WEEK 2 - CARDIO Pt1 Flashcards
What are the organs of the cardiovascular system?
heart - pump
arteries - supply
capillaries - exchange
veins/lymphatics - drainage
what is the blood vascular system?
a continuous loop, closed supply and drainage system.
what is the lymphatic (vascular) system?
an open entry drainage system (one way)
any blood that leaves the blood vascular space in institial tissue:
can be picked up by capillaries and drained into the lymph system.
what are the supply path?
arteries
explain the location of arteries:
major arteries are placed specifically to avoid damage - deep within the trunk, on the flexor side of the limb.
what are the protective mechanisms of arteries?
- deep within trunk/far from surfaces
- flexor side of limb
- important structures have two main arteries so that if one is damaged or blocked then the part of the body will still have blood flow.
capillaries have varying degrees of _____.
permeability.
what are the three levels of capillary permeability?
- continuous (controlled/light)
- fenestrated (leaky)
- sinusoidal (very leaky)
what are the three types of drainage things?
- deep veins
- superficial veins
- lymphatics
what is the pointed end of the heart called?
apex
what is the blunt end of the heart called?
base
what is the part of the chest that the heart is in?
mediastynum
which way does the apex point?
anteriorly
explain the heart’s loction in relation to the ribs:
the base is between the 2nd and 3rd rib
the apex is between the 5th and 6th rib
what is the name of the part of the chest that the apex beats against?
Point of maximal intensity - PMI
what is the name of the tbing that seperates the left and right ventricles?
the interventricular septum
what is the right pump made of and what blood does it pump?
right atrium and right ventricle - unoxygenated blood
what is the left pump made of and what blood does it pump?
left atrium and left ventricle - oxygenated blood
what is the name of the valve between the atrial and ventricular chambers?
atrioventricular valves (right: tricuspid, left: bicuspid)
what is the pulmonary valve?
makes sure blood doesnt flow backwards from the pulmonary gland artery into the left ventrical
where does the right atrium recieve blood from and what blood?
deoxygenated bloodfrom the superior vena cava, corony sinus, and inferior vena cava.
where does the left atrium recieve blood from and what type of blood?
the 4 pulmonary veins, oxygenated blood.
what are the 3 layers of the heart?
endocardium (within)
myocardium (muscle - bulk of the wall)
epidcarium (outer)
All sits within the pericardium
what is the pericardium?
the sack that the heart sits in to lubricate/protect it as it beats continuously.
what type of tissue is endocardium?
squamous epithelium (endothelium)
what are the features of the endocardium?
- stops blood from clotting against the walls
- loose irregular fibrous connective tissue (FCT)
- small blood vessels
- punkinje fibres (electrical)
why is the right side wall thinner than the right?
bc pulmonary artery to lungs is a short distance. 0.5cm thick vs 1.5cm.
what are the features of the epicardium?
- large blood vessels
- padding: FCT, adipose tissue
- some of the pericardium is overlaped with the epicardium as it is fused to it.
what lines every artery, vein and capillary?
endothelium
what are the features of the pericardium?
- the part that touches the heart is the ‘viseral layer’
- the other side is called the parietal layer
- the inside is called the pericardial space (fluid filled)
- the other is fibrous pericardium
what are punkinji cells?
cardiac muscle cells that stop contracting and turn into communicative cells.
what is the function and names of AV valves?
atrioventricular valves prevent blood from retuning into the atria during ventricular contraction.
right: tricusbid
left: mitral/bicuspid
what is the stage called in which the ventricle is being filled?
diastole
what happens during diastole?
