Biology chapter Control and Coordination

CHAPTER 7

7.1 ANIMALS – NERVOUS SYSTEM

• 7.1.1 What happens in Reflex Actions?
• 7.1.2 Human Brain
• 7.1.3 How are these Tissues protected?
• 7.1.4 How does the Nervous Tissue cause Action?

7.2 COORDINATION IN PLANTS

• 7.2.1 Immediate Response to Stimulus
• 7.2.2 Movement Due to Growth

7.3 HORMONES IN ANIMALS

Introduction

Control and coordination are essential for the proper functioning of any living organism. All the activities of an organism are controlled and coordinated by its nervous and hormonal systems. The nervous system is responsible for the control and coordination of all the voluntary activities of an organism, while the hormonal system is responsible for the control and coordination of all the involuntary activities of an organism. For example, the nervous system coordinates the activities of the various organs and systems of the body, and the endocrine system regulates the production of hormones.

Why do we associate such visible movements with life? There are a few reasons why we might associate visible movements with life. For one, living things are generally the only things that we see moving around in our environment. This means that when we see something moving, our brain automatically assumes that it must be alive. Additionally, we know that all living things are made up of cells, and cells are constantly moving and changing. This means that even something as small as a bacterium is always in a state of flux, which is something that we can observe with our own eyes. Finally, we also know that all living things require energy to move, and this energy comes from food. So, when we see something moving, it is a reminder that this thing is alive and needs to eat in order to survive. For example, a plant growing toward the light or an animal hunting for food are both examples of purposeful movement.

A final reason why we associate visible movement with life is that living things are the only things that change over time. Non-living things, such as rocks and rivers, may change over time as well, but only as a result of external forces, such as the wind or the tide. For example, a plant growing taller over time or an animal learning a new behavior are both examples of change that can only be attributed to life. In sum, living things are the only things that move on their own, move in a purposeful way, and change over time. These three characteristics are all strong evidence for the presence of life.

7.1 ANIMALS – NERVOUS SYSTEM

The skin is the body's largest organ and is made up of many different types of cells. The cells that detect touch are called mechanoreceptors. The epidermis is made up of three layers: the outermost layer is the stratum corneum, the middle layer is the stratum granulosum, and the innermost layer is the stratum basale. The mechanoreceptors are found in the stratum basale. There are many different types of mechanoreceptors, but the ones that are responsible for detecting touch are called Merkel cells. Merkel cells are found in the deepest layer of the epidermis. They are connected to the nervous system and are responsible for sending signals to the brain when they are touched. When the skin is touched, the mechanoreceptors are stimulated and send signals to the brain. The brain then interprets these signals and we are able to feel touch. In simple words we can say that When we touch hot water, the hot water molecules stimulate the pain receptors in our skin. This sends a signal through our nervous system to our brain. The brain then sends a signal back to the muscles in our hand to tell them to move away from the hot water.

7.1.1 What happens in Reflex Actions?

A 'reflex' is an involuntary and rapid movement in response to a stimulus. It is a basic form of learning that does not require conscious thought. The most common example of a reflex is the knee-jerk reflex, which occurs when the patellar tendon is tapped. The reflex is initiated by a stretch receptor in the muscle, which sends a signal to the spinal cord. The signal is then transmitted to the muscles, causing them to contract and the leg to extend.

Now lets us take an example of touching a flame. When we touch a flame, our body's natural reaction is to quickly pull away. This reflex is known as the withdrawal reflex and is a protective mechanism to prevent us from being burned. The withdrawal reflex is a reflex arc, which means that it consists of a series of nerve impulses that travel from the stimulus (in this case, the flame) to the muscles (in this case, the muscles that cause us to pull away from the flame).

This reflex arc is a series of neurons (nerve cells) that are located in the spinal cord. The first neuron in the reflex arc is called the afferent neuron and it carries the impulse from the stimulus (in this case, the flame) to the spinal cord. The second neuron in the reflex arc is called the efferent neuron and it carries the impulse from the spinal cord to the muscles (in this case, the muscles that cause us to pull away from the flame). The efferent neuron is located in the motor cortex of the brain.

In conclusion, the reflex arc is an important part of the human body. It allows the body to react quickly to stimuli. Without the reflex arc, the body would have to think about how to react to a stimulus, which would take too long. The reflex arc is a simple way for the body to protect itself.

7.1.2 Human Brain

The human brain is also responsible for control and coordination of the body. It is the main gear center for all the human functions. The brain controls the body's movement, balance, and coordination. It also controls the body's organs, such as the heart and lungs. The brain is composed of different vital parts, each of which has a quite specific function/job to do. The cerebrum is the largest part of the brain. It is responsible for thinking, learning, and controlling the body's movement. The cerebellum is responsible for balance and coordination. The brainstem controls the body's organs and breathing.

Lets discuss the role of cerebrum during reflex actions. The cerebrum is the largest part of the human brain and is responsible for all higher brain functions. This includes consciousness, thought, imagination, emotion, and voluntary movement. The cerebrum is also involved in the brain's reflex actions. Reflexes are automatic, involuntary responses to stimuli.

They help us to quickly respond to potentially dangerous situations without having to think about them. The cerebrum is responsible for sending signals to the rest of the body that tell it how to respond to a stimulus. For example, if you touch something hot, the cerebrum will send a signal to your hand to quickly move away from the heat before you get burned.

Also, the cerebellum part of human body is responsible for coordinating voluntary actions and movement. It is located at the back of the brain, below the cerebral cortex while the medulla oblongata is responsible for involuntary actions, such as breathing and heart rate. It is located in the brain stem, just above the spinal cord.

7.1.3 How are these Tissues protected?

The human brain is protected by the skull, which is a hard, bony structure that encases and protects the delicate tissues of the brain. It is made up of many bones that are fused together. The skull protects the brain from injury by absorbing the impact of blows to the head. It is made up of 22 bones that are joined together by sutures. The bones of the skull provide a strong and rigid structure that protects the brain from impact. The skull also has several openings that allow for the passage of nerves and blood vessels.

The meninges, a system of three membranes that surround and protect the brain, also help to cushion the brain and prevent it from being damaged. The meninges are the dura mater, the arachnoid mater, and the pia mater. These layers protect the brain from injury and infection.

7.1.4 How does the Nervous Tissue cause Action?

The nervous tissue is composed of long-thread-like structured cells called neurons. These neurons are responsible for sending and receiving electrical signals between the brain and the body. The electrical signals are sent through the nerves to the muscles, which then contract and cause movement. Muscle cells have special proteins that change both their shape and their arrangement in the cell in response to nervous electrical impulses.

Proteins are composed of chains of amino acids, and the muscle cell proteins that are responsible for muscle contraction are called myosin and actin. These proteins are arranged in a repeating pattern along the length of the muscle cell. When an electrical impulse arrives at the muscle cell, it causes the myosin and actin proteins to change shape. This change in shape pulls the actin proteins towards the center of the cell, causing the muscle cell to contract.

7.2 COORDINATION IN PLANTS

Plants do not have a nervous system or muscles, but they can still respond to stimuli. One example of this is the mimosa plant family. When touched, the leaves of these plants will fold up. This is an example of a plant responding to a physical stimulus. Plants can also respond to light and temperature changes. For example, some flowers will open during the day and close at night. This is an example of a plant responding to a light stimulus. Similarly, some plants will curl up their leaves when it is cold outside. This is an example of a plant responding to a temperature stimulus. There are many other ways that plants can respond to stimuli. Some plants can even move in response to stimuli. For example, the tendrils of a climbing plant will wrap around something in order to climb it. This is an example of a plant responding to a touch stimulus. Overall, plants are able to respond to stimuli in a variety of ways. They do not have a nervous system or muscles, but they can still detect changes in their environment and respond accordingly. Further in this chapter we will learn about two types of plant moments – one dependent on growth and the other independent of growth.

7.2.1 Immediate Response to Stimulus

Plants detect touch via electrical-chemical signals. When a touch stimulus is received, an electrical signal is transmitted through the plant tissue. This signal triggers a chemical response in the plant cells, which causes the leaves to move in response. This can be either a swelling or a shrinking of the leaves. The plant will also usually release a chemical called histamine, which can help to protect the plant from damage.

For example, when a caterpillar crawls on a plant, the plant's leaves will move in response to the touch. The electrical signal transmitted by the caterpillar's movement triggers a chemical reaction in the plant cells, which causes the leaves to move. This movement allows the plant to protect itself from being eaten by the caterpillar.

7.2.2 Movement Due to Growth

The pea plant climbs up other plants or fences by means of tendrils. Tendrils are thin, thread-like structures that grow out of the stems of some plants. They wrap around objects, such as plants or fence posts, and help the plant to climb. Pea plants produce tendrils at the tips of their leaves. When a tendril comes into contact with an object, it wraps around it and begins to grow. The plant produces new cells at the base of the tendril, which makes it thicker and stronger. The tendril continues to grow until it reaches the top of the object. The plant then produces new leaves and flowers.

Phototropic movement - When a plant is exposed to light, it will begin to grow towards the light. This is called phototropic movement, and it is caused by a plant hormone called auxin. Auxin is produced in the shoots of a plant, and it moves towards the roots. Gravity also plays a role in phototropic movement, as auxin will move towards the roots if the plant is tilted. For example, a plant may bend towards a light source in order to receive more light.

Hydrotropism - When a plant grows in water, it typically grows towards the water in a process called hydrotropism. This is because the water provides the plant with nutrients and moisture, which the plant needs to survive. The plant uses its roots to anchor itself in the soil and its leaves to absorb sunlight and carbon dioxide from the air. The plant also needs to be able to move its leaves in order to get the most sunlight possible.

