Exam 1: The Heart and Vessels Flashcards
What is the cavity between the lungs that contains the heart?
Mediastinum
What are the subdivisions of the pericardium?
Parietal pericardium
Visceral pericardium
What is the sac that surrounds the heart (externally)?
Parietal pericardium
What is adhered to the heart muscle?
Visceral pericardium
What is another name for the epicardium?
Visceral pericardium
What are the layers of the parietal pericardium?
Serous layer
Fibrous layer
What is the inner layer of the parietal pericardium that produces fluid?
Serous layer
What is the outer layer of the parietal pericardium that is made of connective tissues?
Fibrous layer
What is the outermost layer of the heart?
Epicardium
How thick is the epicardium?
Very thin
What is the middle layer of the heart?
Myocardium
What is the innermost lining of the heart?
Endocardium
How thick is the endocardium?
Very thin
What layer of the heart is known as the heart muscle?
Myocardium
What type of cells is the endocardium made of?
Simple squamous epithelium
List the layers of the heart from most external to most internal:
Fibrous parietal pericardium
Serous parietal pericardium
[Pericardial cavity]
Visceral pericardium
Myocardium
Endocardium
What chamber of the heart receives blood flow returning from the entire body (excluding lungs)?
Right atrium
What structure returns blood to the heart from structures above the heart?
Superior vena cava
What structure returns blood to the heart from structures below the heart?
Inferior vena cava
What appendage-like chamber adds volume to the right atrium?
Right auricle
What does the fossa ovalis mark?
The location of the fetal pulmonary bypass
What is the fetal pulmonary bypass?
Foramen ovale
Where is the fossa ovalis/foramen ovale located?
In the interatrial septum
What are bundles of muscles only seen in the right atrium? (exist in left, can’t see them)
Pectinate muscles
What is the wall between the two atria?
Interatrial septum
Where does blood return from the heart itself?
The opening of the coronary sinus
What is the valve between the right atrium and ventricle?
Tricuspid valve
What are the string-like cords that connect the cusps of the atrioventricular valves to specific muscles of the heart?
Chordae tendineae
What is the purpose of chordae tendineae?
They prevent the valve from pushing up into the atrium
What is another term for an anatomical part that is displaced?
Prolapse
What is the pathology when:
The chordae tendineae break?
Ruptured chordae
What is the pathology when:
A valve is forced up into the atrium during ventricular contraction, thus causing blood to go in the wrong direction?
Mitral/bicuspid valve prolapse or tricuspid valve prolapse
What is the pathology when:
Some blood goes back up into the atrium (the wrong way)
Atrioventricular regurgitation
Where should blood go out through in the heart?
The semilunar valves
What do ruptured chordae cause?
Mitral/bicuspid valve prolapse or tricuspid valve prolapse
Which chamber of the heart pumps blood to the lungs?
Right ventricle
What are specialized muscles of the heart that hold tension on the chordae tendineae?
Papillary muscles
What muscles keep tension on the chordae tendineae to keep the atrioventricular valves closed during ventricular contraction?
Papillary muscles
What are the internal heart muscles that create “nooks and crannies” in the ventricles?
Trabeculae carneae
Which heart muscles are like “struts”?
Trabeculae carneae
What is the valve between the right ventricle and the pulmonary trunk?
Pulmonary semilunar valve
What is the pulmonary semilunar valve also known as?
The pulmonary valve
What is the large artery that leads from the right ventricle to the pulmonary arteries?
Pulmonary trunk
What takes deoxygenated blood to the lungs where the blood can become oxygenated?
[Right and left] pulmonary arteries
What, in birthed humans, used to be a fetal pulmonary bypass between the pulmonary artery and aortic arch?
Ligamentum arteriosum
What, in fetal humans, is a pulmonary bypass between the pulmonary artery and aortic arch?
Ductus arteriosus
Where do the pulmonary veins obtain oxygenated blood from?
The lungs
Where do pulmonary veins take oxygenated blood from the lungs to?
The left atrium
What adds volume to the left atrium?
Left auricle
What is an atrioventricular valve between the left atrium and left ventricle?
Mitral or bicuspid valve
Are there chordae tendineae supporting both atrioventricular valves?
Yes, they are on both valves
What is the chamber that pumps blood to the entire body [except for the lungs]?
Left ventricle
Are there papillary muscles and trabeculae carneae in both ventricles?
Yes
What is the valve between the left ventricle and ascending aorta?
The aortic semilunar valve
What is another name for the aortic semilunar valve?
Aortic valve
What is the first part of the aorta that leaves the heart?
Ascending aorta
What is the part of the aorta that gives off the first 3 major arteries?
Aortic arch
What part of the aorta has blood flowing inferiorly?
Descending aorta
What region of the descending aorta is above the diaphragm?
Descending thoracic aorta
What region of the descending aorta is below the diaphragm?
Descending abdominal aorta
What is the wall between the two ventricles?
Interventricular septum
What is the wall between the two atria?
Interatrial septum
Is cardiac muscle striated or smooth?
Striated
Is cardiac muscle voluntary or involuntary?
Involuntary
Are there branches in cardiac muscle?
Yes
Is cardiac muscle mono or multinucleated?
Mononucleated
What mineral does cardiac muscle require extracellularly?
Cardiac muscle requires extracellular calcium
Why can calcium channel blockers be used to treat certain pathologies?
Cardiac muscle relies upon extracellular calcium to function normally. For example, if calcium is limited to the heart by CCBs, this may lower blood pressure (treating hypertension)
What are intercalated discs?
Structures in the heart that connect cardiac muscle cells together and allow communication
What are gap junctions?
Channels that connect the cytoplasms of neighboring cells, allowing the passage of ions and the spread of cardiac APs
What is the main function of intercalated discs and gap junctions?
Allow AP to pass from cell to cell throughout the heart with little resistance
What does it mean for the heart to be a functional or physiological syncytium?
While the heart muscle cells are mononucleated, they still behave as if they were all one giant multinucleated cell (or one unit)
What allows for the heart to behave as a functional or physiological syncitium?
