Bio 13.1 part 1 . Cardiovascular System Overview

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Questions and Answers

What initiates the process of platelet activation in response to vascular injury?

Chemical signals released by red blood cells

Platelets adhering to undamaged endothelial cells

Platelets sticking to exposed collagen fibers (correct)

Vasodilation of blood vessels

Which component is directly involved in the conversion of soluble fibrinogen to insoluble fibrin during coagulation?

Prothrombin

Collagen

Plasminogen

Thrombin (correct)

What is the role of plasmin in the hemostatic process?

It digests the fibrin mesh during fibrinolysis. (correct)

It forms a plug by aggregating platelets.

It activates platelet aggregation.

It converts prothrombin to thrombin.

Which process enhances platelet stickiness and leads to the formation of a platelet plug?

Positive feedback Signup and view all the answers

What happens to the blood clot after the damaged blood vessel has healed?

It undergoes fibrinolysis and dissolves. Signup and view all the answers

What is the primary role of red blood cells (RBCs) in the body?

Transport oxygen and carbon dioxide Signup and view all the answers

Which blood group antigens are known to cause severe transfusion reactions if mismatched?

ABO and Rh Signup and view all the answers

How are the ABO blood group alleles inherited?

Co-dominant alleles pattern Signup and view all the answers

What condition can arise in an Rh− mother who has already formed anti-Rh antibodies?

Hemolytic disease of the newborn Signup and view all the answers

Which blood type results from the homozygous genotype ii?

O Signup and view all the answers

Which antibodies can be found in individuals without prior exposure to type A or type B antigens?

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

What is the Rh factor based on?

Presence or absence of the Rh antigen Signup and view all the answers

What is the primary function of the circulatory system?

To transport materials throughout the body. Signup and view all the answers

What role do erythrocytes play in the body?

They carry oxygen to the body's cells. Signup and view all the answers

What leads to the production of anti-Rh antibodies in an Rh− individual?

Exposure to Rh+ red blood cells Signup and view all the answers

Which component of blood is responsible for immune defense?

Leukocytes Signup and view all the answers

How does the body regulate blood flow to different tissues?

By adjusting the pumping action of the heart and vessel diameter. Signup and view all the answers

What type of blood vessel primarily carries blood away from the heart?

Arteries Signup and view all the answers

What is the nonliving extracellular matrix in blood called?

Plasma Signup and view all the answers

What contributes to the regulation of body temperature in the circulatory system?

Distribution of blood between the body's core and periphery. Signup and view all the answers

Platelets in the blood are derived from which type of cell?

Megakaryocytes Signup and view all the answers

What effect does an increase in temperature have on hemoglobin's O2 affinity?

Decreases O2 affinity Signup and view all the answers

What is the term used to describe the right shift of the oxygen-hemoglobin dissociation curve due to increased PCO2 and decreased pH?

Bohr effect Signup and view all the answers

How does the concentration of 2,3-bisphosphoglycerate (2,3-BPG) affect hemoglobin’s O2 affinity?

Decreases O2 affinity Signup and view all the answers

Under what conditions does hemoglobin's O2 affinity increase?

Decreased temperature and increased pH Signup and view all the answers

What characteristic difference allows fetal hemoglobin (hemoglobin F) to have a higher O2 affinity compared to adult hemoglobin (hemoglobin A)?

Different amino acid sequence in polypeptides Signup and view all the answers

In which physiological state is a left shift in the oxygen-hemoglobin dissociation curve most likely to occur?

At rest without elevated oxygen demand Signup and view all the answers

What triggers the release of bound CO2 from carbaminohemoglobin within RBCs?

Diffusion of CO2 out of RBCs Signup and view all the answers

What is the primary role of 2,3-bisphosphoglycerate (2,3-BPG) in relation to hemoglobin's function?

To facilitate oxygen unloading Signup and view all the answers

As O2 saturation approaches 100%, what happens to the shape of the oxygen-hemoglobin dissociation curve?

It flattens Signup and view all the answers

What is the role of carbonic anhydrase in RBCs during CO2 transport?

It converts H2CO3 into CO2 and H2O Signup and view all the answers

How does a decrease in RBC HCO3− concentration affect the overall CO2 transport process?

It leads to more HCO3− being pulled into the RBCs from the plasma Signup and view all the answers

What immediate physiological response occurs to limit blood loss after a blood vessel injury?

Vasoconstriction of the damaged vessel Signup and view all the answers

What condition usually results from an impairment in the blood clotting process?

Hemophilia Signup and view all the answers

Which of the following statements about hemostasis is true?

It is a process that can stop blood loss Signup and view all the answers

What chemical signals are released by damaged endothelial cells during vascular spasms?

