The first time ever I held you near
and felt your heart beat close to mine
I thought our joy would fill the world
and would last till the end of time, my Love.
--Peter, Paul and Mary
Audesirk, Audesirk & Byers Chapter 32, Case study, Chapter 12
Today's musical selection
Huey Lewis and the News Heart
of rock and roll
Figure (chapter 12 opener)
Flo Hyman, 1984 Olympic silver medalist, died at age 32 when her aorta ruptured.
She had a dominant mutation of fibrillin
Figure (chapter 13 opener)
St. Louis Cardinals pitcher Darryl Kile died at age 33 in 2002.
He had blocked coronary arteries, and there was a family history
In multicellular metazoan, need a vascular system (in terestrial plants
above mosses, xylem and phloem)
Circulation : Cardiovascular system
Open circulation Blood = interstitial fluid - hemolymph is term for blood
- most molluscs and all arthropods have open circulation
hemocoel is the space where the blood is
- important in insects that gas transport (via air filled trachea) does
not rely on circulation being closed
Closed circulation - annelids, cephalopods, echinoderms, vertebrates
Chambers of heart -
Fish have 2 chambers (gills and body "wired" in series)
The "circuit" is "in series" - heart -> gills ->
body -> back to heart
Amphibia and reptiles have 3 chambers (2 atria, 1 ventricle)
As long as blood does not fully mix, there is some separation of non-oxygenated
blood to the pulmonary circulation and of oxygenated blood to the systemic
Anatomy of the heart
Note that right is drawn on left as if looking into the chest of a supine
Here is the circuit: LA - LV - Arteries (aorta, etc.) (blood pressure taken
here) - Arterioles (regulate blood flow to muscles, brain, digestion, kidneys
and skin) - Capillaries (near, exchange, WBC's) - venules - veins (no pressure,
valves)- RA - RV - Pulmonary arteries - Lung capillaries - Pulmonary veins
Heart valves and sounds
pulmonary valve (semilunar) feeds pulmonary arteries
aortic valve (semilunar) feeds aorta
These valves snap shut from arterial back pressure at the end of systole
to make second heart sound- "dub"
Superior and inferior vena cava feed right atrium -> ventricle via tricuspid
Pulmonary veins feed left atrium -> ventricle via bicuspid (atrioventricular)
Tricuspid & bicuspid snap shut at start of ventricular contraction to
make first heart sound- "lub."
If there is backslosh through valves, this is called a heart murmur.
artery is like hose
blood flow to emptying into vascular bed: regulation by smooth muscle of
capillary is one layer of endothelial cells
Blood moves slowly and with very little pressure in veins. Movement in veins
is mostly passive with a series of valves and where contraction of skeletal
Lymphatic circulation helps to percolate interstitial fluid back to circulation
Cardiac cycle and blood pressure
Diastole (between heart beats), systole is during ventricular contraction,
hence terms systolic and diastolic blood pressure.
Ventricle fills during diastole.
Ventricle empties during systole.
Ventricular pressure builds during systole.
Measuring blood pressure
It is arterial blood pressure that is usually measured.
close off artery, when it opens (systolic pressure), blood flow is turbulent
and noisy (Korotkoff sounds), when it is always open (diastolic pressure),
blood flow is no longer noisy
Blood pressure is measured in arteries
High blood pressure is called the "silent killer."
hypertension 45 million Americans - salt intake is still debated, >140/95
high 140/70 normal
high diastolic is especially bad
Heart muscle cells branch and come together and are joiined at intercalated
discs with gap junctions that spread the electrical signal from cell to
cardiac muscle - automatic (explained below)
here is a picture
from our histology
course of heart muscle cells joined at intercalated discs
Electrical activity of heart cells
Electrical - SA (sinoatrial) node (or electrical pacemaker) - spread - automatic.
Sympathetic nervous system speeds it up, parasympathetic nervous system
slows it down.
AV (atrioventricular node) is eventually stimulated.
If it were not, it is also automatic but slower and would generate a heart
beat in the venticals.
Bundle of His, bundle branches, and Purkinje fibers get ventricular depolarization
to happen almost synchronously.
This will be covered in lab
Because a lot of cells in heart work together, and because extracellular
fluid has high conductivity, electrical activity can be recorded non-invasively.
P is atrial depolarization.
QRS is ventricular depolarization.
T is ventricular repolarization.
A layer of fat with ccholesterol between media and externa
ulceration lining lumen
atherosclerosis - hardening of the arteries - plaques
atheroma with macrophages
Cholesterol is a problem
Myocardial cells not regenerate (by mitosis in the adult). This is why heart
attack is so damaging. The same is true for the nerves in the central nervous
system where similar damage is called stroke.
Coronary arteries clog -> myocardial infarction - coronary thrombosis
- ischemia (too little blood flow for oxygen delivery)
Angina, chest pain, and referred pain
Heart muscle is aerobic
Anaerobic metabolism would build up lactic acid and cause pain (angina pectoris)
In CPR (cardiopulmonary resuscitation) chest pressure keeps blood flowing
a little and rescue
Platelet aggregation - thrombus (local), embolism (from elsewhere) cause
tissue plasmogen activator (TPA) dissolve clots
aspirin inhibits clotting, coumaden is a strong anticoagulant
catheter with balloon angioplasty insert stent
bypass operations, replace coronary artery with vessel from somewhere else
in the body,
Risk facrors for heart attack
(1) High blood pressure (the silent killer) -- Wiggers diagram --heart has
to work harder to open semilunar valves.