Gap junctions in the intercalated discs
Where is a true anatomical syncytium seen?
Multinucleated cells in skeletal muscle
What fibers conduct AP throughout the heart?
Conductive fibers
Where does the AP begin in the heart?
The primary pacemaker, the sinoatrial node
Are nodes nerves?
NO! They are modified muscle cells
Where is the SA node located?
The roof of the right atrium between the superior vena cava and right auricle
What pace does the primary pacemaker set in bpm?
100 bpm
What slows the hearts rhythm from the SA’s pace (100bpm)?
The vagus nerve
What does the vagus nerve slow the heart down to?
75bpm
What nervous system controls the vagus nerve and makes the heart slow?
Parasympathetic
What is normal sinus rhythm in bpm?
75bpm
Can the SA node create an AP by itself?
Yes, as seen in hearts still beating after being taken out of a body… Just not for terribly long
What is the “normal” rate of the heart called?
Sinus rhythm
What is normal sinus rhythm in adults?
75bpm
What is normal sinus rhythm in neonates?
120-160bpm
What can overstimulation of the vagus nerve cause?
A vasovagal episode
What are symptoms of a vasovagal episode?
Dizziness and concomitant syncope (fainting)
Why do you faint in a vasovagal episode?
Increased vasodilation and reduction of blood pressure
What does concomitant mean?
Along with
What is the secondary pacemaker of the heart?
Atrioventricular node
What takes over if the SA node stops?
AV Node
Where is the Atrioventricular node located?
Interatrial septum
Which node is located just behind the opening for the coronary sinus?
AV node
What is the purpose of the AV node delay? Is it a pathology?
AV node delay is seen in healthy normal hearts. The AP speed is slowed down by the AV node to allow for optimal filling of the ventricles
Which node is faster? AV or SA?
SA node is faster. If the AV node has to take over, it will be much slower
What does nodal or junctional rhythm indicate?
Pathology! It suggests the SA node is not working and the AV node took over
What is the bpm of nodal or junctional rhythm?
40-50bpm
What is another name for the atrioventricular bundle?
Bundle of His
Where does the AV bundle leave the AV node?
Interventricular septum
How long is the bundle of His before it splits in two?
About 1cm long
What are the two divisions of the AV bundle called?
Right and left bundle branches
Where do the right and left bundle branches go down?
The thick portion of the interventricular septum to the heart’s apex
What conductive fibers begin at the heart’s apex and move up the sides of the heart into the papillary muscles?
Purkinje fibers
What takes over if both the SA and AV nodes stop working?
Purkinje fibers
How fast are Purkinje fibers?
Very slow- 30bpm
Are Purkinje fibers an acceptable pacemaker?
No, the bpm of 30 is so slow it may result in brain damage. If the SA and AV nodes are both broken you will need an artificial pacemaker
What is electrical potential?
The difference in charges on the inside and outside of the cell
What is the natural resting electrical potential of a cell?
Negative inside, positive outside
What is chemical potential?
Difference in chemical ions inside and outside the cell
What is the natural resting chemical potential of a cell?
K+ inside
Cl-, Na+, Ca+ outside
What is an influx or efflux of ions called?
Current
Where does action potential travel from? (from neuron to neuron)
Axon hillock to the terminal of a typical neuron
What is threshold?
The point of no return where AP will be generated
What enters the cell to bring it to threshold?
Positive Na+ ions
When does a cell reach threshold? What kind of potential?
A local potential/stimulus is strong enough to bring lots of Na+ ions into the cell
Is a resting cell polar or nonpolar?
Polar (neg inside)
What is the cell’s state when Na+ enters?
Cell becomes depolarized
What effluxes outside the cell for it to become repolarized?
Potassium
What is the impact of K+ efflux?
Cell becomes negative (polar) again, but now the chemical gradient is messed up. This leads to hyperpolarization (too negative)
What fixes hyperpolarization?
Sodium potassium pump
What is the Na-K pump ratio?
3 Na+ OUT
2 K+ IN
What does the Na-K pump regulate?
Cell volume and secondary active transport
What is the plateau in heart cell AP?
Influx of Ca++ stops the cell from becoming too negative and creates a plateau
What is the benefit of the heart cell’s Ca++ plateau?
This optimizes ejection/emptying of ventricles
How does repolarization complete in the heart?
Ca++ influx stops and K+ efflux continues
Does the Na-K pump function differently in the heart?
It still pumps 3 Na+ OUT and 2 K+ IN to restore the gradient.
The only difference is the Ca++ plateau due to Ca++ influx
What does the Ca++ plateau represent?
A prolonged contraction to maximize emptying of the heart’s chambers (pumping blood OUT)
What slows the heart by using the mechanism described by the Na-K pump?
Calcium channel blockers. These prevent the influx of Ca++, which in turn prevents the optimization of the heart’s contractions
What stage of the AP cycle is different in the heart than the neuron?
There is no hyperpolarization in the heart’s cycle, there’s a Ca++ plateau
Which has a longer refractory period: nerves or the heart?
The heart
Why does the heart have a longer refractory period?
To prevent the myocardium from entering tetanus or fatigue
Does the heart’s Ca++ plateau occur at the peak?
No, there is a decline/slight repolarization first
How does digitalis poison the Na-K pump?
Digitalis prevents Na+ from exiting the cell. This means there is less of a Na+ gradient and Ca++ accumulates inside the heart cell
What does > Ca++ inside the heart muscle do for the strength of contraction?
Increases strength of contraction
What kicks Ca out of the heart normally? (I.e., when digitalis is not interfering)
The sodium/calcium counter transport
What does an ECG/EKG represent?
All of the electrical events in the heart muscles combined
What wave occurs just prior to contraction?
P wave
What wave represents atrial depolarization?
P wave
What wave represents atrial repolarization?
It is hidden by the QRS complex
What wave represents ventricular depolarization?
QRS complex
What wave represents ventricular repolarization?
