Heart Cardio Study_Guide Su23
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School
Piedmont Virginia Community College *
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Course
142
Subject
Medicine
Date
Dec 6, 2023
Type
Pages
7
Uploaded by BailiffGiraffe3876
Lecture Study Guide
Heart and Cardiovascular Func6on
The student should be able to:
PART 1
1.
General func5ons: What is the overall role of the heart, blood vessels, and blood for cardiovascular
func5on of the body?
Pulmonary and systemic circuts-
Two sided pump
Right atrium, receives blood returning from the systemic circuit
LeD atrium, receives blood returning from the pulmonary circut.
Pumping chambers of the heart
Right ventricle, pumps blood through pulmonary circuit
LeD ventricle, pumps blood through systemic citcut.
2.
Describe 3 layers of the heart wall (endo, myo and pericardium), their 5ssue types, func5ons and their
loca5on to each other. (fibrous pericardium, parietal and visceral layers, pericardial cavity, serous fluid)
Pericardium, double walled sac surrounds heart made of layers
superficial fibrous pericardium, func5ons to protect anchor heart, to surrounding structures and
prevent overfilling.
serous pericardium- parietal layers lines internal surface of fibrous pericardium
Pericardial cavity contain serous fluid to protect against fric5on
Visceral layer(epicardium) eternal surface heart,
Epicardium, visceral layer of serous pericardium (epithelial 5ssue) make serous fluid.
Myocardium, contrac5le cardiac muscle 5ssue
cardiac skeleton, crisscrossing interlaycing fivers, anchors cardiac muscle fibers, supports greater
vessels and valves, direct spread of ac5on poten5al to specific paths
endocardium, innermost layer, lines chambers of heart.
3.
Describe the loca5on, structural and func5onal differences of the following:
a.
4 chambers: atria, ventricles
-Atria, receiving chambers
-Auricles, increase atrial volume
-Right atrium, receives de-o2 blood from body, anterior por5on is smooth walled posterior and lateral por5on
contain ridges formed by pec5nate muscles, (stretch to increase volume)
-A5ra
superior vena cava, returnes blood from body regions above the diaphragm
inferior vena cava, returnes blood from body below the diaphragm
-LeD atrium, receives oxygenated blood from lungs via pulmonary veins
-Ventricles, discharging chambers
-Trabecule carne, irregular ridges og muscle one ventricular wall or increase contrac5lity,
-Papillary muscles, project into ventricular cavity, anchor, Chonrdae tendineae, that are aVached to the heart
valves.
-Valves make sure blood goin in one direc5on.
-Right ventricle, pumps blood into pulmonary trunk
-LeD ventricle, pumps blood into the aorta.
b.
Interatrial and interventricular septa
c.
Valves: AV valves, semilunar valves, mechanism of opera5on
Valves, ensure blood flows in one direc5on
Open and clase in responce to pressure changes
Atricven5cular valves, located between atria and ventricles
Semilunar valves, located between ventricles and major arteries.
d.
Loca5on and Func5ons of: Papillary muscles, chordae tendinae, trabeculae carnae, fossa ovalis,
foramen ovale
Fossa ovalis, remnant of foramen oval of fetal heart.
Foramen ovale, allows atria to be connected and blood bypasses nonfunc5onal fetal lungs.
Cord tendinae, anchors cusps of AV valves to papillary muscle, func5on to held valve flaps in closed posi5on
Tricuspid valve (right AV valve) 3 cusps and lies between right atria and ventricle
Mitral valve (leD AV valve bicuspid vessel)
Valvular stenosis- s5ff valves/ flaps that constrict opening( narrow the flow) less o2
Incompetent valce (regurgita5on) blood backfows so heart repps same blood over and ver docent shut well
ventricle contracts but blow flows backwards into atrium.
e.
Contrast the atrial vs ventricle walls; right vs leD ventricular walls
f.
Flow to and from the heart, as well as through the heart
4.
Contrast func5on of pulmonary and systemic circuits.
Trace the flow of blood through the pulmonary
and systemic circula5on pathways: from right atrium to the lungs and from the lungs to the body and
back to the right atrium; differen5ate oxygenated vs deoxygenated.
a.
Name the major vessels transpor5ng blood to the right versus leD side of the heart, the type of
blood each is transpor5ng and the source of blood for each.
b.
Describe the loca5on of the superior and inferior vena cava, the type of blood in each vessel,
and from where the blood comes from that is transported by each vessel.
c.
Which chambers sends deoxygenated blood to the right ventricle and into which vessel this
blood is pumped as it exits the right ventricle?
d.
Describe the loca5on of the pulmonary trunk, the type of blood transported by the pulmonary
trunk, the vessels into which the pulmonary trunk bifurcates, and which chamber pumps blood
into the pulmonary trunk.
e.
What are the names and number of vessels that transport blood to the leD atrium and into
which chamber blood flows as it exits the leD atrium.
f.
From which chamber does the leD ventricle receive oxygenated blood and state into which
vessel the blood is pumped from the leD ventricle.
g.
Describe the loca5on of the aorta, the type of blood transported by the aorta, the circula5on
into which the aorta pumps blood, and which chamber of the heart pumps blood into the aorta.
h.
