Final Histo - Circulatory System Flashcards
What does the heart wall contain
cardiac muscle fibrous skeleton intrinsic conduction system coronary vasculature serous membrane endothelial cells and underlying connective tissue
What makes up the fibrous skeleton of the heart
four fibrous rings surrounding valve orifices
two fibrous trigones connecting rings
membranous portion of inter ventricular and interatrial septa
What tissue makes up the fibrous rings surrounding the valve orifices
dense irregular connective tissue
This is the outer layer; visceral layer of serous pericardium
epicardium
This is the middle layer; composed primarily of cardiac muscle, also contains the fibrous skeleton of the heart
myocardium
This is the inner layer of the heart wall
endocardium
What are the three components of the endocardium
endothelial cells
underlying dense connective tissue and smooth muscle
connective tissue
This is the inner layer of the endocardium
endothelial cells
This is the middle layer of the endocardium
underlying layer of dense connective tissue and smooth muscle cells
This is the deep layer of the endocardium
connective tissue containing the intrinsic conduction system
This is the “sac” surrounding the beginning and end of the heart and great vessels
pericardium
What type of tissue are the valves covered in
connective tissue with overlying endothelium
This is loose connective tissue covered in endothelium on atrial or blood vessels side of vavlue
spongiosa
What is the function of the spongiosa
shick absorber; it contains loosely arranged collagen and elastic fibers infiltrated with proteoglycans
This is the core of a valve; contains fibrous extensions from the dense irregular connective tissue of skeletal rings
fibrosa
This is the dense connective tissue with layers of elastic fibers covered in endothelium; adjacent to ventricular side of the valve
ventricularis
What is special about the cardiac muscle of the heart
it is able to depolarize and contract without impulses from the nervous system, due to the intrinsic cardiac conduction system
What type of cell is the intrinsic cardiac conduction system composed of
the 1% non contractile cardiac cells called cardiac conducting cells or auto rhythmic cells
How are the auto rhythmic cells organized
into nodes and highly specialized conducting fibers/tracts called Purkinje fibers
What are auto rhythmic cells responsible for
the initiation and distribution of impulses throughout the heart
What is the rate of the intrinsic cardiac muscle contraction controlled by
it is set by the pacemaker cell and is altered by the sympathetic and parasympathetic nervous system as well as hormones
These modified cardiac muscle cells are found in the SA and AV nodes and are smaller than surrounding atrial contractile cardiac cells; contain fewer myofibrils and lack intercalated discs
nodal cardiac cells
These modified cardiac muscle cells are found in the AV bundle, bundle branches, and sub endothelial branches and are larger than the surrounding ventricular contractile cells
purkinje fibers
Purkinje cells contains what in their periphery and what is different about their nuclei
contain myofibrils at periphery
nuclei are round and larger than nuclei of regular cardiac fibers
What is specifically found in the Purkinje fibers
large amounts of glycogen
What are the three layers of blood vessels
tunica interna or tunica intima
tunica media
tunica externa or tunica adventitia
What are the three parts of the tunica interna
endothelium
basal lamina
subendothelial layer
This is the internal elastic membrane of arteries and some arterioles; part of the tunica interna
subendothelial layer
This contains rings of smooth muscle cells responsible for vasoconstriction and vasodilation; can also contain sheets or lamellae or laminae of elastin
tunica media
This is found in larger vessels and contains the vasa vasorum (vessels of the vessel) and nervi vascularis
tunica externa or tunica adventitia
In cross section, which vessel looks more open and which one looks more collapsed
arteries = open veins = collapsed