T wave
Which wave is of an unknown origin and is not always seen on EKGs?
U wave
What can enhance the U wave?
Hypokalemia (low potassium)
Where is the AV node delay on an EKG?
Right after the p wave, there is a flat line prior to the Q dip. This is the delay.
What does this EKG pathology mean?
Enlarged P wave
Atrial hypertrophy (enlargement)
What does this EKG pathology mean?
Missing p wave
SA node damage
How do you know that the AV node has taken over as pacemaker?
There’s a missing P wave, and the bpm has slowed to 40-50
What does this EKG pathology mean?
Extra QRS complex, sometimes inverted
Premature ventricular contractions (PVC), where the ventricles beat twice for the beat of one atria
What is another name for Premature ventricular contractions (PVC)?
Extra systole
What does this EKG pathology mean?
Enlarged Q, S-T elevation, and/or inverted T
Myocardial infarction (MI)
What is a myocardial infarction (MI)?
Ischemic necrosis of the myocardium
What does this EKG pathology mean?
Enlarged R
Ventricular hypertrophy (enlargement)
What does this EKG pathology mean?
Flattened T
Cardiac ischemia or hypoxia
What does this EKG pathology mean?
Prolonged P-Q
Damage in the atria blocking APs
What does this EKG pathology mean?
Bifid R wave (2 peaks)
An R wave with 2 peaks indicates left bundle branch block
What is an ectopic focus?
An AP that originates anywhere except the SA node
What is a premature contraction of the heart that results in an early beat? (You get two beats together followed by an asystolic period)?
Extra systole
What is an asystolic period?
Period without systole or contraction
Is the recovery beat after an extra systole strong or weak?
Recovery beat is very strong and is felt as a thud or flutter
Where is the cardioacceleratory center?
In the medulla oblongata
What NS increases heart rate and SOC from the cardioacceleratory center?
Sympathetic NS
What sympathetic NS receptors can impact the heart?
Adrenergic receptors
What are the neurotransmitters that bind to adrenergic receptors?
Norepinephrine and epinephrine
What’s another name for the NTs that bind to adrenergic receptors?
Receptor ligands
What does the adrenergic receptor Alpha 1 do to the heart?
Causes vasoconstriction increasing BP
What does the adrenergic receptor Beta 1 do to the heart?
Increases HR, SOC, BP when bound to norepi
What does the adrenergic receptor Beta 2 do to the heart?
Causes relaxation of smooth muscle around blood vessels (vasodilation) which reduces BP around bronchi and bronchioles (bronchodilation)
Which adrenergic receptor is associated with bronchodilation?
Beta 2
What does “chronotropic factors” mean? Positive vs negative?
Things that effect heart rate
Positive increases HR, negative decreases HR
Does this increase or decrease HR?
Beta 1 receptors
Increase HR
Does this increase or decrease HR?
Cardioacceleratory center
Increase HR
Does this increase or decrease HR?
Sympathetic NS
Increase HR
Does this increase or decrease HR?
Epinephrine/adrenalin
Increase HR
Does this increase or decrease HR?
Caffeine and nicotine
Increase HR
When is epinephrine released? What does this do to HR and BP?
Epi is released due to anxiety and increases HR and BP… This makes anxiety even worse.
What does long-term epi from anxiety do to the body?
Cortisol is released from the adrenal glands
Does this increase or decrease HR?
Parasympathetic NS
Decrease HR
Does this increase or decrease HR?
Vagus nerve
Decrease HR
What is the NT for the vagus nerve?
Achtylcholine
What does inotropic factors mean?
Things that effect the heart’s SOC
Does this increase or decrease SOC?
Parasympathetic NS
Decrease SOC
Does this increase or decrease SOC?
Vagus nerve-Ach
Decrease SOC
Where is the cardioinhibitory center located?
Also the medulla oblongata
What is in the cardioinhibitory center?
Parasympathetic nerves from the vagus nerve
What are proteins/receptors involved in the Parasympathetic NS?
Muscarinic receptors
What is another name for muscarinic receptors?
Cholinergic receptors
What cranial nerve # is the vagus nerve?
10
Is the vagus nerve large or small?
Large
What does the vagal NT Ach do to K+ channels?
Acetylcholine opens K+ channels, allowing K+ to flood OUT. This hyperpolarizes muscle cells
What is continuous vagal stimulation that keeps the HR down?
Vagal tone
What happens to the HR if you cut the vagus nerves?
HR increases to 100bpm (the actual pacing of the SA node naturally)
What makes the first sound of the heart?
Closure of the atrioventricular valves (especially the mitral valve)
What makes the second sound of the heart?
Closure of the semilunar valves, especially the aortic valve
What makes the third sound of the heart?
Too much volume in the atrium causes a gallop that sounds like “Kentucky”
Is a third heart sound normal?
In children and young adults, it is normal. For those over 40 it can indicate heart failure
How many heart sounds might you hear if you have mitral valve regurgitation?
3
When does the third heart sound happen?
Immediately following S2 in early diastole
What makes the fourth sound of the heart?
Stiff walls (noncompliant or non-elastic) vibrate when blood hits them and it makes a gallop sound like “Tennessee”
What does 4 heart sounds indicate?
Myocardial damage
When does the fourth heart sound take place?
Occurs immediately before S1
What is diastole?
The heart relaxing and filling with blood
What is systole?
The heart contracting and ejecting blood
What is the normal pressure for diastole?
Low pressure or 75mmHg for periphery
What is normal pressure for systole?
High pressure or 120mmHg for periphery
How do you calculate pulse pressure?
Diastole - Systole
What is the pulse pressure for the average healthy person?
Diastole - Systole
75mmHg - 120mmHg = 45mmHg
What is the first step in the cardiac cycle?
Ventricular filling
What brings blood into the heart, and where?
Veins return deoxygenated blood to the heart through the atria
Does pressure increase or decrease in ventricular filling?
Atrial pressure increases as blood begins to fill
Ventricular pressure decreases, as systole (ejection) just finished
What happens when the pressure in the atrium is greater than the pressure in the ventricle?
