Physiology Flashcards
Cardiovascular
Changes
Increased SV, HR, CO
Decreased BP, PVR
Mild hypertrophy
Pulmonary Changes
Increased O2 consumption by 70%
Ventilation increases by 40%
Tidal volume increased from 500mls to 700mls
Decreased residual volume due to compression
No change in vital capacity or respiratory rate
Bronchodilation, increased airway odema
Renal /Urinary Changes
80% increase in renal blood flow
55% increase in eGFR
Increased creatinine clearance
Increased renin and aldosterone secretion – keep sodium and therefore water
Hypotonia of smooth muscles, compression of ureter, dextrorotation of uterus due to sigmoid
Increased bladder volume due to smooth muscle relaxation, pressure from gravid uterus
Haematological Changes
Increased blood volume by 30-45% - 30% increase in red cell mass, 50% increased in plasma volume
WCC increases, mainly neutrophils
Platelets decrease due to increased consumption
Increased coagulation – increased fibrinogen and factors, decreased fibrinolytic activity
Gastrointestinal Changes
Relaxation of lower oesophageal sphincter, delayed gastric emptying, increased bowel transit times
Impaired bile transport- increased production, reduced gall bladder emptying
Decreased total protein as less albumin
2-4 times increased ALP due to placenta and bone
Metabolic/Endocrine Changes
Increased basal metabolic rate
Increased insulin secretion and sensitivity
Increased prolactin, ACTH, CRH, cortisol, RAAS
Stable GH
Decreased FSH, LH (negative feedback)
Pelvic Organ Changes
4x increased blood flow to uterus – 800ml/minute
Can cause IVC compression
Psychological/Emotional Changes
Fatigue and sleep deprivation
Estrogen and progesterone effects
Cardiovascular System Effects
Sinus tachycardia
Systolic ejection murmur
3rd heart sound, split heart sounds
Premature beats, paroxysmal atrial tachycardia, lateral deviation
Palpitations, syncope, fatigue, decreased exercise tolerance
Respiratory System Effects
Physiological hyperventilation causes respiratory alkalosis – increased pO2, decreased pCO2, increased pH 7.44
Dyspnoea
Predisposed to pulmonary oedema – due to reduction in colloid osmotic pressure and pulmonary capillary wedge pressure
Difficulty intubating and ventilating- increased risk of aspiration
Renal/urinary system effects
Increased urinary excretion of glucose and protein
Total body water increases
Ureteric dilation especially on right
Increased likelihood of UTI
Urinary urgency
Haematological Effects
Dilutional anaemia
Neutrophilia
Gestational thrombocytopenia
Increased risk of VTE
Normal APTT, PT, TT
GI effects
Reflux
Constipation
Gallstones
Increased ALP
Changes in taste
Nausea
Metabolic Effects
Anabolic state in early pregnancy, catabolic state in late pregnancy
Pelvic Organ Effects
IVC compression can cause varicose veins, swelling, syncope
