Circulatory system Flashcards
the blood brings nutrients and
removes wastes in tissues
SYSTEMIC CIRCULATION
oxygenated blood
PULMONARY CIRCULATION
Propels blood through the circulatory system
HEART
From the convergence of venules into a system
of larger channels that continue enlarging as
they approach the heart, toward which they
carry the blood to be pumped again
VEINS
Series of vessels efferent from the heart that
become smaller as they branch into the various
organs, and carry blood to the tissues
ARTERY
From the convergence of venules into a system
of larger channels that continue enlarging as
they approach the heart, toward which they
carry the blood to be pumped again
VEINs
Smallest vessels are the sites of oxygen, carbon
dioxide, nutrients, and waste product exchange
between blood and tissues
CAPILLARIES
Supporting layer of fibroelastic connective tissue with scattered
fibers of smooth muscle
● Deeper layer of connective tissue
ENDOCARDIUM
Consists mainly of typically contractile cardiac muscle fibers
arranged spirally around each heart chamber
● THICKEST LAYER
MYOCARDIUM
Corresponds to the visceral layer of the pericardium
EPICARDIUM
Serves as a lubricated surface
EPICARDIUM
reflection of the epicardium where large
vessels enter and leave the heart
PARIETAL PERICARDIUM
Forms part of the interventricular and interatrial septa
CARDIAC SKELETON
Anchors the valves which surrounds the two atrioventricular canals
CARDIAC SKELETON
Attached to the chordae tendineae
CARDIAC SKELETON
Anchoring and support of heart valves
CARDIAC SKELETON
Assists in heartbeat coordination by acting as electrical insulation
between the atria and ventricles.
CARDIAC SKELETON
Provides firm points of insertion for cardiac muscle
CARDIAC SKELETON
Assists in heartbeat coordination by acting as electrical insulation
between the atria and ventricles
CARDIAC SKELETON
Pacemaker of the heart
Sinoatrial node
Located at the Right Atrial Wall near the superior vena cava
Sinoatrial node
Located at the floor of the right atrium near the AV valve
Atrioventricular node
Conducting myocytes from the AV node that are made into a
specialized bundle of cardiac muscle fibers
Bundle of his
Subendocardial conducting network of cardiac muscle fibers
(myofibers)
Purkinje fibers
A specialized epithelium that acts as a semipermeable barrier
between two major compartments: the blood and interstitial fluid
ENDOTHELIUM
Appearance: Squamous, polygonal, and elongated
ENDOTHELIUM
prevents blood clot through actively
secreting heparin that controls clot formation
Non thrombogenic surface
Regulates local vascular tone and blood flow
ENDOTHELIUM
Role in inflammation and local immune response
ENDOTHELIUM
Promotes cell proliferation by secreting growth factors
ENDOTHELIUM
Located at the apex of the heart
Purkinje fibers
provide the resiliency required for the vascular
wall to expand under pressure
ELASTIC FIBERS
is a major component of large arteries where it forms
parallel lamellae
ELASTIN
contribute to the physical and metabolic properties
GROUND SUBSTANCE
THE TUNICAS
Tunica Intima
Tunica Media
Tunica adventitia
consists of the endothelium and subendothelium
Tunica intima
separates the intima from the media (in
arteries)
Internal elastic lamina
concentric layers of smooth muscle cells
TUNICA MEDIA
consists of type 1 collagen
and elastic fibers bound to the organ stroma
Tunica adventitia
Called “conducting arteries” because of its function to carry blood
to smaller arteries
Elastic arteries
Distributing arteries
○ Distribute blood to all organs
○ Regulate blood pressure and flow
Muscular arteries
No vasa vasorum
○ Distributes the blood to arterioles
Small arteries
Smallest arterial branch with no
intimal connective tissue or smooth
muscle
ARTERIOLES
Absent elastic laminae
ARTERIOLES
Major determinant of systolic blood
pressure
ARTERIOLES
Indicates the beginning of an organ’s
microvasculature
ARTERIOLES
Network of smallest blood vessels → regulates metabolic
exchange between the blood and surrounding tissues
Capillary beds
supplied by one or more terminal arteriole branches
and branches to metarterioles
capillary beds
may be seen in:
muscles, connective tissue, lungs,
exocrine glands, and nervous tissue
Continuous capillaries
Allows extensive molecular
exchange across the endothelium
FENESTRATED CAPILLARIES
Penetrated by numerous small
circular openings or fenestrations
FENESTRATED CAPILLARIES
Most common type
● Have many tight, well-developed
occluding junctions
Continuous capillaries
may be
identified in the kidneys, intestine,
choroid plexus, and endocrine
glands
FENESTRATED CAPILLARIES
The endothelium has large perforations
without diaphragm and irregular
intracellular clefts
SINUSOID
can be
identified in: Liver, Spleen, Bone
Marrow
SINUSOID
carry deoxygenated blood back to the heart from all over the
body
Vein
has a thin tunica intima and tunica media
vein
very thick and filled with abundant collagen
adventitia layer
have intimal projections with elastic fibers, lined by
the endothelium.
venous valves
Allows easier movement of cells
between tissues and blood
SINUSOID
primary site where leukocytes stick
to endothelium and leave the circulation at sites of infection or
damaged tissue
POST CAPILLARY VENULES
located to corresponding muscular
arteries
small to medium veins
located at big venous trunks, paired with elastic
arteries which are close in proximity to the heart
large veins
transition from capillaries to venules
venules
found in the subendothelium, between the
smooth muscle layers, and in the outer covering
COLLAGEN FIBERS
