CBSE Class 10 Science Chapter 7 Control and Coordination Notes

Control and coordination are essential processes for all living organisms. They allow us to respond to stimuli from the environment, maintain homeostasis, and move around in a purposeful way. In animals, control and coordination are carried out by the nervous system and the endocrine system.

The Nervous System

The nervous system is a complex network of nerves and cells that transmits information throughout the body. It is made up of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

The CNS consists of the brain and spinal cord. The brain is the control center of the body, and it is responsible for processing information from the senses, controlling movement, and regulating other bodily functions. The spinal cord is a long bundle of nerves that runs down the back and connects the brain to the rest of the body.

The PNS consists of all the nerves outside the CNS. It includes sensory nerves, which carry information from the senses to the CNS, and motor nerves, which carry instructions from the CNS to the muscles.

Neurons

The structural and functional unit of the nervous system is the neuron. Neurons are specialized cells that transmit nerve impulses. Each neuron has three main parts: the cell body, dendrites, and axons.

The cell body contains the nucleus and other organelles of the cell. Dendrites are short, branched extensions of the cell body that receive nerve impulses from other neurons. Axons are long, thin extensions of the cell body that transmit nerve impulses to other neurons.

Nerve Impulses

Nerve impulses are electrical signals that travel along axons. They are generated when a neuron is stimulated by a stimulus such as light, sound, or touch. The nerve impulse travels down the axon to the synapse, which is the junction between two neurons.

At the synapse, the nerve impulse is transmitted to the next neuron by the release of neurotransmitters. Neurotransmitters are chemicals that diffuse across the synapse and bind to receptors on the next neuron. This binding opens the ion channels on the next neuron, allowing ions to flow in and generate a new nerve impulse.

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Types of Neurons

There are three main types of neurons: sensory neurons, motor neurons, and interneurons.

Sensory neurons carry information from the senses to the CNS. Motor neurons carry instructions from the CNS to the muscles. Interneurons connect sensory neurons to motor neurons and other interneurons.

The Reflex Arc

A reflex arc is a neural pathway that controls an involuntary response to a stimulus. It involves a sensory neuron, a motor neuron, and one or more interneurons.

When a stimulus is received by a sensory receptor, it sends a nerve impulse to the CNS. The nerve impulse is then transmitted to a motor neuron, which sends a nerve impulse to the muscle that produces the response.

The Endocrine System

The endocrine system is a network of glands that produce and secrete hormones. Hormones are chemical messengers that travel through the bloodstream to target cells throughout the body.

Hormones play a role in a wide range of bodily functions, including growth and development, reproduction, metabolism, and mood. They also play a role in control and coordination.

The Adrenal Glands

The adrenal glands are two small glands located above the kidneys. They produce two main hormones: adrenaline and cortisol.

Adrenaline is released in response to stress. It prepares the body for the “fight-or-flight” response by increasing heart rate, blood pressure, and blood sugar levels.

Cortisol is released in response to prolonged stress. It helps the body to cope with stress by regulating blood sugar levels, metabolism, and inflammation.

Other Hormones Involved in Control and Coordination

Other hormones that are involved in control and coordination include:

• Thyroid hormone: Regulates metabolism and growth and development
• Insulin: Regulates blood sugar levels
• Gonadotropins: Regulate reproduction
• Growth hormone: Stimulates growth and development
• Oxytocin: Promotes bonding and maternal behavior
• Vasopressin: Regulates blood pressure and water balance

Control and Coordination in Plants

Plants do not have a nervous system, but they do have a variety of mechanisms for control and coordination. These mechanisms include:

• Hormones: Plant hormones, such as auxin, gibberellin, and cytokinin, regulate plant growth and development.
• Tropisms: Tropisms are movements of plants in response to a stimulus. For example, phototropism is the movement of plants towards light.

Nastic movements

Nastic movements are non-directional movements of plants in response to a stimulus. For example, the closing of a Venus flytrap when an insect lands on it is a nastic movement.

Phototropism

Phototropism is the movement of plants towards light. It is caused by the uneven distribution of auxin, a plant hormone, in the stem. Auxin is more concentrated on the shaded side of the stem, which causes the cells on that side to grow longer. This results in the stem bending towards the light.

Geotropism

Geotropism is the movement of plants in response to gravity. Roots grow down (positive geotropism) and shoots grow up (negative geotropism). This is caused by the uneven distribution of auxin in the roots and shoots.

Thigmotropism

Thigmotropism is the movement of plants in response to touch. It is caused by the uneven distribution of auxin in the stem or leaves. For example, the tendrils of climbing plants wrap around objects when they touch them.

Importance of Control and Coordination

Control and coordination are essential for all living organisms. They allow us to respond to stimuli from the environment, maintain homeostasis, and move around in a purposeful way.

In animals, control and coordination are carried out by the nervous system and the endocrine system. The nervous system is responsible for transmitting information throughout the body and controlling muscle contractions. The endocrine system is responsible for producing and releasing hormones, which regulate a wide range of bodily functions, including growth, development, metabolism, and reproduction.

In plants, control and coordination are carried out by a variety of mechanisms, including hormones, tropisms, and nastic movements. Hormones regulate plant growth and development. Tropisms are movements of plants in response to a stimulus, such as light or gravity. Nastic movements are non-directional movements of plants in response to a stimulus.

