Maternal Adaptations to Pregnancy II Flashcards
What changes occur to ADH secretion during pregnancy?
Osmolarity set point for ADH release is lower
Pregnancy does not interfere with the capacity of the pregnancy woman to respond to the normal physiological stimuli that affect ADH release
What occurs to the residual volume, functional residual capacity, total volume, and vital capacity of the lungs during pregnancy?
Both RV and FRC are decreased as a result of the uterus forcing the diaphragm upward
Total volume is decreased slightly
Vital capacity is unchanged
What occurs to alveolar ventilation during pregnancy?
Increases due to an increase in tidal volume
Respiration rate does not increase
Progesterone increases ventilation by increasing the sensitivity of the central chemoreceptors to CO2
What occurs to oxygen consumption during pregnancy?
Oxygen consumption increases in proportion to increasing fetal mass
Alveolar PCO2 decreases because alveolar ventilation exceeds the metabolic rate
The resulting respiratory alkalosis is compensated by the excretion of bicarbonate by the kidney
What occurs to the anterior pituitary during pregnancy?
Increases in size
Hyperplasia of lactotropes, causing an increase in serum PRL levels
What occurs to ACTH, GH, TSH, FSH, and LH during pregnancy?
ACTH - increase 4-5 fold
GH - remains the same, source changes to placenta
TSH - lower in 1st trimerster than 2nd or 3rd
FSH/LH - fall to very low levels
What changes to the thyroid are associated with pregnancy?
Becomes enlarged during the 1st trimester
May be caused by the thyrotropic effect of hCG
What changes occur to the pancreas during pregnancy?
Hypertrophy and hyperplasia of beta cells
Increase in peripheral resistance to the metabolic effects of insulin due to increased levels of maternal hPL and cortisol
What changes occur to the adrenal cortex during pregnancy?
Increase in maternal total cortisol levels
Placenta expresses HSD-II, protecting the fetus from maternal cortisol
RAA increase
What are the changes in the GI system associated with pregnancy?
GI motility, absorption and lower esophageal sphincter tone decrease
Intragastric pressur increases
Gall bladder function and emptying are impaired
What hormone are required for breast development during pregnancy?
Prolactin
human placental lactogen
estrogens
progesterone
What hormone have permissive effects on breast development?
GH
IGF-1
Insulin
Cortisol
How is PRL release controlled in the pituitary?
Under tonic inhibition by dopamine through Gi protein
What occurs to circulating PRL levels during pregnancy?
Steadily rise during pregnancy
Due to lacotrope hypertorphy and hyperlasia
High levels of estrogens promote lactotrope proliferation and prolacting release
How is prolactin released following parturition?
Suckling is the most potent postpartum stimulus for PRL release