The AV valve pops open
What happens when the AV valve opens?
Blood floods the ventricles
What percent of ventricular filling is powered by low pressure venous return?
80%
What powers 20% of ventricular filling?
Atrial contraction
What is the end diastolic volume (EDV)?
Volume in the chamber at the end of diastole, or its max volume
What is the max volume, or EDV in ml?
120ml
What happens after ventricular filling?
Isovolumetric (isovolumic) contraction (IVC)
What happens to the AV valves when ventricles contract?
The valves snap shut (all 4 of them)
What does the word isovolumic mean and how does it relate to the cardiac cycle?
Same volume, meaning the volume remains the same despite pressure rising sharply
When does the aortic and pulmonary semilunar valves open?
When pressure in the ventricles get higher than the pressure in the aorta or pulmonary artery
What phase follows IVC?
Ventricular ejection
Where does blood get ejected out of in the heart?
The two semilunar valves
What is the BP in the right ventricle?
12-25/0 mmHg
What is the BP in the left ventricle?
120/0 mmHg
What is the end systolic volume (ESV)?
Blood left in the ventricle at the end of systole/ejection
What is the minimum ESV?
50 ml
What is the stroke volume?
Actual amount of blood pumped out with each beat
How do you calculate stroke volume?
EDV - ESV
What is the typical stroke volume?
EDV - ESV
120 ml - 50 ml = 70 ml
What is the total blood volume of a woman?
4000-5000ml
What is the total blood volume of a man?
5000-6000ml
What is the normal heart rate or sinus rhythm for an adult?
75bpm
What is normal sinus rhythm for neonatal?
120-160bpm
What is the cardiac output?
Amount of blood pumped out each minute
How do you calculate cardiac output?
Stroke volume (SV) x Sinus rhythm
What is normal cardiac output?
SV x rate
70 ml x 75 bpm = 5250 ml
How often do you pump your entire blood volume?
Every minute of your life
What does the ejection fraction mean?
Percent of blood (EDV) pumped out each beat
How do you calculate ejection fraction?
(Stroke volume/EDV) x 100
What is a normal ejection fraction?
(SV/EDV) x 100
(70 ml / 120 ml) x 100 = 58.33%
How high can ejection fraction get during exercise?
90%
What lowers ejection fraction?
Heart disease
How does increasing HR impact the ejection fraction?
There is reduced time for diastole, not systole, so there is less filling time
What does an ejection fraction below 40% indicate?
Heart damage and possible heart failure
At what point (in bpm) is there not enough filling time so there’s a reduction in the ejection fraction/loss of heart efficiency?
200 bpm
What is the maximum HR?
220-age
What happens in isovolumetric (isovolumic) Relaxation (IVR)?
The heart begins to relax, but all four valves are still closed. This means there is the same volume, but pressure decreases steeply
How does preload affect stroke volume?
The tension/stretch/volume on the heart’s chamber before contraction impacts the amount of venous return. More stretch = more contraction = more stroke volume
What is Frank-Starling’s Law?
The heart pumps more efficiently with increasing volumes (preload stretch).
Increased venous return causes increased SV and increased ejection fraction
How does contractility affect SV?
As SOC increases, stroke volume increases
What is afterload
The pressure the heart must exert to pump blood out of the ventricles during contraction
What is peripheral resistance?
The resistance or pressure the heart must pump against
How does afterload relate to SV?
As afterload increases, SV decreases
How does BP in the arterioles affect afterload?
When arterioles constrict, they increase resistance and therefore increase afterload, leading to higher blood pressure
Does increased afterload make it easier or harder for the heart?
Increased afterload makes the heart work harder
Does this increase or decrease afterload?
Atherosclerosis
Increase afterload
What is atherosclerosis?
Clogging/hardening of the arteries
Does this increase or decrease afterload?
Loss of arteries due to tissue damage, scarring, amputation
Increase afterload
Does this increase or decrease afterload?
Hypertension
Increase afterload
Does this increase or decrease afterload?
Cor Pulmonale
Increase afterload
Why does Cor Pulmonale cause right heart failure?
Pulmonary diseases increase afterload in the right ventricle, making it work harder. This causes an enlargement of the cells (hypertrophy), thickening of the wall, which decreases volume availability, leading to right heart failure
What NS receptor can impact afterload?
Stimulation of the sympathetic NS’s Alpha 1 Receptor causes vasoconstriction, which increases afterload
Pressure of the: right atrium
5/0
Pressure of the: right ventricle
12-25/0
Pressure of the: pulmonary arteries
12-25/8
What keeps the diastole of pulmonary artery pressure from 0?
The pulmonary valve and sympathetic tone of arterial walls
Pressure of the: left atrium
8/0
What causes the foramen ovale to close at birth [normally]?
Left atrial pressure 8/0 being slightly higher than right atrial pressure 5/0 closes the foramen ovale
Pressure of the: left ventricle
120/0
Pressure of the: aortic arch
120/80
What keeps the aortic arch diastole from 0?
Aortic valve and sympathetic tone of arterial walls
What is the mean arterial pressure (MAP)?
96 mmHg
What is an abnormal rate/rhythm of the heart- either too fast or too slow?
Arrhythmia
What is an abnormal rate/rhythm of the heart- irregular, but within normal range?
Dysrhythmia
What is the normal rhythm from the SA node and vagus nerve called?
Sinus rhythm
What happens when the heart beats at <60bpm? Is this ever normal?
Bradycardia…Normal in some top athletes
What happens when the heart beats between 100-150bpm?
Tachycardia
What happens when the APs fire at 250-300 AP/min?
Flutter (Ventricular/Atrial)
Very inefficient pumping
What happens when the APs fire at >300 AP/min?
Fibrillation (Ventricular/Atrial)
No pumping, no flow, no beating at all
How fast can you lose consciousness (LOC) with fibrillation?
3-5 seconds
What are the cardiovascular pathology (“trilogy”) from most treatable to irreversible?
