Untitled Flashcards Set

Cardiovascular Physiology

·       Know the location of heart and understand the basic anatomy (i.e. coverings and layers)

-          Location: Between the 2nd and 5th intercostal spaces when in anatomical position. Located within the thoracic cavity in a space called the mediastinum

-          Coverings of the heart: Pericardium

i.                     Fibrous pericardium

ii.                   Serous pericardium

iii.                 Parietal layer and pericardial cavity

iv.                 Visceral layer (epicardium)

-          Layers of the heart wall

i.                     Epicardium

ii.                   Myocardium (composed mainly of cardiac muscle, and forms the bulk of the heart)

iii.                 Endocardium

·       Understand the path of blood flow through the heart.

·       Be able to elaborate on the heart valve system. Understand the location and function.

-          Semilunar Valves – prevents backflow into the ventricles when ventricles relax

o   Pulmonary valve

§  Controls blood flow of deoxygenated blood from right side of heart into pulmonary trunk

o   Aortic valve

§  Regulates the oxygenated blood flow from the left side of heart into the aorta

-          Atrioventricular Valves (AV) – prevents backflow into the atria when ventricles contract

o   Tricuspid valve

§  Right side between right atrium and ventricle

o   Bicuspid (mitral) valve

§  Left side between left atrium and ventricle

·       Differentiate between the pulmonary, systemic, and coronary circulatory networks.

-          Pulmonary circuit: Blood vessels that carry blood to and from the lungs. Receives oxygen-poor blood from the body tissues and then pumps this blood to the lungs to pick up oxygen and dispel carbon dioxide

-          Systemic circuit: Blood vessels that transport blood to and from all body tissues. Receives oxygenated blood returning from the lungs and pumps this blood throughout the body.

·       Understand the basic characteristics of blood vessels and vascular circulation.

-          Arteries – Carry oxygenated blood away from the heart (except pulmonary arteries). Thick, muscular walls handle high pressure.

-          Veins – Carry deoxygenated blood back to the heart (except pulmonary veins). Thinner walls and valves prevent backflow.

-          Tunica media: Muscular layer in veins and arteries. It moves the blood, and It can widen and shrink. Veins has a smaller tunica media because the pressure is not as much.

-          Vascular Circulation:

i.         Systemic Circulation – Oxygen-rich blood is pumped from the left heart to the body and returns deoxygenated to the right heart.

ii.       Pulmonary Circulation – Deoxygenated blood is pumped from the right heart to the lungs for oxygenation and returns to the left heart.

iii.     Coronary Circulation – Supplies oxygen and nutrients to the heart muscle itself.

·       Understand the basics of auscultating heart sounds.

-          S1 “Lub” – first sound; produced by turbulent blood flow through the AV valves

-          S2 “Dub” – second sound; produced by turbulent blood flow through the semilunar valves

-          5 areas of auscultation:

i.                     Tricuspid

ii.                   Bicuspid (Mitral)

iii.                 Primary pulmonic

iv.                 Secondary pulmonic

v.                   Aortic

·       Know the fundamental aspects of the cardiac cycle.

-          Systole – phase of ventricular contraction, 0.3 seconds of the cardiac cycle

-          Diastole – phase of ventricular relaxation, 0.5 seconds of the cardiac cycle

-          Cardiac output – the amount of blood pumped out by each ventricle in one minute. It is the product of heart rate and stroke volume.

-          Heart rate –  number of contractions per minute (60-100 bpm)

-          Stroke volume – volume of blood ejected from the ventricles with each beat (~70 mL)

i.                     SV = EDV – ESV

-          End systolic volume – total volume of blood left in the ventricles at the end of systole (~50 mL)

-          End diastolic volume – total volume of blood in the ventricles at the end of diastole (~120 mL)

·       Understand the physiology of interpreting blood pressure.

-          When the left ventricle ejects blood into the aorta, the aortic pressure rises. The maximal arterial pressure following ejection is termed the systolic pressure.

-          As the left ventricle is relaxing and refilling, the aortic pressure falls. The minimal arterial pressure following ventricular relaxation is termed the diastolic pressure.

-          Aortic blood pressure is not usually measured directly but is estimated using an instrument called a sphygmomanometer.

-          Systolic Pressure: the pressure at which the first Korotkoff sound is heard

-          Diastolic Pressure: the pressure at which the sound disappears

·       Know the various categories for blood pressure classification.

·       Understand the conduction system of the heart. 

·       Understand the interpretation of an electrocardiogram (i.e. important intervals and waveforms).

-          P wave: Atrial depolarization (initiates atrial contraction)

-          QRS complex: ventricular depolarization (initiates ventricular contraction.)

-          T wave: Ventricular depolarization (ventricles reset for next contraction)

-          PR or PQ interval: atrial conduction (The time for electrical impulse to travel from atria to ventricles av nodes)

-          QT interval: ventricular conduction

-          R interval: heart rate

-          ST segment: ventricular depolarization/repolarization time

·       Be able to identify all of the various arrhythmias discussed in the PowerPoint.

