Question

Atlas of ox have
(A) Foramen Alare
(B) Foramen transversarium
(C) Intervertebral foramen
(D) Vertebral foramen
Choose the correct answer from the options given below:

• A. (A), (C) and (D) only.
• B. (A), (B) and (D) only.
• C. (A), (B), (C) and (D).
• D. (B), (C) and (D) only.

Hint:

To differentiate species based on the Atlas wing:
- Ox: Lacks transverse foramen (has alar and lateral vertebral foramina).
- Horse: Has both alar and transverse foramina.
- Dog: Has alar notch instead of alar foramen, plus a transverse foramen.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
The atlas is the first cervical vertebra (C1). It is ring-shaped and exhibits distinct anatomical variations among different domestic species, particularly regarding its foramina.

Step 2: Detailed Explanation:
Let us evaluate each of the foramina listed with respect to the atlas of the ox (Bos indicus):
- (A) Foramen Alare (Alar foramen):
The atlas of the ox features a well-developed alar foramen located on the wing (ala) of the atlas, which transmits the occipital artery and the internal branch of the first cervical nerve.
Therefore, (A) is present.
- (B) Foramen transversarium (Transverse foramen):
This is a critical comparative feature: the atlas of the ox completely lacks the foramen transversarium on its wing.
This foramen is present in the atlas of the horse, dog, and pig, but absent in the ox and sheep.
Therefore, (B) is absent.
- (C) Intervertebral foramen (Lateral vertebral foramen):
The atlas of the ox contains a prominent lateral vertebral (intervertebral) foramen on the cranial part of the neural arch, transmitting the first cervical spinal nerve and vertebral vessels.
Therefore, (C) is present.
- (D) Vertebral foramen:
The large central canal formed by the dorsal and ventral arches of the atlas, housing and protecting the spinal cord.
Therefore, (D) is present.
Thus, the atlas of the ox possesses (A) Foramen Alare, (C) Intervertebral foramen, and (D) Vertebral foramen, while lacking (B) Foramen transversarium.

Step 3: Final Answer:
The correct option is (A), representing (A), (C), and (D) only.