Advertisements
Advertisements
Question
The diagram given below shows the internal structure of the spinal cord, depicting a simple reflex. Study the same and then answer the questions that follow:
(i) Name the parts numbered 1 to 5.
(ii) Using the letters of the alphabet shown in the figure indicate the direction in which an impulse enters and leaves the spinal cord.
(iii) What is the term given to the point of contact between two nerve cells?
(iv) What is meant by ‘simple reflex’ ? Give two examples of simple reflexes and name the stimuli too.
(v) How does the arrangement of nerve cells in the spinal cord differ from that in the brain?
Advertisements
Solution
(i)
1. Sensory or Afferent fiber.
2. The cell body of the sensory neurons.
3. White matter.
4. The cell body of the motor neurons.
5. Spinal nerve.
(ii) BCA
(iii) Synapse.
(iv) Simple reflex: It is an involuntary automatic, quick response to a stimulus.
Examples:
(a) The closing of the eyelids when a strong beam of light is flashed.
(b) The withdrawal of the hand when it is pricked.
(v) In spinal cord white matter is outside and gray matter is inside. In brain white matter is inside and gray matter is outside.
APPEARS IN
RELATED QUESTIONS
Name the following:
Inability to speak.
Give one point of difference between the following on the basis of what is indicated:
Cerebrum and spinal cord. (Arrangement of neurons)
Fill in the blank with the function in the following:
Meninges: ______
The diagram given below represents the spinal cord of a mammal, seen in a transverse section together with the nerves. Study the diagram and then answer the questions given below:
(i) Label the parts 1—8 indicated by guidelines.
(ii) What do the arrows indicate? What is the pathway indicated termed?
(iii) What type of nerve is shown in the diagram?
Identify the odd item from the following series of words.
Sketch and label T. S. of Spinal cord.
There are ______ pairs of cranial nerves and ______ pairs of spinal nerves.
Describe the structure of the spinal cord.
In humans, the number of spinal nerves are ______.
Given below is the transverse section of the spinal cord. Read the information below the diagram and fill in the blanks:
The spinal cord extends from the medulla oblongata of the brain and runs down through the whole length of the vertebral column. The spinal cord is covered by the meninges. It conducts impulses from the skin and muscles to the brain. It also conducts impulses from the brain to the muscles of the trunk and limbs.
The spinal cord is a part of the (a) ______ Nervous System. The grey matter in the picture given above consists of (b) ______ while the white matter consists of (c) ______. The spinal cord is concerned with the (d) ______ actions below the neck. (e) ______ is the bony structure that protects the spinal cord.
