Question

Which of the following is a richly vascular layer with lots of blood capillaries?
a) Dura mater
b) Pia mater
c) Epidermis of skin
d) Both A and B

Answer 1

Hint: Human body consists of many layers that securely envelopes all blood, flesh and bone as a single unit. However, the vascular layer is one that consists of many blood vessels. Therefore, this layer envelopes all the arteries and veins of the body.

Complete answer
Let's study each of these layers to find whether they are vascular or not.
Dura mater: It is the top most layer of meninges (3 layered covering of brain). It is present beneath the skull bone as an envelope carrying the brain and spinal cord. It is made up of dense irregular connective tissues that are void of blood vessels this being an avascular layer. Its outer cells keep specialising to form the internal layer of skull bone. Thus, it is clearly an incorrect option.
Pia mater is the third layer of meninges present exactly above the brain muscles. This layer is enriched with heavy blood supply through arteries and veins in order to perform various actions in the brain. This layer plays a crucial role in proper functioning of the brain by managing effective blood flow. Since, it is a richly vascular layer with lots of blood capillaries thus is the correct answer.
Epidermis of skin in the outermost layer of the body. It works as an envelope that holds all the blood, flesh and bones of the body. Its main purpose is to protect internal organs, tissues and blood vessels. It needs to be quite tough to withstand environmental wear and tear effects. Thus, it is void of any blood cells which makes it an avascular layer. Therefore, C is an incorrect option.

Note:
The middle layer of meninges that is arachnoid, is filled with some cerebrospinal fluid that acts as a cushion for the other two layers of the brain. It is made up of fibrous tissues that also keeps the Dura mater and pia mater connected.