AV valves open, semilunar valves closed. ventricles are filled from atrium.
what is systole?
av valves closed, semilunar open, ventricle muscles contracted.
what are the functions and names of semilunar valves?
prevent blood returning to ventricles during diastole.
right: pulmonary valve
left: aortic valve.
pushed open as blood flows out of the heart, closes when blood starts to flow back in.
what is the papillary muscle?
small muscle on the ventricular wall that is attached to the chordae tendinae which attaches to the mitral valve to stop the valve from slamming shut.
where is the right coronary artery?
in the cardiac circulation. it runs iver the epicardium on heart wall and branches off at the aorta.
where is the left coronary artery?
in the cardiac circulation. it runs iver the epicardium on heart wall and branches off into the anterior interventricular artery (anterior part of the heart towards the apex) and the circumflex artery (supplies to posterior side of heart)
what are the cardiac veins called and where do they drain to?
left - small cardiac vein
right - great cardiac vein
drain into coronary sinus which drains into the right atrium for reoxygenation.
what are cappilaries made of? how big are they?
rolled up epithelial cells. big enough for one red blood cell in single file.
what is the difference between cardiac/smooth/skeletal muscle?
has nuclei in middle of cells (rather then in periphery like skeletal)
is striated unline smooth muscle.
what are the features and function of myocardium/cardiac muscle
beating of the heart with no breaks.
- striated, short, branched cells
- one or two nuclei in the center of the cells
- cytoplasm organelles are in the poles of the nucleus.
how much % is mitrochondria in cardiac muscle?
20% compared to 2% in skeletsal muscle
very oxy dependant metabolism
what is the adhesion belt?
gap between the cardiac cells linking actin to actin in vertical positon. this means that when one cell contracts the cells linked also contract.
what are desmosones?
link cytokeratin from cells to keep them together during contractions. Attached to ‘cell skeletons’
what are gap junctions?
electrochemical communcation, horizontal positon parallel to cells
what si the conduction system?
- it greatly increases the efficiency of the heart
- makes sure the heart beats in the right sequence
- coordination of the heart contractions and the opening of AV val es
- autonomic nerves alter the rate of conduction
what is the start point of the conduction network?
the sa node - superior to the right atrium.
what increases and decreases the rate of beating?
the rate is increased by the synthetic nerves and decreased by the parasynthetic nerves.
where does the conduction network go to after the sa node?
- spreads through the intermodal pathways
- av node
- av bundle
- right and left bundle branches
what are the branches of the conduction network made out of?
pukinji fibres.
What is the order of arteries through the lower part of the body?
aorta common iliac artery external iliac artery femoral artery (from pelvis to knee) popliteal artery (knee) posterior tibial artery plantar arch (foot)
what is the order of veins through the lower part of the body?
inferior vena cava common iliac vein external iliac vein femoral vein popliteral vein posterior vein plantar venous arch
what is the great saphenous vein?
the biggest vein in the body from ankle to groin (superficial)
what is the largest vein in the body?
great saphenous vein
what are the three layers of blood vessels?
tunica intima
tunica media
tunica adventitia
what are the features of tunica intima?
lined with endothelium and sub-endothelium. made of Intimal elastic lamina (IEL)
what is endothelium?
squamous epithelium which lines blood vessels
what is sub-endothelium?
pad of loose FCT that cushions endothelium.
what is Intimal elastic lamina (IEL)
a condensed sheet of elastic tissue which is well developed in arteries but less so in veins. A thin layer of the tunica intima.
what are the three conponents of the tunica intima?
endothelium, sub-endothelium, Intimal elastic lamina
what are the features of tunica media?
- mainly comprised of smooth muscle
- has variable content of connective tissue (elastin and collagen)
- thickness is proportional to vessel diameter and blood pressure
- biggest layer of the vessel wall.
what are the features of tunica adventitia?
- loose FCT with high content of collagen and variable amount of elastin
- in larger vessels it contains vesa vasorium (blood supply)
- lymphatic and autonmic nerves for dialating and constricting.
as you get closer to the heart, the size of blood vessels:
gets thicker in diameter
what are arterioles and what is their function?
small arteries - they are the resistance vessels of the circulation system, they determine the blood pressure. when they’re constrictedf the blood pressure is high.
what are venules?
the first part of the vein drainage system. They have venus valves to stop backflow.
the vein system is:
low pressure, high volume
what are the features of veins?
