deficiency is associated with megaloblastic anemia?

Vitamin B12 Signup and view all the answers

Which of the following is NOT considered a cause of nutritional anemia?

Congenital spherocytosis Signup and view all the answers

What is the main physiological trigger for hemorrhagic anemia?

Acute blood loss Signup and view all the answers

Which of the following is a corpuscular cause of hemolytic anemia?

Sickle cell anemia Signup and view all the answers

Which of the following statements about microcytic hypochromic anemia is FALSE?

It features normal MCV values. Signup and view all the answers

Study Notes

RBC and Anemia

Red blood cells (RBCs) are also known as erythrocytes
RBCs are non-nucleated, biconcave discs
The biconcave shape is created by proteins called ankyrin and spectrin
RBC cytoplasm is mainly (34%) hemoglobin (Hb)
Each RBC contains about 30 pg of hemoglobin, electrolytes (especially K+ and HCO3-), and enzymes (carbonic anhydrase and glucose-6-phosphate dehydrogenase (G-6-PD))
RBC life span is 120 days, then they are destroyed and removed by the spleen
Male RBC count ranges from 4.7 to 6.1 million/uL, while female count is from 4.2 to 5.4 million/uL
The biconcave shape increases surface area for gas diffusion
It allows flexibility for squeezing through capillaries
Important in differential diagnosis of anemias
RBCs transport hemoglobin, which carries respiratory gases
Hemoglobin acts as a buffer for acid-base balance
Carbonic anhydrase in RBCs catalyzes the reaction between CO2 and water to form carbonic acid (H2CO3)
Essential for maintaining diastolic arterial blood pressure
The thin cell membrane allows free diffusion of O2 and CO2
Plays a role in producing blood viscosity, essential for diastolic arterial blood pressure
Membrane glycoprotein layer contains agglutinogens that determine blood group
Blood groups are classified as O, A, B, AB
Blood type O is a universal donor
Blood type AB is a universal recipient

Blood Components

Blood is a specialized connective tissue
Blood is a thick, homogeneous liquid
Blood has cellular (formed elements) and liquid (plasma) components
Plasma (55% of whole blood) contains water, plasma proteins, lipids, hormones, nutrients, waste products, and various electrolytes
Formed elements (40-45% of whole blood) include red blood cells (erythrocytes: about 5 million/mm³), white blood cells (leukocytes: 4000-11000/mm³), and platelets (thrombocytes: 100000-400000/mm³)
Plasma proteins (7.1%) include albumin, globulins, and fibrinogen

Plasma Proteins

Albumin ranges from 3.5-5g/dL (average 4g/dL)
Globulins (α, β, γ) range from 2.3-3.5g/dL (average 2.7g/dL)
Fibrinogen is about 0.3g/dL
All plasma proteins are synthesized in the liver, except γ-globulins, synthesized by B-lymphocytes and plasma cells
Plasma proteins are formed from food proteins and tissue proteins (reserve type) in starvation

Blood Cells

Platelets (thrombocytes): 100,000-400,000/mm³
Red blood cells (erythrocytes): 4-5 millions/mm³
White blood cells (leukocytes): 4000-11000/mm³

Blood Groups

Two antigens (agglutinogens)-type A and type B-occur on surfaces of red blood cells
Blood is classified into four major blood types: O, A, B, and AB
Blood types depend on the presence or absence of A and B agglutinogens
Blood type O is a universal donor
Blood type AB is a universal recipient

RBC Formation

Erythropoiesis is the process of RBC formation
Stages of erythropoiesis include: stem cell, committed cell, developmental pathway (phases 1-3), ejection of nucleus
Sites of erythropoiesis include yolk sac (0-2 months), liver and spleen (2-7 months), and bone marrow (5-9 months) in utero
In adults, erythropoiesis is primarily in the red bone marrow of axial skeleton, proximal ends of femur and humerus
Inactive bone marrow is called yellow marrow

Factors Needed for Erythropoiesis

A healthy red bone marrow is essential
Diet containing high biological value proteins, copper, cobalt, and vitamins (especially B12 and folate)
Liver forms the globin part of hemoglobin, stores vitamin B12 and iron, secretes erythropoietin
Hormonal factors, including androgens and thyroxine
Decrease in oxygen tension (hypoxia) stimulates erythropoietin release

Fate of Anemia

Anemia effects mostly on the circulatory system
Increases the workload on the heart
Accompanied by hyperdynamic circulation and functional murmurs
Leads to tissue hypoxia and acute heart failure

Types of Anemia

Etiological Classification: by cause
Hemorrhagic (blood loss)
Decreased production of RBCs (Aplastic/nutritional or deficiency anemias)
Hemolytic (excessive breakdown) anemia
Morphological Classification: by size and hemoglobin concentration.
Normocytic normochromic
Microcytic hypochromic
Macrocytic normochromic

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Description

This quiz explores the critical functions and characteristics of red blood cells (RBCs), their structure, and their role in human physiology. Learn about their lifespan, composition, and importance in diagnosing anemias. Understand how hemoglobin and enzymes within RBCs contribute to gas transport and acid-base balance.