Cardiovascular System - Lymphatic Development: Difference between revisions

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This system was first identified by Aselli G. 1627 in a paper "De Lacteibus sive Lacteis Venis", Quarto Vasorum Mesarai corum Genere novo invento. Milan: Mediolani
This system was first identified by Aselli G. 1627 in a paper "De Lacteibus sive Lacteis Venis", Quarto Vasorum Mesarai corum Genere novo invento. Milan: Mediolani
'''Links:''' [[2009_Lecture_7|2009 Lecture - Early Vascular Development]] | [[2009_Lecture_21|2009 Lecture - Heart]] | [[Cardiovascular System Development]] | [[Cardiac_Embryology|Student Project - ILP Heart Embryology Education]] |  [[OMIM_References#Cardiovascular|OMIM selected abnormality entries]] | [http://embryology.med.unsw.edu.au/Notes/heart31.htm Lymphatic original page]


==Lymphatic Vessels==
==Lymphatic Vessels==

Revision as of 09:52, 25 March 2010

Introduction

An important part of the cardiovascular system is the lymphatic vasculature, which functions to return interstitial fluid (lymph) to the bloodstream.

This system was first identified by Aselli G. 1627 in a paper "De Lacteibus sive Lacteis Venis", Quarto Vasorum Mesarai corum Genere novo invento. Milan: Mediolani

Links: 2009 Lecture - Early Vascular Development | 2009 Lecture - Heart | Cardiovascular System Development | Student Project - ILP Heart Embryology Education | OMIM selected abnormality entries | Lymphatic original page

Lymphatic Vessels

  1. Lymph capillaries
  2. Lymph collecting vessels
  3. Lymph ducts

Lymphatic Vessel Contraction

Lymphatic vessels undergo spontaneous rhythmic contractions which aid lymph flow. This is most easily demonstrated in models based upon mesentry lymphatics of the gastrointestinal tract. Contractile activity is regulated by physical factors (transmural pressure) and neurological (alpha-adrenergic, histamine, bradykinin) acting on lymphatic smooth muscle. Contractility and receptor expression may also be different in different parts of the lymphatic system.

Alpha-adrenergic - alpha 1- and not alpha 2-adrenoceptors.

Histamine - lymphatic smooth muscle via stimulation of H(1) (and in some vessels H(2)) receptors.

Bradykinin - chronotropic but not inotropic effects on lymphatic pump activity via stimulation of B1 receptors.

Molecular Development

Angiopoietins (Ang1–Ang4)

Notch probably mediates choice of fate between arterial and venous.

Prox1 Prospero-related Homeobox 1 - expressed in a subpopulation of blood endothelial cells that then generate, by both budding and sprouting, cells of the lymphatic vascular system. (OMIM - PROSPERO-RELATED HOMEOBOX 1; PROX1)

Tie (Tie1 and Tie2) tyrosine kinase receptors.

Vascular endothelial growth factor (VEGF) family of proteins and angiopoietin/Tie, Notch, and ephrin/Eph pathways play major roles in eary vessel development.


Abnormalities

Lymphangioma - dysplasia of childhood form lymphatic capillaries or collectors, which form fluid-filled cysts.

lymphatic spaces lined by endothelium smooth muscle fascicles in the septa between the lymphatic spaces lymphoid aggregates in the delicate collagenous stroma