Lab Exam 2 Flashcards
location of heart
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
Fibrous pericardium, serous pericardium
Fibrous pericardium
looks like a ligament, very dense connective tissue, very loose covering surrounding the heart, outermost covering of the heart, prevent the overfilling of blood within the heart, anchoring in the pulmonary trunk (anchor the heart into an anatomical position)
Serous pericardium
right below the fibrous pericardium. Consists of the parietal layer and visceral layer
Parietal layer
outermost region of the pericardium
Visceral layer
(also called epicardium) innermost region of the pericardium
Pericardial cavity
between the parietal and visceral layer, contains pericardial fluid that will help create a friction free environment for the heart allowing the heart to fully relax and fill with blood, also allow for the heart to contract and bring that blood into pulmonary and systemic circulation
Layers of the Heart Wall
Epicardium, myocardium, endocardium
Epicardium
outermost layer of the heart wall
Myocardium
Composed mainly of cardiac muscle and forms the bulks of the heart
contains cardiac myocytes that are specialized to allow for contraction of the heart, so allow for us to bring blood into both pulmonary and systemic circulation
Endocardium
very thin, aligns the chambers of the heart
Pericarditis
inflammation of the pericardium, the cause is often unknown, associated with viral infections and many other autoimmune disorders
Veins
(Blue) carried deoxygenated blood, brings blood towards the heart
Arteries
(Red) carries oxygenated blood, carry blood away from the heart
the path of blood flow through the heart
Superior vena cava, inferior vena cava, coronary sinus -> right atrium -> tricuspid valve -> right ventricle -> pulmonary semilunar valve -> pulmonary trunk -> pulmonary arteries -> lungs -> pulmonary capillaries -> pulmonary veins -> heart -> left atrium -> mitral valve -> left ventricle -> aortic semilunar valve -> aorta -> systemic capillaries -> body
Semilunar Valve system consists of
pulmonary valve and aortic valve
Semilunar Valves
prevents backflow into the ventricles when ventricles relax
Pulmonary valve
Controls blood flow of deoxygenated blood from right side of heart into pulmonary trunk
Aortic valve
Regulates the oxygenated blood flow from the left side of heart into the aorta
Atrioventricular valve system consists of
tricuspid valve, bicuspid valve
Atrioventricular Valves (AV)
prevents backflow into the atria when ventricles contract
Tricuspid valve
Right side between right atrium and ventricle
Bicuspid valve
Left side between left atrium and ventricle
If semilunar vales are open
atrioventricular valves are closed (vice-versa)
Diastole
filling phase, Atrioventricular valves are open, tricuspid and bicuspid valves are open. Semilunar valves are closed. Phase of ventricular relaxation, 0.5 seconds of the cardiac cycle
Systole
ejection phase, Semilunar valves are open, av valves are closed. Phase of ventricular contraction, 0.3 seconds of the cardiac cycle
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
vascular circulation
tunica adventitia (tunica externa), tunica media, tunica intima
Tunica media
contained in both veins and arteries, much thicker to control blood flow and blood pressure, spindle shaped cells which is indicative of move muscle and responsible for both vasoconstriction and vasodilation
elastic connective tissue
More inward, artery contains an elastic connective tissue that will help and prevent for the artery to be very flexible
Tunica intima
innermost, endothelial cells are inner lining of the blood vessels.
valves and skeletal muscle pump
Veins contains valves and skeletal muscle pump that allow for us to pump blood against gravity
S1 “Lub”
first sound; produced by turbulent blood flow through the AV valves, louder than S2
S2 “Dub”
second sound; produced by turbulent blood flow through the semilunar valves
5 areas of auscultation
Tricuspid, Bicuspid (Mitral), Primary pulmonic, Secondary pulmonic, Aortic
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)
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)
Blood pressure is recorded as
systolic pressure over diastolic pressure
systolic pressure
When the left ventricle ejects blood into the aorta, the aortic pressure rises. The maximal arterial pressure following ejection. The pressure at which the first Korotkoff sound is heard
diastolic pressure
As the left ventricle is relaxing and refilling, the aortic pressure falls. The minimal arterial pressure following ventricular relaxation. The pressure at which the sound disappears
Aortic blood pressure
is not usually measured directly but is estimated using an instrument called a sphygmomanometer
Normal blood pressure
Systolic less than 120 and Diastolic less than 80
Elevated blood pressure
Systolic 120-129 and Diastolic less than 80
High blood pressure (hypertension) stage 1
Systolic 130-139 or Diastolic 80-89
High blood pressure (hypertension) stage 2
systolic 140 or higher or Diastolic 90 or higher
Hypertensive crisis (consult your doctor immediately)
systolic higher than 180 and/or Diastolic higher than 120
conduction system of the heart 1.
Sinoatrial node (SA node) – pacemaker, located near point superior vena cava enters right atrium, contractile cells that initiate stimulus that results in heart contraction. Stimulates internodal pathway
conduction system of the heart 2.
Internodal pathway – conductile cells, receives stimulus from SA node, distributes stimulus throughout atria, stimulates atrial contraction and AV node.
conduction system of the heart 3.
