Brainscape's Knowledge GenomeTM

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


See full index

RED > L20: Fetal Neonatal Cardiorespiratory Physiology > Flashcards

L20: Fetal Neonatal Cardiorespiratory Physiology Flashcards

1
Q

Which artery brings in maternal blood to the placenta

A

Maternal spiral arteries

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

Which vessel carries oxygenated blood from the placenta back to the baby by going through the umbilical cord

A

Umbilical vein

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

Which vessel does the umbilical vein join to

A

The inferior vena cava

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

Which vessel brings deoxygenated blood form the baby to the placenta so blood is oxygenated

A

Umbilical artery

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

Where does exchange with the fetal blood and maternal blood occur

A

Chorionic villus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the partial pressure of oxygen at the uterine artery

A

12.7kpa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the partial pressure of oxygen at the uterine vein

A

5.6kpa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the partial pressure of oxygen at the umbilical artery

A

3.2kpa

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

What is the partial pressure of oxygen at the umbilical vein when it picks up oxygen

A

4.2kpa

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

As the partial pressure of oxygen in the umbilical vein (4.2) is lower than the partial pressure of oxygen in the uterine artery (12.7kpa) is low what does this indicate

A

The fetal umbilical vein does not reach equilibrium with the maternal blood for oxygen

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

What is the partial pressure of carbon dioxide in the uterine artery

A

Pco2=5.3kpa

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

What is the partial pressure of co2 in the uterine vein

A

6.1kpa

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

What is the partial pressure of co2 in the umbilical artery

A

6.6kpa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the partial pressure of co2 in the umbilical vein

A

5.8kpa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What does the close partial pressure of the uterine vein and umbilical vein suggest

A

Carbon dioxide has diffused the maternal side i.e uterine vein and almost equilibrium has occurred

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

Why do we get a close equilibrium with carbon dioxide but not for oxygen

A
  • placental barrier is more permeable to co2 than o2
  • not all maternal blood comes in contact with the villi
  • placental tissue if highley active and consumes 20% of oxygen so there is less in the fetal blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What type of haemoglobin does the fetus have

A

Fetal haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When does the fetal haemoglobin reach a peak level

A

At 10 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What happens to the levels of fetal haemoglobin at term i.e after birth

A

Declines by 80% and disappears completely after 6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the features of fetal haemoglobin

A

Has a higher affinity for oxygen

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

Which polypeptide chain in the fetal haemoglobin allows for a higher affinity for oxygen

A

Gamma polypeptide chain that does not interact with 2,3DPG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does having a higher affinity for oxygen mean

A

Fetal haemoglobin picks up more oxygen at a lower partial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

If the fetal haemoglobin has a higher affinity for oxygen what is the saturation of oxygen for the fetal haemoglobin like

A

75% saturated with oxygen (more than adult haemoglobin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the fetal haemoglobin saturation further affected/influenced by

A

The Bohr effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the Bohr shift/effect

A

The fetal haemoglobin gives off more carbon dioxide to pick up oxygen and the adult haemoglobin releases more oxygen to pick up the fetal carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the concentration of fetal haemoglobin like in the Fetal blood compared to the maternal blood

A

Fetal haemoglobin concentration is higher in the fetal blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What does a higher concentration of fetal haemoglobin mean

A

More oxygen is picked up at Po2=4.2kpa compared to the maternal blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the 3 shunts present in the fetal circultion

A
  • ductus venosus
  • foramen ovale
  • ductus arteriosus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Where is the ductus venosus located

A

At the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Where is the foramen ovale located

A

At the heart between the right atrium and left atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where is the ductus arteriosus located

A

Between the pulmonary and systemic circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the flow of each shunt dependent on

A

Intravascular pressure gradient i.e from high to low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe the flow of the fetal blood from the umbilical vein back to the placenta via umbilical arteries

A

1) blood from the umbilical vein passes through the ductus venosus at the liver to the inferoir Vena cava
2) the umbilical vein has a higher oxygen concentration than the inferoir vena cava which brings blood back form the feet/legs
3) blood then goes through the foramen ovale from the right atrium to the left atrium as blood pressure from the umbilical vein is greater than the inferior vena cava pressure And right atrial pressure is greater than the left atrium
4) blood from the right ventricle goes through the pulmonary artery through the descending aorta by the ductus arteriosus as the lungs are not working
5) blood from the ascending aorta takes the highest conc of oxygenated blood to the brain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

