cardiovascular system

how much muscle is in an artery, a capillary, and a vein

- artery has little bit -capillary has none -vein has the most

what are the advantages of dual circulation compared to parallel circulation? who experiences parallel circulation?

-amphibians -greater oxygenation of blood -parallel circuits mix oxy and deoxy blood in the ventricle

explain the shape of an artery, a capillary, and a vein

-arteries are round -capillaries are round -veins are roundish

explain the purpose of an artery, a capillary, and a vein

-arteries delivery OXYGENATED blood TO THE BODY -capillaries allow oxygen to transfuse to muscle -veins deliver and store DEOXYGENATED blood to the heart

how many layers are in an artery, a capillary, and a vein

-artery has 3 -capillary has 1 -vein has 3

describe the thickness (lumen and wall) of an artery, a capillary, and a vein

-artery has a narrow lumen, thick wall -capillary has no lumen, VERY thin wall -vein has a wide lumen, thin wall

what do the capillaries in the lungs do? what about those in the trunk/lower limbs?

-capillaries in the lungs allows O2 to diffuse from the lungs to the blood -capillaries in the trunk and lower limbs allow O2 to diffuse from the blood to the muscle cells

describe the sounds of the heart? what makes the first dub? what makes the second dub?

-first dub is made by the tricuspid and bicuspid valves closing -second is made from the aortic and pulmonary valves shutting

what are the advantages of dual circulation compared to single circulation? who experiences single circulation?

-fish -greater pressure, greater flow, more oxygen -increase in metabolic activity -less energy is lost during reoxygenation -greater circulatory rate -greater ability to increase circulatory rate during fight/flight -increased capacity for tissue oxygenation -increase efficiency for blood supply and the heart (coronary arteries branch right off of the aorta)

explain the anatomy of the coronary veins on the heart

-great cardiac vein travels along side anterior interventricular artery then curves posteriorly with the circumflex artery -middle cardiac vein travels with the posterior interventricular artery -small cardiac vein drain blood from the right side of the heart

what is in the pericadial cavitity?

-it is filled with pericardial fluid to keep it slippery and lubricated (reduces friction)

Oxyhemoglobin, vs deoxyhemoglobin, vs carboxyhemoglobin

-oxyhemoglobin is red (oxygen filled in your arteries) -deoxyhemoglobin is dark red/purple (no oxygen in venous blood) -carboxyhemoglobin is bright cherry red (CO2 binds to your hemoglobin so O2 can't bind- happens during carbon monoxide poisoning)

some congenital heart diseases mirror the effect of which type of circulation? which are the congenital defects?

-parallel circulation -ventricular septal defect (hole in septum) -univentricular heart -has same increase in pressure and flow

if there is too much fluid/presence of blood in the pericardial cavity what happens?

-pressure increases, space decreases, so the heart has difficulty beating

What are capillaries? size and function

-the smallest blood vessels -"exchange vessels" (only place where oxygen moves in and out of the blood)

how does the cardiovascular system function as a transport system?

-transports blood to the body -delivers O2 to cells -removes CO2 from body via lungs -delivers nutrients and hormones -balances H20 + electrolyte balance (Na+, K+) -removes metabolic waste (urea) via kidney -transports heat for thermoregulation

Fibrous vs Serous pericardium

1. fibrous is the loosely fitting outer layer (inelastic, tough, protects the heart and anchors it to the surrounding tissues and retains its position in the mediastinum) 2. serous is thin, slippery, 2-layered, membrane that wraps around the heart

parietal layer (epicardium) vs visceral layer

1. paretial is the outer layer that lines the inner surface of the fibrous pericardium 2. visceral layer or epicardium is the inner layer that lines the external surface of the heart

The ratio of capillaries:myocardial cells

1:1

blood flow through the coronary artery is ______ because

Blood flow through the coronary circulation is intermittent. especially true in the left c.a. (which supplies the left ventricle)

how does the heart get its oxygen?

