click below
click below
Normal Size Small Size show me how
Neo Unit 1-4
spc
Question | Answer |
---|---|
What are the fetal germ layers? | Ectoderm, Mesoderm, Endoderm |
The ectoderm is the outside layer and creates? | Hair, epidermis, nails, CNS system |
The mesoderm is the middle layer and makes? | dermis, muscle, bone, C/V system, PLEURAE |
The endoderm is the innermost layer and makes the? | respiratory system, liver, gut, epithelium |
The mesoderm and the endoderm both make the? | respiratory system, the mesoderm makes the pleurae(musculature), the endoderm makes the parenchyma(functional units) |
A full term baby is between? | 37-42 weeks |
The embryonic stage is the first 6 weeks? | primitive lung bud forms at 24 days |
The pseudoglandular phase is 7-16 weeks? | conducting airways are developed |
The canalicular pahse is 17-26 weeks? | pulmonary capillaries develop |
The saccular phase is 27 weeks to post term? | definitive alveolar epithelium is established, type 1 and 2 cells |
The conducting airways? | sequestrian of the conducting airways is completed by the end of the 16th week of gestation |
The respiratory bronchioles develop? | between week 16 to 2 months post term |
At full term there are about 24 million developed alveoli, they keep developing until? | 8 years of age |
Fetal lung fluid is secreted into the amniotic fluid, therefore? | an amniocentesis can be done to analyze lung fluid |
Lung maturity can be assessed by comparing the level of? | lecithin to the sphingomyelin, L/S ratio |
Lecithin is short for dipalmitoyl lecithin, it is mature surfactant. Levels rise as the? | fetal lung matures and type 2 cells proliferate. Surfactant is made by type 2 cells |
Sphingomyelin, which is a sphingolipid remains? | fairly stable through out gestation |
The L/S ratio increases as the fetal lung matures, a ratio of 2:1 can? | sustain extra uterine life |
What are other markers of fetal development? | ultrasound, alpha fetoprotein, bilirubin, creatinine, shake test |
The diaphragm develops from a ventral mesodermal fold (septum transversum) this is done by? | the end of the 7th week of gestation |
The cilia appear between 10-13 weeks, goblet cells appear at? | 13 weeks |
Cartilage is well established by ? | 24 weeks |
Smooth muscle is poorly developed in the newborn? | begins to dramatically develop after 3 years of age |
Lymphatics appear at 20 weeks and are well developed at? | birth |
Connective tissue develops from mesoderm? | collagen, and elastic tissue |
Collagen makes the large airways and is? | well developed at birth |
Elastic tissue makes the acinus and is poorly developed at birth? | continues to develop through adolecense |
The placental gas exchange is enhanced by? | maternal-fetal 02 gradient (90-100 VS 30mmhg) , fetal HB has a decreased P50 so that 2,3 DPG does not bind with it, Maternal HB has an increase P50 to increase 2,3 DPG levels |
Arterial uterine gas tensions? | 02 90-100mmhg C02 30mmhg progesterone |
Venous uterine gas tensions? | 02 30mmhg C02 45mmhg |
Arterial umbilical tensions? | 02 30mmhg C02 40mmhg |
Venous umbilical gas tensions? | 02 15mmhg C02 55mmhg |
Fetal circulation traces from the? | umbilical vein (only 1) to the umbilical arteries (there are 2) |
The lungs are bypassed with fetal circulation because they are filled with fluid. 02 is brought to the fetus by blood circulation from the mother. The lungs are bypassed by? | the ductus venosus, foramen ovale, and the ductus arteriosus. Objective is to bypass the lungs and get the blood to the aorta to be pused out the fetus's body |
The ductus venosus communicates the? | umbilical vein with the IVC |
The foramen ovale communicate the? | fetal atria |
