#controlandcoordination full chapter | cbse Biology | NCERT class 10 science chapter 7

Summary

This educational script delves into the complex world of biological responses to stimuli, highlighting the roles of the nervous and endocrine systems in both animals and plants. It explains how neurons and receptors function in sensory perception, the process of nerve conduction, and the significance of synapses. The script also covers the reflex arc, the division of the nervous system, and the protective role of the brain's meninges and cerebrospinal fluid. It further explores the coordination of body functions through hormones, detailing the functions of various phytohormones and animal hormones, including their impact on growth, metabolism, and stress responses. Lastly, it touches on the importance of iodine in the diet and its connection to the endocrine system.

Takeaways

• 🧠 The human nervous system is essential for producing responses to stimuli, utilizing neurons and synapses for nerve conduction.
• 👃 Olfactory receptors in the nose and gustatory receptors on the tongue are specialized for detecting smells and tastes, respectively.
• 🚀 Sensory neurons transmit information from sense organs to the brain or spinal cord, while motor neurons carry signals to muscles or glands.
• 🔁 There are two pathways for stimulus response: a longer pathway involving the brain and a quicker reflex arc for immediate reactions.
• 🏃 Reflex actions are quick responses to stimuli, facilitated by the reflex arc, which includes receptors, sensory neurons, relay neurons, motor neurons, and effectors.
• 💊 The endocrine system in animals, including various glands, secretes hormones that help control body functions like growth and reproduction.
• 🌱 Plants respond to stimuli such as sunlight and touch through movements caused by growth or cell shape changes, without a nervous system.
• 🌳 Tropic movements in plants, like phototropism and hydrotropism, are caused by phytohormones, which include auxins, gibberellins, cytokinins, ethylene, and abscisic acid.
• 🤒 Hormones like adrenaline are released in response to stress and help in the 'fight or flight' response by increasing oxygen and glucose supply to muscles.
• 🧂 Iodine is crucial for the production of thyroxine, a hormone that regulates metabolism, and a deficiency can lead to goiter.
• 📈 Growth hormone from the pituitary gland is responsible for body growth, and imbalances can lead to dwarfism or gigantism.
• 🚺 Hormones like testosterone and estrogen are responsible for the development of secondary sexual characteristics in males and females, respectively.

Q & A

What are the two main systems that help organisms produce responses to stimuli?

The two main systems that help organisms produce responses to stimuli are the nervous system and the hormonal system.

What are the specialized tips of neurons present in the sense organs called?

The specialized tips of neurons present in the sense organs are called receptors.

How are receptors in the nose known, and what do they detect?

Receptors in the nose are known as olfactory receptors, and they detect smells.

What is the process by which neurons carry information to different parts of the nervous system called?

The process by which neurons carry information to different parts of the nervous system is called nerve conduction.

What is the gap between the nerve endings of one neuron and the dendrites of another neuron called?

The gap between the nerve endings of one neuron and the dendrites of another neuron is called a synapse.

What are the two types of neurons that carry information from the brain or spinal cord to muscles or glands?

The two types of neurons that carry information from the brain or spinal cord to muscles or glands are sensory neurons and motor neurons.

What is the quick response to stimuli called, and what is the pathway by which it is executed known as?

The quick response to stimuli is called a reflex action, and the pathway by which it is executed is known as a reflex arc.

How is the brain protected from shocks and injuries?

The brain is protected from shocks and injuries by being covered by meninges and cerebrospinal fluid, and it is also protected by an outer bony case called the cranium.

What are the three main parts of the brain, and what are their functions?

The three main parts of the brain are the forebrain, midbrain, and hindbrain. The forebrain is responsible for thought processes and sensory reception. The midbrain controls visual and auditory reflexes and eye movements. The hindbrain consists of the pons, medulla oblongata, and cerebellum, controlling sleep/wake cycles, breathing, heart rate, blood pressure, and coordination of movements.

What are the five major phytohormones in plants, and what are their functions?

The five major phytohormones in plants are auxins, gibberellins, cytokinins, ethylene, and abscisic acid. Auxins stimulate cell elongation and are involved in tropic movements. Gibberellins also promote stem and root elongation. Cytokinins promote cell division, especially in fruits and seeds. Abscisic acid acts as a growth inhibitor and is involved in wilting of leaves. Ethylene stimulates fruit ripening.

Why is iodine important in our diet, and how is it related to the endocrine system?

Iodine is important in our diet because it is essential for the production of thyroxine, a hormone produced by the thyroid gland. Thyroxine controls the metabolism of carbohydrates, proteins, and fats, and a deficiency can lead to goiter and other symptoms related to an underactive thyroid.

What is the role of adrenaline in the body, and how does it help during a dangerous situation?

Adrenaline is a hormone secreted by the adrenal glands in response to stress or danger. It increases the supply of oxygen and glucose to the skeletal muscles, dilates blood vessels to enhance blood flow, increases heart rate, and boosts breathing rate, preparing the body for a fight or flight response.

What are the roles of testosterone and estrogen in the development of secondary sexual characteristics?

Testosterone, known as the male sex hormone, helps in the development of secondary sexual characteristics in males, such as growth of facial hair, development of testes, and production of sperms. Estrogen, known as the female sex hormone, helps in the development of secondary sexual characteristics in females, such as breast development, onset of menstruation, and development of ovaries.

Why do doctors suggest some people to eat less sugar and starchy foods, and what is the condition called?

Doctors suggest some people to eat less sugar and starchy foods because they may have diabetes, a condition where the body either does not produce enough insulin or cannot use it effectively, leading to high blood sugar levels which can cause harmful effects on the body.