Coronary Artery Disease
Myocardial Ischemia
Myocardial Infarction
What causes coronary artery disease?
Arteriosclerosis
Atherosclerosis
What is arteriosclerosis?
Loss of elasticity or hardening due to clogging/scarring
What is atherosclerosis?
Clogging of arteries (a type of arteriosclerosis)
What causes 50% of all deaths, 1/3 of those between 35-50 years old?
Atherosclerosis
What causes atherosclerosis?
Obesity, sedentary lifestyles, hyperlipidemia, hormones, alcohol, age, hypertension, smoking, diabetes
Is coronary artery disease permenant?
No, it is reversible
What is myocardial ischemia?
Reduced blood flow due to vascular occlusion or atherosclerosis
Is myocardial ischemia fixable?
Yes, it is reversible
What is a symptom of myocardial ischemia?
Angina pectoris
What is angina pectoris?
Chest and left neck/arm pain due to build up of lactic acid in the heart
What is myocardial infarction caused by?
Tissue death (ischemic necrosis)
What is a symptom of myocardial infarction?
Crushing chest pain, a “heart attack”
What does a heart attack look like on an EKG?
Prolonged Q wave, elevated ST, inverse T wave
Is a myocardial infarction fixable?
It is non-reversible
What pulmonary diseases can cause right heart failure/cor pulmonale?
Emphysema, chronic bronchitis, black lung
Why do pulmonary diseases effect the right heart?
Destruction of the pulmonary vasculature increases pulmonary afterload. This backup causes pulmonary hypertension
What happens to the heart when it works too hard?
It hypertrophies and may later atrophy (dilation)
What is the difference between hypertrophy and hyperplasia?
-trophy = enlargement with same # of cells getting bigger
-plasia = enlargement due to increase in cell #
What can right heart failure cause?
Peripheral edema (especially in lower extremities) and hepatic congestion
What is another name for left heart failure?
Congestive heart failure (CHF)
What happens in CHF?
The left heart is unable to pump blood out due to hypertension (etc.) and this increases afterload. The right heart tries to pick up the slack, and forces a back-up in the lungs.
How does CHF impact pulmonary BP?
CHF increases pulmonary BP causing a pulmonary edema, which is where the name gets “congestive” from
How can enzymes help identify pathologies?
When cells die, enzymes are released into the blood. We can test for these enzymes and see what cells died and why
What is an example of an enzyme that transfers a phosphate group to another molecule, thereby activating or inhibiting the recipient molecule?
Creatine Kinase
What does creatine kinase do with creatinine phosphate?
Creatine kinase adds a phosphate group from creatinine phosphate to ADP, making ATP
What enzyme converts lactic acid to pyruvic acid?
Lactic dehydrogenase (LDH)
What does Serum Glutamic-Oxaloacetic Transaminase (SGOT) do in the body and where?
Helps metabolize amino acids in Kreb’s cycle. Seen in the liver, heart, skeletal muscles, kidneys, pancreas, RBCs
Is SGOT specific?
No. When you test for SGOT, you learn cells are dying somewhere, but you do not know which specific organ
What protein indicates heart damage when found in the blood?
Troponin
What is a pericardial or cardiac tamponade?
Fluid accumulation in the pericardial cavity. As pressure builds, it becomes more and more difficult to fill the heart chambers
What happens in patent foramen ovale?
The foramen ovale fails to close. This causes pulmonary bypass and hypoxia
Is patent foramen ovale life threatening?
No, many are asymptomatic and require no treatment
What is patent ductus arteriosus?
A type of fetal pulmonary bypass. When it is closed, it causes hypoxia
What is it called when there is a fetal hepatic bypass causing buildup of metabolic toxins?
Patent ductus venosus
What is coarctation of the aorta?
Aortic stenosis (narrowing) and insufficient perfusion of tissues
What is an example of a ventricular septal defect?
A hole in the interventricular septum
What is difficulty breathing called?
Dyspnea
What is dyspnea when lying down called?
Orthopnea
What does paroxysmal mean?
Sudden extreme attack on your breathing
What does paroxysmal nocturnal dyspnea mean?
Sudden extreme suffocation at night causing difficulty breathing
How does digitalis treat cardiovascular disease? What does it treat?
Buildup of Ca++ from the poisoning of Na-K pump and reduction of the Na-Ca counter transport increases the SOC. This treats CHF and arrhythmias
Does digitalis increase or decrease HR?
Digitalis decreases HR, and can be used to treat hypertension
How can nitrates treat cardiovascular disease?
They vasodilate allowing more blood flow to the heart, increasing HR
What nitrate is used to treat heart problems?
Nitroglycerine
What cardiovascular treatment causes vasodilation and reduces water retention?
ACE Inhibitors
Do ACE inhibitors increase or decrease BP?
Decrease BP, treats hypertension
What do beta blockers do for the heart?
Inhibit Beta 1 receptors. This slows HR down, reduces SOC, and reduces BP
What do calcium channel blockers do for the heart?
If there is less Ca+ in the heart, the HR, SOC, and BP will all DECREASE
What reduces blood volume by increasing urine output?
Diuretics
How do diuretics impact BP?
Lowers BP
What does lidocaine do for the heart?
Lidocaine resets heart muscles to re-establish sinus rhythm by forcing Na+ channels open
What does lidocaine treat?
Temporary arrythmias/dysrhythmias
What is the innermost layer/inner lining of a blood vessel?
Endothelium
What is the endothelium made of?
Simple squamous epithelium
What is the subendothelial layer/space made of?
Connective tissue
What are the three components of the tunica intima?
Endothelium
Subendothelial space
Internal elastic lamina
Which layer of blood vessels contain smooth muscle?
Tunica media
Does the tunica media have an elastic lamina?
Yes, the external elastic lamina
What part of the blood vessel is involved in vasoconstriction/dilation?
Smooth muscle in the tunica media
Does vasoconstriction make the diameter bigger or smaller?
