Q1. A recent paper described a left cranial vena cava in a 25-year-old Arabian mare that was being dissected by veterinary students in a gross anatomy laboratory. Where would you expect this vessel to enter the heart?

a. through the left atrium

b. at the normal site of the right cranial vena cava

c. ventral to the opening of the caudal vena cava

d. with the right azygos vein

e. through the tip of the right auricle

ANSWER

Q2. Surgical examination of a bilaterally cryptorchid Miniature Schnauzer with an otherwise normal mate phenotype and a karyogram of 100% 7BXY lymphocytes (normal.. 76 autosomes) reveals a completely developed uterus, with uterine tubes adjacent to the epididymis and ductus deferens. What would explain this duct system?

a. insufficient testosterone

b. interstitial-cell hypertrophy

c. inadequate paramesonephric duct-inhibiting substance

d. unrecognized gonadal 78XX cells

e. lack of 5-alpha reductase receptors

ANSWER

Q3. The nucleus pulposus of intervertebral disks is a remnant of the embryonic..
a. sclerotomes

b. notochord

c. primitive node

d. primitive streak

e. perichordal mesenchyme

ANSWER

Q4. If the inherited abnormality that results from breedings to produce the "new look' Eastern type of Burmese cat is due to a disturbance in the prosencephalon and/or its associated neural crest, which change would not be expected?
a. meningoencephalocele

b. brachygnathia

c. microphthalmos

d. atlantooccipital malformation

e. duplicated maxillary processes

ANSWER

Q5. A 3-year-old female Morgan horse with increased respiratory effort during stress or exercise was small at birth and grew poorly. The horse is in poor physical condition, and has increased heart and respiratory rates. Auscultation reveals a prominent systolic murmur over the left cranioventral thorax, with a palpable thrill at that site. Mild exercise provokes respiratory distress and cyanosis of the oral mucosa. Which primary lesion would be the most likely cause of these signs?
a. valvular pulmonic stenosis

b. tetralogy of Fallot

c. left atrioventricular valve dysplasia

d. left to right shunting patent ductus arteriosus

e. subvalvular aortic stenosis

ANSWER

Q 6. Which of the following would not be expected to be related to the inherited abnormalities that result from the breeding that produces Manx cats?
a. acaudatus

b. failure of urorectal septal development

c. meningomyelocele

d. spina bifida

e. omphalocele

ANSWER

Q7. Which embryonic structure is not involved in the condition of anodontia?
a. pharyngeal arch 1

b. labiogingival lamina

c. neural crest

d. enamel organ

e. pharyngeal pouch 1

ANSWER

Q8. Which structures are found in the fetal median ligament of the bladder?
a. urachus and umbilical veins

b. yolk sac and vitelline vessels

c. yolk sac and umbilical veins

d. urachus and umbilical arteries

e. urachus and vitelline vessels

ANSWER

Q9. What is the fate of the visceral layer of the vaginal process that surrounds

the extraabdominal gubernaculum proper in males before descent of the testis?
a. it becomes the visceral layer of peritoneum on the testis

b. it is incorporated in the ligament of the tail of the epididymis

c. it becomes the mesoductus deferens

d. it is incorporated in the proper ligament of the testis

e. it becomes the mesorchium

ANSWER

Q10. Mesodiverticula, umbilical fistulas and ileal diverticula represent..
a. abnormal development of the allantoic and vitelline vessels

b. abnormal development of the allantoic and umbilical arteries

c. abnormal development of the yolk sac and umbilical veins

d. abnormal development of the yolk sac and vitelline vessels

e. abnormal rotation of the embryonic intestinal loop

ANSWER

Q11. In female embryos, the urogenital sinus contributes to all of the following except the..
a. cervix

b. vagina

c. urethra

d. bladder

e. vestibule

ANSWER

Q12. A cranial cervical swelling could be caused by any of the following except..

