Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Development > Physiology of pregnancy > Flashcards

Physiology of pregnancy Flashcards

1
Q

what physiological changes occur during pregnancy

A
  1. Support for the developing fetus

2. Prepare the mother for labour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how does blood volume change during pregnancy

A
  • Blood volume starts to increase during first trimester
  • Blood volume expands rapidly during second trimester
  • Blood volume rises at a lower rate during the third trimester
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why does the blood volume change during pregnancy

A
  • During pregnancy the plasma volume may have increased by as much as 45%
  • Rise in plasma volume is followed by an increase in total ertyrhocyte volume
  • RAAS: retention of sodium and increase in total body water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

cardiac output…

A

increases during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

why does haemoglobin concentration fall

A
  • Increase in red blood cell volume is smaller relative to that of the plasma volume this means that overall haemoglobin concentration falls slightly during pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is it called when haemoglobin concentration falls

A
  • Hb concentrations fall from around 150g/l pre-pregnancy to 120g/l during the third trimester (physiological anaemia of pregnancy) - DILUTIONAL ANAEMIA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is erythropoiesis

A
  • This stimulated via an increase in renal erythropoietin production
  • Red cell mass can increase by 20%
  • Causes an increased erythrocyte production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does cardiac output change over the course of pregnancy

A
  • Cardiac output increased by 35-40% in first trimester

- Cardiac output only increases slightly during second and third trimesters, approximately 50% at term

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why does cardiac output over the course of pregnancy increase

A
  • due to an increase in heart rate and stroke volume

- Increased cardiac output is a result of increased heart rate (of about 25%) and increased stroke volume (of about 25%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what causes an increase in stroke volume during pregnancy

A
  • Increase in ventricular wall muscle mass

- The heart is physiologically dilated and myocardial contractility is increased.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where does the increase in cardiac output go in pregnancy

A
  • Blood flow to the uterus increases

- And there is an increase in blood to the Breast and skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what happens to blood pressure during pregnancy

A

There is a slight dip in blood pressure in the late to early second trimester and then it increases back to normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what happens to MABP (mean arterial blood pressure during pregnancy)

A
  • During pregnancy MABP stays the same or even falls slightly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why can MABP fall slightly or remain the same

A
  • Cardiac output is increased
  • MAP = CO x TPR
  • There is a decrease in total peripheral resistance in order to maintain blood pressure as the CO has risen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how does the peripheral vascular resistance change during pregnancy

A

• Peripheral vascular resistance falls by 50% in early pregnancy
- In the late second trimester blood pressure returns to non – pregnant levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why does the peripheral vascular resistance change during pregnancy

A
  • Progesterone – has a key role in relaxing smooth muscle
  • Oestrogen, nitric oxide, relaxin and calcitonin gene-related peptide are also implicated.
  • placenta– contributes an extra blood vessel circuit
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how does posture impact cardiac output

A
  • Large uterus causes compression of the vena cava when laying down
  • Enlarged uterus can cause compression of the vena cava which impedes venous return to the heart.
  • This leads to a reduction in cardiac output and blood pressure (maternal hypotension
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

which way should women lie

A
  • Pregnant women should not lie in the supine position but lie to the side for blood pressure measurements. - left side as this relieves the pressure on the vena cava
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is pre-eclampsia

A
  • Pre-eclampsia characterised by a sudden high blood pressure with proteinuria (and oedema).
  • can be a direct cause ode death due to pregnancy
  • usually occurs later pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

describe how clotting changes during pregnancy

A

hypercoagulable state (that is an increased tendency toward blood clotting)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

easy id hsrmodysdid

A
  • Haemostasis is a continuable between clot initation and breakdown of clots
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what does clotting increase in pregnancy

A
  • Plasma concentrations of fibrinogen and all clotting factors EXCEPT XI and Tissue factor (TF) gradually increase.
  • Overall pregnancy is associated with a decrease in coagulation inhibitors as well
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is clot dissolution called

A
  • The subsequent process of clot dissolution that occurs during the healing phase is known as fibrinolysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

why does clotting increase in pregnancy

A

these changes are thought to be important to maintain placental function during pregnancy and as preparation for haemostatic challenge (prevent excessive bleeding) during delivery

