thetic system?
Stomach, intestines, salivary glands, reproductive organs, etc., are influenced by para sympathetic system.
What do you understand about the functions of parasympathetic nervous system?
Parasympathetic nervous system slows down the body functions such as feed & breed, rest & digest, sexual arose, lacrimation, urination, defecation and digestion.
What do you understand about the functions of sympathetic nervous system?
Sympathetic nervous system speeds up the body functions. Dilates pupil, heart – increases rate, force of contraction, lungs dilates, blood vessels contraction, etc. are the functions controlled by sympathetic nervous system.
10th Class Biology Textbook Page No. 107
Have you ever observed the duration of anger?
The duration of anger will be sometimes ten minutes or fifteen minutes or according to the situation.
Why does anger come down?
Anger is always short lived factor. Increased levels of adrenalin are responsible for anger. When the levels of adrenalin in the blood come down slowly. We came to normal state.
What may happen if anger persists for a longer period?
If anger persists for longer time, regular metabolic activities are disturbed.
What will happen if it is continued for longer periods of time?
The sugar levels in the blood rise than normal level. Blood pressure increases, burning sensation in the heart, stomach upsets are the some of the abnormal conditions may happen.
10th Class Biology 5th Lesson Coordination – The Linking System Activities
Activity – 1
Holding a falling stick.
Take a long scale or stick at least around V2 meter. Keep your fingers in holding position. Ask your friend to hold the stick / scale near the end and let the other end be suspended between your fingers.
Let there be a very small gap around a centimeter between your thumb and stick/scale and fore finger. Now let you friend allow it to fall. Try to hold it.
- Could you hold it exactly at the point where it was suspended between your fingers?
No. I cannot hold it exactly at the point.
- How far up was this point from the end suspended between your fingers?
2 cm up (nearly at the end of the scale).
- Why did this happen?
Because it is the sudden action. To hold it fastly. The exact point went up.
- How fast do you think the process was?
The process was so fast in a fraction of a second.
- What makes this kind of communication possible?
Rapidity of response indicates an efficient communication system linking those parts that pick up stimuli that trigger a response by the nervous system.
Activity – 2
Observe the permanent slide of nerve cell or neuron under microscope and try to find out its parts. Compare with the following diagram.
Structural unit of the nervous system is the nerve cell or neuron. Neuron is highly specialised cell. Neurons carry impulses or messages. New nerve cells are not produced to replace the damaged or destroyed nerve cell. A neuron has three parts. They are
- axon and
1. The cyton:
- It is also called the cell body.
- It has a large and round nucleus.
- In the cytoplasm of the cyton, nissl granules are present.
- It is the long and cylindrical process that arises from the cyton.
- In some nerve cells, axon is surrounded by a layer of fatty material known as myelin sheath.
- The myelin sheath is not continuous throughout length of the axon.
- It is broken at regular intervals.
- These broken spots are called as nodes of Ranvier.
3. Dendrites: Arise from the cyton they are much branched, when compared to axon.
Activity – 3
What is knee jerk reflex?
Cross the legs, in a seated position, so that the lower half of the uppermost leg hangs freely over the other. Strike the area below the knee cap sharply, while firmly grasping the front part of the thigh with the other hand. Note the changes in shape of the thigh muscles.
- What changes do you observe in the thigh muscle?
The thigh muscles get contracted and becomes short.
- What do we call this type of response?
This type of responses are called involuntary actions. Such type of actions in the body are carried by without our involvement and 