Lecture 6 Flashcards
(16 cards)
Vitelline arteries
Celiac trunk (gut), superior and inferior mesenteric
Dorsal lateral branches
intercostal arteries, lumbar arteries
lateral branches
adrenal, renal and gonards
illiac arteries
umbillical, sacral, external and internal illiacs (legs)
Development of venous system
left and right sided venous system that eventually all shifts to/fuses with the right side
Vitellin and umbillical venous system
Vitelline and umbillical develop the hepatic portion/segment of the inferior vena cava. L and R vitelline merge to right portal vein to drain gut and spleen. Exception: umbilical system (only left side remains)
cardinal venous system
Left side regresses and forms bridge via brachial cephallic vein. Anterior portion drains everything above heart. Eventually superior vena cava. Posterior cardinal veins form bridge via angiogenesis called intercardinal anastamosis. Drains everything below heart.
change in blood circulation and pressure
blood flow through the CVS requires a difference of pressure. Flow occurs from areas of high to low pressure.
Blood vessel maturation
BV maturation allows increases regulation of BP through smooth M recruitment. Deposition of elastin
foetal vs post-natal circulation
in foetus, O2 blood makes its way from placenta to CS via foetal shunt known as Ductus Venosus. Body constricts vessels towards lungs as they aren’t working (fluid filled) preventing blood flow. It instead goes to left side of heart through foraminal valve them to left ventricle then body. However, there is a small volume of blood that makes its way to lungs. Uses ductus arterious to enter circulation. When baby is born, umbillical cord is cut and the baby breaths. This triggers the release of clamps around pulmonary artery decreasing BP in surrounding vessels and allowing for pulmonary circulation. Foraminal valve closed. Right and left side separated.
Heart anatomy adaptations
Closure of the foramen ovule separates 4 chambers. Thickening of left ventricular wall increases heart pumping strength.
cardiac performance
Heart rate: calculated in beats per min
Stroke volume: blood volume ejected by heart/beat
Cardiac output: volume of blood pumped (/ventricle) per given time (mL/min)
CO = HR * SV
Influences on cardiac performance
age, heart size
Heart when young
HR is highest when young to compensate for heart size. HR decreases as we age due to loss of pacemaker cells and autonomic system desensitivity.
Myocardial and vascular stiffening
increase collagen production by fibroblasts (fibrosis)
Decrease breakdown of collagen impairs tissue elasticity
decreases pumping efficiency due to fibrosis
Increase BP due to fibrosis of vasculature
Decrease in cardiac output
CO peaks during early adulthood. CO is a dynamic metric that constantly changes in response to physiological stimulus. CO should stay within a range to maintain function and health of all physiological systems. Influenced by sex, lifestyle choices, genetic risk, BMI and environment.
