Cadiovascular System 1 Flashcards
Cardiovascular system includes the:
Heart
Blood Vessels
Lymphatic Vessels
Circulation Pathway that transports blood from the heart to the lungs and from the lungs to the heart
Pulmonary Circulation
Circulation Pathway that transports blood from the heart to the other tissues of the body and from other tissues to the heart
Systemic Circulation
Visceral layer of serous pericardium composed of Single layer of mesothelial cells, blood vessels, and nerves.
Epicaridum
Myocardium:
Complex spiral arrangements of cardiac myocytes. Striated muscle branching in nature central nucleus intercalated discs
Attachment site between cardiac muscle cells
Intercalated Discs
Risers of stairway in intercalated discs with Fascia Adherens as major constituent
Transverse Component
Steps of stairway in intercalated discs with Gap Junctions as major constituent
Lateral Components
Found in both lateral and transverse components
Maculae adherents
Inner layer of endothelium and subendothelial connective tissue.
Endocardium
Subendocardial layer location of the conducting system of the heart
Core of the valve, extensions of heart skeletal rings
Fibrosa
Loose connective tissue, collagen fibers and elastic fibers, shock absorber
Spongiosa
Dense connective tissue, many layers of elastic fibers
Ventricularis
Layer of the blood vessel wall that includes the endothelium, subendothelial connective tissue, and internal elastic lamina
Tunica Intima
Primarily of circumferential layers of smooth muscles cells
– secrete the ECM components of this layercollagen, elastin, ground substance
Tunica Media
Mainly collagen type I fibers and a few elastic fibers .
Contains nerves, vasa vasorum, fibroblasts, and macrophages
Tunica Adventitia
Simple squamous epithelium of the vessels, tight junctions, gap junctions
Endothelium
Endothelial Cells: Functions
Permeability barrier - controls the composition of interstitial tissue fluid.(brain, lung vs inflamm.sites)
VEGF ( vascular endothelial growth factor ) provides for angiogenesis in the embryogenesis. (As well as in vascular trauma, tumor..)
Provides signals that control blood pressure
Rod-shaped inclusions found in Endothelium that store von Willebrand factor (glycoprotein) that binds Factor VIII
Weibel Palade bodies
Arteries are …… that allows for recoiling to maintain intra vascular pressure and accommodate the large volume of blood during systole
Elastic
Elastic Arteries have:
- Have fenestrations – permitting diffusion of nutrients
• Vascular smooth muscle between layers of elastic fibers
Blood vessel layer made of dense irregular connective tissue that prevents the excessive expansion of the vessel
Tunica Adventitia
Function of Muscular Arteries (Medium Sized Arteries):
– Serves as a muscular conduit to distribute blood from elastic vessels to smaller vessels
-Muscular Arteries are most abundant in the body and have External Elastic Laminae
The major determinants of blood pressure
Arterioles
T. Intima – endothelium
T. Media - 1 – 2 layers of smooth muscle cells
T. Adventitia - ill-defined: merges with surrounding connective tissue
Vessel that allows exchange of material and may be encircled by pericytes
Capillaries
Type of Capillary that:
• Continuous basal lamina
• Uninterrupted endothelium
• Tight junctions present between cells
Continuous/Somatic Capillary
Significance:
➢complete control over diffusion, endocytosis and exocytosis
➢Vessels that form barriers in organs such as brain, thymus, lung, testis etc)
Type of Capillary that:
• Continuous basal lamina
• Tight junctions present between endothelial cells
• Fenestrations of about 80-100nm in diameter on endothelial cell membrane Numerous pinocytotic vesicles
Fenestrated / Visceral Capillary
Significance:
➢ Presence of thin, non membranous diaphragm across the fenestrations (exception –glomerular capillaries of kidney)
Type of Capillary that:
• Discontinuous basal lamina
• Absence of tight junction between the cells
• Presence of large fenestrations •Separated by wide, irregular, intercellular gaps
Discontinuous / sinusoidal
Significance:
➢Fenestrations- large and variable reach several microns.
➢Size of fenestrations vary in different organs.
➢Allow passage of macro molecules.
