ICAR AIEEA PG 2024 - Veterinary Science

In pigs (swine), the yolk sac is transient; it reaches maximal functional development during early embryonic stages and undergoes rapid involution/regression between 3 and 4 weeks (day 20–25) of gestation as the allantois expands and vascularizes the chorion.

In the mare, the placenta is diffuse (microcotyledonary distribution of microvilli over the entire chorionic surface), villous (composed of microscopic chorionic villi tufts), epitheliochorial (all 6 maternal and fetal tissue layers are intact), and non-deciduate (no loss of maternal tissue at parturition). Thus, all four (A, B, C, D) are correct.

In the boar, the bulbourethral (Cowper's) glands are exceptionally large, cylindrical, compound tubular glands extending along the pelvic urethra that produce a large volume of viscous, gelatinous secretion forming the pre-sperm and post-sperm plug. In bulls and stallions they are compound tubuloalveolar, and they are present (not absent) in cats.

Clinical nerve blocks match as follows:
Pudendal nerve block -> desensitizes the penis, prepuce, and retractor penis muscle for catheterization or surgery (I)
Paravertebral lumbar block (T13, L1, L2) -> anesthetizes the paralumbar fossa for laparotomy / rumenotomy (II)
Auriculopalpebral nerve block -> motor block of orbicularis oculi muscle to immobilize the eyelids for eye examination (III)
Tibial nerve block -> provides regional anesthesia to the distal hindlimb, leg, and pes (IV).

Light entering the eye passes consecutively through the transparent refractive media: Cornea (A) -> Anterior chamber containing Aqueous humor (D) -> Lens through the pupil (B) -> Vitreous body / chamber (C) before focusing upon the photosensitive layers of the retina. Thus, the sequence is (A), (D), (B), (C).