Control and Coordination Notes for Class 10
Control and Coordination
Control and coordination is the working together of various organs of a living organism in a systematic, controlled and efficient way tp produce proper response to various stimuli.
Coordination in Humans
Coordination in humans is facilitated by the nervous system and hormones secreted by endocrine glands.
Nervous system regulates voluntary and involuntary movements, collects and processes outside information, helps in reasoning, thinking, etc., and controls the reflex action occurring in our body.
Neurons are the structural and functional units of nervous system. They are the longest cell of the body. They use electrical and chemical signals for transferring information.
Synapse is a small gap between neurons where nerve impulse passes from neuron to the next.
Receptors are the specialised tips of the nerve fibres that collect the information to be conducted by the nerves.
Reflex action is an automatic, rapid and immediate reaction to a stimuli which is controlled through the spinal cord via relay neuron.
Reflex arc is the neural pathway that mediates a reflex action.
Central Nervous System ( CNS )
Central nervous system consists of the brain and the spinal cord. Central nervous system receives information from all the parts of the body and integrate it.
*The Human Brain
The human brain is the main coordinating centre of the body which enables an organism to think and take decisions. Forebrain, midbrain and hindbrain are the three parts of the brain.
**Forebrain – Forebrain is the most developed and largest as well as main thinking part of the brain. Forebrain receives sensory impulses from various receptors. Forebrain comprises of :-
***(i) Cerebrum – Cerebrum acts as the main thinking part of the brain. Cerebrum is responsible for reasoning, speech, intelligence sight, hearing and usage of information.
***(ii) Olfactory Lobes – Olfactory lobes are a pair of very small, solid, club-shaped bodies widely separated from each other. Olfactory lobes are responsible for detecting smell from different receptors.
***(iii) Hypothalamus – Hypothalamus is the part of forebrain in the human brain which controls the body tempreture, urge of eating, drinking, etc.
**Midbrain – Midbrain connects forebrain to the hindbrain. Midbrain controls the movement of head, neck, and trunk to locate sounds and visual reflexes that are involved in focussing on the objects. Midbrain also controls reflex movements of the eye muscles, size of the pupil, etc.
**Hindbrain – Hindbrain provides conection between spinal cord and the rest of the brain. Hindbrain consists of the three parts that are as follows :-
***(i) Cerebellum – Cerebellum controls and coordinates different muscular actions. Cerebellum is responsible for precision of voluntary actions. Cerebellum maintains posture and equilibrium of the body during the various types of human activitires i.e. walking, drinking, runnning, catching, riding, etc.
***Pons – Pons lies above the medulla and responsible for respiration. Pons relays impulses between different parts of the human brain.
***Medulla Oblongata – Medulla oblongata is found continuously with the spinal cord. Medulla oblongata controls the involuntary actions i.e. breathing, blood pressure ( BP ), etc, and also regulates reflex responses i.e. salivation and vomiting.
**Functions of the Human Brain
The major functions of the human brain are as follows :- (i) The human brain cordinates activities of the body so that mechanism and hormonal reactions of the body work together. (ii) The human brain receives information carrying nerve impulses from all the sensory organs of the body. (iii) The human brain correlates the various stimulus from different sense organs and produces appropriate response. (iv) The human brain responds to the impulses brought in by sensory organs by sending its own instructions to the muscles and glands causing them to function accordingly. (v) The human brain stores information, so that the behaviour of human being can be modified according to the past experiences.
Spinal cord is a long, tubular bundle of nervous tissue arising from medulla oblongata. Spinal cord functions primarily in the transmission of neural signals between brain and the rest of the body.
Peripheral Nervous System ( PNS )
Peripheral nervous system consists of the nerves that directly enter or leave the Central Nervous System (CNS ) and connect different parts of the body. Peripheral nervous system consists of the following types of nerves, which carry both sensory and motor neurons.
Cranial nerves are the nerves, which emerge from brain and spread throughout the head.
Spinal nerves are the nerves, which arise from spinal cord along most of its length and spread throughout the body ( except the head ).
Visceral nerves are the special kind of nerves that mostly arise from the spinal cord and that are connected to the internal organs of the body.