irregular, flatterned shape, large lumen, thin walls, have spare capacity (can take up extra blood flow volume from movement eg constriction of muscle) aka capacitance vessels.
what are capactiance vessels?
veins that are able to take on extra blood volume.
how is the media different between veins and arteries?
in veins: much thinner than arteries
what is the thickest layer in veins?
adventitia
which has thicker wall veins or arteries?
arteries - because they have to contain high blood pressure.
what is a sign that a vein is a deep vein?
if it is flanked by skeletal muscle
what are varicose veins?
when the venus valves within the veins are deteriated and therefore there is backflow of blood in the direction of gravity and polling of blood in legs.
what is the thoracic artery?
‘elastic artery’ - walls much thicker, reduces pulse pressure.
what is the femoral artery?
‘muscular artery’ - mostly smooth muscle.
what is the function of capillaries?
they are the site of exchange between blood and tissues.
what are the features of capillaries due to their function?
- very thin walls
- large total cross sectional area/surface are
- slow smooth blood flow
- as the area is bigger, the slower the blood flows.
what are venules?
the smallest veins
what are terminale arteriole?
the last artery before entering the capillary bed
what are precapillary sphincters?
smooth muscle of the beginning of capillary branches that constrict and cut off supply to the bed.
what happens when precappilary sphincters constrict?
the blood flows through one central capillary instead of through the bed. this is called the vascular shunt. this is not conciously controlled and can be to do things like draw blood away from the surface to heat internal organs.
what are the three types of cappilary?
- continuous: most widespread, a continuous loop wall of endothelium
- fenestrated (leaky)
- sunusoid (most leaky)
capillary structure varies according to:
the rate of exchange needed (‘leaky’)
what are the features of continuous capillaries?
made of endothelial wrapped cell all around. These cells always have a free space surface and a sruface bonded to underlying tissue. the binded side is the basement membrane/ basal lamina which is part of exchange barrier.
what are fenestrated cappilaries like?
fenestrations are small holes that allow small things to filter out. the outside of the cappilary even through the fenestrations is covered in a membrane filter paper.
what is the size of fenestrated capillary?
8-10ym
what are the sinusoidal capillaries?
30-40ym. Nutriant exchange rather than gas exchange. Large holes in side and in membrane as well.
what are the four ways to get through the caillary wall?
fenestrations, diffusion, intercellular clefts, transport vesicles.
blood is flowed through _____ onthe way back to the heart:
lymph nodes.
what are the 4 roles of lymph vascular drainage syste?
- drain excess fluid/protein from tissue to blood
- filters foreign material ough lymph
- screens for foreign anitgens and responds with anitbdies and immune cells.
- absorbs fat from intestine and transports to blood.
what are lymphatic vessels?
large blind ending capillaries.
what do lymphatic vessels do in the small intestine?
lacteals drain fat into cisterna chyli (storage).
how does fluid get into lymphatics?
the epithelial cells are not bonded close together allowing fluids to enter from surrounding tissue.
name vessels from thinnest to thickest wall:
lymphatics, veins, arteries
What is one thing that you will never find in lymphatics?
red blood cells
what are the 2 main channels which bring lymph fluid back into the vascular system?
- left subclavian vein (rest of body)
- right subclavian vein (right arm down to waist)
what is the series of vessels that lead to the left subclavian vein?
lymphatic collecting vessels
thoracic duct
entrance to left subclavian vein
`what is the small intestine lymph called?
lateal
where does the lateal drain to?
the cisternae chyli “milk jug”
what are the main lymph node clusteres and where are they?
cervical nodes (chin) axillary nodes (armpit) inguinal nodes (groin)
what is in the lymph node?
lymph fluid comes into the node and bathes the immune cells which respond and create anitbodies. “immune surveillance”
How do they tell if breast cancer is metastic?
the take some of the lymph nodes from the axillary cluster and test them to see if the cancer has reach that point
how does the lymph system contribute to the metasticity of breast cancer?
the lymphatics that drain out of the breast can carry cancer into the blood system through the subclavian veins, therefore spreading it.