State which vessels are the first branches of the aorta and state into which circula5on they
transport blood.
5.
Clinical applica5ons.
a.
Define stenosis, effects on blood flow through the heart
b.
Define mitral valve prolapse, effects of MVP on blood flow through the heart
PART 2
6.
Cardiac muscle
a.
Review Skeletal muscle anatomy, physiology
b.
Compare and contrast to cardiac muscle
Skeletal,
1)
long cylinder,
2) mul5nucleate
3)
no gap junc5ons
4)
Does not contract as a unit
5)
Lots of t tubules
6)
Large sarcoplasmic re5culum only (forms triad)
7)
Ca2 binds to 5ponin
8)
No pacemaker cells
9)
Tents possible
10)Anaerobic and aerobic respira5on
Cardiac,
1)
short banded,
2)
gap junc5ons
3)
Few t tubules
4)
sarcoplasmic re5culum and extracellular fluid
5)
Ca2 binds to troponin
6)
Pacemaker cells
7)
No tetanus
8)
Aerobic only
c.
Describe the parts, loca5on and func5on of Intercalated discs
Desmasomes- holds cells together by intermediate filaments, prevents cells from separa5ng doing contrac5on
Gap junc5ons-allow ions to pass from cell to cell, electriaclly couple adjacent cells
1)
Explain syncy5um.
allow heart to be func5onal syncy5um, coordina5ng unit.
d.
Describe the 2 types of cells in the heart: cardiac muscle cells and autorhythmic cells
Contrac5le cells- responsible for contrac5on, atrial and ventricular muscle, receive the depolariza5on
spread
Pacemaker cells- auto rhythmic non contrac5le cells- spontaneously depolarized: sa nod, av node,
nodal pathway,
1)
ini5ate depolariza5on
2)
Do not need nervous system s5mula5on to contrast to skeletal muscle fibers,
3)
NS can change speed, not generate ac5on poten5als
7.
Cardiac conduc5on system
a.
List the components of the conduc5on system, where each is located and how the signal flows:
SA node, AV node, AV bundle, Right and leD bundle branches, Purkinji fibers.
Sa node-
pacemaker of the heart, right atrial wall, generates impulses 75x per Minuit (sinus rhythm) impulses
spread across atria and to av node
Av node-
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from sa spreads via gap junc5ons to AV node
Av bundle-
center of heart, superior intreven5cular system septum, electrical connec5on between atria and
ventricles
Right and leD bundle branches -
Purkinji fibers-
b.
Explain the coordina5on of heart chamber contrac5ons.
8.
Describe the events that occur during excita5on-contrac5on coupling as it relates to heart contrac5le
cells.
a.
Describe the events of the ac5on poten5als in autorhythmic (pacemaker) cells and how they
pass along autorhythmic cells to cardiac (contrac5le) cells for contrac5on of the heart as a
syncy5um
Cardiac pacemaker cells found in sa node and av node networks cells pass impulses across the heart.
4)
pace maker poten5al
5) Depolariza5on
6) Depolariza5on
b.
Describe the events occurring during an ac5on poten5al in cardiac autorhythmic cells and on a
recording of an autorhythmic cell ac5on poten5al, label the regions associated with
sodium
permeability,
Ca
++
permeability,
Ca
++
permeability, and K
+
permeability.
c.
Describe channel types or ions for each event of the ac5on poten5als
d.
Explain pacemaker poten5al, ini5ator for autorhythmic cells, compared to ini5a5on of cardiac
muscle cell ac5on poten5al
e.
Explain the significance of the plateau in cardiac muscle cells
9.
Describe the effects of autonomic innerva5on with regard to depolariza5on of cardiac pacemaker cells
and contrac5le cells
Pacemaker cells- sodium channels open and runs into cell
Na+ channels are unstable at -60mV, allows them to ini5ate ac5on poten5als spontaneously
if these voltage gated channels open rhythmically NA+ flows into
the Nodal cell which increases cell to
-40mV and threshold is reached opening calcium gated channels which will run into the cell. At threshold
voltage gated pota5on channels ea5ng posi5ve ions with them leading back to the original res5ng poten5al.
Nodal cells (autorythmeic cells) have a pacemaker poten5als (with sodium ions channels) one sodium open
and reachers
threshold voltage gated calcium channels open, for depolariza5on calcium goes out making the
nodal cells less posi5ve.
Calcium come in the cardiac myocyte from the nodel cell, at threshold sodium channels open making it more
posi5ve 5ll its at peek depolariza5on, voltage gated potassium channels open and leaves cells as calcium then
comes in to keep it more posi5ve.
This gives the heart 5me to contract and relax meaning there ate no
incoming ac5on poten5als. Calcium will bing to toponym and release 5pomyacyn
a.
Differen5ate the intrinsic and extrinsic cardiac conduc5on systems.
Intrinsic conduc5on set the pace of the hears for 100 beats per minuet
Heartbeat modified by ANS via cardiac centers in. Medulla oblongata
b.
Explain the process by which the sympathe5c nervous system s5mula5on increases heart rate.
