Dr. Noreen Final Revision Notes PDF

GAD Histology Final Revision Notes -Asphyxia: Impaired respiratory gas exchange (Hypoxia and Hypercapnia) accompanied by development of metabolic acidosis -Birth Asphyxia: Failure to initiate and sustain breathing at birth. -Consequences/ Etiology/ Causes of Asphyxia: Hypoxic Ischaemic Encephalopat...

GAD Histology Final Revision Notes -Asphyxia: Impaired respiratory gas exchange (Hypoxia and Hypercapnia) accompanied by development of metabolic acidosis -Birth Asphyxia: Failure to initiate and sustain breathing at birth. -Consequences/ Etiology/ Causes of Asphyxia: Hypoxic Ischaemic Encephalopathy, Organ failure & Neonatal death. -Classifications of Asphyxia:-Acute: Caused by intranatal factors only Chronic: In the background of prolonged fetal hypoxia and placental insufficiency. -Intranatal risk factors for birth asphyxia:- Fetal arterial blood oxygen tension is only 25 ± 5 mm Hg. Rate of oxygen consumption is twice that of the adult per unit weight. Fetal oxygen reserve - 1 to 2 minutes. During uterine contractions: Blood flow - momentarily interrupted. Cord compression: cord compression - during contractions. Failure to progress or dystocia: A prolonged or obstructed labour will eventually exhaust the fetus. -Causes of Fetal Hypoxia:- Maternal Placental Fetal Acute Maternal Hypotension Placental Abruption Cord Prolapse Chronic Maternal Respiratory Any Infection Infection Disease -Intrapartum Resuscitation includes:- 1- Maternal positioning to left lateral: reduces the risk of fetal heart deceleration. - Stopping the contractions (Tocolytics or uterine relaxation): Maternal blood flow to the placental villous space is reduced or altered during a contraction. 2- Intravenous fluids: to correct maternal hypovolaemia and hypotension. 3- Oxygen -Primary Apnea: With oxygen deprivation, there is a transient period of rapid breathing, and if it persists, breathing stops - termed as Primary Apnea. If oxygen deprivation and asphyxia persist, however, the newborn will develop deep gasping respirations, followed by secondary apnea. -Secondary Apnea- associated with a further decline in heart rate, falling blood pressure, and loss of neuromuscular tone. -Management of fetal distress (Resuscitation Protocol for the newborn) -Basic Measures: Warming of the newborn to minimize heat loss. The airway is cleared. The infant dried. Routine gastric aspiration. -Assessment at 30 Seconds of Life: Apnea, gasping respirations, or heart rate < 100 bpm beyond 30 seconds after delivery, perform positive-pressure ventilation with room air. -Percent of oxygen saturation monitored by pulse oximetry.  GAD Histology Final Revision Notes -At this point, supplemental oxygen can be given in graduated. -Adequate ventilation is indicated by improved heart rate. -Assessment at 60 Seconds of Life: If the heart rate persists below 100 bpm beyond 60 seconds, tracheal intubation is performed. The head position should be checked, secretions cleared, and inflation pressure increased. -Clinical findings in fetal distress: Acidaemia, pH < 7 in an umbilical artery blood sample. Apgar score of 0–3 persisting for 10 minutes or longer. -Apgar Score: It is used to identify those neonates who require resuscitation and to assess the effectiveness of any resuscitative measures. -7 or greater at 1 minute - Normal -9 or 10 at 5 minutes. - Normal -A 5-minute Apgar score of 3 correlates poorly with adverse future neurological outcomes -Respiratory Distress Syndrome: Mostly seen in preterm infants, and known as hyaline membrane disease. -Due to a deficiency of surfactant, which is a complex of phospholipids and protein secreted by type II pneumocytes, reduces surface tension in the alveoli of the lung. -Preterm infant with RDS presents as tachypnea. -Corticosteroids to mothers at risk of delivery before 32–34 weeks gestation to hasten maturation of fetal organs. -Hemopoiesis (haematopoiesis): process of origin, development and maturation of all the blood cells. -Site: 1. Mesoblastic stage: (1st two months of intrauterine life, the RBCs are produced from mesenchyme of yolk sac. 2. Hepatic stage: From third month of intrauterine life, liver is the main organ that produces RBCs. Spleen and lymphoid organs are also involved in erythropoiesis. 3. Myeloid stage: During the last three months of intrauterine life- red bone marrow and liver. -In newborn babies, children and adults: only from the red bone marrow.  Up to the age of 20 years: from red bone marrow of all bones (long bones and all the flat bones).  