histo- cardiovascular system Flashcards
what are the major components of the cardiovascular system? what is its major function?
Major components: Heart, blood vessels, blood
major function: transportation
the ____ are the receiving chambers of the heart
atria
the _____ are the discharging chambers of the heart
ventricles
what is the “pump for the systemic circuit”?
left side of the heart
what part of the heart is the “pump for the pulmonary circuit”
right side
Left Atrium – receives __________ blood
oxygenated
Right Atrium – receives _________ blood
deoxygenated
the Fibrous skeleton of the heart is composed of what parts?
- Four fibrous rings surrounding valve orifices
- Two fibrous trigones connecting rings
- Membranous portion of interventricular and interatrial septa
the heart wall is lined with a _____ membrane
serous
what is the Epicardium?
outer layer of the heart
covered with a visceral layer of serous pericardium
what is the Myocardium? what is it primarily composed of?
middle layer of the heart
composed primarily of the cardiac muscle
which heart layer contains the fibrous skeleton?
myocardium
what are the 3 components of the endocardium?
1) endothelial cells
2) layer of dense connective tissue & smooth muscle
3) deep connective tissue (contains intrinsic conduction system)
name the two atrioventricular valves:
1) Tricuspid Valve
2) Bicuspid or Mitral Valve
name the 2 semilunar valves:
1) Aortic Semilunar Valve
2) Pulmonary Semilunar Valve
Heart valves enforce _____ blood flow through the heart
one way
heart valves open/close in response to what?
pressure changes
There are no valves associated with entrances of which structures?
1) venae cavae
2) coronary sinus
3) pulmonary veins into the heart
heart valves are composed of what?
connective tissue with overlying endocardium
what are the 3 layers of heart valves?
1) spongiosa
2) fibrosa
3) Ventricularis
the spongiosa layer of heart valves:
- loose connective tissue covered in endothelium
- located on atrial or blood vessels side of valve
- made of collagen and elastic fibers
- functions as a shock absorber
Fibrosa layer of the heart valves:
-core of valve
contains fibrous extensions from the dense irregular connective tissue of skeletal rings of heart
Ventricularis layer of heart valves:
- dense connective tissue with layers of elastic fibers covered in endothelium
- adjacent to ventricular side of the valve.
from the atrial side to the ventricular side, name the layers of the heart valves
1) spongiosa
2) fibrosa
3) ventricularis
The cardiac muscle of the heart is able to _________________without impulses from the nervous system
depolarize and contract
what system allows the heart to depolarize and contract without input from the nervous system?
intrinsic cardiac conduction system
what are noncontractile cardiac cells called?
cardiac conducting cells or autorhythmic cells
_________ can generate an action potential without nervous system input.
cardiac conducting cells or autorhythmic cells
autorhythmic cells are organized into nodes and highly specialized conducting fibers/tracts called _________
Purkinje Fibers
what can effect the intrinsic heart rate?
- sympathetic input
- parasympathetic input
- hormones
what is the “pacemaker of heart”?
how does it determine heart rate?
Sinoatrial Node
determines heart rate through its sinus rhythm
from the sinoatrial node, impulses travel to the _________
by what pathway do they travel?
atrioventricular node
travel via the internodal pathway/tracts
why is the electric impulse delayed in the atrioventricular node?
to allow the for the atria to contract
from the AV node, where will impulses travel?
impulse travels from atrioventricular node to the right and left AV bundles
what is the only electrical connection between atria and ventricles?
Atrioventicular Bundle (AKA- Bundle of His)
where do the branches of the atrioventricular bundle go?
toward apex of heart through interventricular (IV) septum
where do pacemaker impulses terminate?
Purkinje Fibers
-finish pathway in interventricular septum, around apex of heart, and head back towards atria
what are the 2 Cells of the Intrinsic Conduction System?
1) Nodal cardiac cells
2) Purkinje fibers
Nodal Cardiac Cells: where are they found? what are they made of?
- Found in the SA and AV nodes
- made of modified cardiac muscle cells
Purkinje Fibers: where are they found? what are they made of?
- Found in AV bundle, bundle branches, and subendothelial branches (found in the ventricles)
- made of modified cardiac muscle cells
T/F: Purkinje fibers and nodal cardiac cells are larger than the contractile cardiac cells around them
False:
Nodal cardiac cells are smaller
Purkinje fibers are larger
Three major types of blood vessels are:
1) arteries
2) veins
3) capillaries
The walls of blood vessels (except the smallest) have three layers/tunicas. Name them.
1) Tunica Interna
2) Tunica media
3) tunica externa
what are the three parts of the tunica interna?
a. endothelium
b. basal lamina
c. subendothelial layer
Tunica Media – contains rings of _________
smooth muscles cells
In cross section, arteries will appear more ______ and veins more ______
arteries- open
veins- collapsed
what is the thickest layer of arteries? veins?
arteries- tunica media
veins- tunica externa
name the 4 types of arteries
1) Elastic or Conducting Arteries (Large Arteries)
2) Muscular or Distributing Arteries (Medium Arteries)
3) Small Arteries
4) Arterioles
walls of elastic/conducting arteries contain large amounts of ________
elastic fibers
which type of artery/arteries can contain vasa vasorum and nervi vascularis in their walls?
elastic arteries
muscular arteries
where are Continuous Capillaries found?
muscle, lung, and central nervous system
where are Fenestrated Capillaries found?
endocrine glands and at sites of fluid and metabolite absorption
Fenestrated capillaries contain oval pores called what?
fenestrations
where are discontinuous capillaries found?
Found in the liver, spleen, and bone marrow
in which capillaries can you see pinocytotic vessels?
Continuous & Fenestrated capillaries
which type of capillary can contain pericytes?
continuous capillaries
what structures form a functional unit called the microcirculatory bed?
1) the arteriole
2) the capillary network
3) and the postcapillary venule
Two Types of Vessels in the Capillary Network:
1) True Capillaries
2) Arteriovenous (AV) Anastomoses or Shunts
The More the Precapillary Sphincters Relax (and the smooth muscle of the AV shunt contract), the more……
the more blood will pass through the true capillaries in the capillary beds.
The More the Precapillary Sphincters Contract, the more……
the more blood will pass through the arteriovenous anastomoses and bypass the true capillaries.
name the 4 types of veins, starting from the smallest
1) venule
2) small veins
3) medium veins
4) large veins
what tunica layer is largest in veins? (especially large & medium veins)
Tunica adventitia
what makes up the valves found in the veins of the limbs?
thin folds of tunica intima– endothelial cells over a thin layer of connective tissue
a capillary consists of only one layer: they ______
endothelium
in blood vessels, the internal elastic membrane surrounds the ____________, and the external elastic membrane surrounds the ___________
internal elastic membrane- tunica interna/intima
external elastic membrane- tunica media