Cardiac muscle cells have a highly efficient aerobic metabolism !! - note: approx. 20-30% of the myocardial cell's volume is made up of mitochondria (the O2-dependent energy producing organelles), compared to ~5% in a skeletal muscle cell. • Therefore the cardiac muscle needs a good oxygen supply (i.e. a good blood supply) • Although all the blood passes through the chambers of heart, cardiac muscle cells cannot extract O2 (or other nutrients) from blood in the chambers because... - (i) the endocardium (inner lining) of the chambers is poorly permeable to oxygen - (ii) the cardiac muscle wall is too thick for diffusion of O2 to take place. • The myocardium blood supply is from the coronary arteries

Is the following statement true or false? The left heart receives blood from the pulmonary circulation.

It's TRUE.Blood that has passed through the pulmonary circulation (where it has been loaded with oxygen and had carbon dioxide removed) returns to the left side of the heart from work gets pumped into the high pressure systemic circulation.

Is the following statement true or false? The heart is located in the mediastinum.

It's TRUE.The heart is located in the mediastinum which is the medial cavity of the chest

Is the following statement true or false? Blood flows into the coronary arteries during ventricular systole when blood is flowing into the aorta.

It's false. During ventricular systole blood is ejected from the left ventricle into the aorta. This blood is oxygenated and carries oxygen to the tissues. However, during ventricular sisterly the aortic valve is open and this blocks the coronary sinus which is the origin of the coronary arteries. Blood flows to the myocardium during diastole.

Is the following statement true or false? The internal surface of the heart is lined by pericardium.

It's false. The internal surface of the heart is lined by endocardium. The prefix endo- refers to inside. The pericardial is the sack within which the heart is located. It consists of 2 parts-the fibrous pericardial which provides strength and the serous pericardium which produces fluid that lubricates the pericardial sac.

Is the following statement true or false? The interstitial fluid is part of the intracellular fluid.

It's false. The interstitial fluid and the plasma are the 2 main components of the extracellular fluid

Is the following statement true or false? The amount of blood pumped by the left ventricle each minute is much larger than the amount of blood pumped by the right ventricle.

It's false. The left ventricle is the pump for the systemic circulation and the right ventricle is the pump for the pulmonary circulation. The 2 circulations are in series so the output of each ventricle each minute should be the same.

Is the following statement true or false? The heart can extract the oxygen it needs to function from the blood in the chambers (the chambers are the atria and the ventricles).

It's false. The myocardium relies on blood supply by the coronary circulation. Myocardial infarction occurs when the blood flow through the coronary circulation is blocked causing myocardial cells to die due to lack of oxygen.

Is the following statement true or false? The pericardium is the tissue that lines the internal surface of the atria and ventricles.

It's false. The pericardium is the sack that surrounds the heart. Peri means around. The tissue that lines the inside is the endocardium. Endoo means inside.

Is the following statement true or false? All veins carry deoxygenated blood.

It's false. Veins carry blood back to the heart. The systemic veins carry blood that is travel through the tissues and delivered its oxygen, so that blood is deoxygenated. But the pulmonary veins carry blood that has travel through the lungs and being loaded up with oxygen so it is oxygenated.

Is the following statement true or false? An anastomosis is a connection between 2 blood vessels.

It's true. An anastomoses is connection between 2 blood vessels.

Is the following statement true or false? The blood entering the systemic circulation is oxygenated.

It's true. The blood entering the systemic circulation has passed through the lungs where oxygen has been added to it and carbon dioxide removed.

Is the following statement true or false? The papillary muscles stabilise the heart valves.

It's true. The chordae tendineae are attached to the papillary muscles on the ventricular wall. The chordae tendineae helped to ensure that the close to A-V valves are in the correct position to form a good seal and prevent blood flowing from the ventricle back into the atrium.

Is the following statement true or false? The heart is located in the mediastinum.

It's true. The heart is one of the structures that is located in the mediastinum that separates the thorax into right and left sides. Other structures in the mediastinum include the great veins, the aorta, the trachea and the oesophagus.

Is the following statement true or false? The sodium concentration in the extracellular fluid is much higher than the sodium concentration in the intracellular fluid.

