cardiovascular Flashcards
what are the two anatomically systems of blood vessels which the heart pumps blood into
the pulmonary circulation
the systemic cirucultion
the right side of the heart pumps blood where
to the lungs
when the blood is pumped to the lungs, what occurs here
gas exchange occurs in the lungs
which side of the heart pumps blood into the systemic circulation
the left side
tissue wastes are passed into the blood for excretion and body cells extract nutrients and oxygen, which system of blood vessels is this refering to
the systemic circulation
what are the smaller branches of arteries called
arterioles
arteries and arterioles carry blood to or away from the heart
away from the heart
arterioles branch into networks of what
capillaries
why are the caipllaries good for exchange
thin walls
what exchanges take place in the capillaries, and what exchange happens where components leave the capillaries
nutrients, water, oxygen diffuse into the cappiaries
cellular wasts such as carbon dioxide diffuse into the bloodstream
capillaries merge to form what
small venules
capillaries merge to form small venules, these then merge to form what
large veins
do veins carry blood to or away the heart
to the heart
how many layers of tissue do both the arteries and veins display
3 layers
what are the three layers of tissue in the veins and arteries
tunica adventitia
tunica media
tunica intima
the tunica media is the outer layer of the tissue of the veins and arteries, true or false
false, the tunica adventitia is the outer layer
what is the role of the tunica adventitia
protects and supports the vessel
what layer is the tunica media and what does it contain
middle layer which contains variable amounts of smooth muscle and elastic tissue
how many cells thick is the tunica intima
one cell thick
what layer is the tunica intima
the inner layer
the tunica intima is also known as what
the endothelium
what layer of the veins and arteritues, is the only layer present in cappilary walls
the tunica intima
why are arterial walls thicker than venous walls
to withstad the higher pressure of blood in the arterial system
the structure of artieal walls varies, it depends on what
how close the artery is to the heart
by the tunica media containg more elastic tissue and little smooth muscle. what does this allow for
allows the vessel walls to stretch, absorbing the pressure wave generated by the heart as it beats
the tunica media consitis almost entirley of which type of muscle
smooth muscle
systemic blood pressure is mainly determined by what
determined by the resistance smaller artiers offer to blood flow
what are anastomsos
arteries that form a link between the main arterites supplying an areas
if one artey supplying the area is blocked, what will the anastomic arteries provie and what will this do
they will provide a collateral circulation which will provide an adequate blood supply, giving the anastomtic artiers time to dialate
what is an end artery
an artery that is the sole source of blood to a tissue
is there an alternative blood supply if an end-artery is blocked
no, the tissues it supplies will die as there is no alternate blood supply
the smallest arterioles will branch into huge numbers of what
capillaries
capilarillary walls consist of how many layers of endothelial cells
one single layer
capillary walls consist of a single layer of endothelial cells, these sit on what
a thin basement membrane
are capilliary walls permable or non permaeable, and if so what to
permeable to water and other small molecules
why is capillary diameter much larger in the liver
rapid and extenive exchange of materiel is very important to allow the liver to modify the composition of the blood flowing through it
what is the site of exchange for substances between blood and tissue fluid
capillary bed
what are sinusoids
type of capillary, their walls are incomplete and their lumen is much larger than usual, blood flows through them much more slowly under less pressure and can come directly into conact with the cells outside the sinusoid wall
when an area of skin in pressed firmly with a finger, why does it turn white
becuase the blood in the capillaries under the finger has been squeezed out
blood passing into the venous system is high pressure. true or false
false, blood passing into the venous system does so under very low pressure
when cut veins will collapse, what will the thicker walled arteries do
remain open
some veins possess valvues, what is this for
to prevent backflow
valvues are formed by a fold of the what
formed by a fold of tunica
how are valvues strenghtened
strenghted by connective tissue
what shape are the valves
semilunar
why are valves abuent in the veins of the limbs, particulary the lower limbs
becuase bloos must travel a considerable distance against grvaity when the indivdual is standing
why are veins called capacitance vessels
becuase they stretch
veins have the capacity to hold a large proportion of the body blood, what does this allow for
allows to an extent the vascular system to absorb sudden changes in blood volume
the outer layers of tissue of thick-walled blood vessels recive theur blood supply from where
from a networ of blood vessels called the vasa vasocrum
how do thin walled vessels and the endothelium of the other recive otxygen and nutrients
by diffusion from the blood passing through them
oxygen is carried from the lungs to the tissues in combination with what
haemoglobin and oxyhaemoglobin
when blood arrives in the capillaries, it diffuses via what, from where into where and why is this
diffuses via their permeable walls
diffuses down its concentration gradient
from oxygen-rich arterial blood, into tissues
where oxygen levels are lower becuase of constant tissue consumption
why does oxyhaemoglobin break up easily
to liberate oxygen
when oxyhaemoglobin breaks up easily what is this called
dissociates
carbon dioxide is one of the waste products of what
cell metabolsim
carbon dioxide diffuses into the blood across what
across the thin capillary wall
when carbon dioxide diffuses across the capillary wall does it go to a lower or higher concentration gradient
lower
what are the three different mechanisms that the blood transports carbon dioxide to the lungs for excretion
dissolved in the water of blood plasma
in chemical combination with sodium bicarbonate]in combination with haemoglobin
what does the plasma transport
