Cardiovascular system Flashcards
Cardiovascular system consist of:
- 4 chambered heart
- blood vessels
- blood
The right side of the heart
accepts deoxygenated blood coming from the body and movies it to the lungs by the way of the pulmonary arteries constitutes the first pump (pulmonary circulation)
The left side of the heart
accepts oxygenated blood coming from the lungs by the way of the pulmonary veins and forces it out to the body through the aorta (systemic circulation)
Atria
thing walled structures where blood is received from either the venae cavae (deoxygenated blood entering the right heart) or the pulmonary veins (oxygenated blood entering the left side of the heart)
venae cavae
where deoxygenated blood enters the right side of the heart
pulmonary veins
where oxygenated blood enters the left side of the heart
Atria contraction:
pushes blood into the ventricles and after the ventricles fill, they contract to send blood to the lungs and the systemic circulation
note: the ventricles are far more muscular than the atria, allowing for more powerful contractions necessary to push blood through the rest of the cardiovascular system
AV Valves
- what separates the atria from the ventricles
- allow the pump to create the pressure within the ventricles necessary to propel the blood forward within the circulation
- prevents back flow
SV Valves
- what separates the ventricles from the vasculature
Tricuspid valve (AV Valve)
- what separates the right atria from the right ventricle
- has 3 leaflets
Mitrial or Bicupsid valve (AV Valve)
- what separates the left atria from the left ventricle
- has 2 leaflets
Pulmonary Valve (SA Valve)
- what separates the right ventricle from the pulmonary circulation
- has 3 leaflets
Aortic Valve (SA Valve)
- what separates the left ventricle from the aorta
- has 3 leaflets
The left side of the heart supports
the circulation to the lungs
more muscular than the right heart
The right side of the heart pumps
blood into the systemic circulation
Electical impulse travels through a pathway formed by 4 electrically excitable structures:
SV nodes
AV nodes
Bundle of His and its branches
Purkinje Fibers
Electic Conduction:
- Impulse initiation begins at the SA node (60 - 100 bpm)
- As depolarization wave spreads from the SA node, it causes the two atria to contract simutaneously
- While most ventricular filling is passive (that is, blood moves from the atria to the ventricles based solely on ventricular relaxation), atrial systole (CONTRACTION) results in an increase in atrial pressure that forces a little more blood into the ventricles
- This additional volume of blood is called the atrial kick that accounts for 5-30 percent of the cardia output
- NEXT, the signal reaches the AV node, which sits at the junction of the atria and ventricles – signal is delayed here to allow the ventricles to fill completely before they contract
- THEN, the signal travels down the bundle of His and its branches, embedde in the interventicular septum (wall) and to the parking fibers, which distribute the electrical signal through the ventricular muscle
Muscle cells are connected by
intercalated discs, which contain many gap junction directly connecting the cytoplasm of adjacent cells, thereby allowing for coordinated ventricular contraction
SA node has a rhythm of 60 - 100 bpm so, the normal human heart rate is
60 - 100 bpm
Sympathetic nerves affects the heart in what way?
- increases heart rate
- increases contractility of cardiac muscle
Parasympathetic nerves affects the heart in what way?
- decreases heart rate
- decreases contractility of cardiac muscle
Systole
heart contracts = generating high pressure
ventricular contraction
AV nodes close
blood pumps out of the ventricles
Diastole
heart is relaxed = generating a decrease in pressure
SV nodes close
blood from atria fill the ventricles
Cardiac Output
- the total blood volume pumped by a ventricle in a minute
- two pumps are connected as series so it doesn’t matter which ventricle you choose to calculate; volume of blood passing through each side must be the same
Cardia Output (ml/min) = Heart Rate(beats/min) x Stroke Volume (mL/min) CO = HR x SV
Heart rate: beats per minute
Stroke Volume: of blood pumped per beat
EKG
P wave: occurs immediately before the atria contracts
QRS: occurs before the ventricles contract
T wave: ventricular repolatization
3 major types of vessels:
capillaries
arteries
veins
Arteries
through where the blood travels AWAY from the heart
largest one is AORTA
branch into arterioles which lead to capillaries that refuse to tissues
Arteries branch into
Arterioes which lead to capillaries that refuse to tissues
capillaries join together into venules
which join to form veins
all blood vessels are lined with
endothelial cells
endothelial cells
- help mining the vessel by releasing chemicals that aid in vasodilation and vast constriction
- allow WBCs to pass through the vessel wall and into the tissues during an inflammatory response
- release certain chemicals when damaged that are necessary in the formation of blood clots to repair the vessel and stop bleeding
Arteries
- move blood away from the heart to the lungs and other parts of the body
- contain oxygenated blood
- only pulmonary arteries contain deoxygenated blood
- smaller muscular artieries are known as arterioles
- high muscular and elastic; creating resistance to the flow of blood
- after arteries are filled with blood, the elastic recoil from their walls maintain a high pressure and force blood forward
Capillaries
- vessels with a single endothelial cell layer
- they are so small that RBC must pass through the capillaries in a single file line
- their thin wall allows the capillary to allow easy diffusion of gases (O2, CO2), nutrients (glucose) and wastes (ammonia and urea)
- are the interface for communication of the circulatory system with the tissues
- capillaries allow endocrine signals to arrive at their target tissues
- if damaged, blood can leave the capillaries and enter the interstitial space, if this occurs in a closed space, it results in a bruise
Veins
- thin walled, inelastic vessels that transport the blood to the heart
- all veins are deoxygenated, except for the pulmonary veins
- Venules: smaller venous structures that connect capitalizes to larger veins of the body
- the smaller amount of smooth muscle in the walls of veins gives them less recoil than arteries
- can stretch to accommodate large quantities of blood
- blood flow is upward from the lower body back to the heart against gravity
- inferior vena cava:
after you centrifuge a tube, plasma will be found where?
on the top layer, and RBC in the bottom layer.
molecular oxygen is non polar or polar?
nonpolar; therefore has low solubility in aqueous environments
For the production of ATP, RBCs rely on
glycolysis with lactic acid as the main function
RBC
has no nuclei (therefore can’t divide), mitochondria or membrane bound organelles
does not carry out oxidative phosphorylation to generate ATP
