Comprehensive Blood and Heart Anatomy & Physiology for Exam 1

What are the main functions of blood?

Transporting O2 and nutrients, transporting metabolic wastes, transporting hormones, regulating body temperature, pH, and volume, preventing blood loss, and preventing infection.

What are the formed elements of blood?

Erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.

What represents the majority of whole blood by volume?

Plasma.

What is the normal range of hematocrit for males and females?

Males: 47% ± 5%, Females: 42% ± 5%.

What is the average blood volume of a typical adult?

5 L (Males: 5-6 L, Females: 4-5 L).

What is the average normal pH range of blood?

pH 7.35-7.45.

Which plasma protein is the major contributor to osmotic pressure?

Albumin.

What organelles are not present in red blood cells?

RBCs have no nuclei or other organelles, including no mitochondria.

What three features of RBCs support efficient gas exchange?

Biconcave shape, hemoglobin makes up 97% of cell volume, and no mitochondria.

What is the function of red blood cells?

Dedicated to respiratory gas transport; hemoglobin binds reversibly with O2 and CO2.

How many molecules of oxygen can each hemoglobin molecule carry?

Up to 4.

What is the term for blood cell production? Where does it occur in adults?

Hematopoiesis; occurs in red bone marrow.

What does erythropoietin do and what triggers its release?

Stimulates formation of RBCs; released by kidneys in response to hypoxia.

What is the process of red blood cell breakdown?

Heme, iron, and globin are separated; iron is stored, heme is degraded to bilirubin.

What is anemia? What are its causes and consequences?

Anemia is low O2-carrying capacity; causes include blood loss, low RBC production, and destruction of RBCs.

What are the symptoms of aplastic anemia?

Fatigue, pallor, dyspnea, and chills.

What is polycythemia and what causes it?

Abnormal excess of RBCs; causes include bone marrow cancer and low O2 levels.

What factors affect blood viscosity?

Increased RBC count, dehydration, and increased albumin levels.

What is the main function of leukocytes?

Defense against disease.

What is diapedesis? Which cells perform this process?

Ability of WBCs to squeeze through blood vessel walls.

What is the relative abundance of the 5 types of white blood cells?

Neutrophils > Lymphocytes > Monocytes > Eosinophils > Basophils.

Which white blood cells respond to allergies and asthma?

Eosinophils.

Which white blood cells secrete histamine and heparin?

Basophils.

Which white blood cells become macrophages?

Monocytes.

Which white blood cells typically increase in response to bacterial infections?

Neutrophils.

What is leukopoiesis and what stimulates it?

Production of WBCs; stimulated by interleukins and colony-stimulating factors.

What is leukopenia?

An abnormally low WBC count.

What is leukocytosis?

A WBC count over 11,000 per µl.

What is leukemia?

A cancerous condition involving overproduction of abnormal WBCs.

What cells produce platelets?

Megakaryocytes.

What role do platelets play in hemostasis?

They act in the clotting process.

What are the average amounts of red blood cells, white blood cells, and platelets in the blood?

RBCs: 4.5-6 million/µl, WBCs: 4800-10,800/µl, Platelets: 150,000-400,000/µl.

What is the normal range of red blood cells per microliter?

4-6 million per µl

What is the normal range of white blood cells per microliter?

4800 to 10,800 per µl

What is the normal range of platelets per microliter?

150,000-400,000 platelets per µl

What is hemostasis?

The stoppage of bleeding

What role does ADP play in hemostasis?

Causes more platelets to stick and release their contents

What is the role of serotonin and thromboxane A2 in hemostasis?

Enhance vascular spasm and platelet aggregation

Which vitamin is important for blood clotting?

Vitamin K

What is the role of thrombin in hemostasis?

Converts soluble fibrinogen to insoluble fibrin

What enzyme removes unneeded clots during fibrinolysis?

Plasmin

What is a thrombus?

A clot that develops and persists in an unbroken blood vessel

What is an embolus?

A thrombus freely floating in the bloodstream

How does aspirin affect blood clotting?

Inhibits thromboxane A2

What is thrombocytopenia?

A deficient number of circulating platelets

What causes thrombocytopenia?

Suppression or destruction of red bone marrow

What are common causes of bleeding disorders?

Thrombocytopenia, defects in the clotting cascade, vitamin K deficiency

What determines ABO Rh+/- blood types?