Atrioventricular node (AV node) – located at junction of atria and ventricles, receives stimulus from internodal pathway, stimulates AV bundle, contractile cells may initiate stimulus if SA node does not.
conduction system of the heart 4.
Atrioventricular bundle (AV bundle) – located in interventricular septum, receives stimulus from AV node, conductile cells that carry stimulus to bundle branches, also called bundle of His
conduction system of the heart 5.
Right bundle branch – conductile cells that carry stimulus to apex of right ventricle, stimulates Purkinje fibers. Left bundle branch – conductile cells that carry stimulus to apex of left ventricle, stimulates Purkinje fibers
conduction system of the heart 6.
Purkinje fibers – network in each ventricular wall, conductile cells that carry stimulus to ventricular cardiac muscle cells
Electrocardiogram (EKG)
x-axis time in seconds, y-axis amplitude (mV)
P-wave
atrial depolarization or contraction
QRS complex
represents ventricular depolarization or contraction, atrial repolarization not seen on EKG
T-wave
ventricular repolarization
PR interval (PQ)
the amount of time it takes for the signal to be transduced from the atria and reach the ventricles
QT interval
starts at Q-wave and ends after T-wave represent the amount of time for the ventricle to depolarize and repolarize.
ST segment
flat or plateau phase indicates ventricular cardio myocyte have fully depolarize. Elevation or depression means some sort of cardiac ischemia or myocardial infarction
RR interval
one cardiac cycle, calculate heart rate.
Sinus Bradycardia
sinus rhythm rate less than 60 beats per minute, Normal in sleeping and athletes. Abnormal when exercising.
Sinus Tachycardia
sinus rhythm rate greater than 100 beats per minute, Normal when exercising. Abnormal when sleeping
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)
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
First-degree AV block
Characterized by a consistently prolonged PR interval, PR interval greater than 0.2 second or one large square, Not necessarily a “block” but rather a “delay”
Second-degree AV block
Allows some atrial depolarization (P waves) to conduct to the ventricles while some are blocked, leaving lone P waves without an associated QRS, second degree blocks can be distinguished by repeated P waves prior to the QRS complex or P waves that are missing their corresponding QRS complex
Third-degree AV block
Total block of conduction from the atria to the ventricles, The atria and ventricles have lost communication and are now functioning independently of one another, third degree AV blocks can be distinguished by no relationship between the P and the QRS waveforms.
Hematopoiesis
the process by which blood cells are formed, Begins in the early embryo and continues throughout life, After birth, all blood cells originated in the bone marrow at a rate of 100 billion cells per day, The various types of blood cells all differentiate from a single cell type.
Hematopoiesis functions
Transportation: Respiration, nutrition, excretion, hormonal
Regulation: Thermoregulation
Protection: Immune response
blood composition
plasma and formed elements
plasma
55%, Water, Proteins, Electrolytes, blood gases, nutrients, enzymes, waste products, etc.
formed elements
45%, Erythrocytes, Buffy Coat (<1%): Leukocytes, Platelets
specific components of plasma
Consists of 90% water, remaining 10% consists of proteins, electrolytes, gases, hormones, waste, etc.
Plasma proteins make up 7-9% of the plasma: albumin, globulin, fibrinogen
Albumin
Maintains osmotic pressure, helps keep water from diffusing out of the bloodstream into the extracellular matrix of tissues
Globulin
Alpha and Beta globulins transport lipids and fat soluble vitamins.
Gamma globulins are antibodies produced by lymphocytes
Fibrinogen
Forms fibrin threads essential in blood hemostasis
Thrombin is going to convert fibrinogen to fibrin and these fibrin threads are formed and that will help you achieve a blood clot
RBCs Structural Characteristics:
Lack nuclei and organelles
Biconcave discs
RBC Lack nuclei
without nucleus you can have this in folding of the membrane that allows these red blood cells to take on this biconcave disc shape and it increases the surface area so we can have the exchange of gases across the membrane occurring more efficiently
RBC Lack organelles like Mitochondria
mitochondria use oxygen for respiration so they lack mitochondria so they’re not undergoing aerobic respiration while they’re doing their job transporting that oxygen
Hemoglobin
Each erythrocyte contains approximately 280 million hemoglobin molecules. Each hemoglobin molecule is able to bind four molecules of oxygen.
RBC lifespan
100 -120 day lifespan, Can be altered by “shear effect”, Red blood cells have shear forces acting on both sides of them whenever they’re bouncing around and getting squeezed through capillaries (decrease life span).
