CV A&P and Systemic circulation ppt <3 <3 <3 Flashcards
To pass and say FUCK YOU Boyd!!!111
the average heart weighs how much
250- 350 grams
3 main components of the myocardium
RV wall
LV wall
Myocyte
The RV wall is how thick?
0.3-0.5 cm thick
The LV wall is how thick?
1.3-1.5 cm thick
just know that basiclly the LV is over twice as thick
5 components of the myocyte
- cell membrane + T tubules
- Sarcoplasmic reticulum (SR)
- Contractile elements
- Mitochondria
- Nucleus
**** huge volume of mitochondria!!!!!****
The huge volume of mitochondria in the myocyte means what????
aerobic metabolism
what is greater than 90% of the volume of the myocardium
the myocyte
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what is the contractile elemement of the myocyte?
- sacromere (actin and myocin filaments)
A sarcomere (Greek sárx = “flesh”, méros = “part”) is the basic unit of a muscle. Muscles are composed of tubular muscle cells (myocytes or myofibers). Muscle cells are composed of tubular myofibrils. Myofibrils are composed of repeating sections of sarcomeres, which appear under the microscope as dark and light bands. Sarcomeres are composed of long, fibrous proteins that slide past each other when the muscles contract and relax.
Two of the important proteins are myosin, which forms the thick filament, and actin, which forms the thin filament. Myosin has a long, fibrous tail and a globular head, which binds to actin. The myosin head also binds to ATP, which is the source of energy for muscle movement. Myosin can only bind to actin when the binding sites on actin are exposed by calcium ions
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Sacromeres are integrated by what?
- intercalated disk and gap junctions
intercalcated disk are microscopic identifying features of cardiac muscle. Cardiac muscle consists of individual heart muscle cells (cardiomyocytes) connected by intercalated discs to work as a single functional organ or syncitium. By contrast, skeletal muscle consists of multinucleated muscle fibers and exhibit no intercalated discs. Intercalated discs support synchronised contraction of cardiac tissue. They occur at the Z line of the sarcomere and can be visualized easily when observing a longitudinal section of the tissue.
Three types of adhering junctions make up an intercalated disc — fascia adherens, macula adherens and gap junctions.
Fascia adherens are anchoring sites for actin, and connect to the closest sarcomere.
Macula adherens stop separation during contraction by binding intermediate filaments, joining the cells together. Macula adherens junctions are also called desmosomes.
Gap junctions allow action potentials to spread between cardiac cells by permitting the passage of ions between cells, producing depolarization of the heart muscle
What are 3 specialized myocytes?
- SA node
- AV node
- bundle of his
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Which leads shows an inferior MI?
what artery is invloved
II, III, AVF
Right Coronary Artery
Which leads shows a Lateral MI?
what artery is invloved
I, AVL, V5, V6
Left Circ
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Which leads shows an Anterior MI?
what artery is invloved
V3-V4 (I, AVL)
Left Coronary artery
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Which leads shows an Anteroseptal MI?
what artery is invloved
V1-V2
LAD
myocardial circulation occurs mostly during what?
and why
diastole
BC of interruption of blood flow during
systole, due to mechanical compression of vessels by myocardial contraction and the
absence of anastomoses between the left and right coronary arteries
what is the average ml/min of myocardial circulation?
200-250 ml/ml
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Another characteristic of the coronary circulation is that maximal oxygen extraction of ___1__ %
occurs, resulting in a coronary venous oxygen saturation of about __2____%.
- 70%
- 30%
what is the coronary sinus
a collection of veins joined together to form a large vessel that collects blood from the heart muscle (myocardium) and It delivers deoxygenated blood to the right atrium, as do the superior and inferior vena cava.
The coronary sinus is what % of venous return?
75%
(it seems like a lot but thats what his slides say and I cound’t find anythng in the book slide #10)
what veins make up the coronary sinus?
posterior veins
RV=anterior veins
Thebesian veins (shunt)
Layers of the heart
parietal pericardium
epicardium (visceral pericardium)
myocardium
endocardium
Most of the oxygenated
blood reaching the fetal heart is from the ____1____ vein and the __2___ __2___ __2____
- umbilical
- inferior vena cava
what is the fetal blood flow starting with the IVF
oxygenated blood from the IVC goes into the RA then
diverted through the foramen ovale to the LA to the LV then pumped out the aorta to the head
IVC > RA > FO > LA > LV > AO > systemic (head)
What is fetal circulation starting with the SVC
Deoxygenated blood from the superior vena cava enters the RA goes to the RV, then enters the (PA) the pulmonary artery goes through the patent ductus arteriosus (PDA) to the aorta to the feet and umbilical
arteries.
SVC > RA > RV > PA > PDA > AO > systemic (feet)
in the fetal circulation the RV makes up what part of CO
2/3
anatomic closure of the PDA occurs when after birth
2-3 weeks
what are the 2 main classification of valves in the heart
AV
semilunar
WHat are the 2 AV valves
tricuspid
mitral
what are the 2 semilunar valves of the heart
aortic and pulmonic
what is the blood flow through the heart then into circulation? (17 steps, once you leave the heart gets more basic)
- RA
- tricuspid
- RV
- pulmmonic valve
- PA
- lungs
- PV
- LA
- mitral valve
- LV
- Aotic valve
- aorta
- atreries
- aterioles
- capillaries
- venules
- veins
what do arteries do
transport blood under high pressure
what do arterioles do?
contract and dilate to control blood from into the capillaries
(control resistance)
what do capillaries do?
sites for transfer of oxygen and nutrients and recipients of metabolic byproducts
venules
collect blood from capillaries for delivery to veins
what do veins do?
contract or expand to store blood, venos pump mechanism.
what allows veins to return blood to heart
one-way valves and skeletal muscle pumping
what are the 3 layers of arteries and veins from inner to outer
- Tunica intima
- Tunica media
- Tunica adventitia
what layer is smooth muscle fibers mixed with elastic fibers?
tunica media (middle)
what layer is squamous epithelium, connective tissue, and basement membrane
tunica intima
what layer is a thin layer of connective tissue-lengthwise elastic or collagenous fibers?
tunica adventitia
the systemic circulation is accountable for what % of blood volume?
80%
there is low resistance in systemic circulation until arterioles! what are the pressures at the folowing:
Arterioles
Capillaries
Venous end
Arterioles- 85 mmHg
Capillaries- 30 mmHg
Venous end- 10 mmHg
The arterioles account for _____% of the resistance of systemic circulation?
50%
what is pulse pressure
difference of systolic and diasyolic b/p
what does the dicrotic notch indicate?
closure of the aortic valve
the pulse pressure reflects what?
stroke volume and resistance/compliance