Cardiopulmonary Flashcards
Vasculature Development
3-4 wks after conception. Vasculogenesis and angiogenesis
Vasculogenesis
Formation of arteries and veins during embryonic development
-mesodermal cells differentiate into vessels
Angiogenesis
Formation of branches during the whole life (healing and embryonic development)
3 layers of blod vessels
- Tunica externa: connective tissue
- Tunica media middle smooth lauer
- Tunica intima: inner endothelial layer
Autonomic NS control of circulation
SNS: vasoconstriction and increased heart rate
PSNS: vasodilation and decreased heart rate
Circulatory Receptors
Baroreceptors: in aorta and carotid sinus, BP changes
Chemoreceptors: in aorta and carotid body, pH changes and o2
Cardiovascular development Embryonic
-heart develops at 3 weeks (recognizable at 20 days)
-circulation at 4 wks
- heart becomes 4 chamber structure at 7 wks
Circulatory system Prenatal
Shunting systems
Foramen ovale; r atrium to l
Ductus arteriosus: r pul artery to aorta
Ductus venosus: IVC to umbilical vein
Shunting system
Small passages for blood to travel to bypass body parts not developed
Circulatory system Neonatal
Shunting systems for new structures
Foramen ovale: fossa ovalis
Ductus arteriosus: ligamentum arteriosum
Umbilical vein: ligamentum teres
Ductus venosus: ligamentum venosum
Umbilical arteries: lateral umbilical ligaments
Congenital heart disease
1% of live births
Leading non infectous cause of death under 1
Cardiovascular infancy and childhood
Ratio of heart volume and wight is constant
Increase in: cross sectional area, fibers, force, stroke volume, Left side of heart predominates, LV wall, heart size increases with weight, heart volume,, blood pressure
Decrease: heart rate
Heart volume increases and ratio
40ml at birth, 80ml at 6m, 160ml at 2yrs
-10ml/kg of body weight
vascular development infancy, and childhood
Increased heart vascularization: at birth, one vessel for every six muscle fibers, adulthood, one to one ratio.
Hemoglobin levels of infancy and childhood
Newborn: 20
3 to 6 month old: 10
Adult: 14 to 16
Fetal hemoglobin is higher than postnatal, but with less oxygen saturation (70%) as the lungs are immature (postnatal 97%)
Cardiovascular development adolescence
-As body weight increases blood pressure and heart size increase, left, ventricle, increases, stroke, volume increases
Cardiovascular development adulthood
Heart size may increase due to fatty deposition, most evident in women between 30s and 60s
Cardiovascular development aging
Decreases in: number of myocytes, SA node cells, heart rate, stroke volume, blood volume due to decreasing fluid, red blood cells, lymphocytes
Increases: size of myelocytes (wbc), fat deposition, ventricular wall, thickness of heart valves, and blood vessels, darkness of myocardium
Adult heart disease
Number one cause of death, 1 million heart attacks per year, 5 million adults with heart failure
Controllers of ventilation
Medulla oblongata and pons
Sympathetic nervous system controls: bronchodilation
Parasympathetic nervous system controls: bronchoconstriction
Stretch receptors in lungs
Intercostal, muscles and diaphragm
Pulmonary development prenatal
6 weeks to 7 months
Six weeks: primitive alveolar form
Eight weeks: conductive zone developed (trachea and bronchi)
24 weeks: surfactant is produced
26 to 28 weeks development: viable respiratory zone
Pulmonary development neonatal
8 weeks to 7 months
Six weeks: primitive alveolar form
Eight weeks: conductive zone developed
24 weeks: surfactant is produced
26 to 28 weeks development: viable respiratory zone
Pulmonary development at birth
Rib cage is horizontal accessory muscles are not fully developed
Lack efficient diagram breathing
After sitting: ribs become angled, diaphragm, becomes dome sheet to increase efficiency of breathing
Pulmonary development infancy and childhood
Increase in alveoli number until age 8
Airways are always smaller in children
-Decreased smooth muscle in bronchial walls until 3 to 4yrs
-Decreased alveolar, elasticity until puberty
-Decreased collateral ventilation mechanisms (bronchial collapse, increased work for breathing, increased risk of respiratory infections until eight years old.).
Pulmonary development, adolescence
Increase size of airways, increased alveolar size
19 years old: smooth muscle of alveoli are fully developed
Pulmonary development adulthood, and aging
Decreased compliance and elasticity, vital capacity, increased breathing rate, smaller, capillary bed around alveoli, decrease blood flow volume
Cardiac output
Efficiency of the cardiovascular system
Stroke volume x heart rate
Minute ventilation
Efficiency of the pulmonary system
Tidal volume x respiratory rate
Maximal aerobic capacity
Maximal ability of an individual’s body to transport in use oxygen for energy, determined by level of cardiovascular pulmonary fitness
