Fetal Circuation Flashcards
Wat shape is the placenta
Discoid
Maternal side of plcenta
Dak red side
40 cotelydons
Separated by sulci into which deciduous dips down to for the septa
What are cotelydons
Made up of lobules each of which contain villus with its branches
Tal side
Shiny due to amnion membrane
What is the placenta
Temporary structure that allows exchange of substances between circulatory systems without mixing blood by establishing diffusion gradients
Hat does the placenta allow
Critical for fetal survival
Releases hormones
Grows in a immunological foreign environment
placenta blood low requires synchronous development both uteri-placental circulation and feta-placental circulation
Respiration
O2 diffuses through wall of villi and binds to fetal haeoglobin
Transfer is increased as fetal haemoglbin has higher affinity to o2
Nutrition
Transport of glucose,iron,vitamins and other nutrients
Placenta metabolises proteins fats ad arbs into small molecules
Placenta stores glycogen
Excretion
CO2 and heat cross the placenta to mother
Rtection
Barrier against most bacteria
Syphilis can pass hrough villi
Virus can cross villi
Transfer igG antibodies and rh antibodies
Drugs can pass through
Endocrine role
Trophoblast production hcG
His maintains corpus luteum
CL produces progesterone providing nourishing environment
Oestrogen ad progesterone maintain pregnancy
Human placenta lactogen regulates metabolism makes the body resistant to immune system
Features off fetal circulation
Before birthlung filled with fluid
Gi system and kidneys do not function
What ae the three shunts that direct o2 blood to most essential areas during fetal development
Ductal venosus
Foramen ovale
Ductus arteriosus
Ducal venosus
Continuation off umbilical vein
Shunts cor vein blood flow to nferior vena cava which allows o2 to bypass liver
Foramen ovale
Opening in septum separating 2 atrial
One way valve
Allowin blood flow to. Flow between right and left atria
Most blood flor bypass lungs