Endothelin Signup and view all the answers

What is the primary function of a platelet plug in hemostasis?

To act as a temporary barrier to blood loss Signup and view all the answers

Study Notes

Cardiovascular System Function

The cardiovascular system distributes blood between the heart and the rest of the body.
Blood flow distribution is well-matched to the needs of tissues for delivery of oxygen, nutrients, water, electrolytes, and signaling molecules, as well as for removal of metabolic wastes.
Blood flow also delivers defensive immune system cells and molecules to infected or injured tissues.
The distribution of blood between the body's core and periphery contributes to body temperature regulation.

Blood Components

Blood is a fluid connective tissue composed of living cells (formed elements) and a nonliving extracellular matrix.
Formed elements originate in the bone marrow and include erythrocytes (red blood cells [RBCs]) and leukocytes (white blood cells [WBCs]).
Blood also contains thrombocytes (platelets) which are cell fragments derived from large bone marrow cells called megakaryocytes.
RBCs transport oxygen and carbon dioxide.
WBCs provide immune defense for the body.
Platelets play a crucial role in blood clotting.

ABO Blood Groups

ABO blood groups are determined based on the presence or absence of type A and type B RBC antigens, which are encoded by codominant alleles.
Individuals homozygous for the recessive allele (genotype ii) produce RBCs that lack type A and type B antigens, resulting in type O blood.

Rh Blood Groups

Rh blood groups (Rh+, Rh−) are based on the presence or absence of an antigen called the Rh factor, which follows an autosomal dominant inheritance pattern.

Hemolytic Disease of the Fetus and Newborn

An Rh− mother giving birth to an Rh+ baby can lead to hemolytic disease of the fetus and newborn.
In subsequent pregnancies with Rh+ offspring, previously formed anti-Rh antibodies can cross the placenta and cause destruction of fetal RBCs.

Hemoglobin

Hemoglobin is a protein found in RBCs that has a quaternary structure composed of four polypeptide chains (two alpha chains and two beta chains) and four heme groups.
Each heme group can bind to one molecule of oxygen.
Hemoglobin’s O2 binding affinity increases (due to positive cooperativity during O2 loading) as O2 saturation approaches 100%.
Environmental factors affect hemoglobin’s O2 affinity and can result in changes to the OHDC known as left or right shifts.

Factors Affecting Hemoglobin's Oxygen Affinity

Increased temperature, PCO2, or 2,3-BPG concentration, as well as decreased pH, decrease hemoglobin’s O2 affinity and shift the OHDC to the right.
Decreased temperature, PCO2, or 2,3-BPG concentration, as well as increased pH, increase hemoglobin’s O2 affinity and shift the OHDC to the left.

Bohr Effect

A right shift in the OHDC caused by increased PCO2 and/or decreased pH is referred to as the Bohr effect.

Fetal Hemoglobin

Fetal hemoglobin (hemoglobin F) has greater O2 affinity than adult hemoglobin (hemoglobin A).

Carbon Dioxide Transport

Carbon dioxide in the blood is transported as dissolved CO2, carbaminohemoglobin, and bicarbonate ions (HCO3−).
Carbonic anhydrase in RBCs catalyzes the rapid and reversible reaction between CO2 and H2O to form carbonic acid (H2CO3).

Hemostasis

Hemostasis is the process by which blood clots are formed to prevent excessive blood loss from injuries to blood vessels.
The process involves vasoconstriction, platelet plug formation, and coagulation.

Vasoconstriction

Vasoconstriction causes narrowing of the broken blood vessel.
It is triggered by contraction of smooth muscle cells in the wall of the blood vessel and release of chemical signals (eg, endothelin).

Platelet Plug Formation

Platelets adhere to exposed collagen in damaged blood vessels and release chemical signals, causing further stickiness and aggregation.
This signaling process, which enhances vasoconstriction and activates even more platelets, is an example of positive feedback.

Coagulation

Coagulation involves a complex series of steps in which multiple clotting factors in the blood plasma are sequentially activated.
Prothrombin is converted into thrombin, which cleaves soluble fibrinogen molecules into insoluble fibrin molecules.
Fibrin molecules polymerize and cross-link to form a mesh that traps platelets and red blood cells, producing a clot.

Fibrinolysis

Fibrinolysis is the process in which the fibrin mesh is digested by plasmin, and the clot dissolves.
Plasmin is produced via activation of an inactive precursor, a plasma protein known as plasminogen.

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Description

This quiz explores the functions and components of the cardiovascular system. Learn about blood flow distribution, the role of blood components, and their importance in maintaining health. Test your understanding of how blood carries essential elements while supporting immune responses.