It's true. The sodium concentration in the extracellular fluid is much higher than the sodium concentration in the intracellular fluid because the Na-K ATPase pump in the cell membrane moves sodium ions out of the cell and potassium mines into it by active transport. Remember the rule: sodium and potassium are always opposite, ICF and ECF are always opposite. If you remember that the sodium ion concentration in the ECF is high you can apply the rule to recall that the sodium ion concentration in the ICF is low, the potassium ion concentration in the ECF is low

Is the following statement true or false? The right heart pumps blood into the pulmonary circulation.

Its TRUE. The right heart pumps blood into the pulmonary circulation. The pulmonary circulation is a low pressure circulation.

Where does the left side of the heart pump blood to? what kind of blood does it carry? what type of circulation is this?

LEFT side of the heart pumps OXYGENATED blood TO THE BODY -systemic circulation (receives oxygenated blood from the lungs and then pumps to the rest of the body)

What is meant by describing the systemic and pulmonary circulation is as being in series?

Passes from one circulation into the next in a continuous circuit. In other words blood goes from the systemic circulation and pulmonary circulation, and from the pulmonary circulation back into the systemic circulation in a never-ending circuit.

Where does the right side of the heart pump blood to? what kind of blood does it carry? what type of circulation is this?

RIGHT side of the heart pumps DEOXYGENATED blood TO THE LUNGS -pulmonary circulation (blood gets oxygenated in the lungs then pumped to left heart)

What is meant by describing the cell membrane is semipermeable?

Semipermeable means that some things can pass freely through the membrane, whereas others things can't.

Which type of blood vessels have the thickest walls?

The arteries have the thickest walls because they need to cope with blood under high pressure.

Describe the structure of the cell membrane.

The cell membrane is described as a phospholipid bilayer, meaning that it is made up of 2 layers of phospholipid molecules. The phosphate components of the molecules are in contact with the intracellular and extracellular fluid. The lipid tails are directed towards the centre of the bilayer.

Which type of blood vessels are considered the exchange vessels?

The exchange vessels are the capillaries.

Which type of blood vessels are considered the resistance vessels?

The most important resistance vessels are the arterioles. They have smooth muscle in their walls, and their diameter can be changed to alter the resistance to blood flow. This helps in distributing blood flow around the body and in control of blood pressure.

What is the myocardium?

The myocardium is the muscle of the heart. The prefix Myo- indicates muscle and the suffix -cardium indicates the heart

what does the left coronary artery divide into?

anterior interventricular artery and circumflex artery

during ventricular diasystole, describe the following: aortic valve, left AV valve (bicuspid), chordae tendinae, papillary muscles, and left ventricle

aortic valve: CLOSED left AV valve (bicuspid): OPEN chordae tendinae: LOOSE papillary muscles: RELAXED left ventricle: RELAXED (and filling with blood)

during ventricular systole, describe the following: aortic valve, left AV valve (bicuspid), chordae tendinae, papillary muscles, and left ventricle

aortic valve: OPEN left AV valve (bicuspid): CLOSED chordae tendinae: TENSE papillary muscles: CONTRACTED left ventricle: CONTRACTED

what links the branches of the left and right coronary arteries? what is the point of this?

arterial anastomoses -the back-up plan in case of coronary occlusion (heart disease)

the circulatory system is comprised of what 2 systems?

arterial system and venous system

how do we define an artery and a vein?

arteries carry blood AWAY from the heart, veins carry blood TOWARDS the heart

the pulmonary arteries carry ____ blood and the pulmonary veins carry ____ blood

arteries carry deoxygenated veins carry oxygenated

the systemic arteries carry ____ blood and the systemic veins carry ____ blood

arteries carry oxygenated veins deoxygenated

what is very resistant to high pressure and is elastic?

artery

what are the three features of the circulatory system?

artery capillary vein

what kind of blood has more hemoglobin? why?

bright red arterial blood -hemoglobin allows for it to carry oxygen which makes it more red

what is microscopically small and has pores?

capillary

capillary beds are highly dense in _____

cardiac muscle

cardiac muscle cells are _____ to capillaries because

cardiac muscle cells are only 1 RBC distance away from capillaries because this maximizes O2 delivery

the heart relaxes/contracts during ventricular systole?

