Module 10: Neonatal Physiology

Question 1

At birth adaptive immunity if fully functional and independent of the mother, while innate immunity in the neonate is still immature.
True or False?

Answer 1

False

Question 2

Which of the following statements is correct concerning antibodies during pregnancy or in the neonate?

Select one:

a. IgM is an antibody which crosses the placenta to provide protection from infection in utero.

b. Colostrum does not contain antibodies.

c. Neonates do not have antibodies in their blood until they are first exposed to an infectious agent

d. IgG provides passive immunity to the neonate.

Answer 2

d. IgG provides passive immunity to the neonate.

Question 3

Respiration in the neonate is aided by an increase in alveolar surface tension as a result of surfactant production.
True or false?

Answer 3

False

Question 4

________ is the most well developed sense in the neonate due to the presence of ________

Answer 4

THE SKIN is the most well developed sense in the neonate due to the presence of MYELINATED AXONS

Question 5

Stimulation of the GI hormones is initiated by _________ and ___________ .

Answer 5

Stimulation of the GI hormones is initiated by ‘FEEDING’ and ‘MECONIUM PASSAGE’

Question 6

Match the following feature of the neonatal nephrons with the effect they have on body fluid balance.

increased renal vascular resistance

Answer 6

decreased renal blood flow

Question 7

Which of the following is occurring at a similar rate to adults shortly after birth?

Select one:
a. Protein synthesis

b. Gluconeogenesis

c. Glycogenolysis

d. Lipolysis

Answer 7

d. Lipolysis

Question 8

Match the following feature of the neonatal nephrons with the effect they have on body fluid balance.

shorter loops of Henle

Answer 8

decreased urine concentration

Question 9

Match the following feature of the neonatal nephrons with the effect they have on body fluid balance.

decreased tubular reabsorption

Answer 9

increased loss of solutes in urine

Question 10

Match the following feature of the neonatal nephrons with the effect they have on body fluid balance.

decreased GFR

Answer 10

inability to deal with increased fluid loads

Question 11

Match the following feature of the neonatal nephrons with the effect they have on body fluid balance.

acid excretion is maximal

Answer 11

cannot excrete excess acids (risk of acidosis)

Question 12

Closure of the ductus arteriosus:

Select one:
a. leads to formation of the ligamentum teres.

b. occurs completely within minutes of birth.

c. is facilitated by decreased pressure within the pulmonary circulation.

d. occurs once the placenta is removed.

Answer 12

c. is facilitated by decreased pressure within the pulmonary circulation.

As pressure/resistance drops in the pulmonary circulation, right-to-left shunting through the ductus arteriosus is decreased and the musculature begins to constrict.

Question 13

Which of the following is the main method used to increase neonatal internal body temperature if it drops below set point range?

Select one:
a. Vasoconstriction of blood vessels

b. Shivering

c. Metabolism of brown adipose tissue

d. Inhibition of thyroid hormone (TH)

Answer 13

c. Metabolism of brown adipose tissue

Question 14

In the neonate:

Select one:
a. insulin levels fall to allow the breakdown of glycogen and mobilization of fatty acids as an energy source

b. blood glucose levels drop after the first feed

c. there is a transition from a predominantly catabolic fetal state to a predominantly anabolic neonatal state.

d. blood glucose levels remain elevated for the first hour after birth.

Answer 14

a. insulin levels fall to allow the breakdown of glycogen and mobilization of fatty acids as an energy source

Question 15

A reduced internal body temperature in the neonate is a risk factor for:

Select one:
a. Jaundice
b. Dehydration
c. Hypoglycemia
d. Hypocoagulation

Answer 15

Hypoglycemia

Question 16

Match the following immunological protein in breastmilk with their actions.
- LYSOZYME

Answer 16

Disrupts bacterial cell walls, killing them,

Question 17

What adaptation of the cardiorespiratory system must occur at birth to prevent persistent fetal circulation?

SELECT ONE:

a. Respiratory rate must increase to 50 breaths/minute

b. Production of adult hemoglobin (HbA) must overtake production of fetal hemoglobin (HbF)

c. Pulmonary vascular resistance (PVR) must decrease

d. Placental circulation must be removed

Answer 17

Pulmonary vascular resistance (PVR) must decrease.

The decrease in PVR allows increased blood flow to the lungs and increased blood return from the lungs to the heart, reducing right-to-left shunting of blood and facilitating closure of the fetal shunts.

Question 17

Match the following immunological protein in breastmilk with their actions.
- LACTOFERRIN

Answer 17

Binds iron, making it unavailable

Question 18

Match the following immunological protein in breastmilk with their actions.
- LACTOPEROXIDASE

Answer 18

Inhibits bacterial growth

Question 19

Match the following immunological protein in breastmilk with their actions.
- BIFIDUS FACTORS

Answer 19

Promotes the growth of Bifidobacterium bifidus

Question 20

Match each of the following reflexes with the correct action.

Grasping reflex _________
Babinski reflex __________
Rooting reflex ___________
Moro reflex _____________

Answer 20

Grasping reflex → fingers curl to grip object,
Babinski reflex → toes extend & abduct,
Rooting reflex → turn head & open mouth,
Moro reflex → arms spread and palms open

Question 21

Which of the following factors are elevated in the neonate (compared to the older child/adult)?

Select one or more:

a. Blood pressure (BP)
b. Total peripheral resistance (TPR)
c. Heart rate (HR)
d. Coagulation
e. Cardiac output (CO)

Answer 21

Heart rate (HR),
Cardiac output (CO)

Question 22

Which of the following factors makes it more difficult for a neonate to concentrate urine?

Select one:

a. They have a low GFR

b. They have increased activity of the renin-angiotensin system

c. They have an increased ability to reabsorb bicarbonate

d. Shorter length of nephron tubules

Answer 22

d. Shorter length of nephron tubules

Question 23

Which of the following statements about the gastrointestinal (GI) system of the neonate is true?

Select one:

a. There is no lipase activity

b. Peristalsis of the GI tract is reduced

c. Digestive enzyme levels are similar to those in adults.

d. When they no longer produce meconium, the GI system is mature

Answer 23

b. Peristalsis of the GI tract is reduced.

Due to reduced development of smooth muscle, tone is reduced and so is smooth muscle movement in the neonate. However, in the neonate this compensates for other immaturities of the GI tract- how?

Question 24

The fontanelles of the skull should all be closed before the end of the neonatal period.

True or False?

Answer 24

False.

The first fontanelle to close- the posterior fontanelle- doesn’t close until around 1-2 months. The remaining fontanelles will close at a later date.

Question 25

Which of the following is occurring at a similar rate to adults shortly after birth?

Select one:

a. Protein synthesis
b. Glycogenolysis
c. Lipolysis
d. Gluconeogenesis

Answer 25

Lipolysis

Question 26

Respiration in the neonate is aided by an increase in alveolar surface tension as a result of surfactant production.
True or False?

Answer 26

False.

Surfactant production does aid respiration, but not by increasing alveolar surface tension.

Question 27

At birth adaptive immunity if fully functional and independent of the mother, while innate immunity in the neonate is still immature.
True or False?

Answer 27

False.

Both innate and adaptive immunity are immature in the neonate and the neonate receives much passive immunity from it’s mother via breastmilk to help boost adaptive and innate immunity.