After the age of 20 years: from membranous bones like vertebra, sternum, ribs, scapula, iliac bones and skull bones and from the ends of long bones. -Hemoglobin - conjugated protein, combined with an iron containing pigment. The protein part is globin and the iron containing pigment is heme. -Iron: Normally, it is present in ferrous (Fe2+), unstable or loose form. -Porphyrin: The pigment part of heme. -Globin: contains four polypeptide chains. -Types: Normal Variants: - In the fetus: Hb F (α2γ2)  GAD Histology Final Revision Notes - In newborn : Hb F (α2γ2)  80% -Hb A (α2β2)  20% - In adults:-Hb A (α2β2)  95% - Hb A2 (α2δ2)  1.5 - 3.5% -Hb F  0.8% to 2% Abnormal Variants (changes in β chains): -Hb S (α2βS2) [β6 Glu>Val] sickle cell disease. -Hb C (α2βC2) [β6 Glu>lys]  mild chronic hemolytic anemia. -Hemoglobinopathy: genetic disorder caused by abnormal polypeptide chains of HB. 1. Hemoglobin S: It is found in sickle cell anaemia, α-chains are normal and β-chains are abnormal. 2. Hemoglobin C: β-chains are abnormal, characterized by mild haemolytic anaemia & splenomegaly. 3. Hemoglobin E: β-chains are abnormal, characterized by mild haemolytic anemia & splenomegaly. 4. Hemoglobin M -Variations in size of red blood cells Microcytes - (iron-deficiency anemia) Macrocytes - (megaloblastic anemia) Anisocytes - (pernicious anemia) -Variations in shape of red blood cells – (Sickle cell) -Causes of leukocytosis: -Pathological (one type of leucocytes ↑ on the expense of others): A) Infection: 1. Neutrophilia → Pyogenic infection, Tissue necrosis 2. Eosinophilia → Allergic diseases, parasitic infestations 3. Basophilia → Allergic conditions 4. Lymphocytosis → Chronic infections (TB) 5. Monocytosis → Malaria. -Uterus Hyperplasia (increase in number of cells) of myometrium Hypertrophy (increase in size of the cells) of myometrium -Histological changes:- -Decidua basalis, which is the maternal part. -Decidua capsularis that surrounds fetal sac. -Decidua parietalis, which lines rest of uterine wall. -Stages of Labor First Stage of Labor: Three functional labor divisions: 1. The preparatory division: the cervix dilates little. 2. The dilatational division: dilatation proceeds at its most rapid rate.  GAD Histology Final Revision Notes 3. The pelvic division: deceleration phase of cervical dilatation. Second Stage of Labor: This stage begins with complete cervical dilatation and ends with fetal delivery. Events occur (Delivery of the head, Delivery of the shoulders, clamping the cord). Third stage of labor: Delivery of the placenta. -Causes of growth failure and delayed milestones. 1. Genetic and Chromosomal Conditions 2. Nutritional Deficiencies – Malnutrition 3. Hormonal Imbalance – i) Growth Hormone Deficiency: Can delay physical milestones, such as walking or developing muscle strength. ii) Corticosteroid Use: Long-term use of steroids can interfere with growth and development iii) Thyroid Disorders: Hypothyroidism or other thyroid issues can slow down development and cause delays in physical and cognitive milestones. -Erikson’s theory: child develops sense of industry.  Fails to achieve sense of industry, develops sense of inferiority. -Adolescence: period of transition from childhood to adulthood. It involves three stages:  Early adolescence - (11 - 14yrs)  Middle adolescence - (15 - 17yrs)  Late adolescence - (18 - 20yrs) -Physical Growth: Growth Spurt: A rapid increase in height and weight, usually beginning earlier in girls (around 10–12 years) than boys (around 12–14 years). -Jean Piaget's Theory of Cognitive Development: Adolescents are in the formal operational stage. -Erik Erikson's Psychosocial Development Theory: Adolescence corresponds to the stage of Identity vs. Role Confusion. -Aging: Biological process of growing older. -Gerontology: Scientific study of aging and its effects on individuals. -Geriatrics: Medical specialty that focuses on the health care of older adults. -Common Diseases of Old Age 1. Cardiovascular Diseases: Hypertension, heart disease, and stroke. 2. Arthritis: Osteoarthritis, affecting the joints. 3. Osteoporosis: Weakened bones due to decreased bone density lead to an increased risk of fractures. -Cognitive Changes in Old Age 1. Memory: Short-term memory tends to decline with age, while long-term memory may remain intact. Conditions like Alzheimer's disease - severe memory loss. 2. Processing Speed: The speed at which the brain processes information may slow, making tasks take longer. 3. Attention and Concentration: Difficulty focusing or switching attention between tasks.