Neonatal adaptation

Question 1

Describe the properties that make a species altricial

Answer 1

Short gestation
Large litter size
Poor ambulation (movement)
Poor homeostatsis
Greater maternal care

Question 2

Describe the properties that make a species precocial

Answer 2

Long gestation length
Small litter size
Immediate ambulation 
Rapid onset of homeostasis
Lesser maternal care

Question 3

What are the consequences if intrauterine growth retardation is mild? What about if it’s severe?

Answer 3

Mild = neonate maladjustment
Severe = abortion

Question 4

What is the function of the foramen oval, ductus arteriosus and ductus venosus?

Answer 4

Foramen ovale - allow blood to pass from R-L atria
Ductus arteriosus - connects pulmonary artery to aorta (bypass lungs)
Ductus venosus - connect L umbilical vein to vena cava - bypass liver

Question 5

What are characteristics of prematurity?

Answer 5

Absent suckling reflex
Patent foramen ovale and ductus arteriosus
Little body fat
Thin skin

Question 6

How does the foramen ovale close?

Answer 6

Lung circulation increase pressure in left atrium

Causes septum primundum to be pushed against septum secondum

Question 7

What causes the ductus arteriosus to close?

Answer 7

Sensing oxygenated blood

Question 8

What happens to neonatal circulation after birth?

Answer 8

Umbilical veins collapse
Umbilical arteries and urachus retract into abdomen
Formane ovale closes
Ductus arteriosus and venosus close

Question 9

Do alveoli develop mainly pre or post partum in precocial and altricial species?

Answer 9

Mainly prepartum (precocial)
Mainly postpartum (altricial)

Question 10

When do type II alveolar cells start producing surfactant?

Answer 10

Late gesttaion

Question 11

What happens to lung fluid after parturition?

Answer 11

Most physically removed

Some absorbed

Question 12

What physiologically stimulates breathing in a neonate?

Answer 12

Hypoxia
Hypercapnia
Respiratory acidosis - sensed by medulla oblongata

Question 13

What physically stimulates breathing in a neonate?

Answer 13

Low temperature
Tactile stimuli
Gravity
Air on nares

Question 14

Why do neonates have a pliable ribcage?

Answer 14

Active inspiration and active expiration

Question 15

How do the lungs physically expand?

Answer 15

Gasping against closed glottis

Question 16

Neonates have shivering and non-shivering thermogenesis. How do mammals manage non-shivering thermogenesis?

Answer 16

Brown fat

Question 17

How are foals adapted for non-shivering thermogenesis

Answer 17

Endogenous glycogen

Question 18

Thoroughbred foals have a higher metabolic rate than other breeds. Does this make them more or less tolerant to cold?

Answer 18

More

Question 19

How long does gut flora are to form?

Answer 19

Several weeks

Question 20

How do the functions of the liver change after birth?

Answer 20

Pre birth = blood forming organ

After birth = metabolic organ

Question 21

How does the number of WBCs compare in neonates to adults?

Answer 21

Neonates have more neutrophils

Have 1/3 of B lymphocytes

Question 22

Are non-immune effector cells fully active at birth? What about CMI? What about complement?

Answer 22

Non-immune effector = yes
CMI = yes
Complement = not fully active yet

Question 23

When do neonates acquire their own Igs? How do they have them before?

Answer 23

Few days old

Epithelia chorial placenta

Question 24

How are neonates immune systems able to respond to pathogens at birth?

Answer 24

Able to respond to soluble protein antigens

Not viruses/bacteria/protozoa until few weeks old (not full response)

Question 25

At what point of gestation do the kidneys become functional? How do they excrete waste?

Answer 25

Half way through gestation

Excrete urine via urachus

Question 26

What changes happen in the urinary system after birth? What does this result in?

Answer 26

Increased GFR
Increased renin
Increased aldosterone
Large volume of hypotonic urine

Question 27

When do neonates gain consciousness?

Answer 27

After birth

Question 28

What parts of the neurological system are present at birth?

Answer 28

Pupillary light reflex

Suckling reflex

Question 29

What parts of the neurological system develop early on after birth?

Answer 29

Other reflexes - righting reflex, withdrawal reflex
Skin sensation (+/- hyperaesthesia)

Question 30

When do foetal movements begin?

Answer 30

Mid gestation

Question 31

Describe the stance and gait of neonates

Answer 31

Wide stance

Exaggerate gait

Question 32

Which species has neonates with well ossified skeletal systems?

Answer 32

Horse

Question 33

Describe the tendons and ligaments in a neonate

Answer 33

Laxity

Loose