25
Q

what happens to platelet production in pregnancy

A

there is increased platelet production

• Decreased platelet count

26
Q

what is the leading cause of death in pregnancy

A
  • Thrombosis and thromboembolism is the leading cause of direct deaths in pregnancy
27
Q

what happens to fibrinoyliss during pregnancy

A

• Inhibition of fibrinolysis activity

28
Q

what happens to the oxygen consumption in pregnancy

A
  • Increased oxygen consumption from 250ml/min to 300ml/min at rest
  • This is to maintain the additional metabolic requires of pregnancy
29
Q

describe what happens to respiratory measurements during pregnancy

A
  • There is an increased alveolar ventilation, the amount of air that reaches the alveoli and is available for gas exhcnage with the blood
  • Increased miniute ventilation the volume of gas inhaled or exhaled from a persons lungs per minute - tidal volume and respiration rate is increased
  • Large increase in tidal volume from 500ml to 700 ml and the respiratory rate is slightly increased
30
Q

how do mechanisms of respiration change in pregnancy

A
  • Progesterone-mediated hypersensitivity to CO2 - central chemoreceptors are adjusted and modulated to increase sensitivity to carbon dioxide
  • Progesterone stimulates the respiratory centre directly to increase sensitivity to carbon dioxide
31
Q

how does the lung volume change during pregnancy

A
  • Decrease in total lung capacity
  • Increased tidal volume
  • Decrease in expiratory reserve volume
  • Decrease in residual volume
  • Expanding uterus
32
Q

how do the oxygen and carbon dioxide gases change during pregnancy

A
  • As there is an overall increase in ventilation the mother is actually breathing out more CO2, carbon dioxide decrease in pregnancy and oxygen increases slightly
33
Q

what acid base condition do you get during pregnancy

A
  • Respiratory alkalosis
  • Hyperventilation results in the removal of carbon dioxide this leads to chronic respiratory alkalosis
  • There is a renal compensation by the loss of bicarbonate and hydrogen ion retention
34
Q

how does the renal system change

A
  • Kidneys increase in length (~1cm) (possibly due to an increase in cell size)
  • Dilation of renal calyces, pelvis and ureter mainly due to the action of progesterone to relax smooth muscle.
  • Increased renal plasma flow (from 1.2 l/min to 1.5 l/min) and this effects the GFR
  • Increased glomerular filtration rate (to 140-170ml/min)
35
Q

what happens to urea creatinine, rate clearance and extraction of bicarbonate during pregnancy

A
  • There is an increase in urea, creatnine, urate clearance and exreteion of bicarbonate
  • Outcome is a slight decrease in the plasma concentrations
36
Q

what is glycosuria

A
  • Decrease in re-absorption of glucose
37
Q

why does glycosuria happens during pregnancy

A
  • Probably due to increase in filtered load of glucose which is greater than the ability of the proximal tubule to reabsorb glucose
38
Q

how is the RAAS system regulated during pregnancy

A
  • System is activated during pregnancy
  • Prorenin peaks 8-12 weeks of gestation
  • Renin rises around 20 weeks of gestation
  • Significant increase in angiotensinogen
39
Q

oestrogen upregulates…

A

angiotensinogen production in the liver

40
Q

what is the role of RAAS system in pregnancy

A
  • Increased activity of RAAS in early pregnancy- leads to water retention and a decrease in plasma osmolarity.
  • Increase in aldosterone secretion during pregnancy which favours reabsorption of salt and water.
  • Decreased sensitivity to angiotensin II to offset its actions on vasoconstriction. – inreasesing peripheral ressitance, but there is a decrease sensitivity to angiotensin II to offset these actions on vasoconstriction this acts on its receptors
41
Q

how does oestrogen act on the RAAS system

A
  • There is potentially a direct action of progesterone and oestrogen in the kidney.
  • Oestrogen thought to act directly to increase renin secretion from granular cells.
  • Oestrogen also acts to upregulate angiotensinogen production in the liver.
42
Q

