Anatomy and Physiology

Question 1

Eyes

Answer 1

(1) Visual acuity develops from birth throughout early childhood

(2) Sclera may be slightly bluish tinged but becomes white within weeks

(3) The eyeball of the infant and young child occupies a relatively larger space within the orbit than the adult does, making it more susceptible to injury

(4) Optic nerve is not fully myelinated until age 3 months and the spherical shape of the newborn’s lens negatively affects distance

(5) Visual acuity improves over the first few years of the child’s life, with 20/20 vision achieved by 5 years old

(6) The rectus muscles are uncoordinated at birth and mature over time so that binocular vision is achieved between 3-7 months

(7) In the preterm infant, retinal vascularization is incomplete, so visual acuity may be affected

Question 2

Ears

Answer 2

(1) Short, wide and horizontally placed Eustachian tubes allow bacteria and viruses to gain access to the middle ear easily, resulting in increased numbers of ear infection

(2) As the child matures, the tubes assume a more slanted position

(3) Enlargement of the adenoids contributes to obstruction of the Eustachian tubes, leading to infection