The organ A which is located inside the skull of our body is protected by a bony shell B. It is surrounded by three layers membranes C. The spaces between these layers are filled with a liquid D which protects organ A from mechanical shocks. Organ A in combination with another organ E makes up the central nervous system.

(a) What is organ A?
(b) What are B, C and D?
(c) Name the organ E.
(d) While walking barefoot, if we happen to step on a sharp piece of stone, we immediately lift our foot up. Which of the two organs: A or E, is directly involved in this action?
(e) If we step out from a darkened room into bright sunlight, we close our eyes for a moment. Which of the two organs: A or E, is directly involved in this action?

Open in App

Solution

(a) The organ A is the brain. The brain is located inside the skull of our body at the top of the spinal cord.
(b) (i) B is the cranium. The brain is protected by a bony box in the skull called the cranium.
(ii) C are meninges. The brain is surrounded by three layers of membranes called the meninges.
(iii) D is the cerebrospinal fluid. It is present in between the meninges and protects the brain from mechanical shocks.
(c) The organ E is the spinal cord. The brain (organ A) and the spinal cord (organ E) together make central nervous system.
(d) A person walking barefoot lifts his foot at once on stepping on to a sharp piece of stone. The spinal cord (E) is involved in this action. Those reflexes that involve only the spinal cord are called spinal reflexes.
(e) A person closes his eyes at once when he steps out from a darkened room to bright light. The brain (A) is involved in this action. Those reflexes that involve only the brain are known as cerebral reflexes.

Suggest Corrections

Similar questions

Q. The organ A which is located inside the skull of our body is protected by a bony box B and it is surrounded by three membranes C. The space between the membranes is filled with a liquid D which protects the organ A from mechanical shocks. The organ A in combination with another organ E makes up the central nervous system.
(a) What is organ A?
(b) What are (i) B, (ii) C and (iii) D?
(c) Name the organ E.
(d) While walking barefoot, if we happen to step on a sharp piece of stone, we immediately lift our foot up. Which of the two organs: A or E, is directly involved in this action?
(e) If we step out from a darkened room into bright sunshine, we close our eyes for a moment. Which of the two organs, A or E, is directly involved in this action?

The organ A which is located inside the skull of our body is protected by a bony box B and it is surrounded by three membranes C. The space between the membranes is filled with a liquid D which protects the organ A from mechanical shocks. The organ A in combination with another organ E makes up the central nervous system.

(a) What is organ A ?

(b) What are (i) B (ii) C, and (iii) D ?

(d) While walking barefooted, if we happen to step on a sharp piece of stone, we immediately lift our foot up. Which of the two organs, A or E, is directly involved in this action ?

(e) If we step out from a darkened room into bright sunshine, we close our eyes for a moment. Which of the two organs, A or E, is directly involved in this action ?

Q. A cylindrical structure P in our body begins in continuation with medulla and extends downwards. It is enclosed in a bony cage Q and surrounded by membranes R. As many as x pairs of nerves arise from the structure P. The structure P is involved in the reflex actions of our body and conduction of nerve impulses to and from another organ S of our body with which it forms CNS.
(a) Name the structure P.
(b) Name (i) bony cage Q, and (ii) membranes R.
(c) How much is x?
(d) Name the organs S.
(e) What are the reflexes involving structure P only known as?

The organisms A, B and C can obtain their food in three different ways. Organism A derives its food from the body of another living organism which is called its D, without killing it. The organism B takes in the solid food by the process of ingestion, digests a part of this food and throws out undigested food in the process called E. The organism C obtains its food from dead and decaying plants.

(a) What is the mode of nutrition of (i) organism A (ii) organism B, and (iii) organism C?
(b) What is the organism like D called?
(c) Name the process E.
(d) Give one example each of organisms like (i) A (ii) B, and (ii) C.
(e) What is the general name of three modes of nutrition exhibited by organisms A, B and C?

Our internal organs are protected by which layer of skin ?

Join BYJU'S Learning Program