A patient has a P-R interval that is 3 times longer than normal? What causes this?
1.) Hypercalcemia 2.) Acute Cardiovascular Disease
Known as first-degree atrioventricular block when the PR exceeds 200 milliseconds.
The known causes of first-degree AVB are numerous and include ischemic heart disease, degenerative conduction system disease, congenital heart disease, connective tissue disease, inflammatory diseases, and medications. However, in ambulatory individuals, first-degree AVB typically occurs in the absence of acute cardiovascular disease
The PR Interval:
The PR interval is the interval from the beginning of the P wave to the beginning of the QRS complex. It represents the time frame from the beginning of atrial depolarization to the beginning of ventricular depolarization.
P-wave =
atrium depolarizing
QRS =
Ventricular depolarization and atrial repolarization
T-wave =
Ventricular re-polarization. Re-polarization is a slower process so T-wave is longer.
PR segment =
after P-wave before QRS
S-T Interval =
S-T segment =
Interval = Starts after QRS and ends after T-wave
Segment = Starts after QRS and end before T-wave. Period of no net current. Ventricles are contracting, pumping blood to aorta and to pulmonary artery.
Describe the postural effects on the EKG, as indicated by your data in Table 1 of moving from lying down position to sitting up:
The postural effects on the EKG are an increase in BPM. The remaining segments/intervals remain relatively stable with minimal change.
Does your data indicate a change in heart rate after moving to the sitting up position?
Yes, the heart has to work harder when standing up due to gravity in order to circulate blood.
Acidic acid =
lysis red blood cells so that you just see WBC
Crystal Violet =
Dyes WBC purple
Never Let Monkeys Eat Bananas
Neutrophil, Eosinophil, Basophil, Lymphocyte, Monocyte
BIOPAC: where do you place the 3 electrodes on the subject?
Salt and pepper (right forearm, right leg), Ketchup (left leg)
BIOPAC: how do you analyze the data?
Click the magnifying glass to activate zoom function. Click to represent about 4 seconds of data. Select display menu at top, and click autoscale waveforms. Click "adjust baseline" Move to center wave forms then click exit.
BIOPAC: How to measure Delta T and BPM?
Using I-beam, highlight from the start of one peak R wave to the next peak R wave.
Delta T = computes the elapsed time bw the beginning and end of highlighted area
BPM = computes beats per minute when the area from R wave of one cycle to the R wave of another cycle is highlighted.
Normal Blood Pressure =
120/80 mm Hg
g/dL is the units of measure for what?
Hemoglobin concentration
- Adult males: 14 to 18 gm/dL
- Adult women: 12 to 16 gm/dL
Physical characteristics of plasma? pH? Color?
pH = 8.0 Color opacue, fairly transparent
Normal human blood contains WBC, RBC?
WBC = 5,000-9,000 per mm3
RBC = 4.5-5.5 million per mm3
Viral infections are often associated with a drop in WBCs (leukopenia)
Bacterial infections are often associated with an elevated WBC (leukocytosis)
How do you count WBCs?
add up all 16 squares and multiply by 50
How do you count RBCs?
Count the RBCs in the four tiny corner squares plus the very center tiny square. (this square is surrounded by a double etched line)
What are the 5 Leukocytes? Which ones are granulocytes and which ones are agranulocyte?
Agranulocytes: Lymphocyte (large spherical nucleus), Monocyte (kidney shaped nucleus)
Granulocytes: Neutrophil (multilobed nucleus), Eosinophil, Basophil
What is the Frog Ringer's Solution Made of?
