- Living organisms respond and react to various stimuli like heat, light, cold, touch, pressure etc. Plants and animals both respond to stimuli but in different manner.
- Example: withdrawal of hand on touching a hot object.
Control and Coordination in Animals
It is brought about in all animals with the help of two main
a) Nervous System b) Endocrine System
Nervous System:
Functions
- To receive the information from environment
- To receive the information from various body parts. (Stimuli Response)
- To act accordingly through muscles and glands.
Stimulus: Any change in environment or within that bring about reaction e.g. touching a hot plate.
Response: The reaction of our body to these changes. e.g. withdrawal of our hand
Read Other Class 10 Notes here
How do we detect that we are touching a bot object?
Receptors: Are specialized tips of some nerve cells that detect the information from the environment.
Synapse: The point of contact between the terminal braches of axon of one neuron with the dendrite of another neuron is called synapse.
Reflex Action: A quick, sudden, immediate response of the body to the certain stimuli that involves Spinal cord . e.g. (not brain) withdrawal of hand , Knee jerk etc.
Reflex are: The pathway through which impulses pass is called reflex arc.
Response
Response are of three main types
Voluntary: Controlled by fore brain e.g. Talking, Writing
Involuntary: Controlled by mid and hind brain e.g. Heartbeat, vomiting, regulation of heartbeat
Reflex action: Controlled by spinal cord e.g. Withdrawal of hand on touching a hot object.
Human Brain
Human brain has three major parts of regions
- Fore Brain
- Mid Brain
- Hind Brain
Fore Brain
Most complex / specialized part of the brain is CEREBRUM
FUNCTIONS:
- Thinking part of the brain
- Control the voluntary actions.
- Store information (Memory)
- Centre associated with HUNGER
- Receives sensory impulses from various body parts and integrates it
PROTECTION OF BRAIN AND SPINAL CORD
BRAIN: Brain is protected by a fluid filled balloon which acts as shock absorber and enclosed in cranium
Spinal Cord: Spinal Cord is enclosed in vertebral column.
Coordination between Nervous and Muscular Tissue
Plant hormones : These are chemical compounds which help to coordinate growth, development and response to the environment.
Plant hormones: Main plant hormones are:
- Auxin: [Synthesized at shoot tip]
Function: Helps in growth
Phototropism: more growth of cells towards light.
- Gibberellin: Helps in the growth of the stem
- Cytokinin: Promotes cell division
d) Abscisic acid: Inhibits growth, cause witting of leaves. (Stress hormone)
Hormones in Animals
Hormones: These are the chemical messengers secreted in very small amounts by specialized tissues called ductless glands. They act on target tissues/organs usually away from their source.
Endocrine System helps in control and coordination through chemical compounds called HORMONES
IODISED SALT IS NECESSARY BECAUSE :
- Iodine mineral is essential part of thyroxine hormone so it is important that we must consume iodized salt as in turn it is essential for thyroid gland as it controls carbohydrate, proteins and fat metabolism for best balance of growth deficiency of iodine might cause disease called goitre
Diabetes:
- Cause: It is due to deficiency of Insulin hormone secreted by Pancreas that is responsible to lower/control the blood sugar levels.
Treatment: Patients have to internally administer injections of insulin hormone which helps in regulating blood-sugar level.
Feedback Mechanism
- makes sure that hormones should be secreted in precise quantities and at right time, which is regulated by feedback mechanism.