Oxidative stress
can also affect lifespan. Undergo this by continually binding and unbinding oxygen over and over again so they’re going to end up forming some oxidative byproducts that could be toxic to the cell and while they can get rid of some, over their lifespan it can start accumulating and cause them to die
Hematocrit
the proportion of the blood that consists of red blood cells
* In healthy men, the hematocrit is 46% +/- 5%
* In healthy women, the hematocrit is 42% +/- 5%
Erythropoietin (EPO)
maintains the balance between production and destruction of red blood cells
Formed Elements – WBCs
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, agranulocytes
Granulocytes
have brightly stained granules; basophils, eosinophils, neutrophils
Agranulocytes
does not have brightly stained granules; lymphocytes, monocytes
Neutrophils
most abundant white blood cell, granules are pale red and not as prominent, larger than RBC, nucleus is dark purple and multi-lobed
Eosinophils
prominent large bright-red granules, larger than RBC, large lobed dark purple staining nucleus
Basophils
prominent large dark purple-blue granules, larger than RBC, large lobed dark purple staining nucleus often hidden by granules
Monocytes
largest leukocyte, dark-staining nucleus has C-shaped or kidney bean -shape, abundant cytoplasm with no granules visible
Lymphocytes
smallest leukocyte, slightly larger than RBC, large round dark-staining nucleus occupies most of the cell, little cytoplasm with no granules visible
Antigens
found on the surface of cells to help the immune system recognize self cells
Antibodies
secreted by lymphocytes in response to foreign cells or antigens
ABO System
There are four major blood groups determined by the presence or absence of antigens on the surface of red blood cells: Group A, Group B, Group AB, Group O
Group A
has the A antigen on RBCs and B antibody in the plasma
Group B
has the B antigen on RBCs and A antibody in the plasma
Group AB
has both A and B antigens on RBCs, but neither A nor B antibody in the plasma
Group O
has neither A nor B antigens on RBCs, but both A and B antibody are in the plasma
Type A
cannot have B or AB blood but can have A or O blood
Type B
cannot have A or AB blood but can have B or O blood
Type AB
can have any type of blood, is the universal recipient
Type O
can only have O blood, is the universal donor
O- is the universal donor and AB+ is the universal recipient because
it doesn’t have any of those antigens so there’s nothing there for the patient’s antibodies to attack. AB+ can receive anything because they don’t have any antibodies so it doesn’t really matter what we give them because they won’t attack it
Rh antigen
is sometimes referred to as D antigen
Rh negative blood
is given to Rh negative patients
Rh positive blood or Rh negative blood
may be given to Rh positive patients
Most and least common blood type
O+ is the most common blood type, AB- is the least common
Blood doping
manipulating your red blood cell count so that you have more erythrocytes so that you can bind more oxygen so you can perform better athletically
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:
Insufficient number of erythrocytes
Inability of the erythrocytes to bind the normal amount of oxygen
Anemia symptoms
fatigue, shortness of breath, light headiness, dizziness, increased heart rate, paleness
Pernicious anemia
autoimmune response that destroys the cells of their own mucosa -> lack of intrinsic factor which is a protein made in the stomach which is needed to absorb vitamin b12 -> vitamin b12 deficiency
Iron deficiency anemia
lacking iron so hemoglobin can’t bind to oxygen. Cause- too much blood loss, diet is lacking iron, absorption issues
Aplastic anemia
destruction or inhibition of the red bone marrow, affects the formation of all the formed elements. The cause is unknown but can be a result from exposure to toxins, radiation, chemotherapy, autoimmune disease, viral condition. Severe, no cure. Treatment: blood transfusions and stem cell transplants but it’s not widely successful.
Sickle cell anemia
red blood cells have a sickle shape and looks like a crescent moon, affects hemoglobin and makes the cells really vulnerable because they’re easily damaged and destroyed. Genetic mutation that most occurs in African descendants. Treatment: blood transfusions and stem cell transplants but it’s not widely successful
Hemorrhagic anemia
occurs when there is some type of hemorrhage or blood loss. Acute hemorrhagic occurs when blood loss happens rapidly. Chronic hemorrhagic anemia – occurs overtime, stomach ulcers or GI bleeds
Polycythemia
Meaning “many blood cells”
Abnormal excess of erythrocytes in the blood
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.
Hemolytic diseases 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
Complete blood count (CBC)
provides a basic assessment of a patient’s overall health, Helpful in detecting a wide range of disorders such as anemia, leukemia, infection, etc.
Complete blood count with differential (CBC with diff)
provides a more in depth preliminary assessment of a patient’s overall health, Determines the percentage and absolute concentration of each class of leukocyte, Helpful in determining the type of infection a patient may have i.e. bacterial, fungal, viral
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%
Comprehensive Metabolic Panel (CMP)
provides information about the current status of your metabolism including:kidney and liver function, electrolyte and acid/base balance, levels of blood glucose and blood proteins.
Also used to monitor known conditions, such as hypertension, and to monitor the use of medications to check for any kidney- or liver-related side effects
Full Lipid Panel
Used as part of a cardiac risk assessment to help determine an individual’s risk of heart disease.
Includes: total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein, (LDL), and triglycerides
Total cholesterol
- Optimal: <200
- Borderline High: 200-239
- High: >240
HDL
- Low: <40
- High: >60
LDL
- Optimal: <100
- Near Optimal: 100-129
- Borderline High: 130-159
- High: 160-189
- Very High: >190
Triglycerides
- Optimal: <150
- Borderline High: 150-199
- High: 200 -499
- Very High: >500
