Neonatal adaptation

Terminology :

Altricial - born weak, large litter size, high care needs, poor homeostatic control.

Precocial - long gestation, small litter size, immediate ambulation, lesser maternal care needs

• Describe what anatomical and physiological changes take place to adapt to life ex-utero with regard to the cardio-vascular system and respiration

The foramen ovale closes to increase lung circulation and pressure in left atrium. 

Ductus arteriosus closes by 24h old

umbilical vein collapses, arteries contract when cord ruptures. 

alveoli form post-partum in altricial species several days after birth 

surfactant present 

lung fluid removed / absorbed. 

• List four natural stimuli of respiration and how these may be utilised to resuscitate a neonate.

air on nares- can clear nostrils of mucus when born    

hypoxia / hypoxeamia 

respiritory acidosis  

colder temp 

tactile stimulus - phrenic nerve 

• Outline the capabilities & development (adaptations) of the immune system, gastro-intestinal tract, renal function, and nervous and muscular system

GI- gut glora takes weeks to form, kick started by milk

Liver changes from blood formation to metabolic animal

immune systerm - high neutrophils compared to adults, complement system ?? complement cascade, is a part of the humoral, innate immune system and enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen's cell membrane.

immunoglobulins - born with none, get from colostrum until own produced.  

Meconium - first feces within 24h. sterile, water, hair, bile, epithelial cells, fat, amniotic fluid 

lymphoid cells - present at birth, t cells and b lymphocytes. 

renal function - fullt formed by 2nd trimester, prenatal urine secreted by urachus

    postpartum- increased GFR, high renin and aldosterone, produces large volume of             hypotonic urine.  

neurological / musculoskeletal  - strong neuro-activatioon and reduction in inhibitors 

    spinal reflexes present in utero and after birth 

    skin sensitive 

sucking associated reflexes kick in quickly 

pupillary light reflex is present at birth, menace reflex is learned

• State a breed- or species-specific example of thermoregulation

foal have lots of endogenous glycogen to burn to generate heat 

• Apply your knowledge on the capabilities and adaptations of body systems to describe what a neonate requires to perform essential tasks (like suckling).

breathing, conscious muscle control, sight, reflexes, some thermoregultion.

• List 2 body features that may indicate prematurity

inscisors not erupted, tendon laxity, coat not fully formed, floppy ear pinna