Control and coordination are essential for all living organisms because they allow us to maintain homeostasis, respond to stimuli, and move around in a purposeful way.

Here are some examples of how control and coordination are important in animals and plants:

Animals

• Maintaining homeostasis: The nervous system regulates homeostasis by controlling body temperature, heart rate, blood pressure, and other bodily functions.
• Responding to stimuli: The nervous system allows animals to respond to stimuli from the environment, such as predators, food, and danger.
• Moving around in a purposeful way: The nervous system controls muscle contractions, which allows animals to move around in a purposeful way.

Plants

• Maintaining homeostasis: Plant hormones regulate homeostasis by controlling plant growth and development.
• Responding to stimuli: Plants can respond to stimuli from the environment, such as light, gravity, and touch, through tropisms and nastic movements.
• Growing towards light: Phototropism allows plants to grow towards light, which is essential for photosynthesis.
• Growing roots down and shoots up: Geotropism allows plants to grow roots down and shoots up, which helps them to anchor themselves in the ground and reach sunlight.
• Avoiding predators: Nastic movements, such as the closing of a Venus flytrap when an insect lands on it, can help plants to avoid predators.

Overall, control and coordination are essential processes for all living organisms. They allow us to respond to stimuli from the environment, maintain homeostasis, and move around in a purposeful way.

Control and Coordination in Humans

The human nervous system is one of the most complex systems in the body. It is responsible for controlling and coordinating all of the body’s functions, from simple movements to complex cognitive tasks.

The human nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

The CNS consists of the brain and spinal cord. The brain is the control center of the body, and it is responsible for processing information from the senses, controlling movement, and regulating other bodily functions. The spinal cord is a long bundle of nerves that runs down the back and connects the brain to the rest of the body.

The PNS consists of all the nerves outside the CNS. It includes sensory nerves, which carry information from the senses to the CNS, and motor nerves, which carry instructions from the CNS to the muscles.

The Endocrine System

The endocrine system is a network of glands that produce and secrete hormones. Hormones are chemical messengers that travel through the bloodstream to target cells throughout the body.

Hormones play a role in a wide range of bodily functions, including growth and development, reproduction, metabolism, and mood. They also play a role in control and coordination.

The Adrenal Glands

The adrenal glands are two small glands located above the kidneys. They produce two main hormones: adrenaline and cortisol.

Adrenaline is released in response to stress. It prepares the body for the “fight-or-flight” response by increasing heart rate, blood pressure, and blood sugar levels.

Cortisol is released in response to prolonged stress. It helps the body to cope with stress by regulating blood sugar levels, metabolism, and inflammation.

Other Hormones Involved in Control and Coordination

Other hormones that are involved in control and coordination include:

• Thyroid hormone: Regulates metabolism and growth and development
• Insulin: Regulates blood sugar levels
• Gonadotropins: Regulate reproduction
• Growth hormone: Stimulates growth and development
• Oxytocin: Promotes bonding and maternal behavior
• Vasopressin: Regulates blood pressure and water balance

Coordination of Movement

The coordination of movement is a complex process that involves the nervous system and the muscular system. The nervous system sends signals to the muscles, telling them when and how to contract. The muscles then contract, producing movement.

There are two main types of movement: voluntary movement and involuntary movement.

Voluntary movement is movement that we consciously control, such as walking, talking, and writing. Involuntary movement is movement that we do not consciously control, such as breathing, heartbeat, and digestion.

The Cerebellum

The cerebellum is a part of the brain that is responsible for coordinating movement. It receives information from the senses and the cerebrum (the thinking part of the brain) and uses this information to control the muscles.

The cerebellum is also responsible for maintaining balance and posture.

The Basal Ganglia

The basal ganglia are a group of structures in the brain that are involved in the control of movement and reward-motivated behavior. They work with the cerebellum to coordinate movement and to ensure that movements are smooth and coordinated.

Disorders of Control and Coordination

There are a number of disorders that can affect control and coordination. These disorders can be caused by a variety of factors, including genetics, injury, and disease.

Some common disorders of control and coordination include:

• Cerebral palsy: A group of disorders that affect movement and coordination. Cerebral palsy is caused by damage to the brain that occurs before or during birth.
• Parkinson’s disease: A neurodegenerative disorder that affects the nervous system. Parkinson’s disease is characterized by tremors, slowness of movement, and stiffness.
• Multiple sclerosis: An autoimmune disease that affects the myelin sheath, which insulates the nerves. Multiple sclerosis can cause a variety of symptoms, including muscle weakness, fatigue, and vision problems.
• Huntington’s disease: A neurodegenerative disorder that affects the nervous system. Huntington’s disease is characterized by involuntary movements, cognitive decline, and psychiatric symptoms.

Conclusion

Control and coordination are essential processes for all living organisms. They allow us to respond to stimuli from the environment, maintain homeostasis, and move around in a purposeful way.

The human nervous system is responsible for controlling and coordinating all of the body’s functions. The endocrine system also plays a role in control and coordination by producing and secreting hormones.

There are a number of disorders that can affect control and coordination. These disorders can be caused by a variety of factors, including genetics, injury, and disease.