G-D-MIDTERMS-review PDF

1. Ectoderm 2. Mesoderm 3. Endoderm Forms the Develops into organs Forms the inner lining exoskeleton of the organs CNS (brain and the Supporting str...

1. Ectoderm 2. Mesoderm 3. Endoderm Forms the Develops into organs Forms the inner lining exoskeleton of the organs CNS (brain and the Supporting structures of the Lining of pericardium, spinal cord) body pleura, and peritoneal PNS Connective structures cavities Skin, Hair, Nails and Bones , Cartilages, Lining of GIT, Tooth Enamel Muscle, ligaments, Respiratory Tract, Sense Organs and tendons Upper Tonsils, Parathyroid, Mucus membrane of portion of the urinary and Thymus Gland the anus, mouth, and system Lower Urinary nose Mammary Reproductive System System glands Heart, Lymph, and Bladder and Urethra Outer Layer Circulatory system Lines embryonic and blood cells digestive tract Partly fills the space between the endoderm and ectoderm Ec-Me-En EcMeEn cMeEn 4th Height = 0.75 Spinal cord - Formed and fused at the midpoint Embryo cm Head Large in proportion and represents about Weight = 400 one-third of the entire structure. 0.75 cm mg Rudimentary heart - Appears as a prominent bulge on 400 mg the anterior structure. Arms and Legs bud-like structures Rudimentary eyes, ears, and nose are discernible. 8th Length = 5 cm Organogenesis is complete Fetus Weight = 20 g Heart (with septum and valves) -Beats rhythmically Facial features - Definitely discernible 5 cm Arms and leg are develop 20 g External genitalia are forming but sex is not yet distinguishable by simple observation Abdomen bulge forward because the fetal intestine is growing rapidly Sonogram shows a gestational sac, which is diagnostic of pregnancy 12th Length = 7-8 Nail beds forming on fingers and toes cm Spontaneous movements are possible - although 7-8 cm Weight = 45 g they are usually too faint to be felt by the mother. 45 g Some reflexes, such as the Babinski reflex, are present. - Bone ossification centers begin to form - Tooth buds are present Sex o Distinguishable on outward appearance Urine Secretion o Begins but may not yet be evident in amniotic fluid. Heartbeat audible through Doppler technology 16th Length = 10 to Actively swallows amniotic fluid, demonstrating an 17 cm o Weight intact but uncoordinated swallowing reflex 10-17 = 55 to 120 g Fetal heart sounds audible by an ordinary cm stethoscope 55-120g Lanugo is well formed - Both the liver and pancreas are functioning Urine is present in amniotic fluid Sex can be determined by ultrasonography 20th Length = 25 cm Spontaneous fetal movements can be sensed by the Weight = 223 g mother. 25 cm Antibody production is possible - 223 g Hair including eyebrows, forms on the head; vernix caseosa begins to cover the skin. Meconium present in the upper intestine 24th Length = 28 to Meconium Present as tar as the rectum 36 cm Lung surfactant active production begins 28-36 Weight = 550 g Eyelids previously fused since the 12th week, now open cm Pupils react to light 550g Hearing o Can be demonstrated by response to sudden sound When fetuses reach 24 weeks, or 500 to 600 g, they have achieved a practical low-end age of viability if they are cared for after birth in a modern intensive care nursery. 28th Length = 35 to Lung alveoli almost mature 38 cm Surfactant can be demonstrated in amniotic fluid 35-38 Weight = 1,200 Testes Begin to descend into the scrotal sac from cm g the lower abdominal cavity. 1,200 g Blood vessels of the Retina formed but thin and extremely susceptible to damage from high oxygen concentrations An important consideration when caring for preterm infants who need oxygen 32nd Length = 38 to Subcutaneous fat begins to be deposited 43 cm The former stringy, ‘little old man’ appearance is lost 38-43 Weight 1,600 g Fetus responds by movement to sounds outside the cm pregnant person’s body. 1,600 g An active Moro reflex is present.  Iron stores which provide iron for the time during which birth the neonate will ingest only breast milk after birth, are beginning to be built Fingernails reach the end of fingertips 36th Length = 42 to Body stores of glycogen, iron, carbohydrate and 48 cm calcium are deposited. 42-48 Weight = 1,800 Additional amounts of subcutaneous fat are deposited cm to 2, 700 g (5 to Sole of the foot 1,800- 6 lb) Has only one or two crisscross creases compared with 2,700g a full crisscross pattern evident at term. 5-6 lbs Amount of lanugo begins to diminish 2.5-3 kg Most fetuses turn into a vertex (head down) presentation during this month. 40th Length = 48 to Fetus kicks actively 52 cm ▪ Crown Sometimes hard enough to caused the pregnant person 48-52 to rump (35 to considerable discomfort, cm 37 cm) o Fetal hemoglobin Begins its conversion to adult Weight = 3,000 hemoglobin - 3,000 g g (7 to 7.5 lb) Vernix Caseosa Starts to decrease after the infant reaches 37 weeks gestation 7-7.5 May be more apparent in the creases than covering of lbs the body as the infant approached 40 weeks or more gestational age. - Fingernails extends over the fingertips Creases on the soles of the feet cover at least two-thirds of the surface. In primiparas (i.e. people having their first baby) The fetus often sinks into the birth canal during the last 2 weeks of pregnancy, giving the pregnant person a feeling the load they are carrying is less. This event, termed lightening, is a fetal announcement that the fetus is in a ready position and birth is nearing