In a normal adult what are the right and left stroke volumes like

A

The same because there are no shunts therefore the exact volume of blood from the right ventricle is the same as the left ventricle as the same volume of blood enters to the left ventricle .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the cardiac output

A

The total volume of blood the heart pumps in one minute

Co= SV x HR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

As the fetal heart contains shunts what is the stroke volume of the left and right

A

Not equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Which ventricle contains the least stroke volume

A

The left ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Why does the left ventricle in the fetus have a lower stroke volume

A

Because less blood passes to the lungs to return back to the left ventricle due to the ductus arteriosus passing blood from the right ventricle to the aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the fetal cardiac output

A

The combined ventricles output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Which hormones play a role in the fetal circulation control

A

Catecholamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Which receptors does catecholamines act on

A

Alpha and beta adrenoceptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What influence does the circulating catecholamines have on the fetal circulation

A

Tonic adrenergic vasoconstrictor influence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Which other hormone also produce a vasoconstriction influence on the fetal circulation

A

Vasopressin

Angiotensin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the heart rate of the fetus at the 11 week of gestation

A

160 beats per min

45
Q

From 28 weeks onwards what develops

A

Autonomic control from nerves

46
Q

When the autonomic control has developed what happens to the heart beat of 160bpm

A

Decreases to 140bpm due to the vagus nerve

47
Q

At the 11 week of gestation what is the arterial blood pressure (ABP) at

A

70/45 mmHG

48
Q

What happens to the ABP when the sympathetic nervous system begins to develop

A

Increases to 80/55mg at term

49
Q

When the sympathetic NS is beginning to develop what reflex is also being developed

A

The baroreceptor reflex

50
Q

What type of chemoreceptors are also beginning to develop

A

Peripheral chemoreceptors

51
Q

What can peripheral chemoreceptors detect

A

Hypoxia

52
Q

When there is hypoxia what adjustment does the peripheral chemoreceptors cause

A

Bradycardia

Vasoconstriction

53
Q

Why does the peripheral chemoreceptors produce bradycardia and vasoconstriction

A

So the blood flow to the brain is preserved

54
Q

What is the fetal breasting movement

A

When the baby uses the diaphragm and intercostal muscles to develop the strength of the thorax

55
Q

What are the 2 types of fetal breathing movement

A
  • regular breathing

- irregular breathing in REM sleep

56
Q

What type of fetal breathing movement indicates hypoxia

A

Decreased fetal breathing movement

57
Q

What are the lungs filled with in a fetus

A

Fluid

58
Q

What happens to the fluid in the lungs during vaginal childbirth

A

Become squeezed out

59
Q

What is the first breath of the baby triggered by

A

Cooling, sensory stimulation and chemoreceptor stimulation due it increases carbon dioxide and low oxygen

60
Q

What structure allows the first breath to be possible

A

Surfactant

61
Q

Which cells in the lungs secrete surfactant

A

Type 2 cells

62
Q

Which hormone allows for the secretion of surfactant

A

Fetal cortisol

63
Q

What is the role of surfactant

A

Decrease surface tension that opposes lung inflation

64
Q

When can surfactant be decreased

A

In pre-term mature babies

65
Q

What happens to the fluid in the lungs when air moves in

A

The fluid gets pushed back into the lungs across the alveoli by the air that moves in
Fluid it then taken away from the lymphatics

66
Q

What happens to the compliance and functional residual capacity as the fetus breaths

A

Increases

67
Q

At the first breath what happens to the pulmonary vascular resistance

A

Decreases

68
Q

Why does the pulmonary vascular resistance decrease

A

The lungs expand as the air fills them and the pulmonary circulation open (increase in diameter that decreases resistance)

69
Q

If the pulmonary vascular resistance decreases what happens to the blood flow to the lungs

A

Increases

70
Q

When there is more blood flow through the pulmonary circulation what happens to the volume returning back to the left atrium

A

Increases

71
Q

What happens when the left artial pressure is greater than the right atrium

A

The foramen ovale closes as it gets pushed to close

72
Q

What happens to the systemic ABP when the umbilical cord is clamped

A

Increases

73
Q

Why does the abp increase after clamping the umbilical cord

A

Because the systemic TPR increases

74
Q

As a result of the systemic pressure increasing and the pulmonary abp decreasing due to the pulmonary circulation opening what happens

