Question

The opening at the base of the skull for the spinal cord is called:
A. Foramen magnum
B. Foramen of Monro
C. Obturator foramen
D. Foramen of Magendie

Answer 1

Hint: It is present in the occipital bone. It is the largest foramen in the cranium.
It is a part of the occipital bone of the skull/ cranium in humans and other mammals

Complete answer:
The foramen magnum is a large ovoid opening/ foramen.
It is one of the several openings/ foramina in the base of the skull (jugular foramen, foramen ovale, foramen spinosum, etc.) The spinal cord which is an extension of the medulla oblongata of the brain stem passes through the foramen magnum as it exits the posterior cranial cavity.
The layer of meninges also passes through it.
The foramen magnum also transmits the vertebral arteries, the anterior and posterior spinal arteries, the tectorial membranes (modifications of the dura mater), and alar ligaments.
It also transmits the spinal accessory nerve (11th cranial nerve) into the skull.

So, the correct answer is “Option A”.

Note: Obturator foramen is the large opening formed in the pelvis by the ilial and the ischial bones. It is present inside the obturator fossa. It transmits the obturator artery, obturator vein, and the obturator nerve is enclosed in the obturator canal and passes through the obturator foramen.
The foramen of Monro is a short connection between the paired lateral ventricles of the ventricular system of the brain and the third unpaired ventricle of the brain.
They are two in number. The foramen of Magendie (median aperture) is one of the foramina in the ventricular system of the brain. It links the fourth ventricle and the cisterna magna. It is one of the three sites in the central nervous system that cerebrospinal fluid (CSF) can leave the fourth ventricle and enter the subarachnoid space (space between the arachnoid mater and the pia mater) in the meninges.