The ductus arteriosus communicate the? | pulmonary artery with the descending aorta |
The umbilical cord is made of? | whartons jelly, surround the arteries and vein to stabilize and prevent kinking or occlusion of blood flow |
The umbilical arteries return blood? | to the placenta, away from fetus |
The umbilical vein delivers blood? | to the fetus |
The amnion is the sac that surround the fetus and is filled with? | 500-1500ml of amniotic fluid |
Excessive amniotic fluid >2L is called? | polyhydramnios |
Decreased amniotic fluid <500ml is called? | oligohydramnios |
Disorders that can cause excessive amniotic fluid are? | hydrocephalus, spina bifida, esophageal atresia, pyloric stenosis, and major complications like PROM during delivery |
Disorders that can cause decreased amniotic fluid are? | renal dysplasia, urethral stenosis, and major complications like asphyxia due to cord compression and lung hypoplasia |
How does closure of the ductus venosus happen at birth? | The umbilical cord is clamped, the umbilical vein has no flow and collapses, the ductus venosus then collapses and becomes the ligamentum teres |
Closure of the foramen ovale? | Rt atrial pressure decreases from decreased IVC flow cause by umbilical clamping, the Lt atrial pressure increases from increased pulmonary blood flow |
Closure of the ductus arteriosus? | Increased Pa02 that decreases the synthesis of PGE1, indomethacin inhibits the synthesis of PGE1. PGE1 causes ductal dilatation in utero. |
Loss of Fetal Lung Fluid =Gain Air. | 1/3 is squeezed out w/ vaginal delivery. 1/3 is drained by the lymphatics. Some is eliminated via swallowing & coughing |
INCREASE PaO2 = INCREASE pH = | decreased PVR |
INITIATION OF RESPIRATION? | BIRTH ASPHYXIA - PRIMARY STIMULUS. COLD ENVIRONMENT NOISY ENVIRONMENT TRANSPULMONARY PRESSURES OF -40 to -60 mmHg are witnessed. |
Newborn >2500 grams blood pressure? | SYSTOLIC: 55-65 mmHg DIASTOLIC: 30-40 mmHg MEAN: 40-50 mmHg |
A blood gas five hours post delivery should be? | pH: 7.35 PaCO2: 35 mmHg PaO2: 70 mmHg |
Norms for a full term baby? | VT: 5ml/Kg f: 30-40/minute FRC: 20-30ml/Kg |
CCW (THORAX): HIGH due to: | Incomplete bone & muscle development. |
SPECIFIC CL = ADULT CL | NEWBORN = 75 ml/cmH2O/L ADULT = 80 ml/cmH2O/L |
SPECIFIC Raw = | < 0.6 cmH2O/l/sec/L |
The peripheral chemoreceptors are sensitive too? | low Pa02 |
Central chemoreceptors are sensitive too? | PaC02 and PH |
Hering-Breuer inflation reflex is to prevent over distension of the lung? | causes shorter exhalation when lung is under inflated |
The Gasp Reflex? | A reflex augmentation of the newborn’s first breath with a subtle “breath stack”. Helps establish the newborn’s FRC. |
J receptors are Sensory nerve endings within the alveolar walls in juxtaposition to pulmonary capillaries, they are Triggered with? | Pulmonary edema, pulmonary emboli, pneumonia, barotrauma, etc May cause dyspnea and increased RR |
Propriocepters are Responsible for stabilizing the chest wall during non-REM sleep. During REM sleep? | they are disengaged & the chest wall becomes unstable. Thus, paradoxical movement of the chest & abdomen is seen. |
Common patterns? | periodic breathing and recurrent apnea |
Periodic breathing is Most common in SGA < 2 Kg preemie? . | Onset is after 1st week of extrauterine life. Periods of apnea last up to 10 seconds. Innocuous |
Recurrent apnea? | Serious apneic spells that last more than 20 seconds. Oxygen saturation drops significantly. Bradycardia is noted. |
Recurrent apnea factors? | PREMATURITY SEPSIS INTRACRANIAL HEMORRHAGE |
True alveoli appear around weeks? | 32-34 |
The combination of L/S ratio and testing for PG is called the? | lung profile |