Neonatal adaptation Flashcards
Describe the properties that make a species altricial
Short gestation Large litter size Poor ambulation (movement) Poor homeostatsis Greater maternal care
Describe the properties that make a species precocial
Long gestation length Small litter size Immediate ambulation Rapid onset of homeostasis Lesser maternal care
What are the consequences if intrauterine growth retardation is mild? What about if it’s severe?
Mild = neonate maladjustment Severe = abortion
What is the function of the foramen oval, ductus arteriosus and ductus venosus?
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
What are characteristics of prematurity?
Absent suckling reflex
Patent foramen ovale and ductus arteriosus
Little body fat
Thin skin
How does the foramen ovale close?
Lung circulation increase pressure in left atrium
Causes septum primundum to be pushed against septum secondum
What causes the ductus arteriosus to close?
Sensing oxygenated blood
What happens to neonatal circulation after birth?
Umbilical veins collapse
Umbilical arteries and urachus retract into abdomen
Formane ovale closes
Ductus arteriosus and venosus close
Do alveoli develop mainly pre or post partum in precocial and altricial species?
Mainly prepartum (precocial) Mainly postpartum (altricial)
When do type II alveolar cells start producing surfactant?
Late gesttaion
What happens to lung fluid after parturition?
Most physically removed
Some absorbed
What physiologically stimulates breathing in a neonate?
Hypoxia
Hypercapnia
Respiratory acidosis - sensed by medulla oblongata
What physically stimulates breathing in a neonate?
Low temperature
Tactile stimuli
Gravity
Air on nares
Why do neonates have a pliable ribcage?
Active inspiration and active expiration
How do the lungs physically expand?
Gasping against closed glottis
Neonates have shivering and non-shivering thermogenesis. How do mammals manage non-shivering thermogenesis?
Brown fat
How are foals adapted for non-shivering thermogenesis
Endogenous glycogen
Thoroughbred foals have a higher metabolic rate than other breeds. Does this make them more or less tolerant to cold?
More
How long does gut flora are to form?
Several weeks
How do the functions of the liver change after birth?
Pre birth = blood forming organ
After birth = metabolic organ
How does the number of WBCs compare in neonates to adults?
Neonates have more neutrophils
Have 1/3 of B lymphocytes
Are non-immune effector cells fully active at birth? What about CMI? What about complement?
Non-immune effector = yes
CMI = yes
Complement = not fully active yet
When do neonates acquire their own Igs? How do they have them before?
Few days old
Epithelia chorial placenta
How are neonates immune systems able to respond to pathogens at birth?
Able to respond to soluble protein antigens
Not viruses/bacteria/protozoa until few weeks old (not full response)
At what point of gestation do the kidneys become functional? How do they excrete waste?
Half way through gestation
Excrete urine via urachus
What changes happen in the urinary system after birth? What does this result in?
Increased GFR
Increased renin
Increased aldosterone
Large volume of hypotonic urine
When do neonates gain consciousness?
After birth
What parts of the neurological system are present at birth?
Pupillary light reflex
Suckling reflex
What parts of the neurological system develop early on after birth?
Other reflexes - righting reflex, withdrawal reflex Skin sensation (+/- hyperaesthesia)
When do foetal movements begin?
Mid gestation
Describe the stance and gait of neonates
Wide stance
Exaggerate gait
Which species has neonates with well ossified skeletal systems?
Horse
Describe the tendons and ligaments in a neonate
Laxity
Loose
