AP02 Histology of the Heart and Blood Vessels Flashcards
What T-tubule system is observed in skeletal muscle and cardiac muscle?
diad - cardiac
triad - skeletal
What are cardiac myocytes joined by?
intercalated discs (gap junctions, adherens junctions, demsosomes)
What do intercalated discs allow?
communication
rapid transfer of small ions during the cardiac cycle
Does cardiac muscle have NMJ?
No, as it does not receive somatic innervation
What effect does Sympathetic stimulation have on the heart?
increased HR (chronotropy) increased contractility (inotropy)
What are the features of the tunica intima across all arteries?
Endothelium
Basement membrane
(venules and medium sized veins have pocket valves)
What are the features of the tunica media in elastic arteries?
lots of elastic tissue distributed through the smooth muscle
What are the features of the tunica Adventitia of Elastic Arteries?
Fibrous CT
Nervi Vasorum
Vasa Vasorum
Collagen fibres
What are the features of the tunica media of muscular arteries?
internal elastic membrane
smooth muscle
What are the features of the tunica adventitia of muscular arteries?
external elastic membrane
Fibrous CT
What are the features of the tunica media of arterioles?
smooth muscle
What are the features of the tunica adventitia of arterioles?
fibrous CT
What are capillaries comprised of?
endothelium, basement membrane, and pericytes
What are the features of tunica media in venules?
smooth muscle
What are the features of tunica adventitia in venules?
Fibrous CT
What are the features of the tunica media in medium sized veins?
smooth muscle
what are the features of the tunica adventitita of medium - sized veins?
fibrous CT
What are the features of tunica media of large veins?
smooth muscle
What are the features of tunica adventitia of large veins?
fibrous CT
Nervi Vasorum
Vasa Vasorum
Collagen
What are Pericytes?
incomplete layers of cells surrounding endothelium in capillaries
What controls blood flow into capillaries?
precapillary sphincters
How big is the lumen of elastic arteries?
10nm
What is the function of elastic arteries?
conduct blood away from the heart and withstand increase in cardiac pressure associated with systole
What is the diffference in smooth muscle distribution between elastic arteries and muscular arteries?
muscular arteries have more.
because they’re muscular.
What is the size of the lumen of muscular arteries?
1-10nm
What is the function of muscular arteries?
alter blood flow to different regions of the body by constricting or dilating
How much smooth muscle do arterioles contain?
a lot, relative to their size
What is the difference between atriovenous anastomoses and capillaries?
they are much larger in diameter and have more smooth muscle
What are the outer and inner layers of the ventricular wall?
outer - pericardium
Inner - endocardium
Define Thrombus
a blood clot formed in situ within the vascular system impeding blood flow
define embolus
a blood clot, bit of air, or fatty deposit carried in the bloodstream to lodge in a vessel and cause an embolism
What is an embolism?
an obstruction of an artery
What is atherosclerotic plaque?
specifically fatty plaque
What are the features of fenestrated arteries?
festrations (pores) through cell wall, which are 80-100nm in diameter
What do continuous arteries form?
BBB
What type of epithelial cells comprise the endothelium?
simple squamous
What is the function of the tunica adventitia?
protects the vessels
strengthen its wall
anchors the vessel to surrounding struct
How do blood vessels receive nutrients?
inner half - diffusion from blood
outer half - vasa vasorum
What are the layers of the pericardium?
Fibrous Pericardium Serous Pericardium (parietal and visceral)
What are the layers of the heart wall?
fibrous pericardium parietal serous pericardium pericardial cavity epicardium (visceral layer of serous pericardium) myocardium endocardium heart chamber
What is the difference between sinusoid and fenestrated capillaries?
sinusoid has larger fenestrations, and a disocontinouous BM
