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[[Outflow Tract]]
[[Outflow Tract]]
Neural crest cells in bulbus cordis proliferate in week 5 to create bulbar ridges
The neural crest cells migrate over the aortic arches to reach the outflow tract
Bulbar ridges rotate 180° to create the helical aorticopulmonary septum
As the ridges grow and develop myocardium they fuse. Fusion occurs in a distal to proximal direction during the sixth week allowing for cleavage of the aorta and pulmonary trunk. The spiralling nature of the ridges causes the pulmonary trunk to twist around the aorta. Note that the bulbus cordis accounts for the smooth conus arteriosus (or infundibulum) in the right ventricle and the aortic vestibule in the left ventricle.
[[Heart Valves]]
[[Cardiac Abnormalities]]
[[Overview]]

Revision as of 14:29, 15 October 2009


Lab 10

What is the background to the existing problem / disease condition???

Study Shows Mozobil Induces Mobilization Of Stem Cells But Not Myeloma Tumor Cells

Mozobil- able to mobilise stem cells from bone marrow to blood and doesnt increase mobility of tumor cells in melonoma patients

Treatment for tumor patients- chemotherapy with autologous stem cell transplantation

Before chemotherapy- patients stem cells collected and then transplanted back into patient after chemotherapy, 2 million stem cell required adn can occur through multiple collection sessions, which increases the risk of comtaminating the sample with tumour cells and some patients could not collect enough sample stem cells

Mozobil and Neupogen (filgrastim) solves the above problem Neupogen increases stem cell production in bone marrow Mozobil increases the mobility of stem cells from marrow to blood

Faculty of Medicine at the University of Utah conducted the use of above drugs- they utilized patients with proven poor stem cell mobilizers and potentially poor stem cell mobilizers Found that the majority of patients could produce 2 million stem cells and had successful transplantations

Safety and efficacy assessment of plerixafor in patients with multiple myeloma proven or predicted to be poor mobilizers, including assessment of tumor cell mobilization

This study found that for improved response and survival rates from chemotherapy, stems cell must be mobilized and collected for transplantation back into the patient. However there is a risk of potential contamination of the sample by tumour cells. Those with poor stem cell mobilizers were given pleixafor as it was identified as improving stem cell collection.

Lab 11 Cardiac Embryology

First major function to work in embryo at 4th week Heart defects affect 8-10 of every 1000 births in US

Primordial Heart Tube

Arises from splanchnic mesoderm in cardiogenic region Angioblastic cords develop in this cardiogenic mesoderm and canalise to form bilateral heart tubes Lateral folding of embryo brings heart tubes into midline to fuse into a single primordial heart tube (fusion occurs cranially) After folding- constrictions and dilations occur to differentiate the tube into:

   * Truncus arteriosus
   * Bulbus cordis
   * Primordial ventricle
   * Primordial atrium
   * Sinus venosus 

At 4th week- constrictions are evident and blood is pushed cranially from sinus venosus Heart layers-

   * Endocardium: forms from the endothelium of the heart tube
   * Cardiac Jelly: gelatinous connective tissue separating the myocardium and heart tube endothelium
   * Myocardium: forms from splanchnic mesoderm 
   * Epicardium: develops from mesothelial cells 

Heart Tube Looping

Occurs in late 4th - early 5th week Stage 1. Heart tube elongates, folds ventrally and bends to the right to form a C shape Stage 2. Loop creates an S shape and distance between inflow and outflow tracts diminish

Septation

Superior and inferior cushions arise from the Atrioventricular (AV) Canal Endocaridum mesenchymal cells invade cushions & allows for fuse and proliferate Fusion of cushions separates AV canal into right and left canals Septum primum arises from the roof of the atrium and separates it into left and right halves The space between the septum primum and the endocardial cushions is the foramen primum Cell induced death occurs in the center of the septum primum to form the foramen secundum Septum secundum arises to the right of the septum primum to overlap foramen secundum in weeks 5-6 The foramen ovale arises due to the incomplete partition of atrium by the septum secundum Blood flows through the foramen ovale to the foramen secundum (right to left shunt) There is the existance of a left and right horn of the sinus venosus Right atrium receives superior and inferior vena cava (via right horn) Left horn regresses into coronary sinus Primordial pulmonary vein develops in the left atrium, more branches arise as the atrium increases in size Trabeculations appear during early development of the primordial ventricle Primordial muscular interventricular (IV) ridges arise in the floor of the ventricle, as the ventricle grows the medial walls fuse to form the IV septum The IV foramen, which closes at the end of week 7, arises at the cranial proportion of the IV septum and the endocardial cuchions

Outflow Tract

Neural crest cells in bulbus cordis proliferate in week 5 to create bulbar ridges The neural crest cells migrate over the aortic arches to reach the outflow tract Bulbar ridges rotate 180° to create the helical aorticopulmonary septum

As the ridges grow and develop myocardium they fuse. Fusion occurs in a distal to proximal direction during the sixth week allowing for cleavage of the aorta and pulmonary trunk. The spiralling nature of the ridges causes the pulmonary trunk to twist around the aorta. Note that the bulbus cordis accounts for the smooth conus arteriosus (or infundibulum) in the right ventricle and the aortic vestibule in the left ventricle.

Heart Valves

Cardiac Abnormalities

Overview