A

Th ductus arteriosus closes as blood flow reverses from the aorta to the pulmonary artery

75
Q

In addition to the umbilical cord being clamped what happens to the flow in the umbilical vein

A

Decreases

76
Q

What happens as a result of decreased flow from the umbilical vein

A

Ductus venosus collapses and constricts to close

77
Q

What other factors contribute to the close of the ductus arteriosus

A

A decrease in prostaglandin

78
Q

Why do we get a decrease in prostaglandin synthesis

A

Due to a higher po2 in the lungs

79
Q

Which drugs can be used to block the synthesis of prostaglandins and hence facilitate the closure of the ductus arteriosus

A

NSAID

80
Q

How doe NSAID work to block the production of prostaglandins

A

Block the COX enzyme that are required for prostaglandins production

81
Q

Which other hormone is involved in the closure of the ductus arteriosus

A

Bradykinin

82
Q

What happens the thickness of the wall of the pulmonary arteries and right ventricle

A

Decreases

83
Q

Why does the thickness of the wall of the right ventricle and pulmonary arteries decrease

A

Because there is a decreased pulmonary vascular resistance so less work is required to pump blood to the lungs

84
Q

What happens the wall thickens off the left ventricle

A

Increases

85
Q

Why does the ventricle wall thicken

A

Due to increases peripheral resistance so more work is required

86
Q

What happens to the peripheral chemoreceptors during the neonatal period (over the 2 weeks after birth)

A

Reset

87
Q

Why does the peripheral chemoreceptors need to re-set after birth

A

So they stop firing at a lower po2 i.e 4.2kpa which they were used to and start firing below po2= 12.5kpa

88
Q

What is the baby vulnerable to during this re-set period

A

Hypoxia as the response to hypoxia is going to be weak

89
Q

If the foramen ovale doesn’t close after birth what can this create

A

Left to right shunt

90
Q

What can a left to right shunt present with

A

Pulmonary remodelling

Pulmonary hypertension

91
Q

Why do we get a pulmonary hypertension

A

Because there is too much blood going from the left atrium to the right ventricle that pumps blood to the lungs

92
Q

If a left to right shunt occurs what can happen to the right ventricles

A

Hypertrophy instead of thinning due to the big overload of blood

93
Q

If this continues and the right ventricular pressure becomes greater than the left ventricular pressure what can happen to the shunt

A

Reverse

94
Q

What happens to oxygenation if there is a right to left shunt due to a reversal

A

Compromised

95
Q

Why is oxygenation compromised in a right to left shunt

A

Because blood doesn’t go to the lung to become oxygenated as instead is passes from the right ventricle into the left ventricle

96
Q

What is the syndrome of called when the foramen ovale doesn’t close and you have a reversal of the shunts

A

Eisemenger syndrome

97
Q

When there is a right to left shunt what is the baby called

A

Blue baby

98
Q

What can happen if the ductus arteriosus doesn’t close after birth

A

The left ventricular output from the aorta enters back to the pulmonary circulation

99
Q

What does blood entering from the aorta back to the pulmonary circulation present as

A

Pulmonary hypertension
Right ventricular afterload (high pressure the right ventricle needs to create to overcome the pressure in the pulmonary circulations blood can flow)

100
Q

What is pre-eclampsia due to

A

Poor remodelling of the maternal spiral arteries that results in high resistance due to a smaller lumen and therefore a decreased blood flow to the fetus

101
Q

What can pre-eclampsia present as in the mother

A

High ABP

Proteinuria (protein in the urine)

102
Q

What is the treatment for pre-eclampsia

A

Delivery of the baby

103
Q

What is intra-uterine growth retardation/restriction (IUGR)

A

When the fetus develops in a retarded way i.e doesn’t grow as expected

104
Q

What is IUGR associated with

A

Increased blood pressure
Advanced diabetes
Maternal malnutrition
Maternal smoking

105
Q

What can IUGR lead to

A

Fetal programming

106
Q

What is fetal programming

A

Where the in uterine condition leads to adverse afffects that continue into adulthood life

107
Q

What conditions can the baby get in adult hood due to Fetal programming

A

Diabetes
Obesity
Metabolic syndrome

108
Q

What is fetal programming associated with

A

Increased cortisol
Oxidative stress
Epigenetics process

RED (19 decks)

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