Smaller
Does vasodilation make the vessel diameter bigger or smaller?
Bigger
What is the outer layer of the blood vessel made of?
Connective tissue
What are the three layers of the blood vessel?
Tunica intima
Tunica media
Tunica externa
What is lumen?
The inside cavity of the vessel/organ
What is the BP of: Aorta, a type of elastic artery
120/80 mmHg
What is the BP of: Muscular arteries
96 (Mean Arterial Pressure)
How much of peripheral resistance do arterioles control?
2/3
What is the total area of the body’s capillaries in m2?
6300m2
What is the BP of: Capillaries
14-17 mmHg
What % volume of blood are capillaries?
5%
Where does gas exchange occur?
Capillaries
Is there pulse or pulse pressure in capillaries?
No
What % of blood volume is in the venules?
10%
What is the BP of: Veins
0-5 mmHg
What % blood volume is the veins?
54%
What % blood volume is in the heart?
12%
Where is most of the blood in the body and how much?
Veins (54%)
What are the elastic arteries?
Major branches near the heart, like the aorta
How big are elastic arteries?
Very large, near the heart, thick walled
Do elastic arteries contribute to vasoconstriction?
Very little
What are examples of muscular arteries?
Inferior phrenic, brachial
What type of arteries are most of the named ones?
Muscular arteries
Which have a thicker tunica media: muscular or elastic arteries?
Muscular arteries have thicker tunica media
What is the MAP of muscular arteries?
96 mmHg
What proportionately has the greatest amount of smooth muscle?
Arterioles
What proportion do arterioles regulate peripheral resistance/afterload/BP?
2/3
What are the major regulators of blood pressure through vasoconstriction/dilation?
Arterioles
What is peripheral resistance?
Similar to afterload (pressure against which the heart pumps) and correlated with blood pressure
How big are capillaries? What do they consist of?
Very small, basically only the tunica intima
Where do exchanges of gases, hormones, nutrients, wastes occur?
Capillaries
Are venules thick or thin?
Thin
Which have valves, veins or arteries?
Veins
What % of blood is held in venules and veins?
64%
Do veins and venules have a large tunica media and smooth muscle?
No, relatively little
Where is the vasomotor center?
Medulla oblongata
Where is the sympathetic NS control regulated?
Vasomotor center in medulla oblongata
How does increasing sympathetic NS effect: Vasoconstriction and BP
Increase vasoconstriction, increase BP
How does increasing sympathetic NS effect: HR and BP
Increase HR, increase BP
Does reducing sympathetic NS stimulation decrease BP, SOC, HR?
Yes
How does increasing sympathetic NS effect: SOC and BP?
Increase SOC, increase BP
Does the parasympathetic NS act opposite to the sympathetic NS in regards to BP, HR, etc.?
Yes. Increase of Parasympathetic NS stimulation decreases HR, SOC, BP
Can you exercise arterial muscles?
Yes! Continuous stimulation of arteries, called vasomotor tone, improves the vasomotor (BP) system. This is exercised alongside skeletal muscles
Local vs systemic BP?
Local: POV of a single organ
Systemic: All the arterioles of a body as a whole
How does vasoconstriction of a renal artery affect the kidney’s BP?
Decrease kidney BP
How does vasodilation of renal artery affect kidney BP?
Increase kidney BP
If you vasoconstrict systemically, how does this impact BP?
BP rises
If you vasodilate systemically, how does this impact BP?
BP drops
Should we assume local or systemic in a question?
Systemic
If you reduce a vessel’s diameter by 1/2, how does this impact blood flow volume?
Blood flow volume DROPS to 1/16…That’s a BIG drop
How does systemic BP going up impact local BP for a kidney?
Systemic increase in BP causes local vasoconstriction of the renal artery to reduce internal kidney BP (or keep it from rising with the rest of the system).
Do organs want to stay the same BP?
Yes. They will trigger mechanisms to keep their internal pressure the same, even if the systemic pressure changes
Does this affect BP/vasomotor control in the short term or long term? Baroreceptors
Short
Does this affect BP/vasomotor control in the short term or long term? Chemoreceptors
Short
Does this affect BP/vasomotor control in the short term or long term? Higher centers of the brain
Short
Does this affect BP/vasomotor control in the short term or long term? Adrenal medulla
short
Does this affect BP/vasomotor control in the short term or long term? Antidiuretic hormone
Short
Does this affect BP/vasomotor control in the short term or long term? Atrial natriuretic peptide
Short
Does this affect BP/vasomotor control in the short term or long term? Endothelin
Short
Does this affect BP/vasomotor control in the short term or long term? Nitric oxide
Short
What are baroreceptors?
Stretch receptors or mechanoreceptors
Where are baroreceptors found?
Everywhere in the body, but large concentrations are found in carotid sinus (glossopharyngeal nerve) and aortic arch (vegus nerve)
How does an increase in BP affect baroreceptors?
Increase in BP, increase in arterial stretch, increased stretch of baroreceptors
What happens when baroreceptors are stretched?
AP is sent to the vasomotor control center to reduce sympathetic NS stimulation and/or increase parasympathetic NS stimulation to REDUCE BP
Where are chemoreceptors found?
Everywhere in the body, but large concentrations are found in carotid sinus (glossopharyngeal nerve) and aortic arch (vegus nerve)
What triggers chemoreceptors to send AP to increase HR and SOC?
Decrease of O2 or increase of CO2 and H+
Why do chemoreceptors increase HR and SOC?
To increase perfusion and wash away waste products (like CO2 and H+)
Where in the body do you see vasodilation due to chemoreceptors?
The brain
How do chemoreceptors affect the lungs?
Increase lung ventilation rate
Where in the “higher centers of the brain” causes stimulation of sympathetic NS?
Hypothalamus, cerebrum
What happens in your body when you are angry/afraid and where?
Higher centers of the brain stimulate SNS with norepi and epi. This increases BP
What produces most of the body’s norepi/epi/adrenalin?
Adrenal medulla
What works closely with the higher brain centers and the sympathetic fight/flight?
Adrenal medulla
What is the name of the antidiuretic hormone (ADH)?
Vasopressin
Where is vasopressin made and stored?
Vasopressin is made in the hypothalamus, then stored and released from the posterior pituitary gland
What is ADH responsible for?
Primary hormone for tonicity homeostasis and BP control
What kind of states trigger ADH release?
Hyperosmolar (hypertonic) states trigger ADH release to initiate water retention to bring the body closer to isotonic
What common conditions result in elevated osmolarity and subsequent increased ADH secretion?
High salt diets and hypertension
What hormone promotes water reabsorption in the kidneys?
Vasopressin
Does ADH vasodilate or constrict?
Causes vasoconstriction
How does water retention and vasoconstriction impact BP and volume?
Increase arterial blood volume and increase BP to maintain tissue perfusion
What does ADH turn on when the blood becomes hypertonic/hyperosmotic?
Protein synthesis in the kidneys
What does ADH activating protein synthesis in the kidneys do?
Increase the number of water channels (proteins) in the renal tubules, allowing more water to be returned to the circulatory system
How does more water in the circulatory system affect BP?
Prevent reduction of BP
What is one of the most powerful vasoconstrictors in the body that help increase BP?
Antidiuretic hormone (ADH) vasopressin
Where does ADH get released from?
Posterior pituitary gland, angiotensin 2, pain, nausea, hypoglycemia, nicotine, opiates, certain medications, estrogen
What can be released due to increased estrogen at types of the menstrual cycle?
ADH! This causes edema (bloating) and BP rise
What inhibits ADH?
Ethanol
Alpha-adrenergic agonists
Atrial natriuretic peptide
How does being intoxicated affect water retention?
Increased ethanol due to drinking alcohol, which inhibits ADH, causes diuresis (excessive urination) in drunk people
What makes atrial natriuretic peptide (ANP)?
Heart’s atria
When is ANP released?
When BP rises, the atria stretch and released ANP to turn on Na-K pump
Where does Na+ go when ANP is released?
Pumped out of the blood into urine
Does water follow or go away from Na?
Water always follows Na
Does the body releasing 3 Na+ into the urine due to ANP increase or decrease urination? How is BP affected?
More Na+ in urine causes more water in urine, causing more urination. This decreases blood volume and BP
Where does 2 K+ go when ANP is released?
Into the blood
What hormone pumps Na+ and K+ into opposite directions?
Aldosterone
What releases endothelin?
Endothelium in tissues
What does endothelin do locally?
Local vasoconstriction to decrease local BP
What does endothelin do systemically?
Increases BP systemically
Is endothelin important in systemic or local control?
Local control
What releases nitric oxide?
Endothelium in tissues
What does nitric oxide do locally?
Local vasodilation to increase local BP
What does nitric oxide do systemically?
Decrease in BP as a system
Is nitric oxide important in systemic or local control?
Local control
What is the basic filtering unit of the kidneys?
Nephron
How many nephrons are in the kidney’s cortex?
2 million
Where does urea from unfiltered blood diffuse in a nephron?
Urea diffuses OUT into the tubules, along with a lot of water
How much water does the body need back (that is diffused out with urea)?
99.3%
How does the body get water back IN that was filtered out with urea?
2 hormones: aldosterone and ADH
What are the 3 hormones involved in urine filtration?
Aldosterone
ADH
ANP
Which hormone diffuses substances OUT of the body, through urination?
ANP
What % of water remains in urine?
0.7%
How does Na+ and urea affect the deep medulla?
Makes it hypertonic
Where are the 3 filtration hormones found?
Late distal convoluted tubules (DCT) and the collecting ducts
What is the normal urine isotonic range in the cortex?
280-296 mOSM (roughly 300 mOsm)
How does a concentration of 1200 mOsm in the deep medulla compare to the renal cortex?
Very hypertonic
What makes the deep medulla hypertonic?
Na+ and urea
Does the renin-angiotensin system work for short or long term BP control?
Long term
Where in the kidneys is renin released from?
Juxtaglomerular aparatus
What are the tubules in the kidney that indirectly monitor BP through urine flow?
Macula densa
Where in the juxtaglomerular aparatus is renin released?
Granular cells in the afferent arteriole
Where does renin turn angiotensinogen into angiotensin 1?
The liver
What enzyme turns angiotensinogen into angiotensin 1?
Renin
What turns angiotensin 1 into angiotensin 2?
Angiotensin converting enzyme (ACE)
Where does ACE convert angiotensin from 1 to 2?
Lungs
What does angiotensin 2 do?
Causes intense vasoconstriction, which increases BP
Releases aldosterone
Where is aldosterone released from when activated by angiotensin 2?
Adrenal cortex
What is aldosterone?
A steroid hormone
Where does aldosterone go when released by the adrenal cortex?
To the kidney
What turns on the Na-K pump in the kidney?
Aldosterone
What do ACE inhibitors do to BP?
These block ACE, which lowers BP. Used to treat hypertension
What is it called when you listen to heart sounds?
Auscultation
What is a blood pressure cuff called?
Sphygmomanometer
How do you hear korotkoff’s sounds?
Pump blood in the cuff until cut cuts off blood flow in the brachial artery. Slowly release the pressure and listen
What are the “puffing” sounds you hear from a blood pressure cuff?
The blood flowing into the artery vibrating the walls
What kind of pressure is measured during contraction (the first phase of blood pressure cuff)
Systole (ex. 120 mmHg)
What kind of pressure is noted when the artery is opened enough that there is no more korotkoff sounds?
Diastolic pressure (ex. 75 mmHg)
Why did they use mercury to measure BP?
It is less dense, and if you used water the sphygmomanometer would have to be over 6 feet tall
What is perfusion?
Blood flow to tissues relative to the tissue’s mass
Do organs regulate their own local BP?
Yes! It is called autoregulation
What is metabolic control?
When perfusion is reduced and there is a reduction of O2, and an increase of wastes/CO2, the tissues vasodilate to increase perfusion again
What is myogenic control?
Muscle contraction to stabilize BP
How would muscles react in myogenic control when BP is raised?
When BP is increased and the vessels dilate stretching the walls, the muscle will react with a reflex vasoconstriction to prevent wall damage
Do muscles dilate or contract when stretched?
Muscles contract when stretched
How many capillaries in skeletal muscles are open at rest?
25% (75% are closed)
Why does the metabolic control system cause vasodilation with exercise?
To respond to the increased waste products (ex. CO2)
How much can blood flow increase with exercise?
Up to a 10 fold increase in blood flow
How do arteries in the brain respond to waste products?
Vasodilation
How does the skin respond to high body temperatures (fever, exercise, etc.)?
Arterial dilation
Does cold temperature vasodilate or vasoconstrict the skin?
Vasoconstrict
Are the lung’s autoregulatory mechanisms the same as other regions?
No! The lungs always have to be difficult/different/special/opposite
What do the lungs do when O2 levels are HIGH?
Vessels DILATE to pick up even MORE O2
What do the lungs do when O2 levels are low?
Vessels CONSTRICT…There’s no point in perfusing the lung if there isn’t any O2 to pick up
What happens to the lungs with emphysema?
Lung tissue is destroyed, as chronic low O2 levels make the body abandon those tissues
When does hypoxic pulmonary vasoconstriction occur?
If ventilation is low and there is low O2
Where does fluid leak out of the capillary into and when?
When blood approaches the capillary, fluid leaks into the extracellular matrix (ECF)
What happens to the capillary as blood courses through it and there has been fluid loss?
The capillary is concentrated and hypertonic
What kind of pressure is built from a capillary that is concentrated and hypertonic?
Colloid pressure (PULLING force)
What does colloid pressure do as it increases in the capillary?
Pulls fluid back in from the ECF thanks to the pulling force
How much ECF is drained by the lymphatic vessels?
10%
What is continuously washed by fluid?
The interstitium
What happens if the lymphatics are blocked by tiny worms, tumors, etc.?
Massive swelling as seen in elephantiasis
What is the pushing pressure?
Hydrostatic pressure
What is the pulling pressure?
Colloid or osmotic pressure
Capillary/plasma hydrostatic pressure ____ blood ___ a capillary
pushes fluid OUT of
Capillary/plasma colloid/osmotic pressure ____ blood ___ a capillary
pulls fluid IN
Interstitial hydrostatic pressure ____ blood ___ the interstitium
pushes fluid OUT
Interstitial colloid/osmotic pressure ____ blood ___ the interstitium
pulls fluid IN
Will low plasma colloid pressure push fluid in or out the capillary?
Push fluid out
Will high plasma hydrostatic pressure push fluid in or out the capillary?
Push fluid out
Will high interstitial hydrostatic pressure push fluid in or out the capillary?
Push fluid in
What is the net result of ECF pushing/pulling within the capillary?
Fluid leaves the vessel at the arterial end of the capillary
As blood courses through the capillary and fluid is lost, the blood becomes…
More concentrated or hypotonic
How does prednisone affect Na+ and water retention?
Prednisone increases Na+ reabsorption, which increases water retention. This can result in increased fat in face and neck
What can kidney/heart/and liver failure cause in the interstitium?
An edema
What kind of disease/process is plaque formation?
Inflammatory
What size vessels are inflammatory?
vessels > 1 mm
What does smoking, hypertension, and hyperlipidemia do to the endothelium?
Damages endothelium and causes plaque
What is endothelial dysfunction?
The barrier is compromised allowing LDL P (small LDL particles) to move in the sub-endothelial space and produce free radicals
What is an example of a free radical?
Superoxide radical
What do free radicals like superoxide radical attract?
Monocytes
What do macrophages produce?
Macrophages phagocytize and oxidize LDL P, making “foam cells”
Where is the fatty streak found and why?
The subendothelial space, where macrophages that were full of lipids die (and their contents spill out when they die)
What cells are activated to amplify the inflammatory reaction?
T Cells
Where do smooth muscle cells migrate in plaque formation?
Into tunica intima from the tunica media
What do smooth muscle cells make out of collagen and elastin proteins?
Fibrous cap
What does the fibrous cap do in the subendothelium?
Bulges into the blood vessel narrowing its diameter (atherosclerosis)
What can smooth muscle cells release that cause stiffening of the arterial walls?
Calcium, they cause calcification
What does it mean for an arterial wall to have reduced compliance?
Less flexible, can’t stretch
How does decreased compliance affect BP?
Less stretch increases BP
What is an aneurysm?
Ballooning artery with an increased chance of fatal rupture
What are varicose veins?
Overstretched veins with compromised valves, as seen in tissue edema and pregnancy
What is orthostatic hypotension?
Reduction in BP upon standing
What percent of hypertension is primary or essential?
90%
What causes primary or essential hypertension?
Unknown for sure. Suspected smoking, genetics, stress, obesity, age, race
What percentage of hypertension is secondary?
10%
What causes secondary hypertension?
Atherosclerosis, too much renin
What is the BP of malignant hypertension?
Diastolic BP > 140 mmHg
What can malignant hypertension cause?
Encephalopathy, cerebral edema, intracerebral hemorrhage
What is shock?
Poor tissue perfusion (blood flow) which starves organs
What causes cardiogenic shock?
Heart failure, usually myocardial infarction
Is cardiogenic shock treatable?
Poor response to treatment
What kind of shock is “bleeding out”?
Hypovolemic
What type of shock is from an imbalance of PSNS and SNS?
Neurogenic
What happens in neurogenic shock?
Massive vasodilation and peripheral pooling of blood
What causes anaphylactic shock?
Hypersensitive reaction to allergy
What causes septic shock?
Bacterial or fungal infection in the blood
What does agonist mean?
A helper, works WITH
What does antagonist mean?
Works AGAINST
What would a medicine with Acetylcholine do for BP?
Lower BP, treat hypertension