The presence or absence of specific antigens

What antigens are present in Type A blood?

Only A antigen

What antigens are present in Type B blood?

Only B antigen

What antigens are present in Type AB blood?

Both A and B antigens

What antigens are present in Type O blood?

Neither A nor B antigens

What antibodies are present in Type A blood?

Only anti-B antibodies

What antibodies are present in Type B blood?

Only anti-A antibodies

What antibodies are present in Type AB blood?

Neither anti-A nor anti-B antibodies

What antibodies are present in Type O blood?

Both anti-A and anti-B antibodies

What is the universal donor blood type?

Type O-

What is the universal recipient blood type?

Type AB+

What is hemolytic disease of the newborn?

Occurs in Rh- mom with Rh+ fetus

What are the two major circuits of blood flow?

Pulmonary circuit and systemic circuit

Which chambers of the heart are the receiving chambers?

Atria

Which chambers of the heart are the pumping chambers?

Ventricles

What are the coverings of the heart?

Fibrous pericardium and serous pericardium

What is pericarditis?

Inflammation of the pericardium

What is cardiac tamponade?

Excess fluid in the pericardial space

What is angina pectoris?

Thoracic pain caused by fleeting deficiency in blood delivery to myocardium

What is a myocardial infarction?

Prolonged coronary blockage

What is the foramen ovale?

An opening between the left and right atria in a fetus

What is the ductus arteriosus?

A blood vessel connecting the pulmonary trunk to the aorta in a fetus

Where are pectinate muscles located?

In the atria

Where are trabeculae carneae located?

In the ventricles

What are the four valves of the heart?

Aortic, pulmonary, tricuspid, and mitral valves

What is the left atrioventricular valve also known as?

Mitral or bicuspid valve

What does the left atrioventricular valve prevent?

Backflow of blood from left ventricle into the left atrium

What is the right atrioventricular valve also known as?

Tricuspid valve

What does the right atrioventricular valve prevent?

Backflow of blood from right ventricle into the right atrium

Where is the aortic semilunar valve located?

Between the aorta and the left ventricle

What does the aortic semilunar valve prevent?

Backflow of blood from aorta into the left ventricle

Where is the pulmonary semilunar valve located?

Between the pulmonary trunk and the right ventricle

What does the pulmonary semilunar valve prevent?

Backflow of blood from pulmonary trunk into the right ventricle

What is the sequence of blood flow starting from deoxygenated blood returning to the heart?

Deoxygenated blood from systemic circuit > right atrium > tricuspid valve > right ventricle > pulmonary semilunar valve > pulmonary trunk > pulmonary arteries > pulmonary circuit > pulmonary veins > left atrium > bicuspid valve > left ventricle > aortic semilunar valve > aorta > systemic circuit

Which chambers of the heart contain oxygenated blood?

Left atrium and left ventricle

Which chambers of the heart contain deoxygenated blood?

Right atrium and right ventricle

Do the left and right sides of the heart pump equal volumes of blood?

Yes

Which ventricular wall is thicker and why?

Left ventricular wall is thicker to generate more force for systemic circulation

What type of circulation is pulmonary circulation?

Short, low-pressure circulation

What type of circulation is systemic circulation?

Long, high-friction circulation

What supplies arterial blood to the heart?

Coronary circulation

Where do the left and right coronary arteries arise from?

The base of the aorta

What replaces damaged myocardial tissue?

Fibrous connective tissue/scar tissue

What are the two kinds of myocytes?

Pacemaker cells and contractile cells

What role does extracellular calcium play in cardiac muscle contraction?

Triggers Ca2+ release from the sarcoplasmic reticulum

Which cells have unstable resting membrane potentials?

Cardiac pacemaker cells

What are the components of the conducting system of the heart?

Sinoatrial node, Atrioventricular node, Atrioventricular bundle, Right and left bundle branches, Subendocardial conducting network (Purkinje fibers)

What is the pacemaker of the heart?

Sinoatrial node

What is the expected heart rate if extrinsic regulation is removed?

100 beats per minute

What causes the pacemaker potential in a pacemaker cell?

Open slow Na+ channels causing depolarization

What effect does the parasympathetic nervous system have on the heart?

Slows down the heart rate

What effect does the sympathetic nervous system have on the heart?

Increases heart rate and contractility

What is the benefit of the long refractory period in cardiac muscle cells?

Prevents tetanic contractions