nutrients glucose amino acids fatty acids vitamins mineral salts
plasma contenxt diffuse via the what into the tissues
diffuse through the semi permable membrane
water exchanges freely between the plama and tissue fluid by what
osmosis
what are the two main forces determining overall fluid movement across the capillary wall
hyrdrostatic pressure
osmotic pressure
what effect does the hydrostatic pressure have on fluid movement
tends to push fluid out of the bloodstream
what effect does the osmotic pressure have on fluid moevments
tends to pull fluid back into the bloodstream
extra tissue fluid and some cell waste materials enter the lymph capillaires, forming what
forming lymph
in which cavity does the heart lie in
the thoracic cavity in the mediastinum
the base of the heart extends the level of which rib
the 2nd rib
what are the inferiorly organs associated with the heart
the apex
what are the superiorly organs which are associated with the heart
the blood vessels: aorta, superior vena cava, pulmonary artery and pulmonary veins
what are the posteriorly organs associated with the hearts
the oesophagus, trachea, left and right bronchus, descending aorta, inferior vena cava and thoracic vertebrae
what are the laterally organs associated with the heart
the lungs
what are the anteriorly organs associated with the heart
the sternum, ribs and intercostal muscles
the heart wall is composed of how many layers of tissue
three layers of tissue
what is the outer most layer of the heart called
the pericardium
the pericardium is made up of how many sacs
two sacs
the outer sac of the pericardium consits of what type of tissue
fibrous tissue
is it the inner sac or the outer sac of the pericardium that consists of a continuous double layer of serous membrane
inner sac
the serious pericardium is a membrane formed by how mnay layers of the endothelail cells
one layer
the serous pericardium is folder over itself so that it forms a double membrane around the what
around the heart
the myocardium is composed of what
specialised cardia muscle
what is the out sac of the fibrous pericardium called
the fibrous pericardium
what is the inner sac of the pericardium called
the serous pericardium
the fubrous pericardium is continuous with the what, and attched to the what
cotinuous with the tunica adventita of the great blood vessels and is attached to the diaphragm
by the fibrous pericardium having an inelastic, fibrous nature, what does this protect against
protects and prevent over-distension of the heart
what is in lace between the two layers so that the heart can beat without rubbing against the fibrous pericardium
around 20ml of lubricating fluid called the pericardial fluid
How many chambers does the heart have
Four
High blood pressure is called what
Bradycardia
The average BP for an adult is what
120/80
How many layers of the heart are there
4
What are the layers of the heart
Pericardium
Epicardium
Myocardium
Endocardium
Why is their fluid between serous layers in the pericardial cavity
To prevent friction
What is the outer layer of the heart called
The pericardium
Within the pericardium are what two layers
Fibrous pericardium and serous pericardium
What is serous pericardium made up of
Parietal and visceral pericardium
What layer of the heart makes up the bulk
The myocardium
The myocardium cells are held together by what
Desmosomes
The myocardium is the middle musclar layer of the heart, what are the layers in lies between
Endocardium and outer epicardium
What are the three functions of the myocardium
- Providing scaffolding for the heart chambers
- Assisting in contraction and relaxation of the heart walls so that blood can pass between between the chambers
- conducting electro stimulation through its own tissues and into the epicardium
What is the inner most layer of the heart
The endocardium
The right side of the heart receives deoxygenated blood and pumps it to the lungs, why
So it can be oxygenated
The left side of the heart receives oxygenated blood from the lungs and pumps it where
Around the body
The right atrium receives blood from where
Superior vena cava, inferior vena cava and coronary sinus
The left atrium recievied blood from where, is this blood oxygen or deoxygenated and if so why
Received blood from pulmonary veins, this blood is oxygenated as it has come from the lungs
How many valve are there to prevent back flow
2
What are the names of the two valves
Tricuspid and bicuspid
How many flaps does the tricuspid valvular have
3 flaps
What connects the valvues to the heart walls
Heart strings/ cordial tendinase
Is the tricuspid valve on the right or the left side of the heart
Right
What causes the valves to close
The ventricular pressure
How many ventricles are there
2
The right ventricle pumps blood to where, through the what
Right ventricle pumps to the lungs, through the pulmonary artery
The left ventricle pumps blood where, through the what
Blood pumped around the body, through the aorta
Why is the left ventricle more muscular than the right
It has to pump the blood much further
What divides the right and left ventricles
The interventriclulsar septum
What layer of the heart is supplied with blood directly from the chambers
Endocardium
The heart is supplied with blood from where
The coronary arteries
The coronary artery that supplies the heart itself with blood comes from where
The aorta
When the heart itself is being supplied with blood, the left anterior ascending artery supplies which part of the heart with blood
Front and side of left ventricle and apex
When the heart itself is being supplied with blood, the cicumflex artery supplies what areas of the heart with blood
Back and side of left ventricle
How many valvues does the mitral valve have
2
What are the top chambers of the heart called and what are the bottom chambers of the heart called
Atrium
Ventricles
Blood flows into the heart, via the what
Via the vena cava
Blood from the vena cave will be oxygenated or deoxygenated
Deoxygenated as it has returned from the body
As the two atria contract tighter, they use the blood into the what
Ventricles
After the blood has been pushed into the ventricles it willl enter the what
The pulmonary artery where it will travel to the lukngs
Where are pacemaker cells located in the heart
In the right atrium
The heart needs its own supply of blood which it gets from small arteries that branch of the aorta which are called what
Coronary arteries