what are the liver changes in pregnancy

A
  • High or elevated levels of markers for liver changes in function but this is clinically insignificant
  • Increased plasma concentrations of alkaline phosphatase (as a result of placental production).
43
Q

what does the liver changes that take place in pregnancy make hard to diagnose

A
  • Clinical signs of liver disease e.g. spider naevi and palmar erythema may occur
  • Makes the diagnosis of liver disease more difficult.
44
Q

what are the GI changes that occur during pregnancy

A
  • Heart burn/reflux common,
  • Small and large bowel – decrease in tone and motility
  • 60% increase - water absorption
  • Constipation
  • Haemorrhoid formation
45
Q

why does heartburn occur during pregnancy

A
  • partly due to increased intra-abdominal pressure which is aggravated in the supine position.
    • Progesterone-mediated reduction in lower oesophageal sphincter tone (note: upper oesophageal sphincter not affected as its striated muscle).
46
Q

why do small and large bowel changes occur during pregnancy

A

• Small and large bowel – decrease in tone and motility – progesterone is working on the smooth muscle and causes relaxation

47
Q

what are the changes that take place in the endocrine system

A
  • Pancreatic islets of Langerhans – hyperplasia of insulin producing β-cells: Increased insulin production.
  • Early pregnancy tissues show an increased sensitivity to insulin and plasma glucose may fall
  • Late pregnancy insulin response blunted by placental hormones and plasma glucose may rise- change in glucose concentration throughout pregnancy
  • Increased placental glucose uptake
48
Q

what is parturition

A

labour or the act of giving birth

49
Q

what are the three stages of labour

A
  1. Dilation of cervix/uterine contractions
  2. Fetal expulsion
  3. Placental expulsion
50
Q

what are the cardiac output changes

A
  • During contractions it rises high and there is an increase in cardiac output
  • Increases due to “autotransfusion” from contracting uterus.
  • Further increase in blood may be autotransfused as placenta delivered.
  • Pain or anxiety and stimulation of sympathetic nervous system also increases heart rate and possibly blood pressure.
51
Q

what happens to the blood volume, heart rate and cardiac output and protein and lipids after labour

A

– Blood volume – decrease by 20% in 72hrs postpartum
– Heart rate and cardiac output – decrease to baseline in 2wks
– Proteins and lipids – decrease to baseline in 2-3 wks

52
Q

what happens to the urinary system after labour

A

– Functional change – prompt return to baseline with decrease blood volume
– Structural change – Dilatation of bladder, ureters and renal pelvis – persist for less than or equal to 3 months

53
Q

how does the mammary gland develop during puberty

A
  • Initiated at the start of puberty, progesterone and oestrogen hormones regulate the development of the non-pregnant adult mammary gland.
  • Lactiferous ducts and alveoli (lobes) develop but the breast is not capable of large-scale mile production (lactogenesis).
54
Q

what are the changes that undergo during pregnancy to the mammary gland

A

• Lobular ductal-alveolar system undergoes hypertrophy.
• Proliferation of ducts.
• Alveoli mature.
• Deposition of adipose tissue between lobules of the gland
• Controlled by placental steroids: estradiol and progesterone as well as placental peptide hormone (hPL).
Pituitary growth hormone and prolactin may also have a role

55
Q

when is the Brest fully developed for milk production

A

by the middle of pregnancy

56
Q

what causes lactation to happens after pregnancy

A
  • Prolactin is primary lactogenic hormone (initiates milk production) and it is present at high levels throughout gestation.
  • It is thought that steroid secretion (placental steroids: oestrogen and progesterone) inhibits secretory activity of mammalian tissue.
  • Lactogenesis triggered post delivery by fall in steroid secretion (placental steroids: oestrogen and progesterone
57
Q

what is the primary lactogenic hormone

A

• Prolactin is primary lactogenic hormone (initiates milk production) and it is present at high levels throughout gestation

58
Q

how does the milk ejection efflux happen

A
  • Oxytocin is also necessary for the milk ejection reflex. The hormone is released in response to suckling.
  • Oxytocin causes the Contraction of myoepithelial cells – release milk from alveoli and small ducts into large ducts and sinuses

Human Development (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions