This PSEB 10th Class Science Notes Chapter 7 Control and Coordination will help you in revision during exams.
PSEB 10th Class Science Notes Chapter 7 Control and Coordination
→ Control and coordination are the functions of the nervous system and hormones in our bodies.
→ The responses of the nervous system can be classified as a reflex action, voluntary action, or involuntary action.
→ The nervous system uses electrical impulses to transmit messages.
→ The neuron is the functional unit of the nervous system that responds to stimuli by electrical impulses.
→ The Central Nervous System (CNS) consists of the brain and the spinal cord.
→ The brain is the highest coordinating centre of the body.
→ The nervous system gets information from our sense organs and acts through our muscles.
→ In many animals and some plants, there are some movements not connected with growth.
→ Some movements, in response to the environment, are carefully controlled. Each kind of change in the environment evokes an appropriate movement in response.
→ Living organisms must use systems providing control and coordination.
→ Specialized tissues are used to provide these control and coordination activities.
→ All information from our environment is detected by the specialized tips of some nerve cells.
→ We have generally five sense organs such as the eye, the ear, the nose, the tongue, and the skin.
→ The information is acquired at the end of the dendritic tip of a nerve cell.
→ It sets off a chemical reaction that creates an electrical impulse.
→ The nervous tissue is made up of an organized network of nerve cells or neurons.
→ ‘Reflex’ is a word we use very commonly when we talk about some sudden action in response to something in the environment.
→ Thinking is a complex activity, so it is bound to involve a complicated interaction of many nerve impulses from many neurons.
→ The thinking tissue in our body consists of dense networks of intricately arranged neurons. It sits in the forward end of the skull.
→ Nerves from all over the body meet in a bundle in the spinal cord on their way to the brain.
→ Nerves supply information to various organs of the body.
→ The reflex arcs have evolved in animals because the thinking process of the brain is not fast enough.
→ Brain and reflex arcs receive information from all parts of the body.
→ In fact, many animals have very little or none of the complex neuron networks needed for thinking.
→ The spinal cord is made up of nerves that supply information to think about.
→ The brain and spinal cord constitute the central nervous system.
→ The brain also has to send messages to muscles.
→ The brain allows us to think and take actions based on that thinking.
→ The brain has three major parts or regions, namely the fore-brain, mid-brain, and hind-brain.
→ The fore-brain is the main thinking part of the brain. It has regions that receive sensory impulses of hearing, smell, sight, and so on.
→ Many involuntary actions are controlled by the mid-brain and hind-brain.
→ All the involuntary actions including blood pressure, salivation, and vomiting are controlled by the medulla in the hind-brain.
→ The vertebral column or backbone protects the spinal cord.
→ The plants also use electrical-chemical means to convey the information from cell to cell.
→ Some tendrils are sensitive to touch.
→ Light and gravity change the directions of growing parts of the plant.
→ The directional or tropic movements can be either towards the stimulus or away from it.
→ The stimulated cells release a chemical compound, this compound would diffuse all around the original cell.
→ Hormones are used by multicellular organisms for control and coordination, show a great deal of diversity.
→ Different plant hormones help to coordinate growth, development, and responses to the environment.
→ A hormone called auxin, synthesized at the shoot tip, helps the cells to grow longer.
→ The plant hormones are gibberellins which, like auxins, help in the growth of the stem.
→ Adrenaline is a hormone secreted by the adrenal (kidney) gland in humans. It affects the heart, respiration, digestion, skeleton muscles in humans and other organisms.
→ Iodine is necessary for the thyroid gland to make the thyroxine hormone.
→ Thyroxine regulates carbohydrate, protein, and fat metabolism in the body so as to provide the best balance for growth.
→ In case of iodine is deficient in our diet, there is a possibility that we might suffer from goiter.
→ Growth hormone is one of the hormones secreted by the pituitary. As its name indicates, growth hormone regulates the growth and development of the body.
→ There is the secretion of testosterone in males and estrogen in females.
→ Insulin is a hormone that is produced by the pancreas and helps in regulating blood sugar levels.
→ Neuron: The structural and functional unit of the nervous system is called a neuron.
→ Sensory organ: The organs which sense the changes in the surrounding environment and pass on the information to the central nervous system are called sensory organs.
→ Hormone: The special chemical substances secreted by endocrine glands (ductless glands) and transported by the blood to control the body functions.
→ Phototropism: The movement of plants towards light is called phototropism.
→ Geotropism: The movement of plant roots due to the earth’s gravity is called geotropism.
→ Chemotropism: The movement of plant parts or plants due to the chemical stimulus is called chemotropism.
→ Phytohormones: These are the hormones secreted by plants to perform various functions.
→ Nastic movements: When the stimulus does not produce any movement in plants.
→ Phytochrome: These are special pigments that respond to the photoperiod.
→ Ganglion: The group of cell bodies of nerve cells is called a ganglion.
→ Reflex action: The involuntary actions towards emergency situations.
→ Reflex arc: The path through which the signal travels during reflex action is called the reflex arc.
→ Spinal cord: Nerves from all over the body meet to form a bundle/cord on their way to connect with the hindbrain is called the spinal cord.
→ Central nervous system: The brain and nerve cord together constitute the central nervous system.
→ Motor neurons: The neurons which carry the responses to the concerned organs.
→ Sensory neurons: The neurons which carry the message from sensory organs to the brain.
→ Nerve impulse: The conduction of chemical or electric signals by nerve cells is called nerve impulse.
→ Voluntary action: These are the actions that need thinking. They are performed knowingly, i.e., controlled by conscious thought. Example. Speaking to a friend, writing a letter, etc.
→ Involuntary action: These are not under the control of the will of an individual. They are automatic responses to a stimulus that is not under the voluntary control of the brain. Example. Touching a hot plate unknowingly.
→ Endocrine glands secrete the hormones directly into the blood.
→ Exocrine glands are glands with ducts that pour their secretion at the site of action.
→ Insulin is the hormone produced by β-cells of islets of Langerhans which controls sugar metabolism.