-          Sinus Bradycardia: Sinus rhythm rate less than 60 bpm

-          Sinus Tachycardia: sinus rhythm rate greater than 100 bpm

-          Supraventricular tachycardia: P and T waves are together instead of separate- P waves are essentially absent

-          Atrial flutter (A-flutter) Consecutive atrial depolarization waves or “flutter” waves. “Saw-tooth” appearance. Different ratios (2:1, 3:1, 4:1) possible

-          Atrial fibrillation (A-fib): Caused by many ectopic atrial foci firing at rapid rates. No distinguishable P waves because the atria are sending impulses erratically. Variable and irregular QRS response

-          Ventricular Tachycardia (V-tach): Characteristic wide QRS complexes. P wave generally blends within the QRS 

-          Ventricular fibrillation (V-fib): Ventricular fibrillation is a type of cardiac arrest. There is no effective pumping action by the heart and thus there is no circulation. Lack of any identifiable waves on the electrocardiogram; it appears as erratic, rapid twitching of the ventricles. Requires immediate CPR and defibrillation

·       Know the AV blocks

Blood Physiology

Blood Physiology

·       Understand the basics of hematopoiesis.

-          the process by which blood cells are formed

o   Begins in the early embryo and continues throughout life

o   After birth, all blood cells originated in the bone marrow at a rate of 100 billion cells per day.

o   The various types of blood cells all differentiate from a single cell type.

·       Understand the various components of blood composition

·       Identify and describe the specific components of plasma.

-          Blood plasma: Consists of 90% water, remaining 10% consists of proteins, electrolytes, gases, hormones, waste, etc.

-          Plasma proteins make up 7-9% of the plasma:

·       Identify and describe the specific components of the formed elements.

- The formed elements of blood are the cells and cell fragments suspended in plasma. They include:

1. Erythrocytes (Red Blood Cells, RBCs)

2. Leukocytes (White Blood Cells, WBCs)

              3. Thrombocytes (Platelets)

·       Identify and describe the specific characteristics of red blood cells.

-          Structural Characteristics: Lack nuclei and organelles , Biconcave discs, Hemoglobin

-          Each erythrocyte contains approximately 280 million hemoglobin molecules. Each hemoglobin molecule is able to bind four molecules of oxygen.

-          100 -120 day lifespan. Can be altered by “shear effect”

-          Hematocrit – the proportion of the blood that consists of red blood cells

i.                     In healthy men, the hematocrit is 46% +/- 5%

ii.                   In healthy women, the hematocrit is 42% +/- 5%

-          Erythropoietin (EPO) – maintains the balance between production and destruction of red blood cells

·       How do these structural characteristics contribute to their ability to transport oxygen?

-          the structural characteristics of RBCs optimize them for oxygen transport in several ways:

i.                     Lack of Nuclei and Organelles – More room for hemoglobin (Hb), maximizing oxygen-carrying capacity. Also, no mitochondria means RBCs don’t consume the oxygen they carry.

ii.                   Biconcave Shape – Increases surface area-to-volume ratio, allowing for more efficient gas exchange. The flexible shape also helps RBCs squeeze through narrow capillaries.

iii.                 Hemoglobin Content – Each RBC contains ~280 million hemoglobin molecules, and each Hb binds four O₂ molecules, making RBCs highly efficient oxygen carriers.

·       Identify and describe the specific characteristics of each white blood cell.

-          Move in an amoeboid fashion via cytoplasmic extensions

-          squeeze through the intracellular junctions between capillary walls via diapedesis or extravasation

-          Classified based on staining properties

-          Granulocytes: Basophils, eosinophils, neutrophils.

-          Agranulocytes: Lymphocytes. Monocytes

·       Be able to differentiate the different WBCs based on their function with specific infections.

·       Be able to elaborate on the various blood types.

·       Understand the clinical applications discussed such as anemia, polycythemia, hemolytic diseases.

-          Anemia: A group of conditions that result from the inability of erythrocytes to deliver the needed amount of oxygen to the cells of the body. There are two ways in which anemia can develop:

i.                     Insufficient number of erythrocytes

ii.                   Inability of the erythrocytes to bind the normal amount of oxygen

o   Pernicious anemia: Deficiency in vitamin B-12. Lack of extrinsic factor

o   Iron deficiency anemia: deficiency in iron

o   Aplastic anemia: red bone marrow is affected where cells are formed

o   Sickle cell anemia: RBC is in a weird shape

o   Hemorrhagic anemia: rapid blood loss

-          Polycythemia: Meaning “many blood cells”. Abnormal excess of erythrocytes in the blood. Blood doping

-          Hemolytic Diseases: Rh incompatibility of mother and second child. When an Rh- woman carries and delivers an Rh+ baby, a small amount of the baby’s blood comes in contact with the mother’s blood at birth. Post-partum, the immune system of some women develop Rh+ antibodies. So if this woman becomes pregnant with another Rh+ baby her antibodies will cross the placenta and attack the embryos blood. 

·       Understand the importance of each clinical blood test discussed.

-          Complete blood count (CBC)

o   Purpose: provides a basic assessment of a patient’s overall health

o   Quantifies the various blood cells and measures some basic aspects of blood chemistry

o   Includes: hematocrit, hemoglobin content, and the overall concentration of erythrocytes, leukocytes, platelets, etc.

o   Helpful in detecting a wide range of disorders such as anemia, leukemia, infection, etc.

-          Complete blood count with differential (CBC with diff)

o   Purpose: provides a more in depth preliminary assessment of a patient’s overall health

o   Determines the percentage and absolute concentration of each class of leukocyte

o   Helpful in determining the type of infection a patient may have i.e. bacterial, fungal, viral

i.         In healthy adults the distribution of WBCs should be:

Neutrophils: 50% - 70%

Lymphocytes: 25% - 33%

Monocytes: 3% - 9%

Eosinophils: 1% - 4%

Basophils: 0.5% - 1%

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