contracts

The myocardium blood supply comes from____

coronary arteries

where does the heart get its blood supply?

coronary arteries and veins

the vena cava (in the venous system) carries what kind of blood?

deoxygenated

function of the cardiac veins

drain into the coronary sinus which opens into the right atrium

describe the circulatory system of mammanls

dual circulatory system (pulmonary/lungs and tissues/systemic) -two pumps connected in series (output of one pump is the input of the other)

when does intermittent perfusion of the heart become a problem? why?

during exercise when HR is high because diastolic time is reduced - just when demand is greatest -cardiac ischemia (is exacerbated with coronary artery disease)

What do blood vessels consist of?

elastic tissue, smooth muscle, and connective tissue, plus layer of endothelium on internal surface

what are the two components of the pericardium?

fibrous pericardium and serous pericardium

are systemic (or pulmonary) arteries under higher/lower/the same pressure than systemic veins?

higher

are systemic arteries under higher/lower/the same pressure as pulmonary arteries?

higher

are pulmonary veins under higher/lower/the same pressure as systemic veins?

lower

the aorta (in the arterial system) carries what kind of blood?

oxygenated

what two layers make up the serous pericardium?

parietal layer and visceral layer

What is the protective casing the heart is surrounded by?

pericardial sac (fibrous pericardium)

the heart relaxes/contracts during ventricular diasystole?

relaxes

what is the thoracic cavity bound by? where does the heart sit? between what?

ribs (laterally) diaphram (inferior) heart sits in the inferior mediastinum between 2 pulmonary cavities

Here is a list of terms. Put them in the correct sequence to show how blood flows through the circulatory system. left atrium pulmonary artery right ventricle left ventricle pulmonary vein left atrium aorta

right atrium right ventricle pulmonary artery pulmonary veins left atrium left ventricle aorta

what does the right coronary artery divide into?

right marginal branch and posterior interventricular artery

What is the pericardial cavity?

space between the parietal and visceral layers

The coronary arteries arise from____

the base of ascending aorta at the aortic sinuses

the pericardial sac (pericardium) is connected to what?

the diaphragm

what has valves?

veins

when is blood flow in the coronary arteries doubled? why?

ventricular diastole (when ventricle is relaxing) -compression force is low but blood pressure in the aorta remains high, thus blood flow in the coronary arteries is not impeded

when does blood flow in the coronary arteries fall to zero? why?

ventricular systole (when ventricle is contracting) -parlty because the opened cardiac valves cover the openings to the coronary arteries -mostly because contracting cardiac muscle compresses coronary vessels (particularly capillaries)

how many layers are there in a blood vessel? what are they?

3 • Tunica Intima: forms the internal layer & is in direct contact with blood. Innermost layer is endothelium, made of endothelial cells. These cells secrete chemicals that affect the blood flow. In arteries is an outer layer called the internal elastic membrane that contains elastic fibres. • Tunica Media: middle layer. Contains smooth muscle in a framework of connective tissue, SM fibres run circularly around the vessel, reducing the diameter of the vessel when they contract. Arteries have an external elastic membrane • Tunica Externa: (tunica adventitia) is the outer layer of a blood vessel. It consists of elastic and collagen fibres, some SM in veins. Also contains nerves and (in larger vessels) blood vessels (vasa vasorum). Binds to adjacent tissue and anchors vessel in place

What is the adult blood volume?

4.5-5 Liters 7% of body weight

what is the cardiac output of your heart?

5 L/min

What are the components of blood?

55% plasma, 45% formed elements -plasma is mostly water, contains nutrients, gas, waste, proteins, electrolytes) -formed elements are the cells (RBC, WBC, platelets)

what is the function of the cardiac valves?

Allow blood to flow in one direction only

Name the following:

Anterior vena cava Right atrium Right ventricle Aorta Pulmonary Artery Left atrium Left ventricle

what are some structural differences between blood vessels?

Arteries and veins run side by side. • Arteries have thicker walls and higher blood pressure. - a collapsed artery has small, round lumen (internal space), while a vein has a large, flat lumen • Vein tunica externa contracts, artery lining does not • Artery outer lining folds • Arteries more elastic • Veins have valves