Download Physiology Slide#1 : -Blue arteries and veins mean: deoxygenated

Physiology
Slide#1 :
-Blue arteries and veins mean: deoxygenated, red mean: oxygenated.
-All cardiac cells are put together under a very sophisticated collagen matrix
and work as a one unit.
-artery takes blood away from the heart, while vein brings the blood toward the
heart.
Slide#2:
-in females, the heart weight is a bit smaller than in males, it is about 252-255
gm.
- the heart has 4 chambers, 2 in the bottom, and 2 in the top:
Top ones are called: atria: right and left,
in the bottom: veins: right and left.
-Pericardium is very important, since heart beats vigorously and thus it needs
to be surrounded with fluid to reduce friction.
Slide#3:
Location: is midline, top part is between 2nd and 3rd ribs, and the bottom is
between 5th and 6th ribs, and it is shifted to the left, 2/3 of the heart is on the left
side.
-amazingly, the bottom part is called: apex, whereas the top is called: base.
- remember: Blue veins: comes to the right side of the heart.
Slide#5:
-The heart is located at the top part of the chest and very close to the sternum,
and it is between the 2 lungs.
- CPR (Cardiopulmonary resuscitation) is about squeezing the heart when a
heart attack occurs, and pushing the blood forward.
Slide#6:
The pericardial sac has to layers: the outermost fibrous layer and the innermost
serous layer, and between them we find the fluid to lubricate the heart and
prevent friction during heart activity. Another function for the pericardium is to
limit the heart if there is so blood came to it.
Slide#7:
-when the atrium contracts, the both left and right atria contract at the same
time, and same of ventricles, right and left contract at the same time.
-when action potential moves through the heart, it moves in left and right in the
same time.
- right atrium collects the blood from the upper and lower part of the body:
lower part blood comes through the inferior vena cava, where the upper part
blood comes through the superior vena cava. (venous blood returns back into
the right atrium), then it pumps the blood to the right ventricle which pumps the
blood into the pulmonary circulation.
- left atrium collects the blood from the pulmonary circulation (oxygenated
blood)
Slide#8:
-myocardium is the main heart muscle.
Slide#9:
-myocardium is thick and very strong.
-epicardium is close to the pericardial cavity.
Slide#10:
-the right atrium has something called: Auricle ( like a dog’s ear) , which
collects the deoxygenated blood from the bloodstream and moves it into the
heart right ventricle, it works when you need more blood for some reason.
- the right ventricle pumps the heart into the pulmonary artery, to the lungs
where the blood has a lung circulation, then come back through the pulmonary
veins into the left atrium, which receives the oxygenated blood and pumps it
into the left ventricle which pumps it into the aorta.
Slide#11:
-valves open in the heart by pressure differences,
When the atrium pressure is higher than the pressure of the ventricle, the
atrioventricular valves open, and when the pressure in right ventricle is more
than pressure in aorta, the aortic valve opens.
-atrioventricular valves are opened and the aortic/pulmonary valves are closed
when the heart relaxes, atrioventicular valves are closed and the
aortic/pulmonary valves are opened when the heart contracts.
- in the transverse cut of the heart: left ventricle is thicker than the right one,
because it is supposed to have a high pressure in purpose to pump the blood to
whole our body. Since the left ventricle is thicker, it can hold a higher amount of
blood.
-when you hear some say their blood pressure is 120 over 80, it is the left
ventricle that generates this pressure.
Slide#12 = slide#13: go to slide#16 for details.
- pressure difference opens the valve to flow the blood from high to low.
- valves are opened and closed passively.
Slide#14 = slide#15:
-when the oxygenated blood comes from lungs through the pulmonary veins
into the left atrium, the blood fills the atrium while the mitral valve is open (the
heart is relaxed now), aortic and pulmonary valves are closed.
- Papillary muscles: muscles that are present in ventricles of the heart, and
attached to the cusps of the atrioventricular valves via the Chordae Tendineae
which are cord-like tendons.
-papillary muscles are responsible for opening and closing of valves in
response to pressure difference.
Slide#17:
Adequate=sufficient
-generation of the pressure difference is the key step of heart activity, because
all veins, arteries, atria,… (structures of the heart) are working to maintain that
difference.
- pulmonary and systemic circulation happen in the same time, and valves
maintain the unidirectional flow of blood.
- the heart adapts to the metabolic of our body, and is regulated by sympathetic
and parasympathetic regulations.
Slide#19:
Exchange of gases and other substances occur in the capillary level.
Slide#20 + Slide#23:
Reminding of the blood flow, (I will write it here and I won’t repeat it in next
slides even the doctor had done.)
Deoxygenated blood comes to the right atrium through superior and inferior
venae cavae, once the right atrium is full of blood, the tricuspid valve opens,
which allow the blood to move to the right ventricle, once the right ventricle is
full of blood, the tricuspid valve closes and the pulmonary valve opens, which
allow the right ventricle to contract and pump the blood through the pulmonary
valve, blood arrives the lungs via the pulmonary artery, once the right ventricle
is emptied, the pulmonary valve closes to prevent the blood from returning
back to the ventricle, after the blood has a gas exchange in the lungs, it comes
back to the left atrium and once the left atrium is full of oxygenated blood, the
pressure between left atrium and ventricle changes, and thus: the bicuspid
(mitral) valve opens and allows the contraction of left atrium and pumping of
blood to the left ventricle, once the left ventricle is full of oxygenated blood,
mitral valve closes and aortic valve opens, allows the left ventricle to contract
and pump the blood to the aorta (main artery of the body) through the aortic
valve, once the left ventricle is emptied , the aortic valve closes to prevent the
blood that has just been pumped from re-entering the ventricle.
-these two circles happen in the same time !
Slide#22:
-left ventricle pumps blood to your arms and head through the Ascending aorta,
and through the abdominal and descending arteries to the abdominal area
(kidney, liver..) and lower part, once the gas exchange occurs in capillaries,
deoxygenated blood comes back to the right atrium through superior and
inferior veanea cavea.
Slide#24:
-Myogenic: the action potential starts from the heart itself.
-if the heart is cut and got out of a body and supplied with oxygen and blood
vessels, it will keep contracting even no electrical signals were given to it,
because it is myogenic!
-Gap junction is responsible for working of heart structures as a one unit.
Slide#26:
-intercalated discs are histological connections.
Slide#28: cardiac cells are full of mitochondria in order to produce enough
amounts of energy to support effective beats of the heart.
Slide#29:
-Electrical activity moves from the base to the apex of the heart.
-once the action potential starts, the heart begins to contract.
Slide#30:
-SA node is in the top part of the right atrium.
- action potential is initiated in the SA node and it moves to the right atrium in a
very organized manner.
Slide#31:
-Plateau is responsible for the long time of action potential in cardiac muscles.
-myocardium resting potential= -90mV.
- Ca++ has an important role in actin-myosin interaction in contraction of
cardiac muscle as long as making the plateau level.
Slides#32,33 and 34: will be explained later.