Biology - Study Mode

[#661] The outer membrane that covers the brain is
Correct Answer

(B) Dura mater

Explanation

Solution: Three layers of membranes known as meninges protect the brain and spinal cord. The delicate inner layer is the pia mater. The middle layer is the arachnoid, a web-like structure filled with fluid that cushions the brain. The tough outer layer is called the dura mater.

[#662] The innermost membrane that covers the brain is
Correct Answer

(C) Pia mater

Explanation

Solution: The pia mater is the innermost layer of meninges. This thin, delicate membrane is tightly bound to the surface of the brain and spinal cord and cannot be dissected away without damaging the surface. Meningiomas are tumors of the nerve tissue covering the brain and spinal cord.

[#663] Which systems comprise the nervous system?
Correct Answer

(C) Both A & B

Explanation

Solution: The nervous system has two main parts: The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

[#664] At the time of inspiration the diaphragm
Correct Answer

(B) Contract

Explanation

Solution: When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.

[#665] Rate of breathing in a minute by man is
Correct Answer

(A) 16-18

Explanation

Solution: A normal breathing rate for an adult at rest is 8 to 16 breaths per minute.