Chemotropism - is the growth or movement of a plant in response to a chemical stimulus. The most common examples of chemotropism are phototropism (growth towards light) and geotropism (growth towards gravity). However, other chemicals can also trigger plant growth, such as auxins (a class of plant hormones). Chemotropism is an important process in plant development and reproduction, as it ensures that the pollen tube reaches the ovule, and that the ovule is receptive to the pollen tube. One example of chemotropism is the way in which pollen grains are attracted to the stigma of a flower. The stigma is tipped with a sticky substance called pollenkitt, which contains a variety of chemicals that can trigger the growth of pollen tubes. As the pollen tube grows towards the ovule, it is guided by the chemicals in pollenkitt, a process known as pollen tube guidance. Another example of chemotropism is the way in which the ovules of a flower are attracted to the pollen tube. This process, known as ovule reception, is thought to be mediated by chemicals released by the pollen tube. These chemicals trigger the growth of the ovule towards the pollen tube, a process known as ovule guidance.

7.3 HORMONES IN ANIMALS

Many times in response to a scary situation some animals experience increased levels of stress hormones, such as cortisol, when they are in a such situation. This can lead to a variety of changes in the body, including an increase in heart rate and blood pressure, as well as a decrease in appetite. In some cases, these changes can be beneficial, as they can help the animal to escape from a dangerous situation. However, in other cases, the changes can be harmful, as they can lead to a decrease in immunity and an increase in susceptibility to disease. In human beings using a hormone called adrenaline that is secreted from the adrenal glands. Adrenaline help the body deal with stress or danger. When a person experiences a sudden shock or feels threatened, the body releases adrenaline into the bloodstream. This hormone prepares the body for "fight or flight" by increasing heart rate, blood pressure, and blood sugar levels. It also reduces blood flow to the digestive system and directs blood to the muscles, which gives a person extra strength and energy. In addition, adrenaline affects the way a person perceives pain, making it easier to tolerate or ignore.

Likewise there are other hormones also for example Thyroxin which is secreted by thyroid gland and main ingredient is Iodine. Hence, salt is important because it contains iodine, which is a nutrient that the body needs in order to make thyroid hormones. Thyroid hormones are important for regulating metabolism, and they also play a role in brain development. iodine deficiency can lead to goiters, which are enlarged thyroid glands. Iodized salt is the best way to get iodine into the diet, and it is important to make sure that the iodine level in the salt is adequate.

Some people are dwarf and some are gaints, do you notices why? it is because of Growth Hormones (GH). It is a class of hormones that stimulate growth and cell reproduction. GH are secreted by the pituitary gland and are regulated by the hypothalamus. GH are important for the proper development of bones and muscles. GH also play a role in metabolism, and can help to regulate blood sugar levels. GH levels are highest during childhood and adolescence, and decline with age. A number of conditions can cause GH levels to be too high or too low. High GH levels can cause gigantism or acromegaly, while low GH levels can cause dwarfism. GH are sometimes used as performance-enhancing drugs, as they can help to build muscle mass and improve strength. However, the use of GH is banned by many sports organizations. GH have a number of potential side effects, including joint pain, carpal tunnel syndrome, and an increased risk of cancer. GH should only be used under the supervision of a doctor.

Sometimes doctors recommend to take less sugar or gives insulin injections. Insulin is a hormone that is produced by the pancreas. It helps to regulate the level of sugar in the blood. When the level of sugar in the blood is too high, the pancreas will secrete insulin to help bring it down. When the level of sugar in the blood is too low, the pancreas will not secrete insulin. People with diabetes mellitus depend on insulin injections to maintain their blood sugar levels within a normal range. Without insulin, the level of sugar in the blood can become very high, leading to a diabetic coma or even death. People with diabetes mellitus type 1 are completely dependent on insulin injections because their pancreas does not produce any insulin. People with diabetes mellitus type 2 still produce insulin, but not enough to keep their blood sugar levels normal. They may need to take insulin injections or oral medication to help control their blood sugar levels. If you have diabetes mellitus, it is important to monitor your blood sugar levels carefully and to take your insulin injections or medication as prescribed by your doctor.

Hormones are chemical substances that are produced by the endocrine glands. They are released into the bloodstream and act as messengers to target cells. Hormones regulate many body functions, including growth, metabolism, and reproduction.

The release of hormones is controlled by the nervous system. The hypothalamus, a region of the brain, is the master controller of the endocrine system. It produces hormones that regulate the release of other hormones from the pituitary gland. Hormones must be secreted in precise quantities in order to maintain homeostasis. If the body produces too much or too little of a hormone, it can lead to serious health problems. In conclusion, hormones play a vital role in the proper functioning of the body. They must be secreted in precise quantities in order to maintain homeostasis.