cardio vascular system Flashcards
what are the coranaries
the muscular arteries that bring 02 blood back to the outer layer of the heart, the epicardium
The coronaries are the _____ of the heart
vaso vasorum
what can coronaries be affected by?
atheroscelrosis
what is the mechanism of arthrosclerosis
- results in the obstruction of the lumen of the blood vessels
- LDL damages the endothelium of blood vessels ( coroanaries)
- this leads to the deposition of arthrosclerotic plaques and thrombus formation
what does arthrosclerosis lead to
heart attack
what does the vaso vasorum ( coranaries) in the heart correspond to ?
vaso vasorum of the blood vessels
what structure does the endocardium in the heart correspond to in the arteries
tunica initma
what structure does the myocardium of the heart correspond to in the arteries
Tunica media
what structure in the epicardium correspond to in the arteries
tunica adventitia
what do the synthetic smooth muscles in the media produce
- they are secretory and produce the ECM that is part of the interior parts of the blood vessel wall in the media
what are the features of the pericytes (2)
- they are capable when necessary to differentiate into smooth muscle cells and endothelial cells
- they share the basement membrane with the endothelial cells
what type of differentiation does do pericytes have
non terminal differentiation
how are pericytes attached to endothelial cells
by attachment junctions NOT tight junctions
what are the three types of capillaries
- Sinusoidal
- fenestrated
- continuous
what are the characteristics of sinusoidal capillaries
- large diameter
- discontinuous basement membrane
- found in organs where exchange of macromolecules occurs rapidly
- even cells can pass through
which organs can you find sinusoidal capillaries
bone marrow, liver, spleen
what is path of sinusoidal capillaries in the liver what are they boarded by
- ## blood exits trhough the perisinusoidal space borarded on one side by endothelial cells of the cappillaries and on the other by hepatocytes
what are the characteristics of fenestrated capillaries (3)
- squamous cells linked by tight junctions
- small perforations ( fenestrations) allow diffusion accross the membrane
- found in areas where diffusion is high to and from the blood
where can you find fenestrated capillaries
endocrine glands, intestinal walls, choroid plexus
what are the characteristics of continuous capillaries (3)
- only allow diffusion through simple squamous epithelium
- gases and nutrient only
- most common type of capillary
where can you find continuous capillaries
brain and muscles
what are the layers of the heart
- endocardium
- myocardium
- epicardium
what are the characteristics of the endocardium (3)
- what type of CT is the subendocardial layer
What part is the heart is it thicker in
- Endothelial layer with underlying dense connective tissue
- Subendocardial layer is loose connective tissue. (Contains small blood vessels, nerves, and purkinje fibers.)
- Thicker in atria than in ventricles
what is the function of purkinjee fibers
- are the electrical conductance fibers in the heart that relay signals between nodes and chambers
- They are modified cardiomyocytes
where are the purkinjee fibers located in the heart
subendocardial layer
what are the characteristics of the myocardium
- Bulk of heart wall
- Left ventricle myocardium is thicker than the right ventricle. Both ventricles have thicker myocardium than the atria has.
what are the characteristics of the epicardium
- Has two layers (unlike the adventitia)
- Loose fatty connective tissue. (This is definitely part of the heart itself)
- External mesothelial lining (Can be considered as more part of the pericardium)
what is the sac like structure in which the heart sits
- what is its function
- pericardium
- prevents friction when the heart beats
what are the two layers of the pericardium
- what does the visceral layer correspond to?
- the parietal and visceral layer
- the visceral layer corresponds to the epicardium of the heart
what is the pericardium lined by
- simple squamous epithelium - mesothelium
what does the simple squamous epithelium also line? why?
the epicardium because the visceral layer of the the pericardium is the epicardium
what are the purkinjee fibers responsible for in the heart
part of the conduction, modified cardiomyocytes
what do cardiomyocytes correspond to in blood vessels?
smooth muscle cells
how do cardiomyocytes contract?
involuntarily, chaotically, synchronized contraction
what structures mediate the contractions of the heart?
SA and AV nodes
what is considered the pace maker of the heart
the SA node
what do SA nodes do?
- stimulates contraction of the right and left atrium
where is the SA node impulse carried to ?
The AV node
what does the AV node do where is it located?
- where does it send impulses to ?
- located in the floor of the right atrium
- creates a delay in the contraction of the ventricles
- sends impulses to the the bundle of His
what are the high and low pressure paths of the circulatory system
- high pressure = arteries
- low pressure = veins
what vasculature regulates and determines the blood pressure
the arteries
what are the functions of veules
- drain the capillary bed
- site of leukocyte exit from vasculature
if someone has high BP what can be wrong?
something may be wrong with the arterioles
what are the 2 types of circulation in the body and what are their functions
systemic - circulation to the body
pulomnary- circulation to the lungs for the o2 of blood
what do pulmonary arteries and pulmonary veins carry?
- pulmonary arteries = Do2 blood
- pulmonary veins - o2 blood
what triggers arthrioscelrosis
- the damage of the endothelium by the LDL (cholesterol)
what causes blood flow to the dental pulp to decrease
the activation of the sympathetic response which causes the release of norepinepherine and neuropeptide Y and thus reduced blood flow in the dental pulp
what activates the sympathetic nervous system
fear,
what is the function of the arteriole venous shunt in the dental pulp
its not know so this will not be an answer to any question regarding the dental. pulp
what are the layers of the walls of arteries and veins?
- tunica intima
- tunica media
- tunica adventia
- vaso vasorum
what are the charecteristics of the tunica intima (4)
- Simple squamous epithelium layer which rests on a basal lamina.
- Subendothelial loose connective tissue layer. (Contains some smooth muscle cells)
- Internal Elastic Lamina borders between the intima and media.
- Fenestrated to allow for diffusion and is prominent in muscular arteries.
what are the charecteristics of the tunica media (2)
- Smooth muscles. (Thicker in arteries.)
- External elastic lamina
which of the tunicas have the most elastic lamina
tunica media of the elastic arteris
what are the charecteristics of the tunica adventia
Where is it located
- Sits between media and vasa vasorum
- In larger arteries, contains a supply of microvasculature with oxygen and nutrients
what is the function of the vaso vasorum in the blood vessels
- Distributes nutrients from tunica adventitia
- Function the same way as coronary arteries (bring oxygen and nutrients to muscles
why is the tunica media important in pathology
because anything that affects elastin material production will affect them
what is marfans syndrome and what does it affect
effects the elastic deposition and this damages elastic arteries and tunica media
what is the comparison between elastic arteries vs muscular arteries?
elastic arteries - are larger and contain more elastic fibers ( ex: aorta)
muscular arteries- further from the heart and have more smooth muscle
how many layers of cells do capillaries have
a single layer of endothelial cells
what side is the hydrostatic pressure highest and lowest in cappilaries
- on the arteriole side
- low on the venous side
