Parent cells meiosis Ovum (before ovulation) + Spermatozoa Fertilization Zygote

 Also known as the zygote  22 pairs of autosomes & 1 pair of sex chromosomes MotherFather femalemale XXXY

 Early stage of embryonic developement  Zygote under go cell division (32 cells) and forms in to Morula  morula become bound tightly together with the formation of desmosomes and gap junctions, becoming nearly indistinguishable. This process is known as compactiondesmosomesgap junctionscompaction  Gently morula moves to the uterus

 Growing cells reorganize  Outer layer – trophoblast cells  Inner mass – embryoblast  This process is known as Gastrulation  Blastocyst enters uterine cavity

 Trophoblast cells secrete an enzyme which digest the endometrial wall  Blastocyst sinks and completely embed in the uterine wall  This occur at the upper part of the uterus

Week 1-3  contact with the endometrium (implantation) Connections between the mother and the embryo will begin to form, including the umbilical cord.implantationumbilical cord  The embryo's growth centers around an axis which will become the spine and spinal cord. The brain, spinal cord, heart, and gastrointestinal tract begin to form

Week 4 -5  stop the woman's menstrual cycle. Neurogenesis is underway, showing brain activity at about the 6th week.menstrual cycle  The heart will begin to beat around the same time. Limb buds appear where the arms and legs will grow laterheart

Week 6 -8  Myogenesis and neurogenesis  Embryo is capable of motion,  Eyes begin to form. Organogenesis and growth continue. Hair has started to form along with all essential organs.  Facial features are beginning to develop. At the end of the 8th week, the embryonic stage is over, and the fetal stage begins.fetal

Assignment What are the stages of fetal development and how organs develop within this stages

 Round & flat, approximately 1/6 th of fetal weight  Functions, Respiratory, nutritive function Glycogenic function Excretory function Barrier function Endocrine function (HCG,HPL)

 Anatomical changes  Physiological changes  Psychological changes Take 30min and list the possible changes occur in relation to the above

 Relaxation of the ligaments  widening and increased mobility of the pubis and sacro-iliac joints  Hypermobility of joints  Increased lumbar lordosis  Stretching abdominal muscles  Decreased in ligamantous strength  Pelvic floor drops as much 2.5 cm  COG shifts forward and upwards  Balance – mother walks with wider BOS

Cardiovascular System Blood Volume increases progressively Reaches a maximum at approximately weeks Added volume of blood is accounted for by an increased capacity of the uterine, breast, renal, striated muscle and cutaneous vascular systems Decrease in haemoglobin concentration. ( Intake of supplemental iron and folic acid is necessary to restore hemoglobin levels to normal 12 g/dl)

During the first trimester cardiac output is % an increase in stroke volume (35%) & more rapid heart rate (15%). Systemic arterial pressure is never increased decrease in diastolic pressure hypotension develops more readily

Enlarged uterus compresses both the inferior vena cava and the lower aorta when the patient lies supine fall in cardiac output by as much as 24% most women are capable of compensating for the resultant decrease in stroke volume by increasing systemic vascular resistance and heart rate.

All metabolic functions are increased during pregnancy Proteins, lipids and carbohydrate metabolism increased rapidly pregnant women live in a state of "accelerated starvation”

glomerular filtration rate begin to increase progressively mild glycosuria (1-10 gm/day) proteinuria (to 300 mg/day) can occur in normal pregnancy

 capillary engorgement and swelling of the lining in the nose, oropharynx, larynx, and trachea.  Symptoms of nasal congestion, voice change and upper respiratory tract infection  elevation of the diaphragm  total lung capacity decreases  breathing is more diaphragmatic  middle of the second trimester, expiratory reserve volume, residual volume and functional residual volume are progressively decreased

Morning sickness/ hyper-emesis gravidarum Relaxation of lower oesophageal sphincter, increase in intra gastric pressure (symptoms of heart burn and reflux occur)

First trimester whether child is wanted/ not Mid termemotions become more stable Last 3 months anticipation mixed with fear/anxiety