a. craniopharyngioma

b. salivary mucocele

c. abscess

d. pharyngeal (bronchial) cyst

e. thyroid cyst

ANSWER

Q13. Improper development of the nasolacrimal duct relates to faulty development of the.
a. medial and lateral palatine processes

b. nasolateral and nasomedial p

c. choanae

d. maxillary process and nasolateral process

e. lens placode and optic cup

ANSWER

Q14. The left recurrent laryngeal nerve is found caudal to the ligamentum arteriosum on the left, but the right recurrent laryngeal nerve is found caudal to the right subclavian artery because of.
a. loss of connection of the right 6th aortic arch to the dorsal aortic root

b. loss of the dorsal aortic root between the right 3rd and 4th aortic arches

c. the origin of the aorta from the left 4th aortic arch

d. loss of the right distal (caudal) dorsal aortic root at its attachment to the single descending dorsal aorta

e. migration of the left 7th dorsal cervical intersegmental artery cranially on the left dorsal aortic root

ANSWER

Q15. Based on developmental relationships, which of the following is most likely to be found in the spermatic cord near the testis in the scrotum of a stallion?
a. prostate gland

b. adrenal cortex

c. bulbourethral gland

d. pancreatic exocrine tissue

e. gallbladder mucosal epithelium

ANSWER

Q16. The muscles of the tongue are derived from the.
a. neural crest

b. most rostral somitomeres

c. occipital myotomes

d. lot pharyngeal arch mesoderm

e. mesoderm of the first 3 pharyngeal arches

ANSWER

Q17. At birth of a foal, 2 membranes are associated with the umbilical cord.

The one attached to the cord near the foal and that formerly covered the fetus

in the uterus is composed of.
a. amnion internally (next to the fetus) and yolk sac externally

b. amnion internally and chorion externally

c. allantois internally and chorion externally

d. allantois internally and amnion externally

e. amnion internally and allantois externally

ANSWER

Q18. Phocomelia is:
a. synonymous with micromelia

b. an abnormality of the spinal cord

c. a depression in the sternum

d. absence of part of a limb

e. a multiple fusion of digits

ANSWER

Q19. The embryonic ventral hepatic diverticulum gives rise to the..
a. left lobe of the pancreas

b. cystic duct

c. liver sinusoids

d. minor duodenal papilla

e. spleen

ANSWER

Q20. Throughout fetal development, oxygen saturation is higher in the left ventricle than in the right ventricle because the..
a. ductus arteriosus carries oxygenated blood to the aorta

b. pulmonary veins return oxygenated blood to the left atrium

c. right ventricular blood mixes with left ventricular blood via the interventricular foramen

d. caudal vena caval blood enters the left atrium via the foramen ovale

e. cranial vena caval blood enters the left atrium

ANSWER

Q21. At 9 months of age, a dog begins to have episodes of collapse in the pelvic limbs, with occasional cyanosis and syncope following severe exercise. There is no obvious cardiac murmur. The most likely cause of these signs is:
a. tetralogy of Fallot

b. pulmonic stenosis

c. patent ductus arteriosus, with reverse flow

d. persistent right 4th aortic arch

e. persistent foramen secundum

ANSWER

Q22. Peritoneopericardial communication has its genesis in:
a. failed closure of the embryonic peritoneopericardial orifice

b. failed development of pleuroperitoneal membranes

c. failed development of pleuropericardial membranes

d. improper development of the liver and septum transversum

e. retarded growth of the lungs into the lateral body wall

ANSWER

Q23. Concerning salivary mucoceles and pharyngeal (bronchial) cysts, which statement is least accurate?
a. Both can be located in the cranial neck region.

b. Salivary mucoceles lack an epithelial lining.

c. Pharyngeal cysts contain fluid with the consistency of saliva.

d. Both ref'ill if the fluid is drained off.

e. Sialography shows radiopaque dye in a pharyngeal cyst.

ANSWER

Q24. Hepatic encephalopathy has been reported in dogs with various malformations of the portal vein, caudal vena cava and azygos vein. Which of the following would not be implicated in these malformations?
a. vitelline vein

b. subcardinal vein

c. cranial cardinal vein

d. supracardinal vein

e. umbilical vein

ANSWER

Q25. In development of the interatrial septum, the septum secundum forms:
a. the foramen ovale, directed at the cranial vena cava

b. a valve-like structure to the left of the septum primum

c. craniocaudally on the right side of the septum primum

d. simultaneously with the atrioventricular endocardial cushions and closure of the atrioventricular canal

e. a foramen secundum in its dorsal wall

ANSWER