Physiology Chapter: Blood

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary function of blood in transporting nutrients?

To eliminate foreign substances from the body

To regulate body temperature through vasodilation

To transport hormones and oxygen to cells (correct)

To form clots at damaged sites

Which of the following correctly describes the pH range of blood?

7.5 to 8.0

6.5 to 7.0

7.35 to 7.45 (correct)

7.0 to 7.35

How does the volume of blood in males typically compare to that in females?

Females generally have the same blood volume as males

Males usually have a larger blood volume than females (correct)

Blood volume is independent of gender

Males generally have a lower blood volume than females

What is one of the functions of blood in the context of regulation?

pH buffering through hydrogen and bicarbonate ions Signup and view all the answers

What is the term used for the liquid components of blood?

Plasma Signup and view all the answers

Why does venous blood appear darker than arterial blood?

It has given up much of its oxygen in tissues Signup and view all the answers

What constitutes the cellular portion of blood?

Buffy coat and red blood cells Signup and view all the answers

Which of the following is a protective function of blood?

Clot formation to minimize blood loss Signup and view all the answers

How does the color of blood relate to its oxygenation level?

Oxygen-rich blood is bright red, while oxygen-poor blood is darker Signup and view all the answers

What is the average volume of blood plasma in an adult human?

2.7-3.0 liters Signup and view all the answers

What is the primary role of bicarbonate ions in blood?

Regulating pH levels Signup and view all the answers

Which statement accurately reflects the average blood volume in males compared to females?

Males have a greater blood volume than females. Signup and view all the answers

What factor significantly affects the color of blood?

Oxygen saturation levels Signup and view all the answers

In terms of pH, how does venous blood differ from arterial blood?

Venous blood has a lower pH than arterial blood. Signup and view all the answers

What is the primary function of blood's role in protection?

Clot formation to minimize blood loss Signup and view all the answers

How is the blood composition categorized?

Cellular and fluid portions Signup and view all the answers

What is the significance of the average blood plasma volume in terms of total blood volume?

It makes up over 60% of blood volume. Signup and view all the answers

Which explains the method of heat regulation by blood?

Using vasodilation of surface vessels Signup and view all the answers

Study Notes

Physiology (0603302)

Course: Physiology
Chapter: Blood
Semester: Summer 2023/2024
Instructor: Dr. Mohammad A. Abedal-Majed
Institution: The University of Jordan, School of Agriculture

Blood

Liquid connective tissue that circulates through blood vessels, pumped by the heart
Functions:
- Transportation: Transports nutrients (amino acids, lipids, glucose), hormones, and oxygen to cells; transports wastes and carbon dioxide away from cells
- Regulation: Buffers pH (7.35-7.45), regulates body temperature (vasodilation/vasoconstriction)
- Protection: Prevents blood loss through clot formation; protects against foreign substances (antibodies and white blood cells)

Characteristics of Blood

Blood volume: Males (5-6 liters), Females (4-5 liters) (dependent on individual size and gender)
Color: Red; arterial blood is brighter red (high oxygen level); venous blood is darker red (less oxygen)
pH: Venous blood typically has a lower pH than arterial blood (7.35-7.45 arterial, 7.32-7.42 venous)

Blood Composition

Cellular portion (formed elements): Lower portion of a centrifuged blood sample, including buffy coat (white blood cells and platelets) and red blood cells (RBCs)
Fluid portion (plasma): Upper portion of a centrifuged blood sample (55% of blood volume); primarily water and contains proteins, electrolytes, nutrients, waste products, and gases
- Plasma composition: Proteins (albumins, globulins, fibrinogen), other solutes, gases, formed elements (RBCs, WBCs, platelets); various concentrations and levels

Components of Blood

A-plasma (fluid portion):
- Water (91-92%): Transport medium
- Proteins (6-8%): Maintain blood volume and pressure (Albumin, globulins, fibrinogen)
 - Albumin (60%): Transport protein and steroid hormones
 - Globulins (35%): Transport hydrophobic lipids, vitamins, ions, and hormones, including antibodies
 - Fibrinogen (4%): Coagulation protein
 - Regulatory proteins (<1%): Enzymes, proenzymes, and hormones
Other solutes (1-2%): Electrolytes (Na+, Cl-, HCO3-, K+, Ca+2), organic nutrients, and organic wastes (urea, creatinine)
Dissolved gases (O2 and CO2)

Cellular Component of Blood

Erythrocytes (RBCs): Biconcave discs, lack a nucleus and mitochondria; transport oxygen and CO2; lifespan 70-150 days (4.6-6.2 million/mm³ in males and 4.5-5.1 million/mm³ in females).
Leukocytes (WBCs): Immune response, various types with different functions (eosinophils, basophils, neutrophils, monocytes, lymphocytes); crucial role in defending against infection and pathogens
Thrombocytes (Platelets): Cellular fragments, essential for hemostasis and blood clotting; critical role in wound healing and preventing blood loss; average lifespan 7-14 days; (150,000-350,000 /mm3)

Synthesis of Erythrocytes

Areas of erythropoiesis
- Embryonic life (yolk sac)
- Middle trimester of gestation (liver, spleen, lymph nodes)
- Last month of gestation and after birth (bone marrow)
- Up to five years (bone marrow of all bones)
- Age twenty and up (bone marrow only)
Factors stimulating erythropoiesis: Low oxygen levels (hypoxia), high altitudes, lung diseases, heart failure; erythropoietin is a crucial hormone

Hematocrit

Definition: Percentage of blood volume occupied by red blood cells
Normal range: Males (42%-52%), Females (37%-47%)

Anemia

Condition where blood's oxygen-carrying capacity is reduced below normal
Types:
- Nutritional anemia: Diet deficiency (iron deficiency)
- Pernicious anemia: Inability to absorb B12
- Aplastic anemia: Bone marrow failure to produce blood cells

Polycythemia

Condition with excess circulating red blood cells
Types: Primary and secondary; high altitudes, genetic factors, or other underlying medical conditions can cause it

White Blood Cells (Leukocytes)

Mobile units of the immune system
Destroy and remove old or aberrant cells, attacking infectious agents
Functions: Phagocytosis and antibody production
Colorless due to lack of hemoglobin
Contain nuclei and mitochondria, allowing amoeboid movement to infection sites
Lifespan varies from 13 to 20 days
Types of WBCs: Granulocytes (neutrophils, eosinophils, basophils), and Agranulocytes (monocytes and lymphocytes).

Thrombocytes (Platelets)

Cellular fragments with no nucleus, crucial for hemostasis
Irregularly shaped
Cessation of bleeding, maintains vascular integrity
Life span of 7 to 14 days (150,000-350,000 /mm3).

Blood Clotting (Coagulation)

Cascade of reactions activating coagulation factors, leading to the conversion of fibrinogen to fibrin, forming a stable clot
Essential for hemostasis
Factors such as vitamin K are necessry for the process

Hemostasis

Cessation of bleeding
Three mechanisms involved:
- Vasoconstriction
- Platelet aggregation
- Clot formation

Plasma vs Serum

Plasma: Blood fluid that contains clotting factors
Serum: Plasma with clotting factors removed

Clinical Applications

Hemostasis and blood flow for normal functions; dysfunctions (ischemia); clinical signs of oxygenation/perfusion insufficiency (e.g., mucous membrane color, capillary refill time)
Blood tests and assessment of the circulatory system.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the functions and characteristics of blood in this quiz based on the Physiology course. Learn about its roles in transportation, regulation, and protection. This quiz will challenge your understanding of blood volume, color, and pH levels.