Lecture 67 "physiology Of Pregnancy"

Front 1

reasons why BP decreases (2)

Back 1

decreased responsiveness to to angiotensin II (vasoconstrictor)

decreased response to NE and ADH

Front 2

DOC rises due to

Back 2

extra adrenal 21-hydroxylation of progesterone

Front 3

reasons why testosterone does not cause pregnant women to grow a beard or loose temporal hair nor cause the genitalia of a femal fetus to become masculinized (3)

Back 3

sex hormone binding globulin(SHBG) binds testosterone

placenta aromatizes testosterone to estrogen

prolongation of the growth phase of scalp hair

Front 4

changes in heart sounds

*loudness and splitting of first heart sound
*systolic murmurs
*systolic/continuous murmurs
*T wave
*S-T segment

Back 4

*loudness and splitting of first heart sound: increases
*systolic murmurs: present
*systolic/continuous murmurs: present (from mammary arteries)
*T wave: flattened or inverted
*S-T segment: depressed

Front 5

hematocrit (Hct.)

Back 5

decreases (because plasma volume increases more than red blood cell volume does = hemodilution)

"physiologic anemia"

Front 6

Hb concentration

Back 6

remains the same

Front 7

rationale for hypervolemia/hemodilution (5)

Back 7

protects mother from orthostatic hypotension

protects mother from risks of hemorrhage at delivery

increased red blood cell mass meets increased oxygen requirement of pregnancy

most of the increased blood volume goes to the uterus, skin and kidneys (organs for excretion and heat loss)

decrease in viscosity leads to decreased resistance to blood flow (hence decrease in cardiac work needed to maintain circulation)

Front 8

venous arm pressure

Back 8

remains the same

Front 9

femoral venous pressure

Back 9

increases (obstruction by uterine weight on iliac veins and IVC, pressure of fetal head on iliac veins and outflow of blood at high pressure from uterus)

Front 10

rate of blood flow

Back 10

decreases

Front 11

circulation time (lower limbs)

Back 11

increases (due to increase in venous pressure, esp, iliac veins)

Front 12

circulation time (upper limbs - arm to tongue)

Back 12

remains the same

Front 13

cardiovascular clinical implications of pregnancy (4)

Back 13

cardiomyopathy

arrhythmia

thromboembolism (increased blood coagulability, varicose veins, decrease in rate of blood flow in legs)

improvement in Raynaud's Syndrome (6-7X in blood flow to the hands)

Front 14

minute ventilation

Back 14

increases

Front 15

tidal volume (TV)

Back 15

increases

Front 16

inspiratory capacity

Back 16

increases

Front 17

FRC

Back 17

decreases (due in increased inspiratory capacity)

Front 18

TLC

Back 18

decreases

Front 19

RR

Back 19

remains the same

Front 20

VC

Back 20

remains the same

Front 21

IRV

Back 21

remains the same

Front 22

PCO2

Back 22

decreases (due to increased minute ventilation)

Front 23

serum [HCO3]

Back 23

decreases (due to increased minute ventilation)

Front 24

pH

Back 24

increases (slightly)

*respiratory alkalosis* (due to increased minute ventilation)

Front 25

respiratory clinical implications of pregnancy (2)

Back 25

increase respiratory intake of noxious substances

dyspnea (SOB)

Front 26

VO2

Back 26

increases (due to increased minute ventilation)

Front 27

O2 carrying capacity

Back 27

increases (due to increased number of rbc's)

Front 28

a-v O2 difference

Back 28

decreases

Front 29

ureteral dilation stops at _____ due to (2)

Back 29

pelvic brim

progesterone

obstruction (enlarging uterus, dilated ovarian and uterine veins)

Front 30

T/F ureteral dilation is due to reduced tone, i.e., reduced frequency or amplitude of ureteric contractions

Back 30

False (reduced tone is due to smooth muscle hyperplasia)

Front 31

urinary system clinical implications of pregnancy (5)

Back 31

24-hour urine collection errors

radiographic mis-interpretation

urinary tract infections (UTI's)

acute obstruction/non-traumatic rupture of ureter

urine retention

Front 32

serum [TG]

Back 32

increases

Front 33

GI tract clinical implications of pregnancy (6)

Back 33

reduced incidence of peptic ulcer (due to decreased gastric secretions)

amelioration of peptic ulcer (due to decreased gastric secretions)

increased heartburn (due to decreased GI motility)

food retention (vomiting, aspiration)

appendix displaced upwards and laterally

increased gallstone formation (due to thick and viscous bile)

Front 34

changes due to estrogen:

*oxytocin receptors
*depolarization
*gap junctions

Back 34

*oxytocin receptors: increase
*depolarization: increases
*gap junctions: increase

(in preparation for uterine contractions)

Front 35

changes due to progesterone:

*oxytocin receptors
*depolarization
*gap junctions

Back 35

*oxytocin receptors: decrease
*depolarization: decreases
*gap junctions: decrease