(2) prior heart attack
(5) family history -
(1) exercise - increase HDL (endothelial cells do not take up)
(2) antioxidants (oxidized LDLs in endothelial cells are bad)
(3) alcohol in moderation (but people who die of cirrhosis rarely have atherosclerosis)
Questions used in 2007 & 2008 related to this outline
A thrombus is
A) a blood vessel that feeds the heart.
B) the smooth muscle that controls blood flow to a capillary bed from an
C) a phagocytic cell full of cholesterol.
*D) a blood clot that clogs an atherosclerotic artery.
E) the muscle cells that regrow after a heart attack.
An open circulatory system
A) is present in amphibia and reptiles.
B) feeds the lungs in humans.
*C) percolates hemolymph into and out of the hemocoel in insects.
D) refers to the valves between the ventricles and the arteries.
E) is exemplified by the cardiovascular system in birds and mammals.
Which is one reason heart signals can be recorded by connections to the
wrists and ankle?
A) because of ischemia.
*B) because there is little electrical resistance in extracellular fluid.
C) because of angina.
D) because of Korotkoff sounds.
E) because of the endothelium.
The "silent killer" is
C) heart murmers.
*E) high blood pressure.
What keeps blood moving forward through veins in the body's systemic circulation?
A) the driving force of blood pressure.
C) the AV node.
D) the pulmonary circulation.
The right ventricle sends blood to the
B) left atrium.
C) vena cava.
*D) pulmonary circulation.
E) lymph vessels.
A) is used to record the electrocardiogram.
B) measures the diastolic blood pressure.
*C) is used to open atherosclerotic coronary arteries.
D) conducts the electrical signal across intercalated discs.
E) triggers the heartbeat.
*(a) an open circulatory system and separate gas transport via air-filled
(b) a circulatory system that is more like that of vertebrates than of arthropods.
(c) xylem and phloem.
(d) 5 hearts and a closed circulatory system.
(e) a three-chambered heart where one ventricle might allow mixing of systemic
and pulmonary blood.
Why is the wall of the right ventricle thinner than that of the left ventricle?
(a) The right ventricle creates systolic blood pressure while the left ventricle
determines diastolic blood pressure.
*(b) There is not as much pressure in pulmonary circulation as there is
in the systemic circulation.
(c) The right ventricle creates hypertension while the left ventricle is
for lower pressure.
(d) The right ventricle makes Korotkoff sounds while the left ventricle
makes lub-dub sounds.
(e) The right ventricle pumps to the aorta while the left ventricle pumps
to the left atrium.
Atrioventricular valves are open
(b) when muscles contract against the veins.
(c) when stress regulates blood flow to different beds of capillaries.
*(d) during diastole.
(e) while the ventricles are pushing blood into the arteries.
Blood pressure measurements involve
(a) listening to the "lub-dub" heart sounds.
*(b) listening for turbulent blood flow in an artery.
(c) measurements from veins.
(d) electrical measurements from heart muscle.
(e) coronary bypass
Intercalated discs hold heart muscle cells together. What other function
do they serve?
(a) They help in the conversion of CO2 plus H2O to H2CO3.
(b) They allow HDL buildup in atherosclerotic plaques.
*(c) They allow electrical connection by gap junctions.
(d) They keep blood from flowing backwards during ventricular contraction.
(e) They hold open a partially closed coronary artery.
Electrical activity in the heart usually starts in the
*(a) SA node.
(b) pulmonary arteries.
(d) medulla of the brain.
(e) angina pectoris.
The term for too little blood flow for adequate oxygen delivery is
Amphibia and reptiles
A) have a two-chambered heart.
*B) have a three-chambered heart.
C) have an open circulatory system like an insect.
D) have multiple hearts like an earthworm.
E) do not have a vascular system.
How is the amount of blood flow to the different capillary beds of the body
A) by valves
B) by the cerebral cortex
C) by the size of the veins
*D) by smooth muscle of arterioles
E) by insulin
Diastolic and systolic blood pressures
A) are from systemic and pulmonary circulations respectively.
B) are from atria and ventricles respectively.
C) should be the same as eachother in healthy people.
D) are measured from veins.
*E) are measured from arteries.
Questions used in 2003 relating to this outline
Blood goes from the right ventricle to the
(a) pulmonary vein.
*(b) pulmonary artery.
(d) vena cava.
(e) right atrium.
(a) reduces HDL.
(b) reduces LDL.
(c) restores the heart beat.
*(d) circulates oxygenated blood to the brain.
(e) prevents atherosclerosis.
During atrial and ventricular diastole
*(a) AV valves (tricuspid and bicuspid valves) are open.
(b) semilunar valves are open.
(c) the QRS complex of the ECG is generated.
(d) ventricles contract.
(e) blood pressure measured with a cuff on the arm is highest.
The SA node
(a) can have its lumen clogged by a thrombus in a heart attack.
*(b) initiates the electrical activity in the heart beat.
(c) requires a nerve connection, and the heart would stop in severe polio.
(d) is the part of the brain that stimulates breathing when O2 is low.
(e) connects the hypothalamus to the anterior pituitary.
How does electrical excitation spread throughout the heart?
(a) via plasmodesmata
(b) by neurotransmitters
(c) by interleukins
*(d) by gap junctions
(e) by neurons
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