1)
Cardioacceleratory center: rate and force (calcium)
Send singles to sympathe5c neurons which go to hear to increase both rate and force
s5mulates SA and AV nodes, hear muscle and coronary arteries.
c.
Explain the process by which the parasympathe5c nervous system decreases heart rate.
1)
Cardioinhibitory center: rate
Sends singles to parasympathes5s Vagus MO - effect, inhibit rate via SA and AV nodes using vagus nerve.
10. Explain the electrical events associated with the waves of an EKG and describe what each wave
represents
The machine that detects electoral currents generated by heart
PART 3
11. Cardiac Cycle Events
a.
Define cardiac cycle, systole, diastole, isovolumetric contrac5on and isovolumetric relaxa5on
ventricular ejec5on, ventricular filling
Cardiac cycle- what is happing to the heart (mechanical events)
Systole- contrac5on
Diastole- relaxed
Cardiac cycle, blood flow through heart one complete heartbeat
a)
atrial contrac5on force ventricle filling av valves open sl closed
b)
Isovoulumeric contrac5on: ventricles start to contract, push av valves closed, not enough pressure to open
semilunar valves stay closed, (nothing can enter or leave)
c)
Ventricles contrac5on ventricular ejec5on, ventricle pressure increases, pushed open SL valves, eject blood
d)
Is-volumetric relaxa5on, ventricles relax, pressure, drops, blood flows back, closes semilunar valves (av
valves are s5ll closed no back flow)
e)
Atria relaxa5on, chambers relaxes ventricles filling passively chambers in diastole
b.
Describe the phases of the cardiac cycle: late ventricular diastole, atrial systole, early ventricular
systole, late ventricular systole and early ventricular diastole, and relate the heart sounds to
these events.
c.
Relate the electrical events from and electrocardiogram (ECG) to the mechanical evens of the
cardiac cycle
d.
Explain atrial systole rela5ve to ventricular filling
e.
Relate opening and closing of specific heart valves to each phase of the cardiac cycle’s pressure
changes in the heart chambers and vessels
f.
Compare and contrast pressure and volume changes of the leD and right ventricle during one
cardiac cycle
g.
Define end diastolic volume (EDV), end systolic volume (ESV) and calculate SV.
h.
List the first two heart sounds and the physiological events occurring in the heart that are
associated with each sound.
12. Regula5on of cardiac output (CO), stroke volume (SV), and heart rate (HR)
a.
Define cardiac output, stroke volume and heart rate.
co= hrxstroke volume
Sv- stroke volume ml of blood pumped out by each ventricle with each beat
b.
Explain the cardiac output equa5on and be able to calculate.
c.
Predict changes in HR and/or SV and their affect on CO
1)
Explain how cardiac output can remain constant if stroke volume decreases. (heart
rate increases)
The heart can change how much blood it rejects the body wants to maintain balance so
d.
Define venous return, preload, aDerload and the factors that influence them (venous return,
filling 5me, ANS, hormones).
1)
Explain how venous return, filling 5me, ANS, hormone effect EDV, ESV and SV
Sv- end diastolic volume- end systolic volume
EDV and ESV is effected by preload
Preload is the degree to witch the heart stretches
before aDer load
preload controles SV, grester preload+ greater SV ( more we stretch more can pump)
Venus return causes preload (causes cardiac cells sarcomeres stretch) venous return is about of blood retunes
to right atrium helps determine preload
e.
State the Frank-Starling Law of the heart and its significance on preload, venous return
Higher preload, higher stroker volume
As EDV, increases stretch myocytes increase -> preload
if Venus return increases, then EDV increases sarcomere get longer, op5mal length more power beVer
ejec5on
so greater Venus return, greater EDV, greater stroke volume
Oposite: decrease Venus return, means decrease stretch, less overlap, less forkful contrac5ons, decreases SV
Most important factor increasing prelude is Venus return
f.
Define contrac5lity, posi5ve inotropic and nega5ve inotropic agents effects on contrac5lity/SV
Contrac5lity- force of contrac5on
changes in Ca2+ alters cross briges= change in contrac5on strength
Posi5ve isotropic agens- increase contrac5lity results in increased CO
increased contrac5lity, ventricles contract with greater force, decrease ESV, therefor SV increases
Nega5ve inotropic agents- decrease contrac5lity (calcium blockers leading to less cross bridge forma5on.
ADerload- resistance in arteries to the ejec5ons of blood an- normally resistance is due to narrowing of vessels
g.
Describe the influence of posi5ve and nega5ve chronotropic agents on HR
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Posi5ve chronotropic- factors increase HR
Nega5ve chronotropic factors decrease heart rate
Chrono=5me
h.
Explain how HR is influenced by ANS, causes changes in contrac5lity, EDV, ESV and SV and
therefore CO.
i.
Predict why hypocalcemia or calcium channel antagonists would be expected to depress
myocardial contrac5lity
This study guide covers the majority of informa5on on the exam but not all of it. You are s5ll responsible for
any informa5on that was covered in the notes but not put on this guide (inten5onally or uninten5onally).
Good Luck and Study Hard!!