- 110 mM
- NaCl, 2.5
- mM KCL
- 1.0 mM CaCl2
Sympatholytic:
Receptors: Beta Blocker
Action: antihypertensive
Representative Drug: Propranolol
Sympathomimetic:
Receptors: Beta 2 agonist
Action: Bronchial Dilator
Representative Drug: Albuterol
Parasympathomimetic:
Receptors: Muscarinic agonist
Action: decreases pressure in glaucoma
Representative Drug: Pilocarpine
Parasympatholytic:
Receptors: Muscarinic antagonist
Action: Dilates eyes
Representative Drug: Atropine
ACh
Effect on heart: decreased heart rate
Mechanism: reduces slope of pacemaker potential via permeability changes
Notes: parasympathetic/neurotransmitter
Epinephrine
Effect on heart: increased heart rate
Mechanism: increases slope of pacemaker potential via permeability changes
Notes: Sympathetic/neurotransmitter
Atropine
Effect on heart: increased heart rate
Mechanism: blocks ACh receptors
Notes: parasympatholytic
Pilocarpine
Effect on heart: decreased heart rate
Mechanism: enhances release of ACh
Notes: parasympathomimetic
Propranolol
Effect on heart: decreased heart rate
Mechanism: beta blocker
Notes: Sympatholytic
Varapmil
Effect on heart: decreased heart rate
Mechanism: Calcium channel blocker
Notes: an anti-arhythmic agent
Digitalis:
Effect on heart: decreased heart rate and strengthens contractiosn
Mechanism: inhibits Na/K pump and enhances Ca++ entry
Notes: a cardiac glycoside used to control atrial fibrillation
KCL
Effect on heart: decreased heart rate
Mechanism: depolarizes membranes
Notes: Used in Dr. Kevorkian's machine
NaCl
Effect on heart: erratic results
Mechanism: unusual ion ratios affect membrane potential and calcium influx
Notes: Similar to Ringers solution, but lacks K+ and Ca++
CaCl2
Effect on heart: increased force of contractions but may be erratic
Mechanism: Increased intracellular availability of Ca++
Notes: calcium binds to troponin-C and activates the thin filaments
HEART
Define Mitral valve prolapse:
is a heart problem in which the valve that separates the upper and lower chambers of the left side of the heart does not close properly
HEART
Define cardiac tamponade:
is pressure on the heart that occurs when blood or fluid builds up in the space between the heart muscle (myocardium) and the outer covering sac of the heart (pericardium)
HEART
Define myocardial infarction:
a heart attack. The word "infarction" comes from the Latin "infarcire" meaning "to plug up or cram." It refers to the clogging of the artery
The heart requires its own constant supply of oxygen and nutrients, like any muscle in the body. Two large, branching coronary arteries deliver oxygenated blood to the heart muscle. If one of these arteries or branches becomes blocked suddenly, a portion of the heart is starved of oxygen, a condition called "cardiac ischemia."
If cardiac ischemia lasts too long, the starved heart tissue dies. This is a heart attack, otherwise known as a myocardial infarction
HEART
Define coronary bypass:
A surgical procedure to restore normal blood supply to the heart by creating new routes for the blood to travel into the heart when one or both of the coronary arteries have become clogged or obstructed
HEART
Define Congestive heart failures:
Inability of the heart to keep up with the demands on it, with failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs, such as the brain, liver, and kidneys. CHF may be due to failure of the right or left ventricle, or both.
HEART
The conduction system of the heart:
The SA node (anatomical pacemaker) starts the sequence by causing the atrial muscles to contract. From there, the signal travels to the AV node, through the bundle of His, down the bundle branches, and through the Purkinje fibers, causing the ventricles to contract.
This signal creates an electrical current that can be seen on a graph called an Electrocardiogram (EKG or ECG). Doctors use an EKG to monitor the cardiac conduction system’s electrical activity in the heart.
Atrioventricular Node:
is a part of the electrical control system of the heart that coordinates the top of the heart. It electrically connects atrial and ventricular chambers. The AV node is an area of specialized tissue between the atria and the ventricles of the heart.
AV Node creates a delay bw atria and ventricles (.1 sec)... if they contracted simultaneously they would be squeezing blood against each other. It makes sure the blood moves throughout the heart in a coordinated way.
EKG:
Change in voltage over time. Voltage is on y-axis and time is on x-axis.
Lub sound of heart
When the tricuspid valve and mitral valve shut. Pulmonary and aortic valve open at same time.
Dub sound of heart
Pulmonic and aortic valve snap shut. At the same time tricuspid and mitral valve open.
Systole:
In between the lub/dub sound or S1 and S2 blood is being squeezed or pumped out into the body which is called systole.
Diastole:
In between the S2 and the next S1 is diastole. So directly after dub and before the next lub (blood is refilling from the atrium to the ventricles).
Which branch of the nervous system secretes epinephrine?
Sympathetic
Beta 2 agonist falls under what category?
Sympathomimetic
What is the effect of acetylcholine (ACh) on the heart rate of the frog?
increases the heart rate
describe what happens when atropine meets an acetylcholine receptor?
Atropine blocks ACh receptors
Atropine is a:
Parasympatholytic
What is the mechanism of varapmil?
calcium channel blocker
What is the effect of propranolol on the heart?
decreased heart rate
What is the effect of K+ on the frog heart?
cardiac arrest
How many ventricles has the heart of a frog?
1
How many atria has the heart of a frog?
2
What is the normal value for the pH of plasma?
7.35-7.45
What is the typical value of hematocrit from a normal male?
47%
What is the likely value for the hemoglobin of a male with polycythemia?
...
How many red blood cells are in a cubic mm of blood from a normal person?
4.5-5.5 million
What would you expect the hemoglobin concentration to be in a normal person with a hematocrit of 45%?
...
Which antibodies are present in the blood of a person with type AB blood?
no antibodies
What color was the solution placed on the hemocytometer for the total WBC?
Violet/purple
What effect did the solution have on RBC?
Lysis RBC
What is hematocrit?
The percentage of red blood cells in whole blood