Tag: nervous system in animals

Questions Related to nervous system in animals

In thinking and response to external stimulus the brain take time about

  1. Less than 1/10th sec

  2. 1/10th sec

  3. More than 1/10th sec

  4. About 1 sec


Correct Option: B
Explanation:

The human nervous system is highly developed. The external stimulus leads to generation of impulse. This impulse is conducted through sensory neurons and the response is given by the effector organ on receiving the answer given by the brain. The time taken by the brain and the nervous system to give the response is considered as in fraction of a second. So, the correct answer is option B.

You are watching a horror movie and you notice your heart is beating fast and mouth is dry; it is because

  1. Fight and flight response

  2. Autonomic nervous system

  3. Sympathetic nervous system

  4. Both A and C

  5. Release of acetylcholine


Correct Option: D
Explanation:
You are watching a horror movie and you notice your heart is beating fast and mouth is dry; it is because of fight and flight response and sympathetic nervous system.
Fight and flight response is acute stress response.
The fight-or-flight response occurs in response to a perceived harmful event, attack, or threat to survival. The sympathetic nervous system originates in the spinal cord and its main function is to activate the physiological changes that occur during the fight-or-flight response. This component of the autonomic nervous system utilizes and activates the release of norepinephrine in the reaction.
The physiological changes that occur during the fight or flight response are activated in order to give the body increased strength and speed in anticipation of fighting or running. Some of the specific physiological changes and their functions include:
Increased blood flow to the muscles activated by diverting blood flow from other parts of the body.
Increased blood pressure, heart rate, blood sugars, and fats in order to supply the body with extra energy.
The blood clotting function of the body speeds up in order to prevent excessive blood loss in the event of an injury sustained during the response.
Increased muscle tension in order to provide the body with extra speed and strength.

Sight of delicious food usually makes mouth watery, it is a 

  1. Hormonal response

  2. Neural response

  3. Optic response

  4. Olfactory response


Correct Option: B
Explanation:

The response to food begins even before food enters the mouth. The first phase of ingestion, called as the cephalic phase, is controlled by the neural response to the stimulus provided by food. All aspects, such as sight, sense, and smell, trigger the neural responses resulting in salivation and secretion of gastric juices. The gastric and salivary secretion in the cephalic phase can also take place at the thought of food. The central nervous system prepares the stomach to receive food. 

Who discovered synapse?

  1. R. Y. Cahal

  2. Sherrington

  3. Otto Loewi

  4. None of the above


Correct Option: B
Explanation:

The term synapse was first discovered in 1897 by neurophysiologist Charles Sherrington. The gap between two neurons across which impulses are conducted is known as a synapse. Synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell. It is important for neuronal function. 
Thus, the correct answer is option B.

Destruction of the anterior horn cells of the spinal cord would result in loss of

  1. Sensory impulses

  2. Voluntary motor impulses

  3. Commissural impulses

  4. Integrating impulses.


Correct Option: B
Explanation:

Anterior horn cells are the ventral (front) grey matter section of the spinal cord which contains motor neurons that affect the skeletal muscles. It is also known as anterior grey column, ventral horn. The anterior grey column is the column where the cell bodies of alpha motor neurons are located. The destruction of the anterior horn cells of the spinal cord would result in loss of voluntary motor impulses because it is mainly related to motor impulses.

So, the correct answer is option B.